WorldWideScience

Sample records for antineutrino reactions

  1. Study of charged current reactions induced by muon antineutrinos

    International Nuclear Information System (INIS)

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

  2. Quasielastic production of polarized hyperons in antineutrino--nucleon reactions

    CERN Document Server

    Akbar, F; Athar, M Sajjad; Singh, S K

    2016-01-01

    We have studied the longitudinal and perpendicular polarizations of final hyperon($\\Lambda$,$\\Sigma$) produced in the antineutrino induced quasielastic charged current reactions on nucleon targets. The nucleon-hyperon transition form factors are determined from the experimental data on quasielastic $(\\Delta S =0)$ charged current (anti)neutrino--nucleon scattering and the semileptonic decay of neutron and hyperons assuming G--invariance, T--invariance and SU(3) symmetry. The vector transition form factors are obtained in terms of nucleon electromagnetic form factors for which various parameterizations available in literature have been used. A dipole parameterization for the axial vector form factor and the pseudoscalar transition form factor derived in terms of axial vector form factor assuming PCAC and GT relation extended to strangeness sector have been used in numerical evaluations. The flux averaged cross section and polarization observables corresponding to CERN Gargamelle experiment have been calculated...

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

    International Nuclear Information System (INIS)

    We extend the formalism of weak interaction processes, obtaining new expressions for the transition rates, which greatly facilitate numerical calculations, for both neutrino-nucleus reactions and muon capture. Explicit violation of the conserved vector current hypothesis by the Coulomb field, as well as development of a sum-rule approach for inclusive cross sections, has been worked out. We have done a thorough study of exclusive (ground-state) properties of 12B and 12N within the projected quasiparticle random phase approximation (PQRPA). Good agreement with experimental data achieved in this way put into evidence the limitations of the standard RPA and QRPA models, which come from the inability of the RPA to open the p3/2 shell and from the nonconservation of the number of particles in the QRPA. The inclusive neutrino/antineutrino (ν/ν-tilde) reactions 12C(ν,e-)12N and 12C(ν-tilde,e+)12B are calculated within both the PQRPA and the relativistic QRPA. It is found that (i) the magnitudes of the resulting cross sections are close to the sum-rule limit at low energy, but significantly smaller than this limit at high energies, for both ν and ν-tilde; (ii) they increase steadily when the size of the configuration space is augmented, particularly for ν/ν-tilde energies >200 MeV; and (iii) they converge for sufficiently large configuration space and final-state spin. The quasi-elastic 12C(ν,μ-)12N cross section recently measured in the MiniBooNE experiment is briefly discussed. We study the decomposition of the inclusive cross section based on the degree of forbiddenness of different multipoles. A few words are dedicated to the ν/ν-tilde-12C charge-exchange reactions related to astrophysical applications.

  4. Charged current antineutrino reactions from 12C at MiniBooNE energies

    International Nuclear Information System (INIS)

    A study of charged current induced antineutrino interactions from nuclei has been done for the intermediate energy antineutrinos and applied to 12C, relevant for ongoing experiment by MiniBooNE collaboration. The calculations have been done for the quasielastic and inelastic lepton production as well as for the incoherent and the coherent pion production processes. The calculations are done in local density approximation. In the case of the quasielastic reaction the effects of Pauli blocking, Fermi motion effects, renormalization of weak transition strengths in nuclear medium and the Coulomb distortion of the outgoing lepton have been taken into account. For the inelastic processes the calculations have been done in the Δ dominance model and take into account the effect of Pauli blocking, Fermi motion of the nucleon, and renormalization of Δ properties in a nuclear medium. The effect of final state interactions of pions is also taken into account. The numerical results for the total cross sections for the charged current quasielastic scattering and incoherent pion production processes are compared with earlier experimental results available in freon and freon-propane. It is found that nuclear medium effects give strong reduction in the cross sections leading to satisfactory agreement with the available data

  5. Asymmetry in the neutrino and anti-neutrino reactions in a nuclear medium

    International Nuclear Information System (INIS)

    We study the effect of the density-dependent axial and vector form factors on the electron–neutrino (νe) and anti-neutrino (ν¯e) reactions for a nucleon in nuclear matter or in 12C. The nucleon form factors in free space are presumed to be modified for a bound nucleon in a nuclear medium. We adopt the density-dependent form factors calculated by the quark–meson coupling (QMC) model, and apply them to the νe and ν¯e induced reactions with the initial energy E=8–80 MeV. We find that the total νe cross sections on 12C as well as on a nucleon in nuclear matter are reduced by about 5% at the nuclear saturation density, ρ0. This reduction is caused by the modification of the nucleon structure in matter. Although the density effect for both cases is relatively small, it is comparable with the effect of Coulomb distortion on the outgoing lepton in the ν-reaction. In contrast, the density effect on the ν¯e reaction reduces the cross section significantly in both nuclear matter and 12C cases, and the amount maximally becomes of about 35% around ρ0. Such large asymmetry in the νe and ν¯e cross sections, which seems to be nearly independent of the target, is originated from the differences in the helicities of ν¯e and νe. It is expected that the asymmetry influences the r-process and also the neutrino-process nucleosynthesis in core-collapse supernovae

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

    International Nuclear Information System (INIS)

    In this work we have studied the 4 production reactions of a pion induced by muon anti-neutrino collisions with nucleons: anti-νμp → anti-νμpπ0 or anti-νμnπ+ and anti-νμn → anti-νμnπ0 or anti-νμpπ-. We have processed experimental data from the Gargamelle cloud chamber to assess the pion production cross-sections. Our results are consistent with the theoretical predictions of the Adler model and of the Fogli and Nardulli model within the framework of the Weinberg and Salam unified theory. As for the isospin structure of the weak hadronic neutral current, the iso-vectorial component is highlighted in the invariant mass spectra in the channels pπ0 and pπ-. Our results show that the isospin structure is not purely isoscalar or purely iso-vectorial but rather a mix of I = 0 and I = 1. We confirm that the sign of the product of the 2 coupling constants uL*dL is negative. (A.C.)

  7. 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.

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

    CERN Document Server

    Vale, D; Paar, N

    2015-01-01

    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 $^{56}$Fe and $^{208}$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 $\\mathrm{p}(\\bar{\

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

    Science.gov (United States)

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

    1980-12-01

    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 π0,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 2θW and the data suggest an important contribution of I = {3}/{2} final states.

  10. 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).

  11. Is Deuterium Nuclear Fusion Catalyzed by Antineutrinos?

    Science.gov (United States)

    Shomer, Isaac

    2010-02-01

    The hypothesis of Fischbach and Jenkins that neutrinos emitted from the sun accelerate radioactive decay is noted. It is thought that neutrinos accelerate beta decay by reacting with neutron-rich nuclides to form a beta particle and a daughter product, with no antineutrino emitted. Conversely, it is proposed that antineutrinos can react with proton-rich nuclides to cause positron decay, with no neutrino emitted. It is also proposed that the nuclear fusion of the hydrogen bomb is triggered not only by the energy of the igniting fission bomb, but by the antineutrinos created by the rapid beta decay of the daughter products in the fission process. The contemplated mechanism for antineutrino initiated fusion is the following: 1. The antineutrinos from the fission daughter products cause positron decay of deuterium by the process outlined above. 2. In a later fusion step, these positrons subsequently react with neutrons in deuterium to create antineutrinos. Electrons are unavailable to annihilate positrons in the plasma of the hydrogen bomb. 3. These antineutrinos thereafter react with more deuterium to form positrons, thereby propagating a chain reaction. )

  12. High flux lithium antineutrino source with variable hard spectrum

    CERN Document Server

    Lyashuk, V I

    2016-01-01

    The high flux antineutrino source with hard antineutrino spectrum based on neutron activation of 7Li and subsequent fast beta-decay (T 1/2 = 0.84 s) of the 8Li isotope with emission of antineutrino with energy up to 13 MeV - is discussed. Creation of the intensive isotope neutrino source of hard spectrum will allow to increase the detection statistics of neutrino interaction and it is especially urgent for oscillation experiments. The scheme of the proposed neutrino source is based on the continuous transport of the created 8Li to the neutrino detector, which moved away from the place of neutron activation. Analytical expressions for lithium antineutrino flux is obtained. The discussed source will ensure to increase the cross section for reactions with deuteron from several times to tens compare to the reactor antineutrino spectrum. An another unique feature of the installation is the possibility to vary smoothly the hardness of the antineutrino spectrum.

  13. The measurement of the total cross section for deep inelastic neutrino-iron and antineutrino-iron reactions with charge exchange

    International Nuclear Information System (INIS)

    The cross section for deep inelastic neutrino-iron and antineutrino-iron charge-exchange reactions was determined. The experiment was performed in the CERN-NBB at hadron beam momenta of 100 GeV/c, 160 GeV/c, and 200 GeV/c with both polarities. The events were registrated with the improved CDHS detector. The flux determination ensued indirectly via the measurement of the hadron flux respectively the muon flux. The neutrino flux determined by both methods agrees well. Within the accessible neutrino energy range (10 GeV ν ν = 0.331±0.003±0.009 ( . 10-38 cm2 (nucl. . GeV)-1), σν/Eν = 0.703±0.002±0.019 ( . 10-38 cm2 (nucl. . GeV)-1), and σ sub(anti ν)/σν = 0.471±0.005±0.007. The first error indication means the statistical, the second the systematical error. The systematic error is mainly conditioned by uncertainties in the flux determination. (orig./HSI)

  14. Terrestrial and Reactor Antineutrinos in Borexino

    Science.gov (United States)

    Chen, M. C.; Calaprice, F. P.; Rothschild, C. G.

    1998-10-01

    The Earth is an abundant source of antineutrinos coming from the decay of radioactive elements in the mantle and crust. Detecting these antineutrinos is a challenge due to their small cross section and low energies. The Borexino solar neutrino experiment will also be an excellent detector for barν_e. With 300 tons of ultra-low-background liquid scintillator, surrounded by an efficient muon veto, the inverse-β-decay reaction: barνe + p arrow e^+ + n (Q = 1.8 MeV), can be exploited to detect terrestrial antineutrinos from the uranium and thorium decay chains, with little background. A direct measurement of the total uranium and thorium abundance would establish important geophysical constraints on the heat generation and thermal history of the Earth. Starting with the most recent uranium and thorium distribution and abundance data, and employing a global map of crustal type and thickness, we calculated the antineutrino fluxes for several sites. We estimate a terrestrial antineutrino event rate in Borexino of 10 events per year. This small signal can be distinguished over the neutrino background from the world's nuclear power reactors by measuring the positron energy spectrum from the barνe events. The possibility to perform a long-baseline oscillation experiment, reaching Δ m^2 ≈ 10-6 eV^2, using the nuclear reactors in Europe will also be discussed.

  15. Antineutrino Monitoring of Thorium Reactors

    CERN Document Server

    Akindele, Oluwatomi A; Norman, Eric B

    2015-01-01

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuels types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring.Thorium molten salt reactors (MSR) breed U-233, that if diverted constitute an IAEA direct use material. The antineutrino spectrum from the fission of U-233 has been determined, the feasibility of detecting the diversion of a significant quantity, 8 kg of U-233, within the IAEA timeliness goal of 30 days has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario at a 25 meter standoff by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos. It was found that the diversion of a signifi...

  16. Nuclear reactor fissile isotopes antineutrino spectra

    OpenAIRE

    Sinev, V.

    2012-01-01

    Positron spectrum from inverse beta decay reaction on proton was measured in 1988-1990 as a result of neutrino exploration experiment. The measured spectrum has the largest statistics and lowest energy threshold between other neutrino experiments made that time at nuclear reactors. On base of the positron spectrum the standard antineutrino spectrum for typical reactor fuel composition was restored. In presented analysis the partial spectra forming this standard spectrum were extracted using s...

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

    Directory of Open Access Journals (Sweden)

    Tornow W.

    2015-01-01

    Full Text Available 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, 74,76Ge, 128,130Te and 136Xe and compared to model calculations and evaluations.

  18. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Christopher; Erickson, Anna [Georgia Institute of Technology, Nuclear and Radiological Engineering, G. W. Woodruff School of Mechanical Engineering, 770 State St. NW, Atlanta, Georgia 30332 (United States)

    2015-10-28

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0–6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  19. Antineutrino oscillation study in the muon antineutrino → electron antineutrino channel at the Brookhaven accelerator

    International Nuclear Information System (INIS)

    This thesis is devoted to the E816 experiment which looked for (anti)neutrino oscillations. This experiment was performed in the neutrino beam of the Brookhaven AGS during spring 1986. Following a short recall of the theoretical and experimental status, the beam line and the apparatus are described. The analysis is exposed in details with a special emphasis on final states including at least one electromagnetic shower and one prong. Preliminary results have been obtained and show an excess of 23 ±8.7±14.6 events interpreted as charged current antineutrino electron interactions. In terms of a limit we obtain for the probability P(antineutrino muon → antineutrino electron): P<4.4% (95% C.L.)

  20. Long-Term Testing and Properties of Acrylic for the Daya Bay Antineutrino Detectors

    CERN Document Server

    Krohn, M; Heeger, K M

    2012-01-01

    The Daya Bay reactor antineutrino experiment has recently measured the neutrino mixing parameter sin22{\\theta}13 by observing electron antineutrino disappearance over kilometer-scale baselines using six antineutrino detectors at near and far distances from reactor cores at the Daya Bay nuclear power complex. Liquid scintillator contained in transparent target vessels is used to detect electron antineutrinos via the inverse beta-decay reaction. The Daya Bay experiment will operate for about five years yielding a precision measurement of sin22{\\theta}13. We report on long-term studies of poly(methyl methacrylate) known as acrylic, which is the primary material used in the fabrication of the target vessels for the experiment's antineutrino detectors. In these studies, acrylic samples are subjected to gaseous and liquid environmental conditions similar to those experienced during construction, transport, and operation of the Daya Bay acrylic target vessels and detectors. Mechanical and optical stability of the ac...

  1. KamLAND and Solar Antineutrino Spectrum

    CERN Document Server

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

    2004-01-01

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

  2. AGM2015: Antineutrino Global Map 2015

    CERN Document Server

    Usman, Shawn M; Dye, Stephen T; McDonough, William F; Learned, John G

    2015-01-01

    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 a...

  3. The Daya Bay Antineutrino Detector Filling System and Liquid Mass Measurement

    CERN Document Server

    Band, H R; 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

    2013-01-01

    The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing angle \\theta_{13} 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 sin^{2}2\\theta_{13} 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.

  4. 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 1025 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.

  5. Antineutrino Oscillations in the Atmospheric Sector

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-01

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

  6. Antineutrino Oscillations in the Atmospheric Sector

    Energy Technology Data Exchange (ETDEWEB)

    Himmel, Alexander I.; /Caltech

    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 {nu}{sub {mu}} {yields} {bar {nu}}{sub {mu}} 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 |{Delta}{bar m}{sub atm}{sup 2}| = (3.36{sub -0.40}{sup +0.46}(stat) {+-} 0.06(syst)) x 10{sup -3} eV{sup 2} and sin{sup 2}(2{bar {theta}}{sub 23}) = 0.860{sub -0.12}{sup +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.

  7. Reactor Antineutrinos Signal all over the world

    CERN Document Server

    Ricci, B; 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.

  8. Antineutrino Geophysics with Liquid Scintillator Detectors

    CERN Document Server

    Rothschild, C G; Calaprice, F P; Rothschild, Casey G.; Chen, Mark C.; Calaprice, Frank P.

    1997-01-01

    Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution in the Earth, we calculate the antineutrino event rate for two new neutrino detectors. We show that spectral features allow terrestrial antineutrino events to be identified above reactor antineutrino backgrounds and that the uranium and thorium contributions can be separately determined.

  9. Low Energy Antineutrino Detection Using Neutrino Capture on EC Decaying Nuclei

    CERN Document Server

    Cocco, Alfredo G; Messina, Marcello

    2009-01-01

    In this paper we present a study of the interaction of low energy electron antineutrino on nuclei that undergo electron capture. We show that the two corresponding crossed reactions have a sizeable cross section and are both suitable for detection of low energy antineutrino. However, only in case very specific conditions on the Q-value of the decay are met or significant improvements on the performances of ion storage rings are achieved, these reactions could be exploited in the future to address the long standing problem of a direct detection of Cosmological Neutrino Background.

  10. Charged current neutrino and antineutrino interactions in hydrogen and deuterium

    International Nuclear Information System (INIS)

    In this dissertation results are presented of two different (anti-)neutrino experiments with the Big European Bubble Chamber (BEBC) filled with hydrogen and deuterium successively and exposed to the wide band (anti-)neutrino beam at the SPS at CERN. Chapter 1 contains the description of the experimental set-up and in chapter 2 results of the experiment with BEBC filled with deuterium and exposed to the antineutrino beam are presented. The multiplicity distributions of the charged hadron shower produced in (anti-)neutrino interactions with protons and neutrons are studied and compared with the results from hadron-hadron experiments. In chapter 3 a study of the exclusive reaction γp→μ-pπ+ is presented, data being obtained from an exposure of BEBC filled with hydrogen to the wide band neutrino beam. The absolute cross-section of the dominant subchannel γp→μ-Δ++(1232) averaged over an energy range of Esub(γ) = 20-200 GeV is measured to be sigma = (0.59 +- 0.06) . 10-38 cm2. This value is in good agreement with the results of other experiments. The differential cross-section dsigma/dQ2, the Δ++ decay angular distributions and the density matrix elements are determined. The value of the axial mass determined using the Schreiner-Von Hippel parametrization of the Adler model by fitting the total cross-section is Msub(A) = 0.85 +- 0.10 GeV/c2. (Auth.)

  11. Web Application for Modeling Global Antineutrinos

    CERN Document Server

    Barna, Andrew

    2015-01-01

    Electron antineutrinos stream freely from rapidly decaying fission products within nuclear reactors and from long-lived radioactivity within Earth. Those with energy greater than 1.8 MeV are regularly observed by several kiloton-scale underground detectors. These observations estimate the amount of terrestrial radiogenic heating, monitor the operation of nuclear reactors, and measure the fundamental properties of neutrinos. The analysis of antineutrino observations at operating detectors or the planning of projects with new detectors requires information on the expected signal and background rates. We present a web application for modeling global antineutrino energy spectra and detection rates for any surface location. Antineutrino sources include all registered nuclear reactors as well as the crust and mantle of Earth. Visitors to the website may model the location and power of a hypothetical nuclear reactor, copy energy spectra, and analyze the significance of a selected signal relative to background.

  12. Daya Bay Antineutrino Detector Gas System

    CERN Document Server

    Band, H R; 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 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...

  13. Reference worldwide model for antineutrinos from reactors

    OpenAIRE

    Baldoncini, Marica; Callegari, Ivan; Fiorentini, Giovanni; Mantovani, Fabio; Ricci, Barbara; Strati, Virginia; Xhixha, Gerti

    2014-01-01

    Antineutrinos produced at nuclear reactors constitute a severe source of background for the detection of geoneutrinos, which bring to the Earth's surface information about natural radioactivity in the whole planet. In this framework we provide a reference worldwide model for antineutrinos from reactors, in view of reactors operational records yearly published by the International Atomic Energy Agency (IAEA). We evaluate the expected signal from commercial reactors for ongoing (KamLAND and Bor...

  14. Antineutrino monitoring of spent nuclear fuel

    OpenAIRE

    Brdar, Vedran; Huber, Patrick; Kopp, Joachim

    2016-01-01

    Military and civilian applications of nuclear energy have left a significant amount of spent nuclear fuel over the past 70 years. Currently, in many countries world wide, the use of nuclear energy is on the rise. Therefore, the management of highly radioactive nuclear waste is a pressing issue. In this letter, we explore antineutrino detectors as a tool for monitoring and safeguarding nuclear waste material. We compute the flux and spectrum of antineutrinos emitted by spent nuclear fuel eleme...

  15. Antineutrino Geophysics with Liquid Scintillator Detectors

    OpenAIRE

    Rothschild, Casey G.; Chen, Mark C.; Calaprice, Frank P.

    1997-01-01

    Detecting the antineutrinos emitted by the decay of radioactive elements in the mantle and crust could provide a direct measurement of the total abundance of uranium and thorium in the Earth. In calculating the antineutrino flux at specific sites, the local geology of the crust and the background from the world's nuclear power reactors are important considerations. Employing a global crustal map, with type and thickness data, and using recent estimates of the uranium and thorium distribution ...

  16. Neutrino Data and Neutrino-Antineutrino Transition

    CERN Document Server

    Alexeyev, E N

    2005-01-01

    A problem, whether a neutrino-antineutrino transition could be responsible for the muon neutrino deficit found in underground experiments (Super-Kamiokande, MACRO, Soudan 2) and in the accelerator long-baseline K2K experiment, is discussed in this paper. The intention of the work is not consideration of concrete models for muon neutrino-antineutrino transition but a desire to attract an attention to another possibility of understanding the nature of the measured muon neutrino deficit in neutrino experiments.

  17. Antineutrino monitoring of spent nuclear fuel

    CERN Document Server

    Brdar, Vedran; Kopp, Joachim

    2016-01-01

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

  18. A Precise Measurement of Reactor Antineutrino at RENO

    Science.gov (United States)

    Jang, J. S.

    2014-06-01

    RENO is the reactor experiment to measure the neutrino mixing angle θ1 3 by observing the disappearance of the reactor antineutrino. Antineutrinos from six reactors at Yonggwang Nuclear Power Plant in Korea, are detected and compared by two identical detectors located at 294 m and 1383 m, respectively, from the center of the reactor array. The far (near) detector observes 73 (780) electron antineutrino candidate events per day after background subtraction with the precise measurement of reactor antineutrino flux. In this paper, an updated result is presented about the energy spectra of antineutrino signals in RENO detectors. A precise measurement of reactor antineutrino flux is also presented in comparison with expectations.

  19. A Precise Measurement of Reactor Antineutrino at RENO

    International Nuclear Information System (INIS)

    RENO is the reactor experiment to measure the neutrino mixing angle θ13 by observing the disappearance of the reactor antineutrino. Antineutrinos from six reactors at Yonggwang Nuclear Power Plant in Korea, are detected and compared by two identical detectors located at 294 m and 1383 m, respectively, from the center of the reactor array. The far (near) detector observes 73 (780) electron antineutrino candidate events per day after background subtraction with the precise measurement of reactor antineutrino flux. In this paper, an updated result is presented about the energy spectra of antineutrino signals in RENO detectors. A precise measurement of reactor antineutrino flux is also presented in comparison with expectations

  20. Long-term testing and properties of acrylic for the Daya Bay antineutrino detectors

    Science.gov (United States)

    Krohn, M.; Littlejohn, B. R.; Heeger, K. M.

    2012-08-01

    The Daya Bay reactor antineutrino experiment has recently measured the neutrino mixing parameter sin22θ13 by observing electron antineutrino disappearance over kilometer-scale baselines using six antineutrino detectors at near and far distances from reactor cores at the Daya Bay nuclear power complex. Liquid scintillator contained in transparent target vessels is used to detect electron antineutrinos via the inverse beta-decay reaction. The Daya Bay experiment will operate for about five years yielding a precision measurement of sin22θ13. We report on long-term studies of poly(methyl methacrylate) known as acrylic, which is the primary material used in the fabrication of the target vessels for the experiment's antineutrino detectors. In these studies, acrylic samples are subjected to gaseous and liquid environmental conditions similar to those experienced during construction, transport, and operation of the Daya Bay acrylic target vessels and detectors. Mechanical and optical stability of the acrylic as well as its interaction with detector liquids is reported.

  1. Workshop applied antineutrino physics 2007

    International Nuclear Information System (INIS)

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

  2. Workshop applied antineutrino physics 2007

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  3. Uncertainties in the Anti-neutrino Production at Nuclear Reactors

    OpenAIRE

    Djurcic, Z.; Detwiler, J. A.; Piepke, A; Foster Jr., V. R.; Miller, L.; Gratta, G.

    2008-01-01

    Anti-neutrino emission rates from nuclear reactors are determined from thermal power measurements and fission rate calculations. The uncertainties in these quantities for commercial power plants and their impact on the calculated interaction rates in electron anti-neutrino detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties and their relevance to reactor anti-neutrino experiments.

  4. Applied Anti-neutrino Physics 2013

    CERN Document Server

    2013-01-01

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

  5. Reactor Antineutrino Anomaly with known \\theta_{13}

    CERN Document Server

    Zhang, C; Vogel, P

    2013-01-01

    We revisit the reactor antineutrino anomaly using the recent reactor flux independent determination of sizable theta?13 by considering the full set of the absolute reactor electron antineutrino flux measurements. When normalized to the predicted flux of Mueller et al. [1], the new world average, after including results from Palo Verde, Chooz, and Double Chooz, is 0.959 +- 0.009 (experiment uncertainty) +- 0.027 (flux systematics). Including the data with kilometer baseline, the new world average is only about 1.4 sigma lower than the unity, weakening the significance of the reactor antineutrino anomaly. The upcoming results from Daya Bay, RENO, and the Double Chooz will provide further information about this issue.

  6. Antineutrino induced antikaon production off the nucleon

    CERN Document Server

    Alam, M Rafi; Athar, M Sajjad; Vacas, M J Vicente

    2011-01-01

    The charged current antikaon production off nucleons induced by antineutrinos is studied at low and intermediate energies. We extend here our previous calculation on kaon production induced by neutrinos. We have developed a microscopic model that starts from the SU(3) chiral Lagrangians and includes background terms and the resonant mechanisms associated to the lowest lying resonance in the channel, namely, the Sigma*(1385). Our results could be of interest for the background estimation of various neutrino oscillation experiments like MiniBooNE and SuperK. They can also be helpful for the planned antineutrino experiments like MINERvA, NOvA and T2K phase II and for beta-beam experiments with antineutrino energies around 1 GeV.

  7. Low-energy Antineutrinos from the Sun

    CERN Document Server

    Pastor, S; Valle, José W F; Pastor, Sergio; Semikoz, Viktor B.; Valle, Jose W.F.

    1998-01-01

    We consider the sensitivity of future neutrino experiments in the low energy region, such as BOREXINO or HELLAZ, to a solar electron antineutrino signal. We show that, if neutrino conversions within the Sun result in partial polarization of initial solar neutrino fluxes, then a new opportunity arises to observe the electron antineutrinos and thus to probe the Majorana nature of the neutrinos. This is achieved by comparing the slopes of the energy dependence of the differential neutrino electron scattering cross section for different neutrino conversion scenarios. We also show how the \

  8. Reactor antineutrino fluxes - status and challenges

    CERN Document Server

    Huber, Patrick

    2016-01-01

    In this contribution we describe the current understanding of reactor antineutrino fluxes and point out some recent developments. This is not intended to be a complete review of this vast topic but merely a selection of observations and remarks, which despite their incompleteness, will highlight the status and the challenges of this field.

  9. Precisely determined the spent nuclear fuel antineutrino flux and spectrum for Daya Bay antineutrino experiment

    CERN Document Server

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

    2015-01-01

    Spent nuclear fuel (SNF) antineutrino flux is an important source of uncertainties for a reactor neutrino flux prediction. However, if one want to determine the contribution of spent fuel, many data are needed, such as the amount of spent fuel in the pool, the time after discharged from the reactor core, the burnup of each assembly, and the antineutrino spectrum of the isotopes in the spend fuel. A method to calculate the contribution of SNF is proposed in this study. In this method, reactor simulation code verified by experiment have been used to simulate the fuel depletion by taking into account more than 2000 isotopes and fission products, the quantity of SNF in each six spend fuel pool, and the antineutrino spectrum of SNF varying with time after SNF discharged from core. Results show that the contribution of SNF to the total antineutrino flux is about 0.26%~0.34%, and the shutdown impact is about 20%. The SNF spectrum would distort the softer part of antineutrino spectra, and the maximum contribution fro...

  10. Nuclear Reactor Safeguards and Monitoring with Antineutrino Detectors

    OpenAIRE

    Bernstein, Adam; Wang, Yifang; Gratta, Giorgio; West, Todd

    2001-01-01

    Cubic-meter-sized antineutrino detectors can be used to non-intrusively, robustly and automatically monitor and safeguard a wide variety of nuclear reactor types, including power reactors, research reactors, and plutonium production reactors. Since the antineutrino spectra and relative yields of fissioning isotopes depend on the isotopic composition of the core, changes in composition can be observed without ever directly accessing the core itself. Information from a modest-sized antineutrino...

  11. The antineutrino energy structure in reactor experiments

    CERN Document Server

    Novella, P

    2015-01-01

    The recent observation of an energy structure in the reactor antineutrino spectrum is reviewed. The reactor experiments Daya Bay, Double Chooz and RENO have reported a consistent excess of antineutrinos deviating from the flux predictions, with a local significance of about 4$\\sigma$ between 4 and 6 MeV of the positron energy spectrum. The possible causes of the structure are analyzed in this work, along with the different experimental approaches developed to identify its origin. Considering the available data and results from the three experiments, the most likely explanation concerns the reactor flux predictions and the associated uncertainties. Therefore, the different current models are described and compared. The possible sources of incompleteness or inaccuracy of such models are discussed, as well as the experimental data required to improve their precision.

  12. Hanohano:A Deep Ocean Antineutrino Observatory

    CERN Document Server

    Batygov, M; Learned, J G; Matsuno, S; Pakvasa, S; Varner, G

    2008-01-01

    This paper presents the science potential of a deep ocean antineutrino observatory being developed at Hawaii and elsewhere. The observatory design allows for relocation from one site to another. Positioning the observaory some 60 km distant from a nuclear reactor complex enables preecision measurement of neutrino mixing parameters, leading to a determination of neutrino mass hierarchy and theta_13. At a mid-Pacific location, the observatory measures the flux of uranium and thorium decay series antineutrinos from earth's mantle and performs a sensitive search for a hypothetical natural fission reactor in earth's core. A subequent deployment at another mid-ocean location would test lateral homogeneity of uranium and thorium in earth's mantle. These measurements have significance for earth energy studies.

  13. JUNO: A Next Generation Reactor Antineutrino Experiment

    OpenAIRE

    Zhan, Liang

    2015-01-01

    The mass hierarchy and the CP phase are the main focus of the next generation neutrino oscillation experiments. Jiangmen Underground Neutrino Observatory (JUNO), as a medium baseline reactor antineutrino experiment, can determine the neutrino mass hierarchy independent of the CP phase. The physics potential on the mass hierarchy, and other measurements are reviewed. The preliminary design options for a 20~kton detector with an energy resolution of $3\\%/\\sqrt{E_{vis}}$ are illustrated. The mai...

  14. Hanohano:A Deep Ocean Antineutrino Observatory

    OpenAIRE

    Batygov, M.; Dye, S. T.; Learned, J. G.; Matsuno, S; Pakvasa, S.; Varner, G.

    2008-01-01

    This paper presents the science potential of a deep ocean antineutrino observatory being developed at Hawaii and elsewhere. The observatory design allows for relocation from one site to another. Positioning the observaory some 60 km distant from a nuclear reactor complex enables preecision measurement of neutrino mixing parameters, leading to a determination of neutrino mass hierarchy and theta_13. At a mid-Pacific location, the observatory measures the flux of uranium and thorium decay serie...

  15. KamLAND, solar antineutrinos and the solar magnetic field

    CERN Document Server

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

    2003-01-01

    In this work the possibility of detecting solar electron antineutrinos produced by a solar core magnetic field from the KamLAND recent observations is investigated. We find a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value. In this way the solar electron antineutrino spectrum can be unambiguosly predicted. We use this scaling and the negative results indicated by the KamLAND experiment to obtain upper bounds on the solar electron antineutrino flux. We get $\\phi_{\\bar\

  16. An improved measurement of muon antineutrino disappearance in MINOS

    OpenAIRE

    Adamson, P.; Ayres, D. S.; Backhouse, C.; Barr, G.; Bishai, M.; Blake, A.; Bock, G.J.; Boehnlein, D. J.; Bogert, D.; Cao, S. V.; Childress, S.; Coelho, J. A. B.; Corwin, L.; Cronin-Hennessy, D.; Danko, I. Z.

    2012-01-01

    We report an improved measurement of muon anti-neutrino disappearance over a distance of 735km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a muon anti-neutrino enhanced configuration. From a total exposure of 2.95e20 protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of the anti-neutrino "atmospheric" delta-m squared = 2.62 +0.31/-0.28 (stat.) +/- 0.09 (syst.) and constrain the anti-neutrino atmospheric mixing ...

  17. Theory of Antineutrino Monitoring of Burning MOX Plutonium Fuels

    CERN Document Server

    Hayes, A C; Nieto, Michael Martin; WIlson, W B

    2011-01-01

    This letter presents the physics and feasibility of reactor antineutrino monitoring to verify the burnup of plutonium loaded in the reactor as a Mixed Oxide (MOX) fuel. It examines the magnitude and temporal variation in the antineutrino signals expected for different MOX fuels, for the purposes of nuclear accountability and safeguards. The antineutrino signals from reactor-grade and weapons-grade MOX are shown to be distinct from those from burning low enriched uranium. Thus, antineutrino monitoring could be used to verify the destruction of plutonium in reactors, though verifying the grade of the plutonium being burned is found to be more challenging.

  18. Target Mass Monitoring and Instrumentation in the Daya Bay Antineutrino Detectors

    CERN Document Server

    Band, Henry R; Greenler, Lee S; Heeger, Karsten M; Hinrichs, Paul; Kang, Li; Lewis, Christine; Li, Shanfeng; Lin, Shengxin; McFarlane, Michael C; Wang, Wei; Webber, David M; Wei, Yadong; Wise, Thomas; Xiao, Qiang; Yang, Li; Zhang, Zhijian

    2012-01-01

    The Daya Bay experiment measures sin^2 2{\\theta}_13 using functionally identical antineutrino detectors located at distances of 300 to 2000 meters from the Daya Bay nuclear power complex. Each detector consists of three nested fluid volumes surrounded by photomultiplier tubes. These volumes are coupled to overflow tanks on top of the detector to allow for thermal expansion of the liquid. Antineutrinos are detected through the inverse beta decay reaction on the proton-rich scintillator target. A precise and continuous measurement of the detector's central target mass is achieved by monitoring the the fluid level in the overflow tanks with cameras and ultrasonic and capacitive sensors. In addition, the monitoring system records detector temperature and levelness at multiple positions. This monitoring information allows the precise determination of the detectors' effective number of target protons during data taking. We present the design, calibration, installation and in-situ tests of the Daya Bay real-time ant...

  19. JUNO: A Next Generation Reactor Antineutrino Experiment

    CERN Document Server

    Zhan, Liang

    2015-01-01

    The mass hierarchy and the CP phase are the main focus of the next generation neutrino oscillation experiments. Jiangmen Underground Neutrino Observatory (JUNO), as a medium baseline reactor antineutrino experiment, can determine the neutrino mass hierarchy independent of the CP phase. The physics potential on the mass hierarchy, and other measurements are reviewed. The preliminary design options for a 20~kton detector with an energy resolution of $3\\%/\\sqrt{E_{vis}}$ are illustrated. The main technical challenges on the PMT and scintillator are discussed and the corresponding R\\&D efforts are presented.

  20. Antineutrino reactor safeguards - a case study

    CERN Document Server

    Christensen, Eric; Jaffke, Patrick

    2013-01-01

    Antineutrinos have been proposed as a means of reactor safeguards for more than 30 years and there has been impressive experimental progress in neutrino detection. In this paper we conduct, for the first time, a case study of the application of antineutrino safeguards to a real-world scenario - the North Korean nuclear crisis in 1994. We derive detection limits to a partial or full core discharge in 1989 based on actual IAEA safeguards access and find that two independent methods would have yielded positive evidence for a second core with very high confidence. To generalize our results, we provide detailed estimates for the sensitivity to the plutonium content of various types of reactors, including most types of plutonium production reactors, based on detailed reactor simulations. A key finding of this study is that a wide class of reactors with a thermal power of less than 0.1-1 GWth can be safeguarded achieving IAEA goals for quantitative sensitivity and timeliness with detectors right outside the reactor ...

  1. Detection of Breeding Blankets Using Antineutrinos

    Science.gov (United States)

    Cogswell, Bernadette; Huber, Patrick

    2016-03-01

    The Plutonium Management and Disposition Agreement between the United States and Russia makes arrangements for the disposal of 34 metric tons of excess weapon-grade plutonium. Under this agreement Russia plans to dispose of its excess stocks by processing the plutonium into fuel for fast breeder reactors. To meet the disposition requirements this fuel would be burned while the fast reactors are run as burners, i.e., without a natural uranium blanket that can be used to breed plutonium surrounding the core. This talk discusses the potential application of antineutrino monitoring to the verification of the presence or absence of a breeding blanket. It is found that a 36 kg antineutrino detector, exploiting coherent elastic neutrino-nucleus scattering and made of silicon, could determine the presence of a breeding blanket at a liquid sodium cooled fast reactor at the 95% confidence level within 90 days. Such a detector would be a novel non-intrusive verification tool and could present a first application of coherent elastic neutrino-nucleus scattering to a real-world challenge.

  2. Long Distance Reactor Antineutrino Flux Monitoring

    Science.gov (United States)

    Dazeley, Steven; Bergevin, Marc; Bernstein, Adam

    2015-10-01

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

  3. Testing Geological Models with Terrestrial Antineutrino Flux Measurements

    CERN Document Server

    Dye, Steve

    2009-01-01

    Uranium and thorium are the main heat producing elements in the earth. Their quantities and distributions, which specify the flux of detectable antineutrinos generated by the beta decay of their daughter isotopes, remain unmeasured. Geological models of the continental crust and the mantle predict different quantities and distributions of uranium and thorium. Many of these differences are resolvable with precision measurements of the terrestrial antineutrino flux. This precision depends on both statistical and systematic uncertainties. An unavoidable background of antineutrinos from nuclear reactors typically dominates the systematic uncertainty. This report explores in detail the capability of various operating and proposed geo-neutrino detectors for testing geological models.

  4. Hypersharp Resonant Capture of Anti-Neutrinos

    CERN Document Server

    Raghavan, R S

    2008-01-01

    Recent ideas suggest that the 18.6 keV antineutrino (nuebar) line from 2-body decay of 3H in crystals is emitted with natural width, motionally narrowed by lattice vibrations as in recoilless emission. It can be resonantly captured in 3He with geometrical cross section sigma ~10 ^ -17 cm2. A key technique solves a basic obstacle for achieving resonance--the chemical difference of H and He in metals. The low nue energy, the high sigma and the hypersharp sensitivity DELTA E/E ~10^--29 make an extraordinary tool for bench scale tests of nue theta13 oscillations and predicted Planck length limits on nuclear level widths in models of quantum gravity.

  5. Geoneutrinos and reactor antineutrinos at SNO+

    CERN Document Server

    Baldoncini, M; Wipperfurth, S A; Fiorentini, G; Mantovani, F; McDonough, W F; Ricci, B

    2016-01-01

    In the heart of the Creighton Mine near Sudbury (Canada), the SNO+ detector is foreseen to observe almost in equal proportion electron antineutrinos produced by U and Th in the Earth and by nuclear reactors. SNO+ will be the first long baseline experiment to measure a reactor signal dominated by CANDU cores ($\\sim$55\\% of the total reactor signal), which generally burn natural uranium. Approximately 18\\% of the total geoneutrino signal is generated by the U and Th present in the rocks of the Huronian Supergroup-Sudbury Basin: the 60\\% uncertainty on the signal produced by this lithologic unit plays a crucial role on the discrimination power on the mantle signal as well as on the geoneutrino spectral shape reconstruction, which can in principle provide a direct measurement of the Th/U ratio in the Earth.

  6. Estimating terrestrial uranium and thorium by antineutrino flux measurements

    Science.gov (United States)

    Dye, Stephen T.; Guillian, Eugene H.

    2008-01-01

    Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations in geological reservoirs relies largely on geochemical model calculations. This article describes the methods and criteria to experimentally determine average concentrations of uranium and thorium in the continental crust and in the mantle by using site-specific measurements of the terrestrial antineutrino flux. Optimal, model-independent determinations involve significant exposures of antineutrino detectors remote from nuclear reactors at both a midcontinental and a midoceanic site. This would require major, new antineutrino detection projects. The results of such projects could yield a greatly improved understanding of the deep interior of the Earth. PMID:18172211

  7. Estimating terrestrial uranium and thorium by antineutrino flux measurements

    CERN Document Server

    Dye, Stephen T

    2008-01-01

    Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations in geological reservoirs relies largely on geochemical model calculations. This research report describes the methods and criteria to experimentally determine average concentrations of uranium and thorium in the continental crust and in the mantle using site-specific measurements of the terrestrial antineutrino flux. Optimal, model-independent determinations involve significant exposures of antineutrino detectors remote from nuclear reactors at both a mid-continental and a mid-oceanic site. This would require major, new antineutrino detection projects. The results of such projects could yield a greatly improved understa...

  8. Observation of electron-antineutrino disappearance at Daya Bay

    CERN Document Server

    An, F P; Balantekin, A B; Band, H R; Beavis, D; Beriguete, W; Bishai, M; Blyth, S; Brown, R L; Cao, G F; Cao, J; Carr, R; Chan, W T; Chang, J F; Chang, Y; Chasman, C; Chen, H S; Chen, H Y; Chen, S J; Chen, S M; Chen, X C; Chen, X H; Chen, X S; Chen, Y; Chen, Y X; Cherwinka, J J; Chu, M C; Cummings, J P; Deng, Z Y; Ding, Y Y; Diwan, M V; Dong, L; Draeger, E; Du, X F; Dwyer, D A; Edwards, W R; Ely, S R; Fang, S D; Fu, J Y; Fu, Z W; Ge, L Q; Ghazikhanian, V; Gill, R L; Goett, J; Gonchar, M; Gong, G H; Gong, H; Gornushkin, Y A; Greenler, L S; Gu, W Q; Guan, M Y; Guo, X H; Hackenburg, R W; Hahn, R L; Hans, S; He, M; He, Q; He, W S; Heeger, K M; Heng, Y K; Hinrichs, P; Ho, T H; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, T; Hu, T; Huang, H X; Huang, H Z; Huang, P W; Huang, X; Huang, X T; Huber, P; Isvan, Z; Jaffe, D E; Jetter, S; Ji, X L; Ji, X P; Jiang, H J; Jiang, W Q; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Lai, C Y; Lai, W C; Lai, W H; Lau, K; Lebanowski, L; Lee, J; Lee, M K P; Leitner, R; Leung, J K C; Leung, K Y; Lewis, C A; Li, B; Li, F; Li, G S; Li, J; Li, Q J; Li, S F; Li, W D; Li, X B; Li, X N; Li, X Q; Li, Y; Li, Z B; Liang, H; Liang, J; Lin, C J; Lin, G L; Lin, S K; Lin, S X; Lin, Y C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, B J; Liu, C; Liu, D W; Liu, H; Liu, J C; Liu, J L; Liu, S; Liu, X; Liu, Y B; Lu, C; Lu, H Q; Luk, A; Luk, K B; Luo, T; Luo, X L; Ma, L H; Ma, Q M; Ma, X B; Ma, X Y; Ma, Y Q; Mayes, B; McDonald, K T; McFarlane, M C; McKeown, R D; Meng, Y; Mohapatra, D; Morgan, J E; Nakajima, Y; Napolitano, J; Naumov, D; Nemchenok, I; Newsom, C; Ngai, H Y; Ngai, W K; Nie, Y B; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Pagac, A; Patton, S; Pearson, C; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Raper, N; Rosero, R; Roskovec, B; Ruan, X C; Seilhan, B; Shao, B B; Shih, K; Steiner, H; Stoler, P; Sun, G X; Sun, J L; Tam, Y H; Tanaka, H K; Tang, X; Themann, H; Torun, Y; Trentalange, S; Tsai, O; Tsang, K V; Tsang, R H M; Tull, C; Viren, B; Virostek, S; Vorobel, V; Wang, C H; Wang, L S; Wang, L Y; Wang, L Z; Wang, M; Wang, N Y; Wang, R G; Wang, T; Wang, W; Wang, X; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Webber, D M; Wei, Y D; Wen, L J; Wenman, D L; Whisnant, K; White, C G; Whitehead, L; Whitten, C A; Wilhelmi, J; Wise, T; Wong, H C; Wong, H L H; Wong, J; Worcester, E T; Wu, F F; Wu, Q; Xia, D M; Xiang, S T; Xiao, Q; Xing, Z Z; Xu, G; Xu, J; Xu, J; Xu, J L; Xu, W; Xu, Y; Xue, T; Yang, C G; Yang, L; Ye, M; Yeh, M; Yeh, Y S; Yip, K; Young, B L; Yu, Z Y; Zhan, L; Zhang, C; Zhang, F H; Zhang, J W; Zhang, Q M; Zhang, K; Zhang, Q X; Zhang, S H; Zhang, Y C; Zhang, Y H; Zhang, Y X; Zhang, Z J; Zhang, Z P; Zhang, Z Y; Zhao, J; Zhao, Q W; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, Z Y; Zhuang, H L; Zou, J H

    2012-01-01

    The Daya Bay Reactor Neutrino Experiment has measured a non-zero value for the neutrino mixing angle $\\theta_{13}$ with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GW$_{\\rm th}$ reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With 55 days of data, 10416 (80376) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is $R=0.940\\pm 0.011({\\rm stat}) \\pm 0.004({\\rm syst})$. A rate-only analysis finds $\\sin^22\\theta_{13}=0.092\\pm 0.016({\\rm stat})\\pm0.005({\\rm syst})$ in a three-neutrino framework.

  9. First Antineutrino Oscillation Results from T2K

    CERN Document Server

    Duffy, Kirsty

    2016-01-01

    As limits improve on the neutrino mixing angles and mass-squared differences, the focus of T2K has shifted towards studying antineutrino oscillation. This will give an insight into CP violation (if P($\\bar{\

  10. Discriminating among Earth composition models using geo-antineutrinos

    OpenAIRE

    H. Nunokawa(Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, C.P. 38071, 22452-970, Rio de Janeiro, Brazil); Teves, W. J. C.; Funchal, R. Zukanovich

    2003-01-01

    It has been estimated that the entire Earth generates heat corresponding to about 40 TW (equivalent to 10,000 nuclear power plants) which is considered to originate mainly from the radioactive decay of elements like U, Th and K, deposited in the crust and mantle of the Earth. Radioactivity of these elements produce not only heat but also antineutrinos (called geo-antineutrinos) which can be observed by terrestrial detectors. We investigate the possibility of discriminating among Earth composi...

  11. Testing Geological Models with Terrestrial Antineutrino Flux Measurements

    OpenAIRE

    Dye, Steve

    2009-01-01

    Uranium and thorium are the main heat producing elements in the earth. Their quantities and distributions, which specify the flux of detectable antineutrinos generated by the beta decay of their daughter isotopes, remain unmeasured. Geological models of the continental crust and the mantle predict different quantities and distributions of uranium and thorium. Many of these differences are resolvable with precision measurements of the terrestrial antineutrino flux. This precision depends on bo...

  12. Monitoring Nuclear Reactors with Antineutrino Detectors: The ANGRA Project

    International Nuclear Information System (INIS)

    Nuclear reactors are intense source of antineutrinos and the thermal power released in the fission process is directly related to the emitted antineutrino flux. As antineutrinos interact very weekly with matter and escape the reactor containment without any significant change in their number, measuring the antineutrino flux can give quasi real time information on the reactor status (on/off) and thermal power. Furthermore as the amount of fissile elements change during the burn up of the nuclear fuel and each fissile isotope has a characteristic antineutrino energy spectrum, measuring the antineutrino energy spectrum escaping the reactor can give also information on the composition of the nuclear fuel. These unique features make antineutrino detectors good candidates to become in the near future a new safeguards tool for monitoring nuclear reactors through counting rates and spectral antineutrino measurements. We will present the status of the ANGRA Neutrinos project, aimed at developing an antineutrino detector for monitoring nuclear reactor activity. The Angra experiment will be deployed at the Brazilian nuclear power plant Angra II. A water Cherenkov detector of one ton target will be placed in a commercial container just outside the reactor containment, about 30 m of the reactor core. The 4 GW thermal power of the Angra II reactor will provide a few thousand antineutrino inverse beta decay interactions per day. The main challenge of the experiment will be to overcome the very high cosmic ray induced background at sea level, consisting mainly of muons, neutrons, gammas and electrons. We have estimated a muon flux of the order of 350 Hz and a neutron flux of about 4 Hz (left after the polyethylene shielding) in the target region. To overcome the background the detector will consist of three subsystems: 1) a muon veto 99% efficient placed in the outer most detector layer; 2) a neutron shield 30cm thick consisting of polyethylene sheets; 3) a central detector

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

    International Nuclear Information System (INIS)

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

  14. 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.

  15. Discriminating among Earth composition models using geo-antineutrinos

    CERN Document Server

    Nunokawa, H; Zukanovich-Funchal, R

    2003-01-01

    It has been estimated that the entire Earth generates heat corresponding to about 40 TW (equivalent to 10,000 nuclear power plants) which is considered to originate mainly from the radioactive decay of elements like U, Th and K, deposited in the crust and mantle of the Earth. Radioactivity of these elements produce not only heat but also antineutrinos (called geo-antineutrinos) which can be observed by terrestrial detectors. We investigate the possibility of discriminating among Earth composition models predicting different total radiogenic heat generation, by observing such geo-antineutrinos at Kamioka and Gran Sasso, assuming KamLAND and Borexino (type) detectors, respectively, at these places. By simulating the future geo-antineutrino data as well as reactor antineutrino background contributions, we try to establish to which extent we can discriminate among Earth composition models for given exposures (in units of kt$\\cdot$ yr) at these two sites on our planet. We use also information on neutrino mixing pa...

  16. KamLAND, solar antineutrinos and their magnetic moment

    CERN Document Server

    Aliani, P; Picariello, M; Torrente-Lujan, E

    2003-01-01

    We investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. The recent evidence from SNO shows that a) the neutrino oscillates, only around 34% of the initial solar neutrinos arrive at the Earth as electron neutrinos and b) the conversion is mainly into active neutrinos, however a non e, mu, tau component is allowed: the fraction of oscillation into non-mu-tau neutrinos is found to be cos^2(alpha) = 0.08^{+0.20}_{-0.40}. This residual flux could include sterile neutrinos and/or the antineutrinos of the active flavors. KamLAND is potentially sensitive to antineutrinos derived from solar ^8 B neutrinos. In case of negative results, we find that KamLAND could put strict limits on the flux of solar antineutrinos, Phi(^8 B) < 1.0 times 10^4 cm^{-2} s^{-1}, more than one order of magnitude smaller than existing limits, and on their app...

  17. 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.

  18. Azimuthal asymmetry of hadrons produced in antineutrino reactions

    International Nuclear Information System (INIS)

    Preliminary results on an azimuthal asymmetry of the hadrons about the current direction in ν-barNe interactions for π- distributions are reported. The distributions of γ show a bremstrahlung effect from the muon. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-01

    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/{sup 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/{sup 6}LiF configurations reliably identify {sup 6}Li neutron captures in 60 cm-long segments using pulse shape discrimination.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kiff, Scott D.; Reyna, David; Monahan, James (Drexel University, Philadelphia, PA); Bowden, Nathaniel S. (Lawrence Livermore National Laboratory, Livermore, CA)

    2010-10-01

    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/{sup 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/{sup 6}LiF configurations reliably identify {sup 6}Li neutron captures in 60 cm-long segments using pulse shape discrimination.

  1. Neutron detection and identification using ZnS:Ag/{sup 6}LiF in segmented antineutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kiff, Scott D., E-mail: skiff@sandia.gov [Sandia National Laboratories, 7011 East Avenue, Livermore, CA 94550 (United States); Bowden, Nathaniel [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Lund, Jim; Reyna, David [Sandia National Laboratories, 7011 East Avenue, Livermore, CA 94550 (United States)

    2011-10-01

    Antineutrino detection using inverse beta-decay conversion has demonstrated capability to measure nuclear reactor power and fissile material content for nuclear safeguards. Current efforts focus on aboveground deployment scenarios, for which a successful background rejection strategy will be needed to measure the anticipated antineutrino event rates. In this paper, we report on initial studies to quantify the intrinsic capture efficiency and particle identification capabilities of a new scintillation-based segmented design that uses layers of ZnS:Ag/{sup 6}LiF to capture and identify neutrons created in the inverse beta-decay reaction. Laboratory efficiency measurements are consistent with MCNP5 calculations, estimating {sup 6}Li neutron conversion efficiency above 50% for practical full-scale detector configurations.

  2. Antineutrino monitoring for the Iranian heavy water reactor

    CERN Document Server

    Christensen, Eric; Jaffke, Patrick; Shea, Thomas

    2014-01-01

    In this note we discuss the potential application of antineutrino monitoring to the Iranian heavy water reactor at Arak, the IR-40, as a non-proliferation measure. We demonstrate that an above ground detector positioned right outside the IR-40 reactor building could meet and in some cases significantly exceed the verification goals identified by IAEA for plutonium production or diversion from declared inventories. In addition to monitoring the reactor during operation, observing antineutrino emissions from long-lived fission products could also allow monitoring the reactor when it is shutdown. Antineutrino monitoring could also be used to distinguish different levels of fuel enrichment. Most importantly, these capabilities would not require a complete reactor operational history and could provide a means to re-establish continuity of knowledge in safeguards conclusions should this become necessary.

  3. A reference worldwide model for antineutrinos from reactors

    CERN Document Server

    Baldoncini, Marica; Fiorentini, Giovanni; Mantovani, Fabio; Ricci, Barbara; Strati, Virginia; Xhixha, Gerti

    2014-01-01

    Antineutrinos produced at nuclear reactors constitute a severe source of background for the detection of geoneutrinos, which bring to the Earth's surface information about natural radioactivity in the whole planet. In this framework we provide a reference worldwide model for antineutrinos from reactors, in view of reactors operational records yearly published by the International Atomic Energy Agency (IAEA). We evaluate the expected signal from commercial reactors for ongoing (KamLAND and Borexino), planned (SNO+) and proposed (Juno, RENO-50, LENA and Hanohano) experimental sites. Uncertainties related to reactor antineutrino production, propagation and detection processes are estimated using a Monte Carlo based approach, which provides an overall site dependent uncertainty on the signal in the geoneutrino energy window on the order of 3%. We also implement the off-equilibrium correction to the reference reactor spectra associated with the long-lived isotopes and we estimate a 2.4% increase of the unoscillate...

  4. Neutrino geophysics at Baksan I: possible detection of georeactor antineutrinos

    International Nuclear Information System (INIS)

    J.M. Herndon in 90s proposed a natural nuclear fission georeactor at the center of the Earth with a power output of 3 - 10 TW as an energy source to sustain the Earth magnetic field. R.S. Raghavan in 2002 pointed out that under certain condition antineutrinos generated in georeactor can be detected using massive scintillation detectors. It is considered that underground Baksan Neutrino Observatory (4880 m w.e.) as a possible site dor development in Geoneutrino physics. Here the intrinsic background level of less than 1 event/yr in a liquid scintillation ∼1000-t target detector can be achieved and the main source of background is the antineutrino flux from power reactors. It is find that this flux is ∼ 10 times lower than at KamLAND detector site and two times lower than at Gran Sasso laboratory and thus at Baksan the georeactor burning nuclear fuel by analysis of the antineutrino energy spectrum

  5. Antineutrino flux from the Laguna Verde Nuclear Power Plant

    CERN Document Server

    Chavez-Estrada, Marisol

    2015-01-01

    We present a a calculation of the antineutrino flux produced by the reactors at the Laguna Verde Nuclear Power Plant in M\\'exico, based on the antineutrino spectra produced in the decay chains of the fission fragments of the main isotopes in the reactor core, and their fission rates, that have been calculated using the DRAGON simulation code. We also present an estimate of the number of expected events in a detector made of plastic scintillator with a mass of 1 ton, at 100 m from the reactor cores.

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

    International Nuclear Information System (INIS)

    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

  7. Investigation of Large LGB Detectors for Antineutrino Detection

    CERN Document Server

    Nelson, P

    2011-01-01

    A detector material or configuration that can provide an unambiguous indication of neutron capture can substantially reduce random coincidence backgrounds in antineutrino detection and capture-gated neutron spectrometry applications. Here we investigate the performance of such a material, a composite of plastic scintillator and $^6$Li$_6^{nat}$Gd$(^{10}$BO$_{3})_{3}$:Ce (LGB) crystal shards of ~1 mm dimension and comprising 1% of the detector by mass. While it is found that the optical propagation properties of this material as currently fabricated are only marginally acceptable for antineutrino detection, its neutron capture identification ability is encouraging.

  8. Investigation of large LGB detectors for antineutrino detection

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-21

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

  9. Measuring Antineutrino Oscillations with the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-01

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

  10. Measuring Antineutrino Oscillations with the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Justin John; /Oxford U.

    2008-09-01

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

  11. Monitoring Akkuyu Nuclear Reactor Using Anti-Neutrino Flux Measurement

    CERN Document Server

    Ozturk, Sertac; Ozcan, V Erkcan; Unel, Gokhan

    2016-01-01

    We present a simulation based study for monitoring Akkuyu Nuclear Power Plant's activity using anti-neutrino flux originating from the reactor core. A water Cherenkov detector has been designed and optimization studies have been performed using Geant4 simulation toolkit. A first study for the design of a monitoring detector facility for Akkuyu Nuclear Power Plant has been discussed in this paper.

  12. Neutron capture and the antineutrino yield from nuclear reactors

    CERN Document Server

    Huber, Patrick

    2015-01-01

    We identify a new, flux-dependent correction to the antineutrino spectrum as produced in nuclear reactors. The abundance of certain nuclides, whose decay chains produce antineutrinos above the threshold for inverse beta decay, has a nonlinear dependence on the neutron flux, unlike the vast majority of antineutrino producing nuclides, whose decay rate is directly related to the fission rate. We have identified four of these so-called nonlinear nuclides and determined that they result in an antineutrino excess at low-energies below 3.2MeV, dependent on the reactor thermal neutron flux. We develop an analytic model for the size of the correction and compare it to the results of detailed reactor simulations for various real existing reactors, spanning 3 orders of magnitude in neutron flux. In a typical pressurized water reactor the resulting correction can reach 0.9% of the low energy flux which is comparable in size to other, known low-energy corrections from spent nuclear fuel and the non-equilibrium correction...

  13. Method for measuring the electron antineutrino rest mass

    Energy Technology Data Exchange (ETDEWEB)

    Lobashev, V.M.; Spivak, P.E.

    1985-10-15

    A method is proposed for measuring the tritium beta spectrum in order to determine the electron antineutrino rest mass. This method includes an electrostatic integral spectrometer with adiabatic collimation. The use of a source in the form of atomic polarized tritium in a strong magnetic field or of a gaseous molecular source is considered. (orig.).

  14. Observation of Reactor Electron Antineutrino Disappearance at RENO

    International Nuclear Information System (INIS)

    The Reactor Experiment for Neutrino Oscillation (RENO) has obtained a definitive measurement of the smallest neutrino mixing angle of θ13 by observing the disappearance of electron antineutrinos emitted from a nuclear reactor, excluding the no-oscillation hypothesis at 4.9 σ. From the deficit, the best fit value of sin22θ13 is obtained as 0.113±0.013(stat.)±0.019(syst.) based on a rate-only analysis. Antineutrinos from six 2.8 GWth reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors at 294 m and 1383 m, respectively, from the reactor array center. In the 229 day data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of the reactor antineutrinos in the far detector is 0.920±0.009(stat.)±0.014(syst.)

  15. Electron Neutrino and Antineutrino Appearance in the MINOS Detector

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-01

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

  16. Improved Measurement of Electron Antineutrino Disappearance at Daya Bay

    CERN Document Server

    An, F P; Balantekin, A B; Band, H R; Beriguete, W; Bishai, M; Blyth, S; Brown, R L; Cao, G F; Cao, J; Carr, R; Chan, W T; Chang, J F; Chang, Y; Chasman, C; Chen, H S; Chen, H Y; Chen, S J; Chen, S M; Chen, X C; Chen, X H; Chen, X S; Chen, Y; Chen, Y X; Cherwinka, J J; Chu, M C; Cummings, J P; Deng, Z Y; Ding, Y Y; Diwan, M V; Dong, L; Draeger, E; Dwyer, D; Edwards, W R; Ely, S R; Fang, S D; Fu, J Y; Fu, Z W; Ge, L Q; Gill, R L; Gonchar, M; Gong, G H; Gong, H; Gornushkin, Y A; Greenler, L S; Gu, W Q; Guan, M Y; Guo, X H; Hackenburg, R W; Hahn, R L; Hans, S; He, M; He, Q; Heeger, K M; Heng, Y K; Hinrichs, P; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, T; Huang, H X; Huang, H Z; Huang, X T; Huber, P; Issakov, V; Isvan, Z; Jaffe, D E; Jetter, S; Ji, X L; Ji, X P; Jiang, H J; Jiang, W Q; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Lai, C Y; Lai, W C; Lai, W H; Lau, K; Lebanowski, L; Lee, J; Leitner, R; Leung, J K C; Leung, K Y; Lewis, C A; Li, B; Li, F; Li, G S; Li, J; Li, Q J; Li, S F; Li, W D; Li, X B; Li, X N; Li, X Q; Li, Y; Li, Z B; Liang, H; Liang, J; Lin, C J; Lin, G L; Lin, S K; Lin, S X; Lin, Y C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, B J; Liu, D W; Liu, J C; Liu, J L; Liu, S; Liu, Y B; Lu, C; Lu, H Q; Luk, A; Luk, K B; Luo, T; Luo, X L; Ma, Q M; Ma, X B; Ma, X Y; Ma, Y Q; McDonald, K T; McFarlane, M C; McKeown, R D; Meng, Y; Mohapatra, D; Morgan, J E; Nakajima, Y; Napolitano, J; Naumov, D; Nemchenok, I; Ngai, H Y; Ngai, W K; Nie, Y B; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Pagac, A; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Raper, N; Rosero, R; Roskovec, B; Ruan, X C; Shao, B B; Shih, K; Steiner, H; Stoler, P; Sun, G X; Sun, J L; Tam, Y H; Tanaka, H K; Tang, X; Tagg, N; Themann, H; Torun, Y; Trentalange, S; Tsai, O; Tsang, R H M; Tsang, K V; Tull, C; Tung, Y C; Viren, B; Virostek, S; Vorobel, V; Wang, C H; Wang, L S; Wang, L Y; Wang, L Z; Wang, M; Wang, N Y; Wang, R G; Wang, T; Wang, W; Wang, X; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Webber, D M; Wei, Y D; Wen, L J; Wenman, D L; Whisnant, K; White, C G; Whitehead, L; Wilhelmi, J; Williamson, Y; Wise, T; Wong, H L H; Wong, J; Worcester, E T; Wu, F F; Wu, Q; Xia, D M; Xiang, S T; Xiao, Q; Xing, Z Z; Xu, J; Xu, J; Xu, J L; Xu, W; Xu, Y; Xue, T; Yang, C G; Yang, L; Ye, M; Yeh, M; Yeh, Y S; Young, B L; Yu, Z Y; Zhan, L; Zhang, C; Zhang, F H; Zhang, J W; Zhang, Q M; Zhang, Q X; Zhang, S H; Zhang, Y C; Zhang, Y H; Zhang, Y X; Zhang, Z J; Zhang, Z P; Zhang, Z Y; Zhao, J; Zhao, Q W; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, Z Y; Zhuang, H L; Zou, J H

    2012-01-01

    We report an improved measurement of the neutrino mixing angle $\\theta_{13}$ from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for $\\sin^22\\theta_{13}$ with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW$_{\\rm th}$ 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 $0.944\\pm 0.007({\\rm stat.}) \\pm 0.003({\\rm syst.})$. An analysis of the relative rates in six detectors finds $\\sin^22\\theta_{13}=0.089\\pm 0.010({\\rm stat.})\\pm0.005({\\rm syst.})$ in a three-neutrino framework.

  17. Captures of Hot and Warm Sterile Antineutrino Dark Matter on EC-decaying Ho-163 Nuclei

    CERN Document Server

    Li, Y F

    2011-01-01

    Capturing low-energy electron antineutrinos on radioactive Ho-163 nuclei, which decay into Dy-163 via electron capture (EC), is a noteworthy opportunity to detect relic sterile antineutrinos. Such hypothetical particles are more or less implied by current experimental and cosmological data, and they might be a part of hot dark matter or a candidate for warm dark matter in the Universe. Using the isotope Ho-163 as a target and assuming reasonable active-sterile antineutrino mixing angles, we calculate the capture rate of relic electron antineutrinos against the corresponding EC-decay background in the presence of sterile antineutrinos at the sub-eV or keV mass scale. We show that the signature of hot or warm sterile antineutrino dark matter should in principle be observable, provided the target is big enough and the energy resolution is good enough.

  18. A new anti-neutrino detection technique based on positronium tagging with plastic scintillators

    CERN Document Server

    Consolati, G; Jollet, C; Meregaglia, A; Minotti, A; Perasso, S; Tonazzo, A

    2015-01-01

    The main signature for anti-neutrino detection in reactor and geo-neutrino experiments based on scintillators is provided by the space-time coincidence of positron and neutron produced in the Inverse Beta Decay reaction. Such a signature strongly suppresses backgrounds and allows for measurements performed underground with a relatively high signal-to-background ratio. In an aboveground environment, however, the twofold coincidence technique is not sufficient to efficiently reject the high background rate induced by cosmogenic events. Enhancing the positron-neutron twofold coincidence efficiency has the potential to pave the way future aboveground detectors for reactor monitoring. We propose a new detection scheme based on a threefold coincidence, between the positron ionization, the ortho-positronium (o-Ps) decay, and the neutron capture, in a sandwich detector with alternated layers of plastic scintillator and aerogel powder. We present the results of a set of dedicated measurements on the achievable light y...

  19. Which reactor antineutrino flux may be responsible for the anomaly?

    CERN Document Server

    Giunti, Carlo

    2016-01-01

    We investigate which among the reactor antineutrino fluxes from the decays of the fission products of $^{235}\\text{U}$, $^{238}\\text{U}$, $^{239}\\text{Pu}$, and $^{241}\\text{Pu}$ may be responsible for the reactor antineutrino anomaly. We find that it is the $^{235}\\text{U}$ flux, which contributes to the rates of all reactor neutrino experiments. From the fit of the data we obtain the precise determination $ \\sigma_{^{235}\\text{U}} = ( 6.34 \\pm 0.10 ) \\times 10^{-43} \\, \\text{cm}^2 / \\text{fission} $ of the $^{235}\\text{U}$ cross section per fission, which is more precise than the calculated value and differs from it by $2.0\\sigma$.

  20. Neutrino mass hierarchy determination at reactor antineutrino experiments

    CERN Document Server

    Yang, Guang

    2015-01-01

    After the neutrino mixing angle $\\theta_{13}$ has been precisely measured by the reactor antineutrino experiments, one of the most important open questions left in neutrino physics is the neutrino mass hierarchy. Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass hierarchy (MH) without exploring the matter effect. The JUNO site location is optimized to have the best sensitivity for the mass hierarchy determination. JUNO will employ a 20 kton liquid scintillator detector located in a laboratory 700 meters underground. The excellent energy resolution and PMT coverage will give us an unprecedented opportunity to reach a 3-4 $\\sigma$ precision. In this paper, the JUNO detector design and simulation work will be presented. Also, RENO-50, another medium distance reactor antineutrino experiment, will do a similar measurement. With the efforts of these experiments, it is very likely that the neutrino mass hierarchy will be determined in the next 10 years.

  1. Development of PROSPECT detectors for precision antineutrino studies

    CERN Document Server

    Norcini, Danielle

    2015-01-01

    PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, will use two segmented detectors positioned 7-20 m from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory to measure the U-235 antineutrino spectrum and perform a search for short-baseline oscillations as a signature of eV-scale sterile neutrinos. PROSPECT has developed Li-6 loaded liquid scintillator detectors for efficient identification of reactor antineutrinos and has measured reactor and cosmogenic backgrounds in the HFIR reactor building. Multiple test detectors have been built, operated, and characterized at HFIR and elsewhere to understand the optical performance of the scintillator and pulse-shape discrimination capabilities for enhanced background rejection. The results from this R&D effort are discussed, in the context of the design and physics potential of PROSPECT.

  2. 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.

  3. The muon system of the Daya Bay Reactor antineutrino experiment

    OpenAIRE

    An, F. P.; Carr, R; McKeown, R.D.; Qian, X.; Tsang, R. H. M.

    2015-01-01

    The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. De...

  4. Estimating terrestrial uranium and thorium by antineutrino flux measurements

    OpenAIRE

    Dye, Stephen T.; Guillian, Eugene H.

    2008-01-01

    Uranium and thorium within the Earth produce a major portion of terrestrial heat along with a measurable flux of electron antineutrinos. These elements are key components in geophysical and geochemical models. Their quantity and distribution drive the dynamics, define the thermal history, and are a consequence of the differentiation of the Earth. Knowledge of uranium and thorium concentrations in geological reservoirs relies largely on geochemical model calculations. This research report desc...

  5. Science Potential of a Deep Ocean Antineutrino Observatory

    OpenAIRE

    Dye, Steve

    2006-01-01

    This paper presents science potential of a deep ocean antineutrino observatory under development at Hawaii. The observatory design allows for relocation from one site to another. Positioning the observatory some 60 km distant from a nuclear reactor complex enables precision measurement of neutrino mixing parameters, leading to a determination of neutrino mass hierarchy. At a mid-Pacific location the observatory measures the flux and ratio of uranium and thorium decay neutrinos from earth's ma...

  6. Towards Earth AntineutRino TomograpHy (EARTH)

    OpenAIRE

    de Meijer, R. J.; Smit, F. D.; Brooks, F. D.; Fearick, R. W.; Woertche, 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. Recent hypotheses target the core-mantle boundary (CMB) as a major source of natural radionuclides and therefore of radiogenic heat. A typical scale of the processes that take place at the CMB is abo...

  7. Investigation of Large LGB Detectors for Antineutrino Detection

    OpenAIRE

    Nelson, P; Bowden, N. S.

    2011-01-01

    A detector material or configuration that can provide an unambiguous indication of neutron capture can substantially reduce random coincidence backgrounds in antineutrino detection and capture-gated neutron spectrometry applications. Here we investigate the performance of such a material, a composite of plastic scintillator and $^6$Li$_6^{nat}$Gd$(^{10}$BO$_{3})_{3}$:Ce (LGB) crystal shards of ~1 mm dimension and comprising 1% of the detector by mass. While it is found that the optical propag...

  8. Neutrino Geophysics at Baksan I: Possible Detection of Georeactor Antineutrinos

    International Nuclear Information System (INIS)

    J.M. Herndon in the 1990s proposed a natural nuclear fission georeactor at the center of the Earth with a power output of 3-10 TW as an energy source to sustain the Earth magnetic field. R.S. Raghavan in 2002 pointed out that, under certain conditions, antineutrinos generated in such a georeactor can be detected using massive scintillation detectors. We consider the underground Baksan Neutrino Observatory (4800 m w.e.) as a possible site for developments in geoneutrino physics. Here, the intrinsic background level of less than 1 event/yr in a liquid scintillation ∼1000-t target detector can be achieved and the main source of background is the antineutrino flux from power reactors. We find that this flux is ∼10 times lower than at the KamLAND detector site and two times lower than at the Gran Sasso laboratory and thus at Baksan the georeactor hypothesis can be conclusively tested. We also discuss possible searches for the composition of georeactor burning nuclear fuel by analysis of the antineutrino energy spectrum

  9. Neutrino Geophysics at Baksan I: Possible Detection of Georeactor Antineutrinos

    CERN Document Server

    Domogatski, G; Mikaelyan, L A; Sinev, V

    2004-01-01

    J.M. Herndon in 90-s proposed a natural nuclear fission georeactor at the center of the Earth with a power output of 3-10 TW as an energy source to sustain the Earth magnetic field. R.S. Raghavan in 2002 y. pointed out that under certain condition antineutrinos generated in georeactor can be detected using massive scintillation detectors. We consider the underground Baksan Neutrino Observatory (4800 m.w.e.) as a possible site for developments in Geoneutrino physics. Here the intrinsic background level of less than one event/year in a liquid scintillation ~1000 target ton detector can be achieved and the main source of background is the antineutrino flux from power reactors. We find that this flux is ~10 times lower than at KamLAND detector site and two times lower than at Gran Sasso laboratory and thus at Baksan the georeactor hypothesis can be conclusively tested. We also discuss possible search for composition of georector burning nuclear fuel by analysis of the antineutrino energy spectrum.

  10. The double chooz experiment: simulation of reactor antineutrino spectra

    International Nuclear Information System (INIS)

    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 θ13. 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 sin22θ13 ≥ 0.05 (at 3σ) or, if no oscillations are observed, to put a limit of sin22θ13 ≤ 0.03 at 90% C.L. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-05

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

  12. Antineutrino Neutral Current Interactions in MiniBooNE

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

    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 105 cm-2 x s-1 (the reliability level of 90%)

  14. 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.

  15. A study of antineutrino spectra from spent nuclear fuel at Daya Bay

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bin; RUAN Xi-Chao; NIE Yang-Bo; ZHOU Zu-Ying; AN Feng-Peng; CAO Jun

    2012-01-01

    The Daya Bay Reactor Antineutrino Experiment is designed to determine the as yet unknown neutrino mixing angle,θ13,by measuring the disappearance of electron antineutrinos from several nuclear reactor cores.The projected sensitivity in sin2(2θ13) of better than 0.01 at a 90% CL should be achieved after three years of data-taking.Antineutrinos emitted from spent nuclear fuel (SNF) distort the soft part of the energy spectrum.In this article,a calculation of the antineutrino spectra from the long-life isotopes in SNF is performed.A non-equilibrium generation of long half-life isotopes during the running time of the reactor is also analyzed.Finally,we show that the antineutrino event rate contribution from SNF,which has been stored in the SNF pool for several years,may be non-negligible.

  16. Nuclear security applications of antineutrino detectors : current capabilities and future prospects.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, A.; Goodman, M.; Baldwin, G.; Learned, J.; Lund, J.; Reyna, D.; Svaboda, R. (High Energy Physics); (LLNL); (SNL); (LANL); (Univ. of Hawaii); (Univ. of California)

    2010-12-10

    Antineutrinos are electrically neutral, nearly massless fundamental particles produced in large numbers in the cores of nuclear reactors and in nuclear explosions. In the half century since their discovery, major advances in the understanding of their properties, and in detector technology, have opened the door to a new discipline - Applied Antineutrino Physics. Because antineutrinos are inextricably linked to the process of nuclear fission, there are many applications of interest in nuclear nonproliferation. This paper presents a comprehensive survey of applied antineutrino physics relevant for nonproliferation, summarizes recent advances in the field, describes the overlap of this nascent discipline with other ongoing fundamental and applied antineutrino research, and charts a course for research and development for future applications. It is intended as a resource for policymakers, researchers, and the wider nuclear nonproliferation community.

  17. A study of antineutrino spectra from spent nuclear fuel at Daya Bay

    International Nuclear Information System (INIS)

    The Daya Bay Reactor Antineutrino Experiment is designed to determine the as yet unknown neutrino mixing angle, θ13, by measuring the disappearance of electron antineutrinos from several nuclear reactor cores. The projected sensitivity in sin2 (2θ13) of better than 0.01 at a 90% CL should be achieved after three years of data-taking. Antineutrinos emitted from spent nuclear fuel (SNF) distort the soft part of the energy spectrum. In this article, a calculation of the antineutrino spectra from the long-life isotopes in SNF is performed. A non-equilibrium generation of long half-life isotopes during the running time of the reactor is also analyzed. Finally, we show that the antineutrino event rate contribution from SNF, which has been stored in the SNF pool for several years, may be non-negligible. (authors)

  18. 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.

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

    International Nuclear Information System (INIS)

    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.)

  20. Neutrino Geophysics at Baksan I: Possible Detection of Georeactor Antineutrinos

    OpenAIRE

    Domogatski, G.; Kopeikin, V.; Mikaelyan, L.; Sinev, V.

    2004-01-01

    J.M. Herndon in 90-s proposed a natural nuclear fission georeactor at the center of the Earth with a power output of 3-10 TW as an energy source to sustain the Earth magnetic field. R.S. Raghavan in 2002 y. pointed out that under certain condition antineutrinos generated in georeactor can be detected using massive scintillation detectors. We consider the underground Baksan Neutrino Observatory (4800 m.w.e.) as a possible site for developments in Geoneutrino physics. Here the intrinsic backgro...

  1. Addendum: Neutrino Mass Hierarchy Determination Using Reactor Antineutrinos

    CERN Document Server

    Ghoshal, Pomita

    2012-01-01

    We update our study of neutrino mass hierarchy determination using a high statistics reactor electron anti-neutrino experiment in the light of the recent evidences of a relatively large non-zero value of \\theta_{13} from the Daya Bay and RENO experiments. We find that there are noticeable modifications in the results, which allow a relaxation in the detector's characteristics, such as the energy resolution and exposure, required to obtain a significant sensitivity to, or to determine, the neutrino mass hierarchy in such a reactor experiment.

  2. Science Potential of a Deep Ocean Antineutrino Observatory

    CERN Document Server

    Dye, S

    2007-01-01

    This paper presents science potential of a deep ocean antineutrino observatory under development at Hawaii. The observatory design allows for relocation from one site to another. Positioning the observatory some 60 km distant from a nuclear reactor complex enables precision measurement of neutrino mixing parameters, leading to a determination of neutrino mass hierarchy. At a mid-Pacific location the observatory measures the flux and ratio of uranium and thorium decay neutrinos from earth's mantle and performs a sensitive search for a hypothetical natural fission reactor in earth's core. A subsequent deployment at another mid-ocean location would test lateral heterogeneity of uranium and thorium in earth's mantle.

  3. Experimental Study Of Terrestrial Electron Anti-neutrinos With Kamland

    CERN Document Server

    Tolich, N R

    2005-01-01

    The analysis presented here uses Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) to measure the rate of electron anti-neutrinos, ne&d1;' s , produced from terrestrial 238U and 212Th. 238U and 212Th are thought to be the main heat source driving mantle convection in the Earth, which in turn is responsible for plate tectonics. The total terrestrial 238U and 212Th content has been estimated from Earth models and rock samples from a very small fraction of the Earth. Until now there have been no direct measurements. Since ne&d1;' s have an exceedingly small cross section, they propagate undisturbed in the Earth interior, and their measurement near the Earth surface can be used to gain information on their sources. Based on a total of (2.63 ± 0.19) × 1031 target proton-years (0.506 kton- years), the 90% confidence interval for the total number of terrestrial 238U and 212Th ne&d1;' s detected is 4 to 40. This is consistent with the best models of terrestrial 23...

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

    International Nuclear Information System (INIS)

    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 independent 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. (authors)

  5. 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.

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

    OpenAIRE

    Adamson, P.; Andreopoulos, C.; Arms, K. E.; Armstrong, R.; Auty, D. J.; Ayres, D. S.; Backhouse, C.; Barnes, JR; Barr, G.; Barrett, W. L.; Devenish, N. E.; Falk, E.; Harris, P.G.; Hartnell, J.; et al, ...

    2010-01-01

    The energy dependence of the neutrino-iron and antineutrino-iron inclusive charged-current cross sections and their ratio have been measured using a high-statistics sample with the MINOS Near Detector exposed to the NuMI beam from the Main Injector at Fermilab. Neutrino and antineutrino fluxes were determined using a low hadronic energy subsample of charged-current events. We report measurements of neutrino-Fe (antineutrinoFe) cross section in the energy range 3-50 GeV (5-50 GeV) with precisi...

  7. Can Radiogenic Heat Sources Inside the Earth be located by their Antineutrino incoming Directions?

    CERN Document Server

    Domogatsky, G; Mikaelyan, L; Sinev, V

    2004-01-01

    Antineutrinos born in the U and Th decay chains inside the Earth (``Geoneutrinos'') carry out information on the amount and distribution of radiogenic heat sources, which is of fundamental importance for geophysics. Models of the Earth distribute U and Th masses mainly between the continental crust and the lower mantle. It has been much discussed recently that a number of detectors stationed at appropriate geographical sites can separate the crust and mantle contributions. In present work we analyze directional separation of antineutrino signals arriving from the crust and the lower mantle with only one detector. We find that with a ~30-kton liquid scintillation antineutrino spectrometer using $\\bar{{\

  8. Search for Differences in Oscillation Parameters for Atmospheric Neutrinos and Antineutrinos at Super-Kamiokande

    CERN Document Server

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

    2011-01-01

    We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande -I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best fit antineutrino mixing is found to be at (dm2bar, sin2 2 thetabar) = (2.0x10^-3 eV^2, 1.0) and is consistent with the overall Super-K measurement.

  9. Decay heat and anti-neutrino energy spectra in fission fragments from total absorption spectroscopy

    Science.gov (United States)

    Rykaczewski, Krzysztof

    2015-10-01

    Decay studies of over forty 238U fission products have been studied using ORNL's Modular Total Absorption Spectrometer. The results are showing increased decay heat values, by 10% to 50%, and the energy spectra of anti-neutrinos shifted towards lower energies. The latter effect is resulting in a reduced number of anti-neutrinos interacting with matter, often by tens of percent per fission product. The results for several studied nuclei will be presented and their impact on decay heat pattern in power reactors and reactor anti-neutrino physics will be discussed.

  10. An Improved Measurement of Electron Antineutrino Disappearance at Daya Bay

    CERN Document Server

    Webber, David M

    2012-01-01

    The theory of neutrino oscillations explains changes in neutrino flavor, count rates, and spectra from solar, atmospheric, accelerator, and reactor neutrinos. These oscillations are characterized by three mixing angles and two mass-squared differences. The solar mixing angle, {\\theta}_12, and the atmospheric mixing angle, {\\theta}_23, have been well measured, but until recently the neutrino mixing angle {\\theta}_13 was not well known. The Daya Bay experiment, located northeast of Hong Kong at the Guangdong Nuclear Power Complex in China, has made a precise measurement of electron antineutrino disappearance using six functionally-identical gadolinium-doped liquid scintillator-based detectors at three sites with distances between 364 and 1900 meters from six reactor cores. This proceeding describes the Daya Bay updated result, using 127 days of good run time collected between December 24, 2011 and May 11, 2012. For the far site, the ratio of the observed number of events to the expected number of events assumin...

  11. Observation of Reactor Antineutrino Disappearance at RENO and Future Plan

    International Nuclear Information System (INIS)

    Reactor Experiment for Neutrino Oscillation (RENO) in South Korea observed electron anti-neutrino disappearance using data taken from August 2011 to March 2012 (about 222 live-days) at Yonggwang nuclear reactor site. The observed deficit resulted in measuring the last unknown neutrino mixing angle, sin22θ13, as 0.113 +/- 0.013 (stat) +/- 0.019 (sys.) which is 4.9 sigma level discovery over no oscillation hypothesis. We have taken about 440 live-days of data in total so far and those data are being analyzed. The ultimate goal of RENO analysis is that we would like to reduce statistical and systematic errors down to more than half of what are now by taking data for 3 years in total and by improving analysis method and reducing background. At the end, our future project, RENO-50, is discussed

  12. Uncertainties analysis of fission fraction for reactor antineutrino experiments using DRAGON

    CERN Document Server

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

    2014-01-01

    Rising interest in nuclear reactors as a source of antineutrinos for experiments motivates validated, fast, and accessible simulation to predict reactor rates. First, DRAGON was developed to calculate the fission rates of the four most important isotopes in fissions,235U,238U,239Pu and141Pu, and it was validated for PWRs using the Takahama benchmark. The fission fraction calculation function was validated through comparing our calculation results with MIT's results. we calculate the fission fraction of the Daya Bay reactor core, and compare its with those calculated by the commercial reactor simulation program SCIENCE, which is used by the Daya Bay nuclear power plant, and the results was consist with each other. The uncertainty of the antineutrino flux by the fission fraction was studied, and the uncertainty of the antineutrino flux by the fission fraction simulation is 0.6% per core for Daya Bay antineutrino experiment.

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

    Science.gov (United States)

    Bowden, Nathaniel; Prospect Collaboration

    2015-10-01

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

  14. A new approach to anti-neutrino running in long baseline neutrino oscillation experiments

    CERN Document Server

    Agarwalla, Sanjib K; Link, Jonathan M; Mohapatra, Debabrata

    2010-01-01

    We study the possibility to replace the anti-neutrino run of a long baseline neutrino oscillation experiment, with anti-neutrinos from muon decay at rest. The low energy of these neutrinos allows the use of inverse beta decay for detection in a Gadolinium-doped water Cerenkov detector. We show that this approach yields a factor of five times larger anti-neutrino event sample. The resulting discovery reaches in theta_13, the mass hierarchy and leptonic CP violation are compared with those from a conventional superbeam experiment with combined neutrino and anti-neutrino running. We find that this approach yields a greatly improved reach for CP violation and theta_13 while leaving the ability to measure the mass hierarchy intact.

  15. Above-ground antineutrino detection for nuclear reactor monitoring

    International Nuclear Information System (INIS)

    Antineutrino monitoring of nuclear reactors has been demonstrated many times (Klimov et al., 1994 [1]; Bowden et al., 2009 [2]; Oguri et al., 2014 [3]), however the technique has not as of yet been developed into a useful capability for treaty verification purposes. The most notable drawback is the current requirement that detectors be deployed underground, with at least several meters-water-equivalent of shielding from cosmic radiation. In addition, the deployment of liquid-based detection media presents a challenge in reactor facilities. We are currently developing a detector system that has the potential to operate above ground and circumvent deployment problems associated with a liquid detection media: the system is composed of segments of plastic scintillator surrounded by 6LiF/ZnS:Ag. ZnS:Ag is a radio-luminescent phosphor used to detect the neutron capture products of 6Li. Because of its long decay time compared to standard plastic scintillators, pulse-shape discrimination can be used to distinguish positron and neutron interactions resulting from the inverse beta decay (IBD) of antineutrinos within the detector volume, reducing both accidental and correlated backgrounds. Segmentation further reduces backgrounds by identifying the positron's annihilation gammas, a signature that is absent for most correlated and uncorrelated backgrounds. This work explores different configurations in order to maximize the size of the detector segments without reducing the intrinsic neutron detection efficiency. We believe that this technology will ultimately be applicable to potential safeguards scenarios such as those recently described by Huber et al. (2014) [4,5

  16. Remote safeguards and monitoring of reactors with antineutrinos.

    Energy Technology Data Exchange (ETDEWEB)

    Reyna, David

    2010-10-01

    The current state-of-the-art in antineutrino detection is such that it is now possible to remotely monitor the operational status, power levels and fissile content of nuclear reactors in real-time. This non-invasive and incorruptible technique has been demonstrated at civilian power reactors in both Russia and the United States and has been of interest to the IAEA Novel Technologies Unit for several years. Expert's meetings were convened at IAEA headquarters in 2003 and again in 2008. The latter produced a report in which antineutrino detection was called a 'highly promising technology for safeguards applications' at nuclear reactors and several near-term goals and suggested developments were identified to facilitate wider applicability. Over the last few years, we have been working to achieve some of these goals and improvements. Specifically, we have already demonstrated the successful operation of non-toxic detectors and most recently, we are testing a transportable, above-ground detector system, which is fully contained within a standard 6 meter ISO container. If successful, such a system could allow easy deployment at any reactor facility around the world. As well, our previously demonstrated ability to remotely monitor the data and respond in real-time to reactor operational changes could allow the verification of operator declarations without the need for costly site-visits. As the global nuclear power industry expands around the world, the burden on maintaining operational histories and safeguarding inventories will increase greatly. Such a system for providing remote data to verify operator's declarations could greatly reduce the need for frequent site inspections while still providing a robust warning of anomalies requiring further investigation.

  17. Above-ground antineutrino detection for nuclear reactor monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sweany, M.; Brennan, J.; Cabrera-Palmer, B.; Kiff, S.; Reyna, D.; Throckmorton, D.

    2015-01-01

    Antineutrino monitoring of nuclear reactors has been demonstrated many times (Klimov et al., 1994 [1]; Bowden et al., 2009 [2]; Oguri et al., 2014 [3]), however the technique has not as of yet been developed into a useful capability for treaty verification purposes. The most notable drawback is the current requirement that detectors be deployed underground, with at least several meters-water-equivalent of shielding from cosmic radiation. In addition, the deployment of liquid-based detection media presents a challenge in reactor facilities. We are currently developing a detector system that has the potential to operate above ground and circumvent deployment problems associated with a liquid detection media: the system is composed of segments of plastic scintillator surrounded by {sup 6}LiF/ZnS:Ag. ZnS:Ag is a radio-luminescent phosphor used to detect the neutron capture products of {sup 6}Li. Because of its long decay time compared to standard plastic scintillators, pulse-shape discrimination can be used to distinguish positron and neutron interactions resulting from the inverse beta decay (IBD) of antineutrinos within the detector volume, reducing both accidental and correlated backgrounds. Segmentation further reduces backgrounds by identifying the positron's annihilation gammas, a signature that is absent for most correlated and uncorrelated backgrounds. This work explores different configurations in order to maximize the size of the detector segments without reducing the intrinsic neutron detection efficiency. We believe that this technology will ultimately be applicable to potential safeguards scenarios such as those recently described by Huber et al. (2014) [4,5].

  18. Remote safeguards and monitoring of reactors with antineutrinos.

    Energy Technology Data Exchange (ETDEWEB)

    Kiff, Scott D.; Dazeley, Steven (Lawrence Livermore National Laboratory, Livermore, CA); Reyna, David; Cabrera-Palmer, Belkis; Bernstein, Adam (Lawrence Livermore National Laboratory, Livermore, CA); Keefer, Greg (Lawrence Livermore National Laboratory, Livermore, CA); Bowden, Nathaniel S. (Lawrence Livermore National Laboratory, Livermore, CA)

    2010-09-01

    The current state-of-the-art in antineutrino detection is such that it is now possible to remotely monitor the operational status, power levels and fissile content of nuclear reactors in real-time. This non-invasive and incorruptible technique has been demonstrated at civilian power reactors in both Russia and the United States and has been of interest to the IAEA Novel Technologies Unit for several years. Expert's meetings were convened at IAEA headquarters in 2003 and again in 2008. The latter produced a report in which antineutrino detection was called a 'highly promising technology for safeguards applications' at nuclear reactors and several near-term goals and suggested developments were identified to facilitate wider applicability. Over the last few years, we have been working to achieve some of these goals and improvements. Specifically, we have already demonstrated the successful operation of non-toxic detectors and most recently, we are testing a transportable, above-ground detector system, which is fully contained within a standard 6 meter ISO container. If successful, such a system could allow easy deployment at any reactor facility around the world. As well, our previously demonstrated ability to remotely monitor the data and respond in real-time to reactor operational changes could allow the verification of operator declarations without the need for costly site-visits. As the global nuclear power industry expands around the world, the burden on maintaining operational histories and safeguarding inventories will increase greatly. Such a system for providing remote data to verify operator's declarations could greatly reduce the need for frequent site inspections while still providing a robust warning of anomalies requiring further investigation.

  19. Detection of reactor antineutrino coherent scattering off nuclei with a two-phase noble gas detector

    OpenAIRE

    Akimov, Dmitri; Bondar, Alexander; Burenkov, Alexander; Buzulutskov, Alexei

    2009-01-01

    Estimation of the signal amplitudes and counting rates for coherent scattering of reactor antineutrino off atomic nuclei in two-phase xenon and argon detectors has been done. A conceptual design of detector based on the existing technologies and experience has been proposed. It is shown that a condensed xenon/argon two-phase detector possesses the necessary sensitivity for the use in experiment on detection of coherent scattering of the reactor antineutrino off nuclei. It is shown that a two-...

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

    OpenAIRE

    Adamson, P.; Ayres, D. S.; Barr, G.; Bishai, M.; Blake, A.; Bock, G.J.; Boehnlein, D. J.; Bogert, D.; Cao, S. V.; Cavanaugh, S.; Childress, S.; Coelho, J. A. B.; Corwin, L.; Cronin-Hennessy, D.; Danko, I. Z.

    2012-01-01

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

  1. Recoilless Resonance Absorption of Tritium Antineutrinos and Time-Energy Uncertainty Relation

    OpenAIRE

    Bilenky, S. M.

    2007-01-01

    We discuss neutrino oscillations in an experiment with M\\"ossbauer recoilless resonance absorbtion of tritium antineutrinos, proposed recently by Raghavan. We demonstrate that small energy uncertainty of antineutrinos which ensures a large resonance absorption cross section is in a conflict with the energy uncertainty which, according to the time-energy uncertainty relation, is necessary for neutrino oscillations to happen. The search for neutrino oscillations in the M\\"ossbauer neutrino expe...

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

    International Nuclear Information System (INIS)

    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

  3. KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments

    CERN Document Server

    Torrente-Lujan, E

    2003-01-01

    We investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. The recent evidence from SNO shows that the solar flux could contain a residual component including sterile neutrinos and/or the antineutrinos of the active flavors. KamLAND is sensitive to antineutrinos originated from solar ${}^8$B neutrinos. From KamLAND negative results after 145 days of data taking, we obtain model independent limits on the total flux of solar antineutrinos $\\Phi({}^8 B)< 1.1-3.5\\times 10^4 cm^{-2} s^{-1}$, more than one order of magnitude smaller than existing limits,and on their appearance probability $P<0.15%$ (95% CL). Assuming a concrete model for antineutrino production by spin-flavor precession, this upper bound implies an upper limit on the product of the intrinsic neutrino magnetic moment and the value of the solar magnetic field $\\mu B&...

  4. Present status of sensitive detector of reactor’s antineutrinos using scintillating detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fajt, L.; Mamedov, F.; Přidal, P.; Špavorová, M.; Štekl, I. [Institute of Experimental and Applied Physics, CTU in Prague (Czech Republic); Belov, V.; Egorov, V. G.; Fomina, M.; Kuznetsov, A.; Ponomarev, D.; Rozova, I.; Zhitnikov, I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Burešová, H. [ENVINET a.s., Nuvia Group, Tǐebíč (Czech Republic)

    2015-08-17

    In 2011, the reanalysis of the reactor antineutrinos spectra led to the formulation of the Reactor Antineutrino Anomaly (RAA) [1], which indicates the discrepancy between measured and expected antineutrino fluxes on short baselines. This discrepancy appears to favor the existence of the fourth “sterile” neutrino with |Δm{sup 2}|>1 eV{sup 2}. To confirm or reject this hypothesis a high sensitive antineutrino detector located close to the reactor is required. In addition to that such a detector could be used to online monitor the isotopic composition of the reactor core and to prevent illegal production and removal of{sup 239}Pu, which is the essential part of nuclear weapons. Detector DANSSino [2] already proved that even a compact antineutrino detector (∼ 1 m{sup 3}) based on polystyrene is capable of antineutrino detection in the close vicinity of a reactor core (∼ 10 m) with signal to background ratio about one. As a common activity between JINR Dubna and IEAP CTU a new prototype of detector (called S{sup 3}) has been proposed and is under construction. The construction design, selected results of Monte Carlo simulations and results of benchmark tests are presented.

  5. Captures of hot and warm sterile antineutrino dark matter on EC-decaying {sup 63}Ho nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.F.; Xing, Zhi-zhong, E-mail: liyufeng@ihep.ac.cn, E-mail: xingzz@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2011-08-01

    Capturing low-energy electron antineutrinos on radioactive {sup 163}Ho nuclei, which decay into {sup 163}Dy via electron capture (EC), is a noteworthy opportunity to detect relic sterile antineutrinos. Such hypothetical particles are more or less implied by current experimental and cosmological data, and they might be a part of hot dark matter or a candidate for warm dark matter in the Universe. Using the isotope {sup 163}Ho as a target and assuming reasonable active-sterile antineutrino mixing angles, we calculate the capture rate of relic electron antineutrinos against the corresponding EC-decay background in the presence of sterile antineutrinos at the sub-eV or keV mass scale. We show that the signature of hot or warm sterile antineutrino dark matter should in principle be observable, provided the target is big enough and the energy resolution is good enough.

  6. A new anti-neutrino detection technique based on positronium tagging with plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Consolati, G. [Department of Aerospace Science and Technology, Politecnico di Milano, via La Masa 34, 20156 Milano (Italy); Franco, D., E-mail: dfranco@in2p3.fr [APC, Univ. Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, 75205 Paris (France); Jollet, C. [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Meregaglia, A., E-mail: amerega@in2p3.fr [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Minotti, A. [IPHC, Université de Strasbourg, CNRS/IN2P3, 67037 Strasbourg (France); Perasso, S.; Tonazzo, A. [APC, Univ. Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, 75205 Paris (France)

    2015-09-21

    The main signature for anti-neutrino detection in reactor and geo-neutrino experiments based on scintillators is provided by the space–time coincidence of positron and neutron produced in the Inverse Beta Decay reaction. Such a signature strongly suppresses backgrounds and allows for measurements performed underground with a relatively high signal-to-background ratio. In an aboveground environment, however, the twofold coincidence technique is not sufficient to efficiently reject the high background rate induced by cosmogenic events. Enhancing the positron–neutron twofold coincidence efficiency may pave the way to future aboveground detectors for reactor monitoring. We propose a new detection scheme based on a threefold coincidence, among the positron ionization, the ortho-positronium (o-Ps) decay, and the neutron capture, in a sandwich detector with alternated layers of plastic scintillator and aerogel powder. We present the results of a set of dedicated measurements on the achievable light yield and on the o-Ps formation and lifetime. The efficiencies for signal detection and background rejection of a preliminary detector design are also discussed.

  7. A new anti-neutrino detection technique based on positronium tagging with plastic scintillators

    International Nuclear Information System (INIS)

    The main signature for anti-neutrino detection in reactor and geo-neutrino experiments based on scintillators is provided by the space–time coincidence of positron and neutron produced in the Inverse Beta Decay reaction. Such a signature strongly suppresses backgrounds and allows for measurements performed underground with a relatively high signal-to-background ratio. In an aboveground environment, however, the twofold coincidence technique is not sufficient to efficiently reject the high background rate induced by cosmogenic events. Enhancing the positron–neutron twofold coincidence efficiency may pave the way to future aboveground detectors for reactor monitoring. We propose a new detection scheme based on a threefold coincidence, among the positron ionization, the ortho-positronium (o-Ps) decay, and the neutron capture, in a sandwich detector with alternated layers of plastic scintillator and aerogel powder. We present the results of a set of dedicated measurements on the achievable light yield and on the o-Ps formation and lifetime. The efficiencies for signal detection and background rejection of a preliminary detector design are also discussed

  8. Search for electron antineutrinos associated with gravitational wave events GW150914 and GW151226 using KamLAND

    CERN Document Server

    Gando, A; 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; Kozolov, 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

    2016-01-01

    We present a search for low energy antineutrino events coincident with the gravitational wave events GW150914 and GW151226, and the candidate event LVT151012 using KamLAND, a kiloton-scale antineutrino detector. We find no inverse beta-decay neutrino events within $\\pm 500$ seconds of either gravitational wave signal. This non-detection is used to constrain the electron antineutrino fluence and the luminosity of the astrophysical sources.

  9. Towards Earth AntineutRino TomograpHy (EARTH)

    CERN Document Server

    De Meijer, R J; Fearick, R W; Mantovani, F; Smit, F D; Wörtche, H J

    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. Recent hypotheses target the core-mantle boundary (CMB) as a major source of natural radionuclides and therefore of radiogenic heat. A typical scale of the processes that take place at the CMB is about 200km. To observe these processes from the surface requires an angular resolution of about 3 degrees. EARTH aims at creating a high-resolution 3D-map of the radiogenic heat sources in the interior of the Earth. It will thereby contribute to a better understanding of a number of geophysical phenomena observed at the surface of the Earth. This condition requires a completely different approach from the monolithic detector systems as e.g. KamLAND. This paper presents, for such telescopes, the boundary conditions set by ph...

  10. Experimental determination of the antineutrino spectrum of the fission products of U238

    International Nuclear Information System (INIS)

    Accurate predictions of the antineutrino spectrum emitted by a nuclear reactor are of paramount importance for current and future reactor neutrino experiments. The antineutrinos are produced in the β - decays of the fission daughters of the four main fuel isotopes 235U, 238U, 239Pu, and 241Pu. One way to calculate the total anti νe - spectrum emitted by a fuel assembly is to experimentally determine the cumulative β-spectra emitted after fission of these four main fuel isotopes and to convert these into the corresponding anti νe-spectra. Three of the four spectra could already be determined in the 1980's, but only recently an experiment at the scientific neutron source FRM II in Garching could be performed to measure the anti νe-spectrum of 238U which contributes 10 % to the total antineutrino output of a standard PWR. With this spectrum, it is now possible to predict the antineutrino output of a reactor without the use of theoretical calculations for the contributing spectra. This talk describes the results of the experiment and discusses the impact on the current analysis of reactor neutrino experiments and the reactor antineutrino anomaly, which may give a hint on the possible existence of light sterile neutrinos.

  11. A search for low-energy neutrino and antineutrino signals correlated with gamma-ray bursts with Borexino

    CERN Document Server

    Agostini, M; Appel, S; Atroshchenko, V; Bellini, G; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Caccianiga, B; Calaprice, F; Caminata, A; Carlini, M; Cavalcante, P; Chepurnov, A; Choi, K; D'Angelo, D; Davini, S; de Kerret, H; Derbin, A; Di Noto, L; Drachnev, I; Etenko, A; Fomenko, K; Franco, D; Gabriele, F; Galbiati, C; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Gromov, M; Hagner, C; Hungerford, E; Ianni, Aldo; Ianni, Andrea; Jany, A; Jedrzejczak, K; Jeschke, D; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Manuzio, G; Marcocci, S; Meroni, E; Meyer, M; Miramonti, L; Misiaszek, M; Montuschi, M; Mosteiro, P; Muratova, V; Neumair, B; Oberauer, L; Obolensky, M; Ortica, F; Pallavicini, M; Papp, L; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Roncin, R; Rossi, N; Scheonert, S; Semenov, D; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Thurn, J; Toropova, M; Unzhakov, E; Vishneva, A; Vogelaar, R B; von Feilitzsch, F; Wang, H; Weinz, S; Winter, J; Wojcik, M; Wurm, M; Yokley, Z; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2016-01-01

    A search for neutrino and antineutrino events correlated with 2,350 gamma-ray bursts (GRBs) is performed with Borexino data collected between December 2007 and November 2015. No statistically significant excess over background is observed. We look for electron antineutrinos ($\\bar{\

  12. Neutrino Geophysics at Baksan (Part II): Possible Studies of Antineutrino- and Radiogenic Heat Sources in Earth Interior

    OpenAIRE

    Domogatsky, G.; Kopeikin, V.; Mikaelyan, L.; Sinev, V.

    2004-01-01

    Antineutrinos born inside the Earth (``geoneutrinos'') carry out information of fundamental importance for understanding of the origin and evolution of our planet. We show that Baksan Neutrino Observatory is one of the best sites for detection and analysis of geoneutrinos using large liquid scintillation spectrometer. Also we present a short story of concept of Earth as antineutrino source (1960 - 2004 yy)

  13. aCORN: A Measurement of the Beta-Antineutrino Correlation in Neutron Decay

    Science.gov (United States)

    Jones, Gordon

    2015-10-01

    The aCORN experiment has measured the electron-antineutrino angular correlation coefficient (the ``a'' coefficient) in free neutron decay. aCORN uses the dependence of the recoil proton momentum on the opening angle between the electron and the neutrino to form an asymmetry. The apparatus accepts decays where the antineutrino is restricted to two momentum groups having equal solid angle. In this geometry, proton time of flight distinguishes between decays with a large or small opening angle between the electron and the antineutrino. The correlation coefficient is determined from the asymmetry between two branches of the time of flight spectrum. The asymmetry was measured on the NG-6 neutron beam at the NIST Center for Neutron Research (NCNR), and a subsequent measurement has been started on the higher flux NG-C beam. An overview of the method and systematic effects will be presented, including results from the NG-6 dataset. National Science Foundation.

  14. Antineutrino emission and gamma background characteristics from a thermal research reactor

    CERN Document Server

    Bui, V M; Fallot, M; Communeau, V; Cormon, S; Estienne, M; Lenoir, M; Peuvrel, N; Shiba, T; Cucoanes, A S; Elnimr, M; Martino, J; Onillon, A; Porta, A; Pronost, G; Remoto, A; Thiolliere, N; Yermia, F; Zakari-Issoufou, A -A

    2016-01-01

    The detailed understanding of the antineutrino emission from research reactors is mandatory for any high sensitivity experiments either for fundamental or applied neutrino physics, as well as a good control of the gamma and neutron backgrounds induced by the reactor operation. In this article, the antineutrino emission associated to a thermal research reactor: the OSIRIS reactor located in Saclay, France, is computed in a first part. The calculation is performed with the summation method, which sums all the contributions of the beta decay branches of the fission products, coupled for the first time with a complete core model of the OSIRIS reactor core. The MCNP Utility for Reactor Evolution code was used, allowing to take into account the contributions of all beta decayers in-core. This calculation is representative of the isotopic contributions to the antineutrino flux which can be found at research reactors with a standard 19.75\\% enrichment in $^{235}$U. In addition, the required off-equilibrium correction...

  15. A Possible Detection of the Cosmic Antineutrino Background in the Presence of Flavor Effects

    CERN Document Server

    Li, Y F

    2011-01-01

    Lusignoli and Vignati have recently pointed out that it is in principle possible to directly detect the cosmic antineutrino background by using the rather stable isotope holmium-163 as a target, which can decay into dysprosium-163 via electron capture (EC) with a very small energy release. In this paper we calculate the rate of the relic antineutrino capture on holmium-163 nuclei against the corresponding EC decay rate by taking account of different neutrino mass hierarchies and reasonable values of theta_13. We show that such flavor effects are appreciable and even important in some cases, and stress that a calorimetric measurement of the cosmic antineutrino background might be feasible in the future.

  16. 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)

  17. A search for neutrino-antineutrino mass inequality by means of sterile neutrino oscillometry

    Science.gov (United States)

    Smirnov, M. V.; Loo, K. K.; Novikov, Yu. N.; Trzaska, W. H.; Wurm, M.

    2015-11-01

    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.

  18. A Experiment to Determine the Mass of the Electron Antineutrino.

    Science.gov (United States)

    Sur, Bhaskar

    The fact that neutrinos may have mass has attracted considerable attention in recent years both on the theoretical and experimental forefronts. The advent of Grand Unified Theories, the candidacy of neutrinos as dark matter, the proposed neutrino oscillation (and MSW effect) solution to the Solar Neutrino Puzzle and the observance of neutrinos from Supernova 1987A have further stimulated experimental efforts to directly probe neutrino masses by looking for dynamical effects. The technique of examining the end -point spectrum of Tritium beta-decay has long been used in this vein. The recent report of a positive electron antineutrino mass of 30 +/- 2 ev by the ITEP group in Moscow and the subsequent results from Los Alamos, Zurich and Japan which are in conflict with this value have stirred some controversy in this field. The present experiment uses a technique which is different from the usual magnetic-electrostatic analysis of the beta-spectrum employed by most groups--that of sperical electrostatic retarding field analysis. This method yields an integrated spectrum of the source and because of this and the large solid angle of acceptance of the spectrometer, the experiment yields very good statistics. Also the proposed source in this case is frozen T_2 for which the various correction factors can be estimated very accurately. The design, construction and testing of the spectrometer is described in detail in this dissertation as is the procedure used for fitting the data and calculating the correction factors to be applied to it. Due to a series of unfortunate accidents, the experiment has not yet been completed, but having proved that the intrinsic (point source) resolution is only 5 to 10 ev, the total efficiency about 2% and the background count rate about 20 counts per second, the experiment is expected to yield a mass limit of the order of 20 ev when run with a source of strength of about 30 milliCurie for a few days in the very near future.

  19. Reactor and Antineutrino Spectrum Calculations for the Double Chooz First Phase Results

    International Nuclear Information System (INIS)

    The Double Chooz reactor oscillation experiment is designed to search for a non-vanishing value of the mixing angle θ13. For the first phase of the experiment with only the far detector running, the reactor electron antineutrino flux is normalized via reactor simulation. For this first phase and from its last results, Double Chooz observed an evidence for a reactor electron antineutrino disappearance. In 227.93 days of far detector live time, we obtained sin22θ13=0.109±0.030(stat)±0.025(syst). This result excludes the no-oscillation hypothesis at 99.8% CL

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

    International Nuclear Information System (INIS)

    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)

  1. Antineutrino Background from Spent Fuel Storage in sensitive Searches for theta_13 at Reactors

    CERN Document Server

    Kopeikin, V; Sinev, V

    2004-01-01

    Sensitive searches for antineutrino oscillations in atmospheric mass parameter region much discussed in recent years are based on accurate comparison of the inverse beta decay positron spectra measured in two (or more) detectors, far and near, stationed e.g. at ~1000 m and ~100 m from the reactor(s). We show that antineutrinos emitted from the stored irradiated fuel can differently distort the soft part of positron spectra measured in the far and near detector and thus mimic (or hide) the oscillation signal

  2. Antineutrino Background from Spent Fuel Storage in sensitive Searches for theta_13 at Reactors

    OpenAIRE

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

    2004-01-01

    Sensitive searches for antineutrino oscillations in atmospheric mass parameter region much discussed in recent years are based on accurate comparison of the inverse beta decay positron spectra measured in two (or more) detectors, far and near, stationed e.g. at ~1000 m and ~100 m from the reactor(s). We show that antineutrinos emitted from the stored irradiated fuel can differently distort the soft part of positron spectra measured in the far and near detector and thus mimic (or hide) the osc...

  3. Experimental Determination of the Antineutrino Spectrum of the Fission Products of $^{238}$U

    CERN Document Server

    Haag, N; Hofmann, M; Oberauer, L; Potzel, W; Schreckenbach, K; Wagner, F M

    2013-01-01

    An experiment was performed at the scientific neutron source FRM II in Garching to determine the cumulative antineutrino spectrum of the fission products of $^{238}$U. This was achieved by irradiating target foils of natural uranium with a thermal and a fast neutron beam and recording the emitted $\\beta$-spectra with a gamma-suppressing electron-telescope. The obtained $\\beta$-spectrum of the fission products of $^{235}$U was normalized to the data of the magnetic spectrometer BILL of $^{235}$U. This method strongly reduces systematic errors in the $^{238}$U measurement. The $\\beta$-spectrum of $^{238}$U was converted into the corresponding antineutrino spectrum. The final $\\bar\

  4. First Test of Lorentz Violation with a Reactor-based Antineutrino Experiment

    CERN Document Server

    Abe, Y; Anjos, J C dos; Bergevin, M; Bernstein, A; Bezerra, T J C; Bezrukhov, L; Blucher, E; Bowden, N S; Buck, C; Busenitz, J; Cabrera, A; Caden, E; Camilleri, L; Carr, R; Cerrada, M; Chang, P -J; Chimenti, P; Classen, T; Collin, A P; Conover, E; Conrad, J M; Crespo-Anadón, J I; Crum, K; Cucoanes, A; D'Agostino, M V; Damon, E; Dawson, J V; Dazeley, S; Dietrich, D; Djurcic, Z; Dracos, M; Durand, V; Ebert, J; Efremenko, Y; Elnimr, M; Erickson, A; Fallot, M; Fechner, M; von Feilitzsch, F; Felde, J; Fischer, V; Franco, D; Franke, A J; Franke, M; Furuta, H; Gama, R; Gil-Botella, I; Giot, L; Göger-Neff, M; Gonzalez, L F G; Goodman, M C; Goon, J TM; Greiner, D; Haag, N; Habib, S; Hagner, C; Hara, T; Hartmann, F X; Haser, J; Hatzikoutelis, A; Hayakawa, T; Hofmann, M; Horton-Smith, G A; Ishitsuka, M; Jochum, J; Jollet, C; Jones, C L; Kaether, F; Kalousis, L N; Kamyshkov, Y; Kaplan, D M; Katori, T; Kawasaki, T; Keefer, G; Kemp, E; de Kerret, H; Konno, T; Kryn, D; Kuze, M; Lachenmaier, T; Lane, C E; Lasserre, T; Letourneau, A; Lhuillier, D; Lima, H P; Lindner, M; López-Castanõ, J M; LoSecco, J M; Lubsandorzhiev, B K; Lucht, S; McKee, D; Maeda, J; Maesano, C N; Mariani, C; Maricic, J; Martino, J; Matsubara, T; Mention, G; Meregaglia, A; Meyer, M; Miletic, T; Milincic, R; Miyata, H; Mueller, Th A; Nagasaka, Y; Nakajima, K; Novella, P; Obolensky, M; Oberauer, L; Onillon, A; Osborn, A; Ostrovskiy, I; Palomares, C; Pepe, I M; Perasso, S; Perrin, P; Pfahler, P; Porta, A; Potzel, W; Pronost, G; Reichenbacher, J; Reinhold, B; Remoto, A; Röhling, M; Roncin, R; Roth, S; Rybolt, B; Sakamoto, Y; Santorelli, R; Sato, F; Schönert, S; Schoppmann, S; Schwetz, T; Shaevitz, M H; Shrestha, D; Sida, J -L; Sinev, V; Skorokhvatov, M; Smith, E; Spitz, J; Stahl, A; Stancu, I; Stokes, L F F; Strait, M; Stüken, A; Suekane, F; Sukhotin, S; Sumiyoshi, T; Sun, Y; Terao, K; Tonazzo, A; Toups, M; Thi, H H Trinh; Valdiviesso, G; Veyssiere, C; Wagner, S; Watanabe, H; White, B; Wiebusch, C; Winslow, L; Worcester, M; Wurm, M; Yanovitch, E; Yermia, F; Zimmer, V

    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 (SME), we set the first limits on fourteen Lorentz violating coefficients associated with transitions between electron and tau flavor, and set two competitive limits associated with transitions between electron and muon flavor.

  5. Large scale Gd-beta-diketonate based organic liquid scintillator production for antineutrino detection

    CERN Document Server

    Aberle, C; Gramlich, B; Hartmann, F X; Lindner, M; Schönert, S; Schwan, U; Wagner, S; Watanabe, H

    2011-01-01

    Over the course of several decades organic liquid scintillators form the basis for successful neutrino detectors. For electron antineutrino detection at nuclear reactor plants, gadolinium loaded liquid scintillators provide efficient background suppression. In the Double Chooz reactor antineutrino experiment a newly developed gadolinium-loaded scintillator is utilized for the first time. Its large scale production and characterization as well as the creation of an additional metalfree scintillator are presented. Both organic liquids are used in the inner part of the Double Chooz detectors.

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

    International Nuclear Information System (INIS)

    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

  7. Precise measurement of neutrino and anti-neutrino differential cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Tzanov, M.; Naples, D.; Boyd, S.; McDonald, J.; Radescu, V.; Adams, T.; Alton, A.; Avvakumov, S.; deBarbaro, L.; deBarbaro, P.; Bernstein, R.H.; Bodek, A.; Bolton, T.; Brau, J.; Buchholz, D.; Budd, H.; Bugel, L.; Conrad, J.; Drucker, R.B.; Fleming, B.T.; Frey, R.; /Pittsburgh U. /Cincinnati U. /Columbia U. /Fermilab /Kansas State U. /Northwestern

    2005-09-01

    The NuTeV experiment at Fermilab has obtained a unique high statistics sample of neutrino and anti-neutrino interactions using its high-energy sign-selected beam. We present a measurement of the differential cross section for charged-current neutrino and anti-neutrino scattering from iron. Structure functions, F{sub 2}(x,Q{sup 2}) and xF{sub 3}(x,Q{sup 2}), are determined by fitting the inelasticity, y, dependence of the cross sections. This measurement has significantly improved systematic precision as a consequence of more precise understanding of hadron and muon energy scales.

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

    CERN Document Server

    An, F P; Band, H R; Bishai, M; Blyth, S; Cao, D; Cao, G F; Cao, J; Cen, W R; Chan, Y L; Chang, J F; Chang, L C; Chang, Y; Chen, H S; Chen, Q Y; Chen, S M; Chen, Y X; Chen, Y; Cheng, J -H; Cheng, J; Cheng, Y P; Cheng, Z K; Cherwinka, J J; Chu, M C; Chukanov, A; Cummings, J P; de Arcos, J; Deng, Z Y; Ding, X F; 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; Guan, M Y; Guo, L; Guo, R P; Guo, X H; Guo, Z; Hackenburg, R W; Han, R; Hans, S; He, M; Heeger, K M; Heng, Y K; Higuera, A; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, T; Hu, W; Huang, E C; Huang, H X; Huang, X T; Huber, P; Huo, W; Hussain, G; Jaffe, D E; Jaffke, P; Jen, K L; Jetter, S; Ji, X P; Ji, X L; Jiao, J B; Johnson, R A; Joshi, J; Kang, L; Kettell, S H; Kohn, S; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Langford, T J; Lau, K; Lebanowski, L; Lee, J; Lee, J H C; Lei, R T; Leitner, R; 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, 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, D W; Liu, J L; Liu, J C; Loh, C W; Lu, C; Lu, H Q; Lu, J S; Luk, K B; Lv, Z; Ma, Q M; Ma, X Y; Ma, X B; Ma, Y Q; Malyshkin, Y; Caicedo, D A Martinez; McDonald, K T; McKeown, R D; Mitchell, I; Mooney, M; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ngai, H Y; Ning, Z; 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; Raper, N; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Steiner, H; Sun, G X; 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 Y; Xu, J L; Xu, Y; Xue, T; Yang, C G; Yang, H; Yang, L; Yang, M S; Yang, M T; Ye, M; Ye, Z; Yeh, M; Young, B L; Yu, Z Y; Zeng, S; Zhan, L; Zhang, C; Zhang, H H; Zhang, J W; Zhang, Q M; Zhang, X T; Zhang, Y M; Zhang, Y X; Zhang, Y M; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhao, Q W; Zhao, Y B; Zhong, W L; Zhou, L; Zhou, N; Zhuang, H L; Zou, J H

    2016-01-01

    A new measurement of the reactor antineutrino flux and energy spectrum by the Daya Bay reactor neutrino experiment is reported. The antineutrinos were generated by six 2.9 GW$_{\\mathrm{th}}$ nuclear reactors and detected by eight antineutrino detectors deployed in two near (510~m and 560~m flux-weighted baselines) and one far (1580~m flux-weighted baseline) underground experimental halls. With 621 days of data, more than 1.2 million inverse beta decay (IBD) candidates were detected. The IBD yield in the eight detectors was measured, and the ratio of measured to predicted flux was found to be $0.946\\pm0.020$ ($0.992\\pm0.021$) for the Huber+Mueller (ILL+Vogel) model. A 2.9 $\\sigma$ deviation was found in the measured IBD positron energy spectrum compared to the predictions. In particular, an excess of events in the region of 4-6~MeV was found in the measured spectrum, with a local significance of 4.4 $\\sigma$. A reactor antineutrino spectrum weighted by the IBD cross section is extracted for model-independent p...

  9. Simulation results of liquid and plastic scintillator detectors for reactor antineutrino detection - A comparison

    Science.gov (United States)

    Kashyap, V. K. S.; Pant, L. M.; Mohanty, A. K.; Datar, V. M.

    2016-03-01

    A simulation study of two kinds of scintillation detectors has been done using GEANT4. We compare plastic scintillator and liquid scintillator based designs for detecting electron antineutrinos emitted from the core of reactors. The motivation for this study is to set up an experiment at the research reactor facility at BARC for very short baseline neutrino oscillation study and remote reactor monitoring.

  10. The Improved Measurement of Electron-antineutrino Disappearance at Daya Bay

    CERN Document Server

    Dwyer, Daniel A

    2013-01-01

    With 2.5x the previously reported exposure, the Daya Bay experiment has improved the measurement of the neutrino mixing parameter sin^2(2theta_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 of 1648 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 theta_13.

  11. The relativistic Green's function model in charged-current quasielastic neutrino and antineutrino scattering at MINER$\

    OpenAIRE

    Meucci, Andrea; Giusti, Carlotta

    2014-01-01

    The analysis of charged-current quasielastic neutrino and antineutrino-nucleus scattering cross sections requires relativistic theoretical descriptions also accounting for the role of final-state interactions. We compare the results of the relativistic Green's function model with the data recently published by the MINER$\

  12. Search for Time-Independent Lorentz Violation using Muon Neutrino to Muon Antineutrino Transitions in MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, P.; et al.

    2016-05-10

    Data from the MINOS experiment has been used to search for mixing between muon neutrinos and muon antineutrinos using a time-independent Lorentz-violating formalism derived from the Standard-Model Extension (SME). MINOS is uniquely capable of searching for muon neutrino-antineutrino mixing given its long baseline and ability to distinguish between neutrinos and antineutrinos on an event-by-event basis. Neutrino and antineutrino interactions were observed in the MINOS Near and Far Detectors from an exposure of 10.56$\\times10^{20}$ protons-on-target from the NuMI neutrino-optimized beam. No evidence was found for such transitions and new, highly stringent limits were placed on the SME coefficients governing them. We place the first limits on the SME parameters $(c_{L})^{TT}_{\\mu\\mu} $ and $(c_{L})^{TT}_{\\tau\\tau}$ at $-8.4\\times10^{-23} < (c_{L})^{TT}_{\\mu\\mu} < 8.0\\times10^{-23}$ and $-8.0\\times10^{-23} < (c_{L})^{TT}_{\\tau\\tau} < 8.4\\times10^{-23}$, and the world's best limits on the $\\tilde{g}^{ZT}_{\\mu\\overline{\\mu}}$ and $\\tilde{g}^{ZT}_{\\tau\\overline{\\tau}}$ parameters at $|\\tilde{g}^{ZT}_{\\mu\\overline{\\mu}}| < 3.3\\times 10^{-23}$ and $|\\tilde{g}^{ZT}_{\\tau\\overline{\\tau}}| < 3.3\\times 10^{-23}$, all limits quoted at $3\\sigma$.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Debdatta; /Pittsburgh U.

    2009-03-01

    This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 10{sup 6} neutrino events and 1.60 x 10{sup 5} antineutrino events. The flux has been extracted using a low hadronic energy sub-sample of the charged current events. The energy dependence of the cross section is obtained by dividing the charged current sample with the extracted flux. The neutrino and antineutrino cross section exhibits a linear dependence on energy at high energy but shows deviations from linear behavior at low energy. We also present a measurement of the ratio of antineutrino to neutrino inclusive cross section.

  14. Measurements of atmospheric neutrinos and antineutrinos in the MINOS Far Detector

    CERN Document Server

    Adamson, P; Barr, G; Bishai, M; Blake, A S T; Bock, G J; Boehnlein, D J; Bogert, D; Cao, S V; Chapman, J D; Childress, S; Coelho, J A B; Corwin, L; Cronin-Hennessy, D; Danko, I Z; de Jong, J K; Devenish, N E; Diwan, M V; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Frohne, M V; Gallagher, H R; Gomes, R A; Goodman, M C; Gouffon, P; Graf, N; Gran, R; Grzelak, K; Habig, A; Hartnell, J; Hatcher, R; Himmel, A; Holin, A; Hylen, J; Irwin, G M; Isvan, Z; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kopp, S; Kordosky, M; Kreymer, A; Lang, K; Ling, J; Litchfield, P J; Loiacono, L; Lucas, P; Mann, W A; Marshak, M L; Mathis, M; Mayer, N; Medeiros, M M; Mehdiyev, R; Meier, J R; Messier, M D; Miller, W H; Mishra, S R; Mitchell, J; Moore, C D; Mualem, L; Mufson, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nowak, J A; Oliver, W P; Orchanian, M; Pahlka, R B; Paley, J; Patterson, R B; Pawloski, G; Phan-Budd, S; Plunkett, R K; Qiu, X; Radovic, A; Ratchford, J; Rebel, B; Rosenfeld, C; Rubin, H A; Sanchez, M C; Schneps, J; Schreckenberger, A; Schreiner, P; Sharma, R; Sousa, A; Speakman, B; Strait, M; Tagg, N; Talaga, R L; Thomas, J; Thomson, M A; Toner, R; Torretta, D; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Walding, J J; Weber, A; Webb, R C; White, C; Whitehead, L; Wojcicki, S G; Zhang, K; Zwaska, R

    2012-01-01

    This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9 kton-years) of data. A total of 2072 candidate events are observed. These are separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons, both produced by charged-current $\

  15. Simulation results of liquid and plastic scintillator detectors for reactor antineutrino detection - A comparison

    International Nuclear Information System (INIS)

    A simulation study of two kinds of scintillation detectors has been done using GEANT4. We compare plastic scintillator and liquid scintillator based designs for detecting electron antineutrinos emitted from the core of reactors. The motivation for this study is to set up an experiment at the research reactor facility at BARC for very short baseline neutrino oscillation study and remote reactor monitoring

  16. A new measurement of antineutrino oscillation with the full detector configuration at Daya Bay

    CERN Document Server

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

    2015-01-01

    We report a new measurement of electron antineutrino disappearance using the fully-constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9$\\times$10$^5$ GW$_{\\rm th}$-ton-days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six $^{241}$Am-$^{13}$C radioactive calibration sources reduced the background by a factor of two for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of $\\sin^{2}2\\theta_{13}$ and $|\\Delta m^2_{ee}|$ were halved as a result of these improvements. Ana...

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

    CERN Document Server

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

    2015-01-01

    This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9~GW$_{th}$ nuclear reactors with six detectors deployed in two near (effective baselines 512~m and 561~m) and one far (1,579~m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296,721 and 41,589 inverse beta decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55 $\\pm$ 0.04) $\\times$ 10$^{-18}$~cm$^2$/GW/day or (5.92 $\\pm$ 0.14) $\\times$ 10$^{-43}$~cm$^2$/fission. This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is $0.946\\pm0.022$ ($0.991\\pm0.023$) relative to the flux predicted with the Huber+Mueller (ILL+Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2$\\sigma$ over the full energy range with a local significance of up to $\\sim$4$\\sigma$ between 4-6 MeV. A reactor antineutrino spectrum...

  18. Search for time-independent Lorentz violation using muon neutrino to muon antineutrino transitions in MINOS

    CERN Document Server

    Adamson, P; Aurisano, A; Barr, G; Bishai, M; Blake, A; Bock, G J; Bogert, D; Cao, S V; Carroll, T J; Castromonte, C M; Chen, R; Childress, S; Coelho, J A B; Corwin, L; Cronin-Hennessy, D; de Jong, J K; de Rijck, S; Devan, A V; Devenish, N E; Diwan, M V; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Flanagan, W; Frohne, M V; Gabrielyan, M; Gallagher, H R; Germani, S; Gomes, R A; Goodman, M C; Gouffon, P; Graf, N; Gran, R; Grzelak, K; Habig, A; Hahn, S R; Hartnell, J; Hatcher, R; Holin, A; Huang, J; Hylen, J; Irwin, G M; Isvan, Z; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kordosky, M; Kreymer, A; Lang, K; Ling, J; Litchfield, P J; Lucas, P; Mann, W A; Marshak, M L; Mayer, N; McGivern, C; Medeiros, M M; Mehdiyev, R; Meier, J R; Messier, M D; Miller, W H; Mishra, S R; Sher, S Moed; Moore, C D; Mualem, L; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nowak, J A; O'Connor, J; Orchanian, M; Pahlka, R B; Paley, J; Patterson, R B; Pawloski, G; Perch, A; Pfützner, M M; Phan, D D; Phan-Budd, S; Plunkett, R K; Poonthottathil, N; Qiu, X; Radovic, A; Rebel, B; Rosenfeld, C; Rubin, H A; Sail, P; Sanchez, M C; Schneps, J; Schreckenberger, A; Schreiner, P; Sharma, R; Sousa, A; Tagg, N; Talaga, R L; Thomas, J; Thomson, M A; Tian, X; Timmons, A; Todd, J; Tognini, S C; Toner, R; Torretta, D; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Weber, A; Webb, R C; White, C; Whitehead, L; Whitehead, L H; Wojcicki, S G; Zwaska, R

    2016-01-01

    Data from the MINOS experiment has been used to search for mixing between muon neutrinos and muon antineutrinos using a time-independent Lorentz-violating formalism derived from the Standard-Model Extension (SME). MINOS is uniquely capable of searching for muon neutrino-antineutrino mixing given its long baseline and ability to distinguish between neutrinos and antineutrinos on an event-by-event basis. Neutrino and antineutrino interactions were observed in the MINOS Near and Far Detectors from an exposure of 10.56$\\times10^{20}$ protons-on-target from the NuMI neutrino-optimized beam. No evidence was found for such transitions and new, highly stringent limits were placed on the SME coefficients governing them. We place the first limits on the SME parameters $(c_{L})^{TT}_{\\mu\\mu} $ and $(c_{L})^{TT}_{\\tau\\tau}$ at $-8.4\\times10^{-23} < (c_{L})^{TT}_{\\mu\\mu} < 8.0\\times10^{-23}$ and $-8.0\\times10^{-23} < (c_{L})^{TT}_{\\tau\\tau} < 8.4\\times10^{-23}$, and the world's best limits on the $\\tilde{g}^{Z...

  19. 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.

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

    Science.gov (United States)

    Porta, A.; Zakari-Issoufou, A.-A.; Fallot, M.; Algora, A.; Tain, J. L.; Valencia, E.; Rice, S.; Bui, V. M.; Cormon, S.; Estienne, M.; Agramunt, J.; Äystö, J.; Bowry, M.; Briz, J. A.; Caballero-Folch, R.; Cano-Ott, D.; Cucouanes, A.; Elomaa, V.-V.; Eronen, T.; Estévez, E.; Farrelly, G. F.; Garcia, A. R.; Gelletly, W.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Jordan, M. D.; Kankainen, A.; Karvonen, P.; Kolhinen, V. S.; Kondev, F. G.; Martinez, T.; Mendoza, E.; Molina, F.; Moore, I.; Perez-Cerdán, A. B.; Podolyák, Zs.; Penttilä, H.; Regan, P. H.; Reponen, M.; Rissanen, J.; Rubio, B.; Shiba, T.; Sonzogni, A. A.; Weber, C.

    2016-03-01

    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.

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

    Science.gov (United States)

    Sonzogni, Alejandro; McCutchan, Elizabeth; Johnson, Timothy

    2015-10-01

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

  2. 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.

  3. Neutrino-nucleus reactions in supernovae

    Directory of Open Access Journals (Sweden)

    Dzhioev Alan A.

    2016-01-01

    Full Text Available We study thermal effects on neutrino-nucleus reactions occurring under supernova conditions. The approach we use is based on the QRPA extended to finite temperature by the thermofield dynamics formalism. For the relevant supernova conditions we calculate inelastic neutrino scattering and neutrino absorption cross sections for two sample nuclei, 56Fe and 82Ge. In addition, we apply the approach to examine the rate of neutrino-antineutrino pair emission by hot nuclei.

  4. Energy dependence of total cross sections for neutrino and antineutrino interactions are energies below 35 GeV

    International Nuclear Information System (INIS)

    Further analysis of experimental data obtained in neutrino IHEP-ITEP experiment in Serpukhov is presented. Energy dependences of total cross sections for neutrino-nucleon and antineutrino-nucleon charged-current interactions in the energy range 5-35 GeV have been obtained. There is a tendency for a slow decrease of neutrino cross section with energy increase and a slope constancy of antineutrino cross section. It agrees well with QCD predictions

  5. A computer study of the experimental feasibility of observing the nuclear excitation of 7Li by reactor antineutrinos

    Science.gov (United States)

    Avignone, F. T.; Donnelly, T. W.

    1981-01-01

    A computer study of the feasibility of observing the 0.478 MeV γ-ray following the antineutrino excitation of 7Li has been carried out in a simple geometry involving two large Ge detectors placed on the axis inside a 20 kg target of natural lithium. The background γ-ray flux was assumed to be that observed by Fiorini and his co-workers in their search for neutrinoless double beta decay of 76Ge. The target was assumed to be inside a rectangular live shield of NaI(Tl) which has a wall thickness of 10.16 cm. The results for the Weinberg-Salam model clearly show that the direct observation of this reaction is feasible even if the background is almost two orders of magnitude more intense than the background observed by Fiorini et al. This conclusion was found to be valid even if most of the background originates inside the cryostat itself. If the background is no more than three times as intense as that observed by Fiorini et al., the excitation can at least be observed with a larger target and with no NaI(Tl) annulus.

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

    International Nuclear Information System (INIS)

    This work is dedicated to the study of the structure functions in neutrino-nucleon interactions and to the interpretation of observed violations of scaling invariance. The first chapter describes the experimental setting, the Cargamelle cloud chamber has been used. The second chapter presents the data analysis, the event selection methodology, the muon identification and the energy correction that takes into account the non-detected particles. We also present the bi-dimensional x and q2 distribution of events that is necessary to the determination of the structure functions. In the third chapter we detail the theoretical basis of our analysis: we define relevant kinematic variables and we discuss the scale invariance in the light of the quark-parton model. The violations of the scale invariance are considered first in the formalism of quantum chromodynamics and then in the view of higher twist or mass corrections. The fourth chapter deals with the experimental determination of the structure functions and of the violations of the scaling invariance. (A.C.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    CERN Document Server

    Li, Yu-Feng

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

  10. Measurement of antineutrino oscillation with the full detector configuration at Daya Bay

    CERN Document Server

    Grassi, Marco

    2016-01-01

    In this poster, we present the latest measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. A total exposure of $6.9 \\times 10^5$ GW$_{\\mathrm{th}}$ ton days was achieved in November 2013 after 617 day of data taking. The most precise estimates to date of the neutrino mass and mixing parameters $|\\Delta \\mathrm{m}^2_{ee}|$ and $\\sin^2 2 \\theta_{13}$ were obtained with an analysis of the relative antineutrino rates and energy spectra between detectors. The value of the two parameters was found to be $\\sin^2 2 \\theta_{13} = 0.084 \\pm 0.005$ and $|\\Delta \\mathrm{m}^2_{ee}| = (2.42 \\pm 0.11) \\times 10^{-3}\\,\\mathrm{eV}^2$. This report focuses in particular on describing how improvements in the calibration and in the energy response model contributed to achieve this result.

  11. Quasielastic neutrino and antineutrino interaction at the Serpukhov accelerator (IHEP-ITEP collaboration)

    International Nuclear Information System (INIS)

    Preliminary results on the energy dependence of quasielastic differential and total cross-sections for neutrino and antineutrino scattering in the νsub(μ)n → μ-p and anti νsub(μ)p → μ+n interactions in the energy region 3 <= E <= 30 GeV obtined in the aluminium spark chamber detector are presented. The data are compared with the predictions of classical V-A theory with current vector conservation assumption. The best fit parameters for axial mass are Msub(A)=1.00+-0.07 and Msub(A)=1.04+-0.08 from the neutrino and antineutrino data respectively. It is shown that experimental data are in good agreement with the predictions of the standart V-A theory

  12. Search for Perturbations of Nuclear Decay Rates Induced by Reactor Electron Antineutrinos

    CERN Document Server

    Barnes, V E; Bryan, C D; Cinko, N; Deichert, G G; Gruenwald, J T; Heim, J M; Kaplan, H B; LaZur, R; Neff, D; Nistor, J M; Sahelijo, N; Fischbach, E

    2016-01-01

    We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos can alter the rates of weak nuclear interaction-induced decays for Mn-54, Na-22, and Co-60. This experiment, while quite sensitive, cannot exclude perturbations less than one or two parts in $10^4$ in $\\beta$ decay (or electron capture) processes, in the presence of an antineutrino flux of $3\\times 10^{12}$ cm$^{-2}$ s$^{-1}$. The present experimental methods are applicable to a wide range of isotopes. Improved sensitivity in future experiments may be possible if we can understand and reduce the dominant systematic uncertainties.

  13. The Physics and Nuclear Nonproliferation Goals of WATCHMAN: A WAter CHerenkov Monitor for ANtineutrinos

    CERN Document Server

    Askins, M; Bernstein, A; Dazeley, S; Dye, S T; Handler, T; Hatzikoutelis, A; Hellfeld, D; Jaffke, P; Kamyshkov, Y; Land, B J; Learned, J G; Marleau, P; Mauger, C; Gann, G D Orebi; Roecker, C; Rountree, S D; Shokair, T M; Smy, M B; Svoboda, R; Sweany, M; Vagins, M R; van Bibber, K A; Vogelaar, R B; Wetstein, M J; Yeh, M

    2015-01-01

    This article describes the physics and nonproliferation goals of WATCHMAN, the WAter Cherenkov Monitor for ANtineutrinos. The baseline WATCHMAN design is a kiloton scale gadolinium-doped (Gd) light water Cherenkov detector, placed 13 kilometers from a civil nuclear reactor in the United States. In its first deployment phase, WATCHMAN will be used to remotely detect a change in the operational status of the reactor, providing a first- ever demonstration of the potential of large Gd-doped water detectors for remote reactor monitoring for future international nuclear nonproliferation applications. During its first phase, the detector will provide a critical large-scale test of the ability to tag neutrons and thus distinguish low energy electron neutrinos and antineutrinos. This would make WATCHMAN the only detector capable of providing both direction and flavor identification of supernova neutrinos. It would also be the third largest supernova detector, and the largest underground in the western hemisphere. In a...

  14. Method of Fission Product Beta Spectra Measurements for Predicting Reactor Anti-neutrino Emission

    OpenAIRE

    Asner, D. M.; Burns, K; Campbell, L. W.; Greenfield, B.; Kos, M. S.; Orrell, J. L.; Schram, M.; VanDevender, B.; Wood, L. S.; Wootan, D. W.

    2014-01-01

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron rich fission products that subsequently beta decay and emit electron anti-neutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to current precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurem...

  15. Advances toward a transportable antineutrino detector system for reactor monitoring and safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Reyna, D. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bernstein, A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lund, J.; Kiff, S.; Cabrera-Palmer, B. [Sandia National Laboratories, Livermore, CA 94550 (United States); Bowden, N. S.; Dazeley, S.; Keefer, G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2011-07-01

    Nuclear reactors have served as the neutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Our SNL/LLNL collaboration has demonstrated that such antineutrino based monitoring is feasible using a relatively small cubic meter scale liquid scintillator detector at tens of meters standoff from a commercial Pressurized Water Reactor (PWR). With little or no burden on the plant operator we have been able to remotely and automatically monitor the reactor operational status (on/off), power level, and fuel burnup. The initial detector was deployed in an underground gallery that lies directly under the containment dome of an operating PWR. The gallery is 25 meters from the reactor core center, is rarely accessed by plant personnel, and provides a muon-screening effect of some 20-30 meters of water equivalent earth and concrete overburden. Unfortunately, many reactor facilities do not contain an equivalent underground location. We have therefore attempted to construct a complete detector system which would be capable of operating in an aboveground location and could be transported to a reactor facility with relative ease. A standard 6-meter shipping container was used as our transportable laboratory - containing active and passive shielding components, the antineutrino detector and all electronics, as well as climate control systems. This aboveground system was deployed and tested at the San Onofre Nuclear Generating Station (SONGS) in southern California in 2010 and early 2011. We will first present an overview of the initial demonstrations of our below ground detector. Then we will describe the aboveground system and the technological developments of the two antineutrino

  16. Improved limit on the electron-antineutrino rest mass from tritium ß-decay

    OpenAIRE

    Weinheimer, Christian; Przyrembel, Michael; Backe, Hartmut; H. Barth; Bonn, Jochen; Degen, Beate; Edling, Thomas; Fischer, H.; Fleischmann, L.; Grooß, Jens-Uwe; Haid, R.; Hermanni, Antje; Kube, Gero; Leiderer, Paul; Loeken, Thomas

    1993-01-01

    The endpoint region of the β-spectrum of tritium was remeasured by an electrostatic spectrometer with magnetic guiding field. It enabled the search for a rest mass of the electron-antineutrino with improved precision. The result is m2v=−39±34stat±15syst(eV/c2)2, from which an upper limit of mv

  17. How Unequal Fluxes of High Energy Astrophysical Neutrinos and Antineutrinos can Fake New Physics

    CERN Document Server

    Nunokawa, Hiroshi; Funchal, Renata Zukanovich

    2016-01-01

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

  18. Supernova Relic Electron Neutrinos and anti-Neutrinos in future Large-scale Observatories

    CERN Document Server

    Volpe, C

    2007-01-01

    We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron anti-neutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core-collapse supernova. We present numerical results on both the relic electron neutrino and anti-neutrino fluxes and on the number of events for electron neutrinos on carbon, oxygen and argon, as well as electron anti-neutrinos on protons, for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino propert...

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

    International Nuclear Information System (INIS)

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

  20. Lithium antineutrino source in the tandem scheme of the accelerator and neutron producting tungsten target

    CERN Document Server

    Lyashuk, V I

    2016-01-01

    The antineutrinos of the neutron rich 8Li isotope is characterized by hard and good defined spectrum - averaged energy is 6.5 MeV and maximal - up to 13 MeV. An intensive antineutrino source with such parameters can be unique instrument for neutrino investigations and especially for search of sterile neutrinos. The 8Li can be produced by (n,gamma)-activation of 7Li isotope. The proposed scheme of the antineutrino source is based on the lithium blanket around the accelerator neutron producting target. We propose to use heavy water solution of the lithium hydroxide instead of lithium in metallic state. Such solution for lithium blanket substance ensure the large perspectives in real steps for creation of this installation. An analyses of neutron fields in the blanket and distribution of 8Li creation allows to propose the next principal steps in the construction of the lithium blanket. We propose to enclose the blanket volume isolating it's central part with more high 8Li production. This solution allows to decr...

  1. Inquiry into antineutrino angular distribution in the experiments on polarized neutron β-decay

    International Nuclear Information System (INIS)

    So far as γ-radiation unescapably accompanies β-decay and thereby the final state of neutron β-decay involves photon beside proton, electron and antineutrino, i.e., not three but four particles, the antineutrino kinematics cannot be reconstructed unambiguously when the proton and electron momenta are given only, the γ-radiation momenta being unknown. Consequently, in the experiments on the polarized neutron β-decay where the electron and proton momentum distributions are observed only, without registering the γ-radiation, the asymmetry factor B of the antineutrino angular distribution cannot be acquired rigorously, but the B value is to be estimated only on the average by drawing into consideration the expectation (mean) value and the dispersion ΔB. The correspondent unavoidable ambiguities in B attainment amount to several percent which is significant for the now-a-days experimental attempts to obtain the B value with the very high precision ∼ (0.1 - 1) %. With allowance for the electromagnetic interaction, experimental measurement of the electron and proton momentum distributions is seen also to be instructive to verify with high accuracy the gA value obtained previously from the electron angular distribution

  2. Upper limit on the cross section for reactor antineutrinos changing 22Na decay rates

    CERN Document Server

    de Meijer, R J

    2014-01-01

    In this paper we present results of a long-term observation of the decay of 22Na in the presence of a nuclear fission reactor. The measurements were made outside the containment wall of and underneath the Koeberg nuclear power plant near Cape Town, South Africa. Antineutrino fluxes ranged from ~5*10^11 to 1.6*10^13 cm^-2 s^-1 during this period. We show that the coincidence summing technique provides a sensitive tool to measure a change in the total decay constant as well as the branching ratio between EC and beta+ decay of 22Na to the first excited state in 22Ne. We observe a relative change in count rate between reactor-ON and reactor-OFF equal to (-0.51+/-0.11)*10^-4. After evaluating possible systematic uncertainties we conclude that the effect is either due to a hidden instrumental cause or due to an interaction between antineutrinos and the 22Na nucleus. An upper limit of ~0.03 barn has been deduced for observing any change in the decay rate of 22Na due to antineutrino interactions.

  3. Neutrino-antineutrino mass splitting in the Standard Model and baryogenesis

    CERN Document Server

    Fujikawa, Kazuo

    2014-01-01

    On the basis of a previously proposed mechanism of neutrino-antineutrino mass splitting in the Standard Model, which is Lorentz and $SU(2)\\times U(1)$ invariant but non-local to evade $CPT$ theorem, we discuss the possible implications of neutrino-antineutrino mass splitting on neutrino physics and baryogenesis. It is shown that non-locality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at $\\sim 10^{-20}$ eV, well below the experimental bound $< 10^{-2}$ eV. The induced $CPT$ violation in the $K$-meson in the Standard Model is expected to be even smaller and well below the experimental bound $|m_{...

  4. Neutrino–antineutrino mass splitting in the Standard Model and baryogenesis

    Directory of Open Access Journals (Sweden)

    Kazuo Fujikawa

    2015-04-01

    Full Text Available On the basis of a previously proposed mechanism of neutrino–antineutrino mass splitting in the Standard Model, which is Lorentz and SU(2×U(1 invariant but non-local to evade the CPT theorem, we discuss the possible implications of neutrino–antineutrino mass splitting on neutrino physics and baryogenesis. It is shown that non-locality within a distance scale of the Planck length, that may not be fatal to unitarity in a generic effective theory, can generate the neutrino–antineutrino mass splitting of the order of the observed neutrino mass differences, which is tested in oscillation experiments, and a non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron–positron mass splitting in the Standard Model is shown to be finite and estimated at ∼10−20 eV, well below the experimental bound <10−2 eV. The induced CPT violation in the K-meson in the Standard Model is expected to be even smaller and well below the experimental bound |mK−mK¯|<0.44×10−18 GeV.

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

    International Nuclear Information System (INIS)

    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.)

  6. Design and tests of a data acquisition system for the Angra anti-neutrinos detector

    International Nuclear Information System (INIS)

    Full text: We describe the design of a Data Acquisition System (DAQ) for the Angra antineutrino project, aimed at developing an antineutrino detector to monitor nuclear reactors through the detection of antineutrino counting rates and spectral measurements. The experiment, presently under construction, will take place at the Brazilian nuclear power plant Angra II and will detect antineutrinos generated in the fusion process of the nuclear reactor fuel. The DAQ system is designed to be able to digitize and to store all the analog signals coming from the photomultiplier tubes (PMT), after going through the front-end electronics. It is composed of VME standard electronic modules. We focus here on the design of a new VME data acquisition card (NDAQ), which will be part of the Angra DAQ. This card is composed of eight analog-to-digital channels (ADC), each one featuring 10 bits of vertical resolution and 125 MHz of sampling rate. In order to measure time between events, or between PMT pulses, an 82 ps resolution time-to-digital converter (TDC) is also included in the card. Other NDAQ features are: one 512K x 8 bits Static RAM for on-board data storage, reprogrammable data processing circuit (through the use of a Field Programmable Gate Array - FPGA), standalone operation (connecting to any computer via USB port) and a 512K x 32 bits output buffer, used to reduce dead time in the data flow. The card allows VME block read cycles, reaching the usual bandwidth of more than 20 MB/s. Considering the worst-case estimated event rate of 1kHz, comprising neutrino and muons events, the Angra project must be able to deal with 10 MB/s event rate, which is safely below the card bandwidth. The design uses off-the-shelf devices from worldwide semiconductor companies. A software framework for the DAQ is developed for Linux platforms by using standard scientific tools and languages like ROOT and C++. The NDAQ design is currently under tests. The design and preliminary results, using

  7. Neutrino mass bound in the standard scenario for supernova electronic antineutrino emission

    OpenAIRE

    Pagliaroli, Giulia; Rossi-Torres, Fernando; Vissani, Francesco

    2010-01-01

    Based on recent improvements of the supernova electron antineutrino emission model, we update the limit on neutrino mass from the SN1987A data collected by Kamiokande-II, IMB and Baksan. We derive the limit of 5.8 eV at 95 % CL, that we show to be remarkably insensitive to the astrophysical uncertainties. Also we evaluate the ultimate mass sensitivity of this method for a detector like Super-Kamiokande. We find that the bound lies in the sub-eV region, 0.8 eV at 95 % CL being a typical outcom...

  8. Terrestrial matter effects on reactor antineutrino oscillations at JUNO or RENO-50: how small is small?

    OpenAIRE

    Li, Yu-Feng; Wang, Yifang; Xing, Zhi-zhong

    2016-01-01

    We have carefully examined, in both analytical and numerical ways, how small the terrestrial matter effects can be in a given medium-baseline reactor antineutrino oscillation experiment like JUNO or RENO-50. Taking the ongoing JUNO experiment for example, we show that the inclusion of terrestrial matter effects may reduce the sensitivity of the neutrino mass ordering measurement by \\Delta \\chi^2_{\\rm MO} \\simeq 0.6, and a neglect of such effects may shift the best-fit values of the flavor mix...

  9. Recent Results of the Relativistic Green's Function Model in Quasielastic Neutrino and Antineutrino-Nucleus Scattering

    CERN Document Server

    Giusti, Carlotta

    2014-01-01

    The analysis of quasielastic neutrino and antineutrino-nucleus scattering cross sections requires relativistic theoretical descriptions also accounting for the role of final-state interactions (FSI). In the relativistic Green's function (RGF) model FSI are described by a complex optical potential where the imaginary part recovers the contribution of final-state channels that are not included in other models based on the impulse approximation. The RGF results are compared with the data recently published by the MiniBooNE and MINER$\

  10. An assessment of antineutrino detection as a tool for monitoring nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Adam Bernstein; Todd West; Vipin Gupta

    1999-06-01

    The antineutrino is the only real-time nuclear signature from a fission explosion that propagates great distances through air, water, and ground. The size and sensitivity of antineutrino detectors has increased dramatically in the last decade, and will continue to do so in the next, thanks in part to the renewed interest in neutrino physics brought on by the recent discovery that neutrinos may have mass. The evolution of antineutrino detectors, and the evident interest of the signature as a means for monitoring nuclear tests motivates this review of the capabilities of existing and possible future detectors as test ban verification tools. The authors find that existing liquid scintillator ionization detectors, operating a few tens of meters below the Earth's surface and containing a few thousand tons of active material, could be used to monitor an area of a few square kilometers for nuclear explosions at the 1 kt level. Purified water Cerenkov detectors of sizes comparable to existing detectors (50,000 m{sup 3}) could be used to detect 1 kt explosions at distances of a few tens of kilometers. If neutron-absorbing dopants such as sodium chloride or gadolinium could be added to purified water, the resulting background reduction would allow extension of the range for sensitivity to a pulse of 10 antineutrino events from a 1 kt explosion out to approximately 1000 km. Beyond 1000 km, backgrounds from the world's nuclear reactors would become prohibitively large. The engineering hurdles for such detectors would be formidable. The size of a doped detector operating at the 100 km range, suitable for cooperative monitoring of existing nuclear test sites, is about 60 times that of the largest existing water detector, and would require a factor of several dozen more photomultiplier tubes than what is now used in large scale physics experiments. At a price per phototube of $1000, capital costs would amount to several billions of dollars, even for a detector at this

  11. Further Evidence for the Decay K+ to pi+ neutrino-antineutrino

    CERN Document Server

    Adler, S; Bergbusch, P; Blackmore, E W; Bryman, D A; Chen, S; Chiang, I H; Diwan, M V; Frank, J S; Haggerty, J S; Hu, J; Inagaki, T; Ito, M; Jain, V; Kabe, S; Kettell, S H; Kitching, P; Kobayashi, M; Komatsubara, T K; Konaka, A; Kuno, Y; Kuriki, M; Li, K K; Littenberg, L S; MacDonald, J A; Meyers, P D; Mildenberger, J; Miyajima, M; Muramatsu, N; Nakano, T; Ng, C; Ng, S; Numao, T; Poutissou, J M; Poutissou, R; Redlinger, G; Sato, T; Shimada, K; Shimoyama, T; Shinkawa, T; Shoemaker, F C; Stone, J R; Strand, R C; Sugimoto, S; Tamagawa, Y; Witzig, C; Yoshimura, Y

    2002-01-01

    Additional evidence for the rare kaon decay K+ to pi+ neutrino-antineutrino has been found in a new data set with comparable sensitivity to the previously reported result. One new event was observed in the pion momentum region examined, 211

  12. Proposed Search for a Fourth Neutrino with a PBq Antineutrino Source

    International Nuclear Information System (INIS)

    Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV2. We show that this hypothesis can be tested with a PBq (ten kilocurie scale) 144Ce or 106Ru antineutrino beta source deployed at the center of a large low background liquid scintillator detector. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unambiguously determine neutrino mass differences and mixing angles.

  13. A side-by-side comparison of Daya Bay antineutrino detectors

    CERN Document Server

    An, F P; Bai, J Z; Balantekin, A B; Band, H R; Beriguete, W; Bishai, M; Blyth, S; Brown, R L; Cao, G F; Cao, J; Carr, R; Chang, J F; Chang, Y; Chasman, C; Chen, H S; Chen, S J; Chen, S M; Chen, X C; Chen, X H; Chen, X S; Chen, Y; Cherwinka, J J; Chu, M C; Cummings, J P; Deng, Z Y; Ding, Y Y; Diwan, M V; Draeger, E; Du, X F; Dwyer, D; Edwards, W R; Ely, S R; Fang, S D; Fu, J Y; Fu, Z W; Ge, L Q; Gill, R L; Gonchar, M; Gong, G H; Gong, H; Gornushkin, Y A; Greenler, L S; Gu, W Q; Guan, M Y; Guo, X H; Hackenburg, R W; Hahn, R L; Hans, S; Hao, H F; He, M; He, Q; He, W S; Heeger, K M; Heng, Y K; Hinrichs, P; Ho, T H; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, T; Hu, T; Huang, H X; Huang, H Z; Huang, P W; Huang, X; Huang, X T; Huber, P; Jaffe, D E; Jetter, S; Ji, X L; Ji, X P; Jiang, H J; Jiang, W Q; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Lai, C Y; Lai, W C; Lai, W H; Lau, K; Lebanowski, L; Lee, M K P; Leitner, R; Leung, J K C; Leung, K Y; Lewis, C A; Li, F; Li, G S; Li, J; Li, Q J; Li, S F; Li, W D; Li, X B; Li, X N; Li, X Q; Li, Y; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, S K; Lin, S X; Lin, Y C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, B J; Liu, D W; Liu, J C; Liu, J L; Liu, S; Liu, X; Liu, Y B; Lu, C; Lu, H Q; Luk, A; Luk, K B; Luo, X L; Ma, L H; Ma, Q M; Ma, X Y; Ma, Y Q; Mayes, B; McDonald, K T; McFarlane, M C; McKeown, R D; Meng, Y; Mohapatra, D; Nakajima, Y; Napolitano, J; Naumov, D; Nemchenok, I; Newsom, C; Ngai, H Y; Ngai, W K; Nie, Y B; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Pagac, A; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Rosero, R; Roskovec, B; Ruan, X C; Seilhan, B; Shao, B B; Shih, K; Steiner, H; Stoler, P; Sun, G X; Sun, J L; Tam, Y H; Tanaka, H K; Tang, X; Torun, Y; Trentalange, S; Tsai, O; Tsang, K V; Tsang, R H M; Tull, C; Viren, B; Vorobel, V; Wang, C H; Wang, L S; Wang, L Y; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Webber, D M; Wei, Y D; Wen, L J; Wenman, D L; Whisnant, K; White, C G; Whitehead, L; Wilhelmi, J; Wise, T; Wong, H L H; Wong, J; Wu, F F; Wu, Q; Xi, J B; Xia, D M; Xiao, Q; Xing, Z Z; Xu, G; Xu, J; Xu, J; Xu, J L; Xu, Y; Xue, T; Yang, C G; Yang, L; Ye, M; Yeh, M; Yeh, Y S; Young, B L; Yu, Z Y; Zhan, L; Zhang, C; Zhang, F H; Zhang, J W; Zhang, Q M; Zhang, S H; Zhang, Y C; Zhang, Y H; Zhang, Y X; Zhang, Z J; Zhang, Z P; Zhang, Z Y; Zhao, H; Zhao, J; Zhao, Q W; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, Y Z; Zhou, Z Y; Zhuang, H L; Zou, J H

    2012-01-01

    The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle $\\theta_{13}$ with a sensitivity better than 0.01 in the parameter sin$^22\\theta_{13}$ at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties exceed requirements.

  14. Neutron \\beta-decay as the origin of IceCube's PeV (anti)neutrinos

    CERN Document Server

    Anchordoqui, Luis A

    2014-01-01

    Motivated by the indications of a possible deficit of muon tracks in the first three-year equivalent dataset of IceCube we investigate the possibility that the astrophysical (anti)neutrino flux (in the PeV energy range) could originate from \\beta-decay of relativistic neutrons. We show that to accommodate IceCube observations it is necessary that only \\sim 10% of the emitted cosmic rays in the energy decade 10^{8.5} \\alt E_{CR}/GeV \\alt 10^{9.5}$, yielding antineutrinos on Earth (10^{5.5} \\alt E_{\\bar \

  15. Light collection and pulse-shape discrimination in elongated scintillator cells for the PROSPECT reactor antineutrino experiment

    International Nuclear Information System (INIS)

    A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron-gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified

  16. Light Collection and Pulse-Shape Discrimination in Elongated Scintillator Cells for the PROSPECT Reactor Antineutrino Experiment

    CERN Document Server

    Ashenfelter, J; Band, H R; Barclay, G; Bass, C D; Berish, D; Bowden, N S; Bowes, A; Brodsky, J P; Bryan, C D; Cherwinka, J J; Chu, R; Classen, T; Commeford, K; Davee, D; Dean, D; Deichert, G; Diwan, M V; Dolinski, M J; Dolph, J; Dwyer, D A; Gaison, J K; Galindo-Uribarri, A; Gilje, K; Glenn, A; Goddard, B W; Green, M; Han, K; Hans, S; Heeger, K M; Heffron, B; Jaffe, D E; Langford, T J; Littlejohn, B R; Caicedo, D A Martinez; McKeown, R D; Mendenhall, M P; Mueller, P; Mumm, H P; Napolitano, J; Neilson, R; Norcini, D; Pushin, D; Qian, X; Romero, E; Rosero, R; Saldana, L; Seilhan, B S; Sharma, R; Sheets, S; Stemen, N T; Surukuchi, P T; Varner, R L; Viren, B; Wang, W; White, B; White, C; Wilhelmi, J; Williams, C; Wise, T; Yao, H; Yeh, M; Yen, Y -R; Zangakis, G; Zhang, C; Zhang, X

    2015-01-01

    A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron/gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell long axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified.

  17. Model-independent determination of the axial mass parameter in quasielastic antineutrino-nucleon scattering

    CERN Document Server

    Bhattacharya, Bhubanjyoti; Tropiano, Anthony J

    2015-01-01

    Understanding the charged current quasielestic (CCQE) neutrino-nucleus interaction is important for precision studies of neutrino oscillations. The theoretical description of the interaction depends on the combination of a nuclear model with the knowledge of form factors. While the former has received considerable attention, the latter, in particular the axial form factor, is implemented using the historical dipole model. Instead, we use a model-independent approach, presented in a previous study, to analyze the muon antineutrino CCQE mineral oil data published by the MiniBooNE collaboration. We combine the cross section for scattering of antineutrinos off protons in carbon and hydrogen, using the same axial form factor for both. The extracted value of the axial mass parameter $m_A = 0.84^{+0.12}_{-0.04} \\pm {0.11} \\, {\\rm GeV}$ is in very good agreement with the model-independent value extracted from MiniBooNE's neutrino data. Going beyond a one-parameter description of the axial form factor, we extract valu...

  18. Simulation results for light propagation in the central detector for the Angra anti-neutrinos experiment

    International Nuclear Information System (INIS)

    Full text: An antineutrino detector to be installed in the surrounding area of the Angra II nuclear reactor in Angra dos Reis is currently under development. The related experiment is intended to create a new tool capable of measuring the antineutrino flux coming from the reactor, making use of detection system placed near the reactor dome, and correlate it to the nuclear fuel fission and burn-up. The proposed detector is a box- shaped volume filled with water doped with 0.2% Gadolinium. The photons generated by the passage of particles are collected by 40 photomultiplier tubes (PMT). Aiming to evaluate the importance of reflecting inner surfaces and to provide directives concerning the best positioning of the PMTs inside the detector, a simulation of light propagation in its active volume has been done. Photons are supposed to be point-like entities traveling in straight lines. In the simulation, we investigate the overall photon counting efficiency by analyzing the number of reflections and the length travelled by the photons before being collected or absorbed, as well as the distribution of these photons in different configurations of the PMTs. Different light reflecting structures around the PMTs are also simulated, in order to find those that reduce the probability for a photon to be bounced back to the direction from which it was emitted. We show that a configuration in which the photon emission direction is preserved may be used as VETO for cosmic events. (author)

  19. New antineutrino energy spectra predictions from the summation of beta decay branches of the fission products

    CERN Document Server

    Fallot, M; Estienne, M; Algora, A; Bui, V M; Cucoanes, A; Elnimr, M; Giot, L; Jordan, D; Martino, J; Onillon, A; Porta, A; Pronost, G; Taín, J L; Yermia, F; Zakari-Issoufou, A -A

    2012-01-01

    In this paper, we study the impact of the inclusion of the recently measured beta decay properties of the $^{102;104;105;106;107}$Tc, $^{105}$Mo, and $^{101}$Nb nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes $^{235, 238}$U, and $^{239,241}$Pu. These actinides are the main contributors to the fission processes in Pressurized Water Reactors. The beta feeding probabilities of the above-mentioned Tc, Mo and Nb isotopes have been found to play a major role in the $\\gamma$ component of the decay heat of $^{239}$Pu, solving a large part of the $\\gamma$ discrepancy in the 4 to 3000\\,s range. They have been measured using the Total Absorption Technique (TAS), avoiding the Pandemonium effect. The calculations are performed using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of $^{235}$U, $^{239,241}$Pu ...

  20. First Observations of Separated Atmospheric Muon Neutrino and Muon Anti-Neutrino Events in the MINOS Detector

    CERN Document Server

    Adamson, P; Allison, W W M; Alner, G J; Anderson, K; Andreopoulos, C; Andrews, M; Andrews, R; Arroyo, C; Avvakumov, S; Ayres, D S; Baller, B; Barish, B; Barker, M A; Barnes, P D; Barr, G; Barrett, W L; Beall, E; Becker, B R; Belias, A; Bergfeld, T; Bernstein, R H; Bhattacharya, D; Bishai, M; Blake, A; Bocean, V; Bock, B; Bock, G J; Bogert, D; Border, P M; Bower, C; Boyd, S; Buckley-Geer, E; Byon-Wagner, A; Böhm, J; Böhnlein, D J; Cabrera, A; Chapman, J D; Chase, T R; Chernichenko, S K; Childress, S; Choudhary, B C; Cobb, J H; Cossairt, J D; Courant, H; Crane, D A; Culling, A J; Dawson, J W; De Muth, D M; De Santo, A; Dierckxsens, M; Diwan, M V; Dorman, M; Drake, G; Ducar, R; Durkin, T; Erwin, A R; Escobar, C O; Evans, J; Fackler, O D; Falk-Harris, E; Feldman, G J; Felt, N; Fields, T H; Ford, R; Frohne, M V; Gallagher, H R; Gebhard, M; Godley, A; Gogos, J; Goodman, M C; Gornushkin, Yu; Gouffon, P; Grashorn, E; Grossman, N; Grudzinski, J J; Grzelak, K; Guarino, V; Habig, A; Halsall, R; Hanson, J; Harris, D; Harris, P G; Hartnell, J; Hartouni, E P; Hatcher, R; Heller, K; Hill, N; Ho, Y; Howcroft, C; Hylen, J; Ignatenko, M A; Indurthy, D; Irwin, G M; James, C; Jenner, L; Jensen, D; Joffe-Minor, T M; Kafka, T; Kang, H J; Kasahara, S M; Kilmer, J; Kim, H; Koizumi, G; Kopp, S; Kordosky, M; Koskinen, D J; Kostin, M; Krakauer, D A; Kumaratunga, S; Ladran, A S; Lang, K; Laughton, C; Lebedev, A; Lee, R; Lee, W Y; Libkind, M A; Litchfield, P J; Litchfield, R P; Liu, J; Longley, N P; Lucas, P; Luebke, W; Madani, S; Maher, E; Makeev, V; Mann, W A; Marchionni, A; Marino, A D; Marshak, M L; Marshall, J S; McDonald, J; McGowan, A; Meier, J R; Merzon, G I; Messier, M D; Michael, D G; Milburn, R H; Miller, J L; Miller, W H; Mishra, S R; Miyagawa, P S; Moore, Cristopher; Morf, J; Morse, R; Mualem, L; Mufson, S; Murgia, S; Murtagh, M J; Musser, J; Naples, D; Nelson, C; Nelson, J K; Newman, H B; Nezrick, F A; Nichol, R J; Nicholls, T C; Ochoa-Ricoux, J P; Oliver, J; Oliver, W P; Onuchin, V A; Osiecki, T; Ospanov, R; Paley, J; Paolone, V; Para, A; Patzak, T; Pavlovich, Z; Pearce, G F; Pearson, N; Peck, C W; Perry, C; Peterson, E A; Petyt, D A; Ping, H; Piteira, R; Pla-Dalmau, A; Plunkett, R K; Price, L E; Proga, M; Pushka, D R; Rahman, D; Rameika, R A; Raufer, T M; Read, A L; Rebel, B; Reyna, D E; Rosenfeld, C; Rubin, H A; Ruddick, K; Ryabov, V A; Saakyan, R; Sanchez, M C; Saoulidou, N; Schneps, J; Schoessow, P V; Schreiner, P; Schwienhorst, R; Semenov, V K; Seun, S M; Shanahan, P; Shield, P D; Smart, W; Smirnitsky, A V; Smith, C; Smith, P N; Sousa, A; Speakman, B; Stamoulis, P; Stefanik, A; Sullivan, P; Swan, J M; Symes, P A; Tagg, N; Talaga, R L; Tetteh-Lartey, E; Thomas, J; Thompson, J; Thomson, M A; Thron, J L; Trendler, R; Trevor, J; Trostin, I; Tsarev, V A; Tzanakos, G S; Urheim, J; Vahle, P; Vakili, M; Vaziri, K; Velissaris, C; Verebryusov, V; Viren, B; Wai, L; Ward, C P; Ward, D R; Watabe, M; Webb, R C; Weber, A; Wehmann, A; West, N; White, C; White, R F; Wojcicki, S G; Wright, D M; Wu, Q K; Yan, W G; Yang, T; Yumiceva, F X; Yun, J C; Zheng, H; Zois, M; Zwaska, R

    2006-01-01

    The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of muon neutrino and muon anti-neutrino charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations giving: R_data(up/down)/R_MC(up/down) = 0.62^{+0.19}_{-0.14} (stat.) +- 0.02 (sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98 % confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field muon neutrino and muon anti-neutrino interactions are separated. The ratio of muon neutrino to muon anti-neutrino events in the data is compared to the Monte Carlo expectation assuming neutrinos and anti-neutrinos osci...

  1. 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.

  2. Status of Development of Antineutrino Detector for Short Baseline Experiment at the HANARO Research Reactor

    International Nuclear Information System (INIS)

    As the burnup proceeds, the neutrino energy spectrum deviates from the initial one. Also the rate of antineutrino production is correlated to the amount of specific fissile elements in the reactor core. By monitoring the antineutrinos during the fission process in the reactor core, scientists can estimate the variation of fissile material. A recent report published by the Department of Safeguards of IAEA also said that a short baseline (SBL) neutrino detector has intrinsic characteristics for monitoring status, operation power and nuclear fuel composition ratio in real time outside the containment building of the nuclear reactor with no-interference mode. Also many reactor neutrino experiments have searched for neutrino flavor oscillation by measuring the electron antineutrinos produced in a nuclear reactor. Since the KamLAND experiments in 2002 gave a precise observation, the neutrino flavor oscillation model has been accepted as an actual phenomenon. One of the interesting issues on reactor neutrino is an anomaly in that an event number of measured neutrinos shows a deficit of 6% compared with the expectation, which means that there should be an undetected sterile neutrino in addition to the known three flavors. It should be created in the flavor oscillations, and does not participate in a weak interaction. The recent high precision and high statistics data from Double Chooz, Daya Bay and RENO experiments may imply this. The research project, which is funded by National Research Foundation of Korea (NRF), started on June, 2012, is developing a short baseline neutrino detector close to the HANARO research reactor, and the technology for reactor monitoring by measuring precisely the neutrino energy spectrum. It is also developing a liquid scintillator containing metals that have large neutron capture cross section, and pulse shape discrimination methods. We will then have a more flexible technology that can detect reactor neutrinos overground. A prototype detector

  3. Status of Development of Antineutrino Detector for Short Baseline Experiment at the HANARO Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gwangmin; Han, Boyoung; Kim, Hongjoo [KAERI, Daejeon(Korea, Republic of); and others

    2014-05-15

    As the burnup proceeds, the neutrino energy spectrum deviates from the initial one. Also the rate of antineutrino production is correlated to the amount of specific fissile elements in the reactor core. By monitoring the antineutrinos during the fission process in the reactor core, scientists can estimate the variation of fissile material. A recent report published by the Department of Safeguards of IAEA also said that a short baseline (SBL) neutrino detector has intrinsic characteristics for monitoring status, operation power and nuclear fuel composition ratio in real time outside the containment building of the nuclear reactor with no-interference mode. Also many reactor neutrino experiments have searched for neutrino flavor oscillation by measuring the electron antineutrinos produced in a nuclear reactor. Since the KamLAND experiments in 2002 gave a precise observation, the neutrino flavor oscillation model has been accepted as an actual phenomenon. One of the interesting issues on reactor neutrino is an anomaly in that an event number of measured neutrinos shows a deficit of 6% compared with the expectation, which means that there should be an undetected sterile neutrino in addition to the known three flavors. It should be created in the flavor oscillations, and does not participate in a weak interaction. The recent high precision and high statistics data from Double Chooz, Daya Bay and RENO experiments may imply this. The research project, which is funded by National Research Foundation of Korea (NRF), started on June, 2012, is developing a short baseline neutrino detector close to the HANARO research reactor, and the technology for reactor monitoring by measuring precisely the neutrino energy spectrum. It is also developing a liquid scintillator containing metals that have large neutron capture cross section, and pulse shape discrimination methods. We will then have a more flexible technology that can detect reactor neutrinos overground. A prototype detector

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-01

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

  5. Development of A Prototype Short Baseline Detector for Antineutrinos from the HANARO Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Eunju; Kim, Jinyu; Kim, Yeongduk [KAERI, Daejeon (Korea, Republic of); and others

    2013-05-15

    The neutrons then cause more fissions, and the daughter nuclei decay emitting an antineutrino with each decay. Because neutrino can penetrate every thick matters composed of heavy concrete, lead and metals and so on, it is considered to be a promising monitoring probe for civil nuclear facilities and nuclear inventories. In fission process of the reactor core, uranium-235 produces antineutrinos in greater abundance than plutonium-239 over a certain energy range. As burnup proceeds, the neutrino energy spectrum deviates from an initial one. Recent report published by the Department of Safeguards of IAEA also said that a short baseline (SBL) neutrino detector has an intrinsic characteristics for monitoring status, operation power, nuclear fuel composition ratio in real time outside the containment building of the nuclear reactor with no-interference mode. Since KamLAND experiments in 2002 gave a precise observation, neutrino flavor oscillation model has been accepted to be an actual phenomenon. One of interesting issues on the reactor neutrino is an anomaly that number of measured neutrinos shows a deficit of 6% comparing with the expectation, which means that there should be an undetected sterile neutrino in addition to the known three flavors. It should be created in the flavor oscillations and does not participate in a weak interaction. The recent high precision and high statistics data from Double Chooz, Daya Bay and RENO experiments may imply it. This research develops a short baseline neutrino detector and the technology for reactor monitoring by measuring precisely the neutrino energy spectrum with a detector located close to the HANARO research reactor. Also it will develop a liquid scintillator containing metals which has large neutron capture cross section, and pulse shape discrimination methods, then we will have a more flexible technology which can detect reactor neutrinos at overground. Reactor antineutrino experiment is under preparation for the

  6. Consistent analysis of neutral- and charged-current (anti)neutrino scattering off carbon

    International Nuclear Information System (INIS)

    Good understanding of the cross sections for (anti)neutrino scattering off nuclear targets in the few-GeV energy region is a prerequisite for the correct interpretation of results of ongoing and planned oscillation experiments. To clarify a possible source of disagreement between recent measurements of the cross sections on carbon, we analyze the available data within an approach based on the realistic spectral function of carbon, treating neutral-current elastic (NCE) and charged-current quasielastic (CCQE) processes on equal footing. We show that the axial mass from the shape analysis of the MiniBooNE data is in good agreement with the results reported by the BNL E734 and NOMAD Collaborations. However, the combined analysis of the NCE and CCQE data does not seem to support the contribution of multinucleon final states being large enough to explain the normalization of the MiniBooNE-reported cross sections

  7. Terrestrial matter effects on reactor antineutrino oscillations at JUNO or RENO-50: how small is small?

    CERN Document Server

    Li, Yu-Feng; Xing, Zhi-zhong

    2016-01-01

    We have carefully examined, in both analytical and numerical ways, how small the terrestrial matter effects can be in a given medium-baseline reactor antineutrino oscillation experiment like JUNO or RENO-50. Taking the ongoing JUNO experiment for example, we show that the inclusion of terrestrial matter effects may reduce the sensitivity of the neutrino mass ordering measurement by \\Delta \\chi^2_{\\rm MO} \\simeq 0.6, and a neglect of such effects may shift the best-fit values of the flavor mixing angle \\theta_{12} and the neutrino mass-squared difference \\Delta_{21} by about 1\\sigma to 2\\sigma in the future data analysis. In addition, a preliminary estimate indicates that a 2\\sigma sensitivity of establishing the terrestrial matter effects can be achieved for about 10 years of data taking at JUNO with the help of a proper near detector implementation.

  8. Nuclear disintegration modes research with missing antineutrino in the Frejus detector

    International Nuclear Information System (INIS)

    The Frejus detector is a 900 tons fine grained calorimeter built in order to look for nucleon decay. It has reached a fiducial sensitivity of 1.3 kt. year after four years of data taking. In this thesis the decay modes with a missing anti-neutrino and one meson are studied. The analyses of all the meson decay channels are described, in particular those where the final state involves only photons or a muon due to K+ decay. The topological and kinematical cuts are different for all the channels; the detection efficiency computed by Monte -Carlo simulation ranges from 10% to 16%. The background is due to atmospheric neutrino interactions in the detector, and is estimated from a simulation. Data are consistent with the calculated background, which is smaller or close to one event per decay channel. Lower nucleon lifetime limits are obtained, which range from 0.9 1031 to 2.9 1031 years

  9. Anharmonicity of internal atomic oscillation and effective antineutrino mass evaluation from gaseous molecular tritium \\beta -decay

    CERN Document Server

    Lokhov, Alexey V

    2016-01-01

    Data analysis of the next generation effective antineutrino mass measurement experiment KATRIN requires reliable knowledge of systematic corrections. In particular, the width of the daughter molecular ion excitation spectrum rovibrational band should be known with a better then 1% precision. Very precise ab initio quantum calculations exist, and we compare them with the well known tritium molecule parameters within the framework of a phenomenological model. The rovibrational band width with accuracy of a few percent is interpreted as a result of the zero-point atomic oscillation in the harmonic potential. The Morse interatomic potential is used to investigate the impact of anharmonic atomic oscillations. The calculated corrections cannot account for the difference between the ab initio quantum calculations and the phenomenological model.

  10. Neutrino Spin-Flavor Conversions and Electron Antineutrino emission from the Sun with Random Magnetic Field

    CERN Document Server

    Semikoz, V B; Popov, V Yu; Rez, A I; Sokoloff, D D

    2000-01-01

    The magnetic field in the solar convective zone has a random small-scale component with the r.m.s. value substancially exceeding the strength of a regular large-scale field. For two Majorana neutrino flavors and two helicities in the presence of a neutrino transition magnetic moment and nonzero neutrino mixing we analize the displacement of the allowed (Delta m^2 - sin^2 2theta)-parameter region reconciled for all Underground experiments with solar neutrinos in dependence on the r.m.s. magnetic field value b. In contrary with the RSFP scenario with a regular large-scale magnetic field, we find an effective production of electron antineutrinos in the Sun even for small neutrino mixing through the cascade conversions like nu_eL -> \\bar{nu}_muR -> forbidden while opening LOW MSW as the allowed one from the non-observation of 100 kG and correlation lengths shorter than L_0 < 1000 km.

  11. SEARCH FOR EXTRATERRESTRIAL ANTINEUTRINO SOURCES WITH THE KamLAND DETECTOR

    International Nuclear Information System (INIS)

    We present the results of a search for extraterrestrial electron antineutrinos (ν-bare's) in the energy range 8.3 MeV ν-bare 8B solar νe's converting into ν-bare's at 5.3 × 10–5 (90% CL), if we assume an undistorted ν-bare shape. This limit corresponds to a solar ν-bare flux of 93 cm–2 s–1 or an event rate of 1.6 events (kton – year)–1 above the energy threshold (Eν-bare>=8.3 MeV). The present data also allows us to set more stringent limits on the diffuse supernova neutrino flux and on the annihilation rates for light dark matter particles.

  12. Four-neutrino analysis of 1.5km-baseline reactor antineutrino oscillations

    CERN Document Server

    Kang, Sin Kyu; Ko, Young-Ju; Siyeon, Kim

    2014-01-01

    The masses of sterile neutrinos are not yet known, and depending on the orders of magnitudes, their existence may explain reactor anomalies or the spectral shape of reactor neutrino events at 1.5km-baseline detector. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements of $\\theta_{13}$ based on the disappearance of reactor antineutrinos at km-order baselines. Our results using 3+1 scheme include the exclusion curve of $\\Delta m^2_{41}$ vs. $\\theta_{14}$ and the adjustment of $\\theta_{13}$ due to correlation with $\\theta_{14}$. The value of $\\theta_{13}$ obtained by RENO and Daya Bay with a three-neutrino oscillation analysis is included in the $1\\sigma$ interval of $\\theta_{13}$ allowed by our four-neutrino analysis.

  13. aCORN: An experiment to measure the electron-antineutrino correlation in neutron decay

    International Nuclear Information System (INIS)

    The aCORN experiment is designed to make a precision (<1%) measurement of the electron-antineutrino angular correlation (a-coefficient) in neutron beta decay. It uses a new method proposed in 1996 by Yerozolimsky and Mostovoy. Electrons and recoil protons from neutron decay in a cold beam are detected in coincidence. The momenta of the particles are selected so that the protons form two kinematically distinct time-of-flight groups as a function of electron energy. The count rate asymmetry in these two groups is proportional to the a-coefficient. Precision spectroscopy of the protons is not required. The apparatus is currently under construction. It will be integrated and tested at the Indiana University Cyclotron Facility (IUCF) and then moved to the NIST Center for Neutron Research for the initial physics run.

  14. Neutrino mass bound in the standard scenario for supernova electronic antineutrino emission

    CERN Document Server

    Pagliaroli, Giulia; Vissani, Francesco

    2010-01-01

    Based on recent improvements of the supernova electron antineutrino emission model, we update the limit on neutrino mass from the SN1987A data collected by Kamiokande-II, IMB and Baksan. We derive the limit of 5.8 eV at 95 % CL, that we show to be remarkably insensitive to the astrophysical uncertainties. Also we evaluate the ultimate mass sensitivity of this method for a detector like Super-Kamiokande. We find that the bound lies in the sub-eV region, 0.8 eV at 95 % CL being a typical outcome, competitive with the values that are presently probed in laboratory. However, this bound is subject to strong statistical fluctuations, correlated to the characteristics of the first few events detected. We briefly comment on the prospects offered by future detectors.

  15. Consistent analysis of neutral- and charged-current (anti)neutrino scattering off carbon

    CERN Document Server

    Ankowski, Artur M

    2013-01-01

    Good understanding of the cross sections for (anti)neutrino scattering off nuclear targets in the few-GeV energy region is a prerequisite for the correct interpretation of results of ongoing and planned oscillation experiments. To clarify a possible source of disagreement between recent measurements of the cross sections on carbon, we analyze the available data within an approach based on the realistic spectral function of carbon, treating neutral-current elastic (NCE) and charged-current quasielastic (CCQE) processes on equal footing. We show that the axial mass from the shape analysis of the MiniBooNE data is in good agreement with the results reported by the BNL E734 and NOMAD Collaborations. However, the combined analysis of the NCE and CCQE data does not seem to support the contribution of multinucleon final states being large enough to explain the normalization of the MiniBooNE-reported cross sections.

  16. Neutrino-Antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis

    Science.gov (United States)

    Fujikawa, Kazuo; Tureanu, Anca

    By adding a neutrino mass term to the Standard Model, which is Lorentz and SU(2) × U(1) invariant but nonlocal to evade CPT theorem, it is shown that nonlocality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at ˜ 10-20 eV, well below the experimental bound bar{K}}| < 0.44 × 10^{-18} GeV.

  17. Measurement of Muon Antineutrino Quasi-Elastic Scattering on a Hydrocarbon Target at E_{\

    CERN Document Server

    Fields, L; Aliaga, L; Altinok, O; Bodek, A; Boehnlein, D; Bradford, R; Brooks, W K; Budd, H; Butkevich, A; Caicedo, D A M; Castromonte, C M; Christy, M E; da Motta, H; Damiani, D S; Danko, I; Datta, M; Day, M; DeMaat, R; Devan, J; Diaz, G A; Dytman, S A; Eberly, B; Edmondson, D A; Felix, J; Fitzpatrick, T; Fiorentini, G A; Gago, A M; Gallagher, H; Gobbi, B; Gran, R; Harris, D A; Higuera, A; Howley, I J; Hurtado, K; Jerkins, M; Kafka, T; Kanter, M O; Keppel, C; Kordosky, M; Krajeski, A H; Kulagin, S A; Le, T; Leister, A G; Maggi, G; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; McGivern, C L; McGowan, A M; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Niculescu, G; Niculescu, I; Ochoa, N; O'Connor, C D; Osta, J; Palomino, J L; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Pena, C; Rakotondravohitra, L; Ransome, R D; Ray, H; Ren, L; Rodrigues, P A; Sassin, K E; Schellman, H; Schmitz, D W; Schneider, R M; Schulte, E C; Sedita, P; Simon, C; Snider, F D; Snyder, M C; Sobczyk, J T; Salinas, C J Solano; Tagg, N; Tan, W; Tice, B G; Tzanakos, G; Velasquez, J P; Walding, J; Walton, T; Wolcott, J; Wolthuis, B A; Zavala, G; Zhang, D; Ziemer, B P

    2013-01-01

    We have isolated muon anti-neutrino charged-current quasi-elastic interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross-section, d{\\sigma}/dQ^2, and compare to several theoretical models of quasi-elastic scattering. Good agreement is obtained with a model where the nucleon axial mass, M_A, is set to 0.99 GeV/c^2 but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross-section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q^2 favor this interpretation over an alternative in which the axial mass is increased.

  18. Study on the 6He β-decay with account for second-class currents and antineutrino mass

    International Nuclear Information System (INIS)

    The effects of the rest mass of electron antineutrino are studied taking into account the induced tensor form factor Ft of second kind current according to the Weinberg classification in the course of 6He nucleus β-decay. The contribution of mν and Ft into the electron-antineutrino angular correlation coefficient Aeν and degree of longitudinal polarization of decay electrons. It is shown that in the case of mν difference from zero independently of second kind current account Aeν coefficient both at the begining and end of the β spectrum asymptotically tends to zero. It is noted that qualitatively new experiments on measurement of the e-ν correlation for pure Gamov-Teller transitions with the 1% accuracy being planned for the nearest future will permit to considerably improve the available estimations by the Ft form factor value

  19. Total neutrino and antineutrino charged current cross section measurements in 100, 160, and 200 GeV narrow band beams

    International Nuclear Information System (INIS)

    Neutrino and antineutrino total charged current cross sections on iron were measured in the 100, 160, and 200 GeV narrow band beams at the CERN SPS in the energy range 10 to 200 GeV. Assuming σ/E to be constant, the values corrected for non-isoscalarity are σν/E=(0.686 ±0.019)x10-38 cm2/(GeV . nucleon) and σν/E=(0.339±0.010)x10-38 cm2/(GeV . nucleon). Between 50 and 150 GeV no energy dependence of σ/E was observed within ±3% for neutrino and ±4% for antineutrino interactions. (orig.)

  20. Comment on Phys. Rev. Lett. 108, 191802 (2012): "Observation of Reactor Electron Antineutrino Disappearance in the RENO Experiment"

    CERN Document Server

    Lasserre, Thierry; Cribier, Michel; Collin, Antoine; Durand, Vincent; Fischer, Vincent; Gaffiot, Jonathan; Lhuillier, David; Letourneau, Alain; Vivier, Matthieu

    2012-01-01

    The RENO experiment recently reported the disappearance of reactor electron antineutrinos consistent with neutrino oscillations, with a significance of 4.9 standard deviations. The published ratio of observed to expected number of antineutrinos in the far detector is R=0.920 +-0.009(stat.) +-0.014(syst.) and corresponds to sin^2 2theta13 = 0.113 +-0.013(stat.) +-0.019(syst), using a rate-only analysis. In this letter we reanalyze the data and we find a ratio R=0.903 +-0.01(stat.), leading to sin^2 2theta13 = 0.135. Moreover we show that the sin^2 2theta13 measurement still depend of the prompt high energy bound beyond 4 MeV, contrarily to the expectation based on neutrino oscillation.

  1. Background for Terrestrial Antineutrino Investigations: Scientific Basis of Knowledge on the Composition of the Deep Interior of the Earth

    OpenAIRE

    Herndon, J. Marvin

    2004-01-01

    I present from a historical perspective a logical progression of understanding, related to the composition of the deep interior of the Earth, that comes from fundamental discoveries and from discoveries of fundamental quantitative relationships in nature. By following step by step the reasoning from that understanding, one might begin to appreciate what is not yet known that pertains to recent interest in geo-antineutrinos and also what should be investigated to further advance that understan...

  2. Film data processing system of the antineutrino experiment in the HYDRA system on the BESM-6 computer

    International Nuclear Information System (INIS)

    Described is the system for mathematical processing of the film data of an antineutrino experiment. The system is based on the HYDRA system with the use of a modular principle. Functionally the mathematical processing system is divided into three parts: primary data processing, geometrical reconstruction of events, and kinematic balance. Use of the said system makes it possible to quickly and efficiently process the film data from measuring devices

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

    CERN Document Server

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

    1999-01-01

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

  4. Neutrino nucleus reactions in the few GeV region

    International Nuclear Information System (INIS)

    We have studied the charged current lepton production induced by neutrinos as well as antineutrinos in 12C and 16O nuclei. The calculations have been done for the quasielastic as well as the inelastic reactions assuming Δ dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of weak transition strengths in the nuclear medium. For the inelastic reaction, the calculations have been done for the incoherent and the coherent processes from nuclear targets. The effect of final state interactions of pions has been taken into account. (author)

  5. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    International Nuclear Information System (INIS)

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  6. Nonstandard interaction effects on neutrino parameters at medium-baseline reactor antineutrino experiments

    International Nuclear Information System (INIS)

    Precision measurements of leptonic mixing parameters and the determination of the neutrino mass hierarchy are the primary goals of the forthcoming medium-baseline reactor antineutrino experiments, such as JUNO and RENO-50. In this work, we investigate the impact of nonstandard neutrino interactions (NSIs) on the measurements of {sin2θ12,Δm212} and {sin2θ13,Δm312}, and on the sensitivity to the neutrino mass hierarchy, at the medium-baseline reactor experiments by assuming a typical experimental setup. It turns out that the true mixing parameter sin2θ12 can be excluded at a more than 3σ level if the NSI parameter εeμ or εeτ is as large as 2% in the most optimistic case. However, the discovery reach of NSI effects has been found to be small, and depends crucially on the CP-violating phases. Finally, we show that NSI effects could enhance or reduce the discrimination power of the JUNO and RENO-50 experiments between the normal and inverted neutrino mass hierarchies

  7. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    International Nuclear Information System (INIS)

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the 102,104,105,106,107Tc, 105Mo, and 101Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes 235,238U, and 239,241Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for 239Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of 238U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics

  8. Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

    International Nuclear Information System (INIS)

    We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic νe and ν-bare fluxes and on the number of events for νe + C12, νe + O16, νe + Ar40 and ν-bare + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

  9. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    International Nuclear Information System (INIS)

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored

  10. Geneva University: Observation of electron-antineutrino disappearance at Daya Bay

    CERN Document Server

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Monday 19 March 2012 COLLOQUE DE PHYSIQUE 5 p.m. - École de Physique, Auditoire Stueckelberg Observation of electron-antineutrino disappearance at Daya Bay  Professor Yifang Wang Institute of High Energy Physics of the Chinese Academy of Sciences Beijing The Daya Bay Reactor Neutrino Experiment, a multinational collaboration operating in the south of China, today reported the first results of its search for the last, most elusive piece of a long-standing puzzle: how is it that neutrinos can appear to vanish as they travel? The surprising answer opens a gateway to a new understanding of fundamental physics and may eventually solve the riddle of why there is far more ordinary matter than antimatter in the Universe today....

  11. Supernova neutrinos and antineutrinos: ternary luminosity diagram and spectral split patterns

    International Nuclear Information System (INIS)

    In core-collapse supernovae, the νe and ν-bar e species may experience collective flavor swaps to non-electron species νx, within energy intervals limited by relatively sharp boundaries (''splits''). These phenomena appear to depend sensitively upon the initial energy spectra and luminosities. We investigate the effect of generic variations of the fractional luminosities (le, lē, lx) with respect to the usual ''energy equipartition'' case (1/6, 1/6, 1/6), within an early-time supernova scenario with fixed thermal spectra and total luminosity. We represent the constraint le+lē+4lx = 1 in a ternary diagram, which is explored via numerical experiments (in single-angle approximation) over an evenly-spaced grid of points. In inverted hierarchy, single splits arise in most cases, but an abrupt transition to double splits is observed for a few points surrounding the equipartition one. In normal hierarchy, collective effects turn out to be unobservable at all grid points but one, where single splits occur. Admissible deviations from equipartition may thus induce dramatic changes in the shape of supernova (anti)neutrino spectra. The observed patterns are interpreted in terms of initial flavor polarization vectors (defining boundaries for the single/double split transitions), lepton number conservation, and minimization of potential energy

  12. Nonstandard interaction effects on neutrino parameters at medium-baseline reactor antineutrino experiments

    CERN Document Server

    Ohlsson, Tommy; Zhou, Shun

    2014-01-01

    Precision measurements of leptonic mixing parameters and the determination of the neutrino mass hierarchy are the primary goals of the forthcoming medium-baseline reactor antineutrino experiments, such as JUNO and RENO-50. In this work, we investigate the impact of nonstandard neutrino interactions (NSIs) on the measurements of {sin^2 theta_{12}, Delta m^2_{21}} and {sin^2 theta_{13}, Delta m^2_{31}}, and on the sensitivity to the neutrino mass hierarchy, at the medium-baseline reactor experiments by assuming a typical experimental setup. It turns out that the true mixing parameter sin^2 theta_{12} can be excluded at a more than 3 sigma level if the NSI parameter varepsilon_{e mu} or varepsilon_{e tau} is as large as 2% in the most optimistic case. However, the discovery reach of NSI effects has been found to be small, and depends crucially on the CP-violating phases. Finally, we show that NSI effects could enhance or reduce the discrimination power of the JUNO and RENO-50 experiments between the normal and i...

  13. Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment

    Science.gov (United States)

    Choi, J. H.; Choi, W. Q.; Choi, Y.; Jang, H. I.; Jang, J. S.; Jeon, E. J.; Joo, K. K.; Kim, B. R.; Kim, H. S.; Kim, J. Y.; Kim, S. B.; Kim, S. Y.; Kim, W.; Kim, Y. D.; Ko, Y.; Lee, D. H.; Lim, I. T.; Pac, M. Y.; Park, I. G.; Park, J. S.; Park, R. G.; Seo, H.; Seo, S. H.; Seon, Y. G.; Shin, C. D.; Siyeon, K.; Yang, J. H.; Yeo, I. S.; Yu, I.; RENO Collaboration

    2016-05-01

    The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν¯e by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν¯e around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν¯e is observed in the deficit of the observed number of ν¯e. Based on the measured far-to-near ratio of prompt spectra, we obtain sin22 θ13=0.082 ±0.009 (stat)±0.006 (syst) and |Δ mee 2|=[2.6 2-0.23+0.21(stat)-0.13+0.12(syst)]×10-3 eV2 .

  14. Earth Radioactivity Measurements with a Deep Ocean Anti-neutrino Observatory

    CERN Document Server

    Dye, S T; Learned, J G; Maricic, J; Matsuno, S; Pakvasa, S; Varner, G; Wilcox, M

    2006-01-01

    We consider the detector size, location, depth, backgrounds, and radio-purity required of a mid-Pacific deep-ocean instrument to accomplish the twin goals of making a definitive measurement of the electron anti-neutrino flux due to uranium and thorium decays from Earth's mantle and core, and of testing the hypothesis for a natural nuclear reactor at the core of Earth. We take the experience with the KamLAND detector in Japan as our baseline for sensitivity and background estimates. We conclude that an instrument adequate to accomplish these tasks should have an exposure of at least 10 kilotonne-years (kT-y), should be placed at least at 4 km depth, may be located close to the Hawaiian Islands (no significant background from them), and should aim for KamLAND radio-purity levels, except for radon where it should be improved by a factor of at least 40. With an exposure of 10 kT-y we should achieve a 24% measurement of the U/Th content of the mantle plus core. Exposure at multiple ocean locations for testing late...

  15. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Burns, Kimberly A.; Campbell, Luke W.; Greenfield, Bryce A.; Kos, Marek S.; Orrell, John L.; Schram, Malachi; VanDevender, Brent A.; Wood, Lynn S.; Wootan, David W.

    2015-03-01

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  16. Data processing and storage in the Daya Bay Reactor Antineutrino Experiment

    CERN Document Server

    He, Miao

    2015-01-01

    The Daya Bay Reactor Antineutrino Experiment reported the first observation of the non-zero neutrino mixing angle $\\theta_{13}$ using the first 55 days of data. It has also provided the most precise measurement of $\\theta_{13}$ with the extended data to 621 days. Daya Bay will keep running for another 3 years or so. There is about 100 TB raw data produced per year, as well as several copies of reconstruction data with similar volume to the raw data for each copy. The raw data is transferred to Daya Bay onsite and two offsite clusters: IHEP in Beijing and LBNL in California, with a short latency. There is quasi-real-time data processing at both onsite and offsite clusters, for the purpose of data quality monitoring, detector calibration and preliminary data analyses. The physics data production took place a couple of times per year according to the physics analysis plan. This paper will introduce the data movement and storage, data processing and monitoring, and the automation of the calibration.

  17. Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam.

    Science.gov (United States)

    Abe, K; Andreopoulos, C; Antonova, M; Aoki, S; Ariga, A; Assylbekov, S; Autiero, D; Barbi, M; Barker, G J; Barr, G; Bartet-Friburg, P; Batkiewicz, M; Bay, F; Berardi, V; Berkman, S; Bhadra, S; Blondel, A; Bolognesi, S; Bordoni, S; Boyd, S B; Brailsford, D; Bravar, A; Bronner, C; Buizza Avanzini, M; Calland, R G; Cao, S; Caravaca Rodríguez, J; Cartwright, S L; Castillo, R; Catanesi, M G; Cervera, A; Cherdack, D; Chikuma, N; Christodoulou, G; Clifton, A; Coleman, J; Collazuol, G; Cremonesi, L; Dabrowska, A; De Rosa, G; Dealtry, T; Denner, P F; Dennis, S R; Densham, C; Dewhurst, D; Di Lodovico, F; Di Luise, S; Dolan, S; Drapier, O; Duffy, K E; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Feusels, T; Finch, A J; Fiorentini, G A; Friend, M; Fujii, Y; Fukuda, D; Fukuda, Y; Furmanski, A P; Galymov, V; Garcia, A; Giffin, S G; Giganti, C; Gizzarelli, F; Gonin, M; Grant, N; Hadley, D R; Haegel, L; Haigh, M D; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, N C; Hayashino, T; Hayato, Y; Helmer, R L; Hierholzer, M; Hillairet, A; Himmel, A; Hiraki, T; Hirota, S; Hogan, M; Holeczek, J; Horikawa, S; Hosomi, F; Huang, K; Ichikawa, A K; Ieki, K; Ikeda, M; Imber, J; Insler, J; Intonti, R A; Irvine, T J; Ishida, T; Ishii, T; Iwai, E; Iwamoto, K; Izmaylov, A; Jacob, A; Jamieson, B; Jiang, M; Johnson, S; Jo, J H; Jonsson, P; Jung, C K; Kabirnezhad, M; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Karlen, D; Karpikov, I; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kikawa, T; Kim, H; Kim, J; King, S; Kisiel, J; Knight, A; Knox, A; Kobayashi, T; Koch, L; Koga, T; Konaka, A; Kondo, K; Kopylov, A; Kormos, L L; Korzenev, A; Koshio, Y; Kropp, W; Kudenko, Y; Kurjata, R; Kutter, T; Lagoda, J; Lamont, I; Larkin, E; Laveder, M; Lawe, M; Lazos, M; Lindner, T; Liptak, Z J; Litchfield, R P; Li, X; Longhin, A; Lopez, J P; Ludovici, L; Lu, X; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Marteau, J; Martin, J F; Martins, P; Martynenko, S; Maruyama, T; Matveev, V; Mavrokoridis, K; Ma, W Y; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Mefodiev, A; Mezzetto, M; Mijakowski, P; Minamino, A; Mineev, O; Mine, S; Missert, A; Miura, M; Moriyama, S; Mueller, Th A; Murphy, S; Myslik, J; Nakadaira, T; Nakahata, M; Nakamura, K G; Nakamura, K; Nakamura, K D; Nakayama, S; Nakaya, T; Nakayoshi, K; Nantais, C; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; Nowak, J; O'Keeffe, H M; Ohta, R; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Ovsyannikova, T; Owen, R A; Oyama, Y; Palladino, V; Palomino, J L; Paolone, V; Patel, N D; Pavin, M; Payne, D; Perkin, J D; Petrov, Y; Pickard, L; Pickering, L; Pinzon Guerra, E S; Pistillo, C; Popov, B; Posiadala-Zezula, M; Poutissou, J-M; Poutissou, R; Przewlocki, P; Quilain, B; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A M; Redij, A; Reinherz-Aronis, E; Riccio, C; Rojas, P; Rondio, E; Roth, S; Rubbia, A; Rychter, A; Sacco, R; Sakashita, K; Sánchez, F; Sato, F; Scantamburlo, E; Scholberg, K; Schoppmann, S; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shah, R; Shaikhiev, A; Shaker, F; Shaw, D; Shiozawa, M; Shirahige, T; Short, S; Smy, M; Sobczyk, J T; Sorel, M; Southwell, L; Stamoulis, P; Steinmann, J; Stewart, T; Suda, Y; Suvorov, S; Suzuki, A; Suzuki, K; Suzuki, S Y; Suzuki, Y; Tacik, R; Tada, M; Takahashi, S; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Terhorst, D; Terri, R; Thakore, T; Thompson, L F; Tobayama, S; Toki, W; Tomura, T; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vacheret, A; Vagins, M; Vallari, Z; Vasseur, G; Wachala, T; Wakamatsu, K; Walter, C W; Wark, D; Warzycha, W; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilkinson, C; Wilson, J R; Wilson, R J; Yamada, Y; Yamamoto, K; Yamamoto, M; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Yoo, J; Yoshida, K; Yuan, T; Yu, M; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Żmuda, J

    2016-05-01

    T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K. PMID:27203315

  18. First Anti-neutrino Oscillation Results from the T2K Experiment

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Neutrinos are some of the most abundant but yet most elusive particles in the universe. They have almost no mass, only interact weakly and relatively little is known about their properties. Furthermore it has been firmly established over the last decade that neutrinos can undergo flavour transitions as mass and flavor eigenstates are not identical. These neutrino oscillations have been studied using natural sources as well as nuclear reactors or with neutrinos produced at accelerators. T2K is a long baseline neutrino oscillation beam that uses a beam of muon (anti-)neutrinos that is directed form J-PARC at the east cost of Japan over a distance of almost 300 km to the SuperKamiokande water Cherenkov detector in the west. The facility is complemented by a near detector complex 280 m downstream of the neutrino production target to characterise the beam and the neutrino interaction dynamics. T2K has taken data with a muon neutrino beam since early 2010 and is studying the disappearance of muon neutrinos as well...

  19. Neutrino-antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis

    CERN Document Server

    Fujikawa, Kazuo

    2015-01-01

    By adding a neutrino mass term to the Standard Model, which is Lorentz and $SU(2)\\times U(1)$ invariant but non-local to evade $CPT$ theorem, it is shown that non-locality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at $\\sim 10^{-20}$ eV, well below the experimental bound $< 10^{-2}$ eV. The induced $CPT$ violation in the $K$-meson in the Standard Model is expected to be even smaller and well below the experimental bound $|m_{K}-m_{\\bar{K}}|<0.44\\times 10^{-18}$ GeV.

  20. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    Energy Technology Data Exchange (ETDEWEB)

    Estienne, M., E-mail: magali.estienne@subatech.in2p3.fr [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, F-44307 Nantes (France); Fallot, M.; Cormon, S. [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, F-44307 Nantes (France); Algora, A. [IFIC (CSIC-Univ. Valencia), Valencia (Spain); Institute of Nuclear Research, Debrecen (Hungary); Bui, V.M.; Cucoanes, A.; Elnimr, M.; Giot, L. [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, F-44307 Nantes (France); Jordan, D. [IFIC (CSIC-Univ. Valencia), Valencia (Spain); Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A. [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, F-44307 Nantes (France); Taín, J.L. [IFIC (CSIC-Univ. Valencia), Valencia (Spain); Yermia, F.; Zakari-Issoufou, A.-A. [SUBATECH, CNRS/IN2P3, Université de Nantes, Ecole des Mines de Nantes, F-44307 Nantes (France)

    2014-06-15

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes {sup 235,238}U, and {sup 239,241}Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for {sup 239}Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of {sup 238}U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.

  1. π0, rho0 ω0 production in high energy neutrino and antineutrino interactions

    International Nuclear Information System (INIS)

    The work presented in this thesis is concerned with the hadronic shower in the neutrino and antineutrino interactions of the high energy charged-current type. The π0 particles issued from this hadronic shower are analysed and the rho0 and ω0 production rate are determined in view to try to understand the quark fragmentation process, that is to say the QCD theory relative to the quark confinement problem. The experimental device is described in the chapter II. Chapter III is dealing with the analysis of the exposures obtained with this device, together with the incident neutrino energy determination methods and a general description of the final data characteristics. The π0 production is studied from the decay γ observed in the bubble chamber. The existing different methods are analyzed and compared with the used one. The π0 properties are studied in detail. In chapter 5, the rho0 and ω0 resonance production rate is calculated, using the previous chapter results. Finally, chapter 6 summarizes the thesis conclusions

  2. The diffuse neutrino flux from supernovae: upper limit on the electron neutrino component from the non-observation of antineutrinos at SuperKamiokande

    CERN Document Server

    Lunardini, C

    2006-01-01

    I derive an upper bound on the electron neutrino component of the diffuse supernova neutrino flux from the constraint on the antineutrino component at SuperKamiokande. The connection between antineutrino and neutrino channels is due to the similarity of the muon and tau neutrino and antineutrino fluxes produced in a supernova, and to the conversion of these species into electron neutrinos and antineutrinos inside the star. The limit on the electron neutrino flux is 5.5 cm^-2 s^-1 above 19.3 MeV of neutrino energy, and is stronger than the direct limit from LSD by three orders of magnitude. It represents the minimal sensitivity required at future direct searches, and is intriguingly close to the reach of the SNO and ICARUS experiments. The electron neutrino flux will have a lower bound if the electron antineutrino flux is measured. Indicatively, the first can be smaller than the second at most by a factor of 2-3 depending on the details of the neutrino spectra at production.

  3. Adaptation of the kinematic program for an antineutrino experiment in the ''HYDRA'' system With the BESM-6 computer

    International Nuclear Information System (INIS)

    A KINEMATIKA program is structurally described and is aimed at kinematic fitting of V0-particles and γ-quanta in each event studied during anti-neutrino experiment. The program contains 17 modules and, due to the fact that it exceeds main memory of the BESM-6 computer, the program has been divided into seven segments. Each segment is briefly described. A computer time to process an event with up to four hypotheses on the type of interaction does not exceed 30-40 seconds

  4. A method for an improved measurement of the electron-antineutrino correlation in free neutron beta decay

    International Nuclear Information System (INIS)

    The angular correlation between the beta electron and antineutrino in nuclear beta decay is characterized by the dimensionless parameter a. The value of a for free neutron decay, when combined with other neutron decay parameters, can be used to determine the weak vector and axial vector coupling constants gV and gA and test the validity and self-consistency of the Electroweak Standard Model. Previous experiments that measured a in neutron decay relied on precise proton spectroscopy and were limited by systematic effects at about the 5% level. We present a new approach to measuring a for which systematic uncertainties promise to be much smaller

  5. Search for sub-eV sterile neutrinos in the precision multiple baselines reactor antineutrino oscillation experiments

    Directory of Open Access Journals (Sweden)

    Shu Luo

    2015-10-01

    Full Text Available According to different effects on neutrino oscillations, the unitarity violation in the MNSP matrix can be classified into the direct unitarity violation and the indirect unitarity violation which are induced by the existence of the light and the heavy sterile neutrinos respectively. Of which sub-eV sterile neutrinos are of most interesting. We study in this paper the possibility of searching for sub-eV sterile neutrinos in the precision reactor antineutrino oscillation experiments with three different baselines at around 500 m, 2 km and 60 km. We find that the antineutrino survival probabilities obtained in the reactor experiments are sensitive only to the direct unitarity violation and offer very concentrated sensitivity to the two parameters θ14 and Δm412. If such light sterile neutrinos do exist, the active–sterile mixing angle θ14 could be acquired by the combined rate analysis at all the three baselines and the mass-squared difference Δm412 could be obtained by taking the Fourier transformation to the L/E spectrum. Of course, for such measurements to succeed, both high energy resolution and large statistics are essentially important.

  6. Global Analysis of the Source and Detector Nonstandard Interactions Using the Short Baseline Neutrino- and Antineutrino-Electron Scattering Data

    CERN Document Server

    Khan, Amir N

    2016-01-01

    We present a global analysis of the semileptonic and purely Leptonic nonuniversal and flavor-changing nonstandard neutrino interactions in all the known short-baseline neutrino- and antineutrino-electron scattering experiments. The nonstandard effects at the source and at the detector can be more transparent in these experiments because of the negligibly small ratio between the baselines and the neutrino energies, which is not enough for the neutrinos to oscillate, and thus can be sensitive to the new physics at the both ends. We use data from two electron-neutrino electron scattering experiments and six electron-antineutrino electron scattering experiments and combine them to find the best fits on the nonstandard parameters using the source-only, detector-only analyses, and then find the interplay between the two cases. The bounds obtained in some cases are stronger and new, in some cases comparable to the current ones, and in the other cases weaker. For instance, the bound obtained from the interplay betwee...

  7. Messung der Impulsverteilung der Antiquarks im Nukleon aus der inklusiven tiefinelastischen Antineutrino Nukleon Reaktion ueber geladene Stroeme

    CERN Document Server

    Klasen, Hans Peter

    1981-01-01

    In this thesis the antiquark momentum distribution in the nucleus as a function of x and Q2 is determined. This determination is based on the measurement of the differential cross-section at high y for inclusive antineutrino nucleon charged current interactions. The portion of antineutrino scattering off quarks is corrected by the also measured neutrino cross-section. For the measurement of the cross-section 150 000 anti v- und 35 000 v-events, which were produced in the CERN wide band beam, in the energy range from 20 GeV to 160 GeV and 27 000 anti v- and 63 000 v-events measured in the narrow band beam in the energy range from 20 GeV to 200 GeV are used. The measurement was performed with the detector of the CERN-Dortmund-Heidelberg-Saclay collaboration. The detector serves at the same time as target, as hadron energy calorimeter and as muon spectrometer. The measured antiquark momentum distribution shows a strong rise for x<0.1 as a function of Q2. It will be shown that this scaling violation cannot be ...

  8. Measurement of the mixing leptonic parameter θ13 at the Double Chooz reactor antineutrino experiment

    International Nuclear Information System (INIS)

    The Double Chooz experiment aims at measuring the neutrino mixing parameter θ13 by studying the oscillations of de ν-bare produced by the Chooz nuclear reactors located in France. The experimental concept consists in comparing the signal of two identical 10.3 m3 detectors, allowing to cancel most of the experimental systematic uncertainties. The near detector, whose goal is the flux normalization and a measurement without oscillation, is expected to be delivered in 2013. The farthest detector from the source is taking data since April 2011 and is sensitive to θ13, which is expected to affect both the rate and the shape of the measured de ν-bare. In this thesis, are first presented the Double Chooz experiment, with its ν-bare source, its detection method, and the expected signal and backgrounds. In order to perform a selection, important quantities have to be reconstructed, calibrated, and saved in data files. The channel time offsets determination, the energy and vertex reconstruction algorithm CocoReco, the reconstruction packages of the Common Trunk, and the light trees maker Cheetah are especially presented. Concerning the data analysis, all the selection cuts and results for signal and backgrounds are discussed, particularly the multiplicity cut, the multiple off time window method, the lithium veto cut, and the cosmogenic 9Li background studies. The Double Chooz experiment observed 8,249 de -bare candidates in 227.93 days in its far detector only. The reactor antineutrino flux prediction used the Bugey 4 flux measurement after correction for differences in core composition. The expectation in case of no-oscillation is 8,937 events and this deficit is interpreted as evidence for ν-bare disappearance. From a rate and shape analysis, is found sin22θ = 0,109± 0,030 (stat) ± 0,025 (syst), with Δm231 = 2,32 x 10-3 eV2, while the no-oscillation hypothesis is even excluded at 2.9 σ. (author)

  9. Anti-Neutrino Charged Current Quasi-Elastic Scattering in MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Chvojka, Jesse John [Univ. of Rochester, NY (United States)

    2012-01-01

    in neutrino interactions. We present the first cross-section measurement for MINER A, the differential cross-section dσ/dQ2 for muon anti-neutrino CCQE scattering on polystyrene scintillator (CH) as well as comparisons to several final state models.

  10. Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for 235U (n ,fission) at Thermal and Fast Neutron Energies

    Science.gov (United States)

    Sonzogni, A. A.; McCutchan, E. A.; Johnson, T. D.; Dimitriou, P.

    2016-04-01

    Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 235U 235 fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of 86Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel.

  11. Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for ^{235}U(n,fission) at Thermal and Fast Neutron Energies.

    Science.gov (United States)

    Sonzogni, A A; McCutchan, E A; Johnson, T D; Dimitriou, P

    2016-04-01

    Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 ^{235}U fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of ^{86}Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel. PMID:27081973

  12. Muon storage rings for a beam-systematic-free measurement of neutrino and antineutrino cross-sections at low energy

    CERN Document Server

    Navas-Concha, S

    2002-01-01

    Precision neutrino cross-section measurements at low energies will be necessary to improve the results of the current and future big neutrino experiments. In order to achieve precision neutrino cross- sections, that will yield a comprehensive understand of the underlying physics, a rather extended program will be required: (1) measurement from kinematical thresholds up to a few GeV; (2) well known and controlled neutrino flux; (3) study of neutrinos and antineutrinos and possibly nu /sub e/ and nu /sub mu / flavors; (4) on several nuclear target; (5) with detectors capable of exclusive final state reconstruction. While the "standard" choice advocated relies on currently existing or on future "traditional" neutrino beams, that will provide very high intensities at near sites, we advocate that neutrinos from muon storage rings provide a better choice to criterias (1)-(3). The currently available statistics from the CERN AD and the FNAL-Debuncher would provide statistical precisions better than 10% in typ. 200 M...

  13. Anharmonicity of internal atomic oscillation and effective antineutrino mass evaluation from gaseous molecular tritium β-decay

    Science.gov (United States)

    Lokhov, Alexey V.; Titov, Nikita A.

    2016-07-01

    Data analysis of the next-generation effective antineutrino mass measurement experiment KATRIN requires reliable knowledge of systematic corrections. In particular, the width of the daughter molecular ion excitation spectrum rovibrational band should be known with better than 1% precision. Very precise ab initio quantum calculations exist, and we compare them with the well-known tritium molecule parameters within the framework of a phenomenological model. The rovibrational band width with accuracy of a few percent is interpreted as a result of the zero-point atomic oscillation in the harmonic potential. The Morse interatomic potential is used to investigate the impact of anharmonic atomic oscillations. The calculated corrections cannot account for the difference between the ab initio quantum calculations and the phenomenological model.

  14. Electron Antineutrino Disappearance at KamLAND and JUNO as Decisive Tests of the Short Baseline Anti-nu_mu to Anti-nu_e Appearance Anomaly

    CERN Document Server

    Conrad, J M

    2013-01-01

    The IsoDAR antineutrino source, which produces a flux from 8Li isotope decay at rest, when paired with the proposed JUNO (Jiangmen Underground Neutrino Observatory) detector, has unprecedented sensitivity to anti-nu_e disappearance for oscillations at high Delta m^2. Assuming CPT invariance, the sensitive region for anti-nu_e disappearance can be used to restrict the allowed parameter space of an anti-nu_mu to anti-nu_e appearance signal. The 5 sigma sensitivity of this experiment covers the entire anti-nu_mu to anti-nu_e allowed parameter space from a combined fit to short-baseline experiments. This represents a decisive test of the LSND and MiniBooNE antineutrino appearance signals within all models that are $CPT$ invariant. Running IsoDAR at KamLAND restricts a large part of the appearance signal region in a similar way.

  15. Analytical orbit calculation of the INS air-core π√2 β-ray spectrometer for the measurement of electron anti-neutrino mass

    International Nuclear Information System (INIS)

    For the measurement of electron anti-neutrino rest mass with the INS air-core(iron-free) β-ray spectrometer, the orbit calculations were carried out for the case of simultaneous use of an extended source and a position-sensitive electron counter. Analytical calculation up to the 3rd-order approximation results in design parameters of 16cm x 7cm source area, 0.095% transmission, 4% momentum acceptance and 67.60 and 4.190 tilt angles of the source and the detector planes, respectively, for 0.05% momentum resolution. These values imply a 7 times larger sensitivity to the electron anti-neutrino mass than in the recent experiment by ITEP group. (author)

  16. Off-shell effects in the relativistic mean field model and their role in CC (anti)neutrino scattering at MiniBooNE kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, M.V., E-mail: martin.inrne@gmail.com [Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, CEI Moncloa, Madrid E-28040 (Spain); Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); González-Jiménez, R.; Caballero, J.A. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Barbaro, M.B. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, 10125 Torino (Italy); Donnelly, T.W. [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Udías, J.M. [Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, CEI Moncloa, Madrid E-28040 (Spain)

    2013-11-25

    The relativistic mean field (RMF) model is used to describe nucleons in the nucleus and thereby to evaluate the effects of having dynamically off-shell spinors. Compared with free, on-shell nucleons as employed in some other models, within the RMF nucleons are described by relativistic spinors with strongly enhanced lower components. In this work it is seen that for MiniBooNE kinematics, neutrino charged-current quasielastic cross sections show some sensitivity to these off-shell effects, while for the antineutrino-nucleus case the total cross sections are seen to be essentially independent of the enhancement of the lower components. As was found to be the case when comparing the RMF results with the neutrino-nucleus data, the present impulse approximation predictions within the RMF also fall short of the MiniBooNE antineutrino-nucleus data.

  17. Neutrino neutral current reactions in 12C

    Science.gov (United States)

    Parthasarathy, R.; Yesudian, Premkumar

    1985-05-01

    The differential and total cross sections for the nuclear reaction ν μ + 12C (g.s) → 12C ∗ (1 +; T = 1, 15.1 MeV) + νμ are investigated for values of 50 ≤ Eνμ ≤ 300 MeV. An effective Hamiltonian for the above nuclear reaction is constructed from the neutrino-quark neutral current weak interaction, by first constructing the neutrino-nucleon neutral current interaction and then using the impulse approximation along with the non-relativistic reduction procedure. The Weinberg-Salam model is the basis of the calculations. Detailed expressions for the differential cross sections are derived including the nucleon momentum-dependent terms. The numerical results are obtained using the general 1 p-shell wavefunctions of Cohen and Kurath. The sensitivity of the total cross sections to the nuclear models and to the Weinberg angle is studied. The corresponding anti-neutrino reaction is also investigated. The ratio R = (σ Tν μ - σ Toverlineνμ) /(σ Tν μ + σ Toverlineνμ) is found to be independent of the nuclear wavefunctions but very sensitive to the Weinberg angle. Thus this observable can be used to determine the free parameter θw in a nuclear reaction, thereby complementing the studies involving free nucleons. The recoil polarization of the final nucleus 12C ∗(1 +; T = 1, 15.1 MeV) is also studied and its importance is pointed out.

  18. Les expériences Nucifer et Stéréo : étude des antineutrinos de réacteurs à courte distance

    OpenAIRE

    Pequignot, Maxime

    2015-01-01

    In spite of a faint interaction with their environment, neutrinos can be now clearly detected thanks to a proven technology based on liquid scintillators and photomultiplier tubes. The advances made these last years allow to reduce the size and the complexity of the detectors and therefore naturally lead to the first applications with these particles. As the first experiment to be placed at 7.2 m of a nuclear core, the Nucifer detector demonstrates the possibility of counting antineutrinos co...

  19. CeLAND: search for a 4th light neutrino state with a 3 PBq 144Ce-144Pr electron antineutrino generator in KamLAND

    CERN Document Server

    Gando, A; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Ishikawa, H; Koga, M; Matsuda, R; Matsuda, S; Mitsui, T; Motoki, D; Nakamura, K; Oki, Y; Otani, M; Shimizu, I; Shirai, J; Suekane, F; Suzuki, A; Takemoto, Y; Tamae, K; Ueshima, K; Watanabe, H; Xu, B D; Yamada, S; Yamauchi, Y; Yoshida, H; Cribier, M; Durero, M; Fischer, V; Gaffiot, J; Jonqueres, N; Kouchner, A; Lasserre, T; Leterme, D; Letourneau, A; Lhuillier, D; Mention, G; Rampal, G; Scola, L; Veyssiere, Ch; Vivier, M; Yala, P; Berger, B E; Kozlov, A; Banks, T; Dwyer, D; Fujikawa, B K; Han, K; Kolomensky, Yu G; Mei, Y; O'Donnell, T; Decowski, P; Markoff, D M; Yoshida, S; Kornoukhov, V N; Gelis, T V M; Tikhomirov, G V; Learned, J G; Maricic, J; Matsuno, S; Milincic, R; Karwowski, H J; Efremenko, Y; Detwiler, A; Enomoto, S

    2013-01-01

    The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) 144Ce-144Pr antineutrino beta-source deployed at the center or next to a large low-background liquid scintillator detector. The antineutrino generator will be produced by the Russian reprocessing plant PA Mayak as early as 2014, transported to Japan, and deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015. KamLAND's 13 m diameter target volume provides a suitable environment to measure the energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile neutrino state. This will provide a comprehensive test of the electron dissaperance neutrino anomalies and could lead to the discovery of a 4th neutrino state for Delta_m^2 > 0.1 eV^2 and sin^2(2theta) > 0.05.

  20. Precise Measurement of Dimuon Production Cross-Sections in muon neutrino Fe and muon antineutrino Fe Deep Inelastic Scattering at the Tevatron

    CERN Document Server

    Goncharov, M; Alton, A; Bolton, T; Goldman, J; Spentzouris, P; Conrad, J; Fleming, B T; Formaggio, J A; Koutsoliotas, S; Kim, J H; McNulty, C; Romosan, A; Shaevitz, M H; Stern, E G; Vaitaitis, A G; Zimmerman, E D; Johnson, R A; Vakili, M; Suwonjandee, N; Bernstein, R H; Bugel, L; Lamm, M J; Marsh, W; Nienaber, P; Yu, J; De Barbaro, L; Buchholz, D; Schellman, H; Zeller, G P; Brau, J E; Drucker, R B; Frey, R; Mason, D; McDonald, J E; Naples, D; Tzanov, M; Avvakumov, S; De Barbaro, P; Bodek, Arie; Budd, H S; Harris, D A; McFarland, K S; Sakumoto, W K; Yang, U K

    2001-01-01

    We present measurements of the semi-inclusive cross-sections for muon neutrino and muon antineutrino-nucleon deep inelastic scattering interactions with two oppositely charged muons in the final state. These events dominantly arise from production of a charm quark during the scattering process. The measurement was obtained from the analysis of 5102 muon neutrino-induced and 1458 muon antineutrino-induced events collected with the NuTeV detector exposed to a sign-selected beam at the Fermilab Tevatron. We also extract a cross-section measurement from a re-analysis of 5030 muon neutrino-induced and 1060 muon antineutrino-induced vents collected from the exposure of the same detector to a quad-triplet beam by the CCFR experiment. The results are combined to obtain the most statistically precise measurement of neutrino-induced dimuon production cross-sections to date. These measurements should be of broad use to phenomenologists interested in the dynamics of charm production, the strangeness content of the nucleo...

  1. Single photon production induced by (anti)neutrino neutral current scattering on nucleons and nuclear targets

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Ruso, L.; Nieves, J. [Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, E-46071 Valencia (Spain); Wang, E. [Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, E-46071 Valencia (Spain); Department of Physics, Zhengzhou University, Zhengzhou, Henan 450001 (China)

    2015-10-15

    We review our theoretical approach to neutral current photon emission on nucleons and nuclei in the few-GeV energy region, relevant for neutrino oscillation experiments. These reactions are dominated by the weak excitation of the Δ(1232) resonance but there are also important non-resonant contributions. We have also included terms mediated by nucleon excitations from the second resonance region. On nuclei, Pauli blocking, Fermi motion and the in-medium Δ resonance broadening have been taken into account for both incoherent and coherent reaction channels. With this model, the number and distributions of photon events at the MiniBooNE and T2K experiments have been obtained. We have also compared to the NOMAD upper limit at higher energies. The implications of our findings and future perspectives are discussed.

  2. Single photon production induced by (anti)neutrino neutral current scattering on nucleons and nuclear targets

    International Nuclear Information System (INIS)

    We review our theoretical approach to neutral current photon emission on nucleons and nuclei in the few-GeV energy region, relevant for neutrino oscillation experiments. These reactions are dominated by the weak excitation of the Δ(1232) resonance but there are also important non-resonant contributions. We have also included terms mediated by nucleon excitations from the second resonance region. On nuclei, Pauli blocking, Fermi motion and the in-medium Δ resonance broadening have been taken into account for both incoherent and coherent reaction channels. With this model, the number and distributions of photon events at the MiniBooNE and T2K experiments have been obtained. We have also compared to the NOMAD upper limit at higher energies. The implications of our findings and future perspectives are discussed

  3. Measurement of Neutrino and Antineutrino Charged-Current Inclusive Cross Sections with the MINERvA Detector

    Energy Technology Data Exchange (ETDEWEB)

    Devan, Joshua D. [College of William and Mary, Williamsburg, VA (United States)

    2015-01-01

    Neutrinos are a nearly massless, neutral particle in the Standard Model that only interact via the weak interaction. Experimental confirmation of neutrino oscillations, in which a neutrino created as a particular type (electron, muon or tau) can be observed as a different type after propagating some distance, earned the 2015 Nobel Prize in Physics. Neutrino oscillation experiments rely on accurate measurements of neutrino interactions with matter, such as that presented here. Neutrinos also provide a unique probe of the nucleus, complementary to electron scattering experiments. This thesis presents a measurement of the charged-current inclusive cross section for muon neutrinos and antineutrinos in the energy range 2 to 50 GeV with the MINERvA detector. MINERvA is a neutrino scattering experiment in the NuMI neutrino beam at Fermilab, near Chicago. A cross section measures the probability of an interaction occurring, measured here as a function of neutrino energy. To extract a cross section from data, the observed rate of interactions is corrected for detector efficiency and divided by the number of scattering nucleons in the target and the flux of neutrinos in the beam. The neutrino flux is determined with the low-$\

  4. Neutral current quasielastic (anti)neutrino scattering beyond the Fermi gas model at MiniBooNE and BNL kinematics

    CERN Document Server

    Ivanov, M V; Barbaro, M B; Giusti, C; Meucci, A; Caballero, J A; Gonzalez-Jimenez, R; de Guerra, E Moya; Udias, J M

    2015-01-01

    Neutral current quasielastic (anti)neutrino scattering cross sections on a $^{12}$C target are analyzed using a realistic spectral function $S(p,E)$ that gives a scaling function in accordance with the ($e,e'$) scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals (NOs) from the Jastrow correlation method and has a realistic energy dependence. The standard value of the axial mass $M_A= 1.032$ GeV is used in all calculations. The role of the final-state interaction (FSI) on the spectral and scaling functions, as well as on the cross sections is accounted for. A comparison of the calculations with the empirical data of the MiniBooNE and BNL experiments is performed. Our results are analyzed in comparison with those when NN correlations are not included, and also with results from other theoretical approaches, such as the relativistic Fermi gas (RFG), the relativistic mean field (RMF), the relativistic Green's function (RGF), as well as with the Super...

  5. Monte-Carlo simulations on the antineutrino detection in heavy ion collisions

    International Nuclear Information System (INIS)

    Aim of the present thesis was to study, how far a large-area neutron detector with high efficiency operated at the Corporation for Heavy Ion Research in Darmstadt can also by applied for experiments on the sub-threshold antineutron production in heavy ion reactions for the study of the equation of state of highly excited nuclear matter. The experimental part consisted in the partition at the construction, the taking into operation, and the calibration measurements of the target-detector system, as well at the experiments with the LAND detector for the study of the Coulomb excitation of 136Xe projectiles in the reaction 136Xe+208Pb at 700 respectively 800 MeV/u. Studies on the suppression of neutron events against antineutron events in the data acquisition in a typical SIS/LAND experiment on the antineutron production in heavy ion collisions were performed. The possibilities available on the level of the hardware trigger for the suppression of (multiple) neutron events were studied. Thereby resulted a reachable suppression factor of ≅ 10-3. Studies on the off-line analysis of antineutron events exhibited problems, which base on the high matter density in the detector. (orig./HSI)

  6. Study of the neutral current properties in the semileptonic inclusive neutrino and antineutrino nucleon interaction

    International Nuclear Information System (INIS)

    In the dechromatic neutron beam of the CERN-SPS results obtained with the CHARM detector from the deep inelastic inclusive neutrino-nucleon scattering were analyzed according to following reactions: #betta#sub(μ)(anti #betta#sub(μ))+N->μ-(μ+) + hadrons and #betta#sub(μ)(anti #betta#sub(μ))+N->#betta#sub(μ)(anti #betta#sub(μ)) + hadrons. The aim of these studies was the determination of the coupling of neutral currents in the weak interaction. All data can be well described by the standard model for the unification of the electrogmagnetic and weak interaction in connection with the quarkparton model, if a Weinberg angle of sin2deltasub(w)=0.222+-0.016 is assumed. (orig./HSI)

  7. Untersuchung der Eigenschaften neutraler Stroeme in der semileptonischen inklusiven Neutrino und Antineutrino Nukleon Wechselwirkung

    CERN Document Server

    Kroger, Bernd

    1981-01-01

    In the dechromatic neutron beam of the CERN-SPS results obtained with the CHARM detector from the deep inelastic inclusive neutrino-nucleon scattering were analyzed according to following reactions: #betta#sub(μ)(anti #betta#sub(μ))+N->μ-(μ+) + hadrons and #betta#sub(μ)(anti #betta#sub(μ))+N->#betta#sub(μ)(anti #betta#sub(μ)) + hadrons. The aim of these studies was the determination of the coupling of neutral currents in the weak interaction. All data can be well described by the standard model for the unification of the electrogmagnetic and weak interaction in connection with the quarkparton model, if a Weinberg angle of sin2deltasub(w)=0.222+-0.016 is assumed. (orig./HSI)

  8. Measurements of cross-section of charge current inclusive of antineutrino scattering off nucleons using carbon, iron, lead and scintillator at MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Rakotondravohitra, Laza [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-08-18

    Neutrino physics is one of the most active fields in the domaine of high energy physics during the last century. The need of precise measurement of neutrino-nucleus interactions required by the neutrino oscillation experiments is a an exiting step. These measurements of cross-section are more than essential for neutrino oscillation experiment. Over the year, many measurements from varieties of experiments have been presented. MINERνA is one of the world leaders in measuring cross-section of neutrino and antineutrino -nucleus interactions. MINERνA is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. In order to study nuclear dependence, MINERνA is endowed with different types of solid nuclear targets as well are liquid targets such as helium and water. This thesis presents measurements of cross-section of antineutrino scattering off nucleons using a variety of solid nuclear targets, carbon, iron, lead and also polystyrene scintillator (CH). The data set of antineutrino used for this analysis was taken between March and July 2010 with a total of 1.60X1020 protons on target. Charged current inclusive interactions were selected by requiring a positive muon and kinematics limitation of acceptance of the muon spectrometer are applied. The analysis requires neutrino energy between 2GeV et 20GeV and the angle of muon θmu < 17degree . The absolute cross-section # as function of neutrino energy and the differential cross-section dσ/ dxbj measured and shown the corresponding systematics for each nuclear targets. Data results are compared with prediction of the models implemented in the neutrino events generators GENIE 2.6.2 used by the experiment.

  9. Reactor anti-neutrinos: measurement of the θ13 leptonic mixing angle and search for potential sterile neutrinos

    International Nuclear Information System (INIS)

    The Double Chooz experiment aims to measure the θ13 mixing angle through the disappearance -induced by the oscillation phenomenon - of anti-neutrinos produced by the Chooz nuclear reactors. In order to reduce systematic uncertainties, the experiment relies on the relative comparison of detected signals in two identical liquid scintillator detectors. The near one, giving the normalization of the emitted flux, is currently being built and will be delivered in spring 2014. The far detector, sensitive to θ13, is located at about one kilometer and is taking data since 2011. In this first phase of the experiment, the far detector data are compared to a prediction of the emitted neutrino flux to estimate θ13. In this thesis, the Double Chooz experiment and its analysis are presented, especially the background studies and the rejection of parasitic signals due to light emitted by photo-multipliers. Neutron fluxes between the different detector volumes impact the definition of the fiducial volume of neutrino interactions and the efficiency of detection. Detailed studies of these effects are presented. As part of the Double Chooz experiment, studies were performed to improve the prediction of neutrino flux emitted by reactors. This work revealed a deficit of observed neutrino rates in the short baseline experiments of last decades. This deficit could be explained by an oscillation to a sterile state. The Stereo project aims to observe a typical signature of oscillations: the distortion of neutrino spectra both in energy and baseline. This thesis presents the detector concept and simulations as well as sensitivity studies. Background sources and the foreseen shielding are also discussed. (author)

  10. Study of the prospective usefulness of the detection of antineutrinos to monitor nuclear power plants for non proliferation purpose

    International Nuclear Information System (INIS)

    The field of applied neutrino physics has shown new developments in the last decade. Indeed, the antineutrinos (ne) emitted by a nuclear power plant depend on the composition of the fuel: thus their detection could be exploited for determining the isotopic composition of the reactor fuel. The International Atomic Energy Agency (IAEA) has expressed its interest in the potentialities of this detection as a new safeguard tool and has created an Ad Hoc working group devoted to this study. Our aim is to determine on the one hand, the current sensitivity reached with the ne detection and on the other hand, the sensitivity required to be useful to the IAEA and then we deduce the required performances required for a cubic meter detector. We will first present the physics on which our feasibility study relies: the neutrinos, the b-decay of the fission products (FP) and their conversion into ne spectra. We will then present our simulation tools: we use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. Thanks to MURE coupled with nuclear data bases, we build the ne spectra by summing the FP contributions. The method is the only one that allows the ne spectra calculations associated to future reactors: we will present the predicted spectra for various innovative fuels. We then calculate the emitted ne associated to various concepts of current and future nuclear reactors in order to determine the sensitivity of the ne probe to various diversion scenarios, taking neutronics into account. The reactor studied are Canadian Deuterium, Pebble Bed Reactor and Fast Breeder Reactor. (author)

  11. Electron Antineutrino Disappearance at KamLAND and JUNO as Decisive Tests of the Short Baseline Anti-nu_mu to Anti-nu_e Appearance Anomaly

    OpenAIRE

    Conrad, J. M.; Shaevitz, M. H.

    2013-01-01

    The IsoDAR antineutrino source, which produces a flux from 8Li isotope decay at rest, when paired with the proposed JUNO (Jiangmen Underground Neutrino Observatory) detector, has unprecedented sensitivity to anti-nu_e disappearance for oscillations at high Delta m^2. Assuming CPT invariance, the sensitive region for anti-nu_e disappearance can be used to restrict the allowed parameter space of an anti-nu_mu to anti-nu_e appearance signal. The 5 sigma sensitivity of this experiment covers the ...

  12. Probing of the neutrino magnetic moment at the level of 10-22 μB with an intense tritium source of (anti)neutrino and helium target (project)

    International Nuclear Information System (INIS)

    We present research results of the preparation project for the experimental measurement of the (anti)neutrino magnetic moment at the level of 10-12 μB using an intense tritium source of antineutrinos and a liquid helium scintillation detector. The neutrino detection in the scintillation detector is based on the scattering of neutrinos by the electrons of the helium atoms that produces fast electrons able to ionize and exciting helium atoms. The detection of the atomic radiation emitted during the relaxation process of the helium atoms and the knowledge of its parameters will allow us to conclude on the neutrino properties

  13. Probing of the neutrino magnetic moment at the level of 10{sup -22} μ{sub B} with an intense tritium source of (anti)neutrino and helium target (project)

    Energy Technology Data Exchange (ETDEWEB)

    Martemyanov, V.P.; Aleshin, V.I.; Tarasenko, V.G.; Tsinoev, V.G.; Sabelnikov, A.A. [NRC Kurchatov Institute, Moscow (Russian Federation); Yukhimchuk, A.A.; Popov, V.V.; Baluev, V.V.; Golubkov, A.N.; Klevtsov, V.G.; Kuryakin, A.V.; Sitdikov, D.T. [RFNC VNIIEF, Sarov (Russian Federation); Bogdanova, L.N. [SSC RF ITEP, Moscow (Russian Federation)

    2015-03-15

    We present research results of the preparation project for the experimental measurement of the (anti)neutrino magnetic moment at the level of 10{sup -12} μ{sub B} using an intense tritium source of antineutrinos and a liquid helium scintillation detector. The neutrino detection in the scintillation detector is based on the scattering of neutrinos by the electrons of the helium atoms that produces fast electrons able to ionize and exciting helium atoms. The detection of the atomic radiation emitted during the relaxation process of the helium atoms and the knowledge of its parameters will allow us to conclude on the neutrino properties.

  14. Measurement of neutrino mixing angle θ13 and mass difference Δ mee2 from reactor antineutrino disappearance in the RENO experiment

    Science.gov (United States)

    Kim, Soo-Bong

    2016-07-01

    RENO (Reactor Experiment for Neutrino Oscillation) made a definitive measurement of the smallest neutrino mixing angle θ13 in 2012, based on the disappearance of reactor electron antineutrinos. The experiment has obtained a more precise value of the mixing angle and the first result on neutrino mass difference Δ mee2 from an energy and baseline dependent reactor neutrino disappearance using ∼500 days of data. Based on the ratio of inverse-beta-decay (IBD) prompt spectra measured in two identical far and near detectors, we obtain sin2 ⁡ (2θ13) = 0.082 ± 0.009 (stat .) ± 0.006 (syst .) and | Δ mee2 | = [2.62-0.23+0.21 (stat .)-0.13+0.12 (syst .) ] ×10-3 eV2. An excess of reactor antineutrinos near 5 MeV is observed in the measured prompt spectrum with respect to the most commonly used models. The excess is found to be consistent with coming from reactors. A successful measurement of θ13 is also made in an IBD event sample with a delayed signal of neutron capture on hydrogen. A precise value of θ13 would provide important information on determination of the leptonic CP phase if combined with a result of an accelerator neutrino beam experiment.

  15. A PRECISION MEASUREMENT OF THE NEUTRINO MIXING ANGLE THETA (SUB 13) USING REACTOR ANTINEUTRINOS AT DAYA BAY.

    Energy Technology Data Exchange (ETDEWEB)

    KETTELL, S.; ET AL.

    2006-10-16

    This document describes the design of the Daya Bay reactor neutrino experiment. Recent discoveries in neutrino physics have shown that the Standard Model of particle physics is incomplete. The observation of neutrino oscillations has unequivocally demonstrated that the masses of neutrinos are nonzero. The smallness of the neutrino masses (<2 eV) and the two surprisingly large mixing angles measured have thus far provided important clues and constraints to extensions of the Standard Model. The third mixing angle, {delta}{sub 13}, is small and has not yet been determined; the current experimental bound is sin{sup 2} 2{theta}{sub 13} < 0.17 at 90% confidence level (from Chooz) for {Delta}m{sub 31}{sup 2} = 2.5 x 10{sup -3} eV{sup 2}. It is important to measure this angle to provide further insight on how to extend the Standard Model. A precision measurement of sin{sup 2} 2{theta}{sub 13} using nuclear reactors has been recommended by the 2004 APS Multi-divisional Study on the Future of Neutrino Physics as well as a recent Neutrino Scientific Assessment Group (NUSAG) report. We propose to perform a precision measurement of this mixing angle by searching for the disappearance of electron antineutrinos from the nuclear reactor complex in Daya Bay, China. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will be vital in resolving the neutrino-mass hierarchy and future measurements of CP violation in the lepton sector because this technique cleanly separates {theta}{sub 13} from CP violation and effects of neutrino propagation in the earth. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will provide important, complementary information to that from long-baseline, accelerator-based experiments. The goal of the Daya Bay experiment is to reach a sensitivity of 0.01 or better in sin{sup 2} 2{theta}{sub 13} at 90% confidence level.

  16. Nuclear Reactions

    OpenAIRE

    Bertulani, C. A.

    2009-01-01

    Nuclear reactions generate energy in nuclear reactors, in stars, and are responsible for the existence of all elements heavier than hydrogen in the universe. Nuclear reactions denote reactions between nuclei, and between nuclei and other fundamental particles, such as electrons and photons. A short description of the conservation laws and the definition of basic physical quantities is presented, followed by a more detailed account of specific cases: (a) formation and decay of compound nuclei;...

  17. Neutrino reactions in hot and dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Lohs, Andreas

    2015-04-13

    In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

  18. Reactor antineutrino experiments

    CERN Document Server

    Lu, Haoqi

    2014-01-01

    Neutrinos are elementary particles in the standard model of particle physics. There are 3 flavors of neutrinos that oscillate among themselves. Their oscillation can be described by a 3$\\times$3 unitary matrix, containing three mixing angles $\\theta_{12}$, $\\theta_{23}$, $\\theta_{13}$, and one CP phase. Both $\\theta_{12}$ and $\\theta_{23}$ are known from previous experiments. $\\theta_{13}$ was unknown just two years ago. The Daya Bay experiment gave the first definitive non-zero value in 2012. An improved measurement of the oscillation amplitude $\\sin^{2}2(\\theta_{13})$ = $0.090^{+0.008}_{-0.009}$ and the first direct measurement of the $\\bar\

  19. New measurements of the antineutrino-spin asymmetry in beta decay of the neutron and restrictions on the mass of a right-handed gauge boson

    International Nuclear Information System (INIS)

    The results of new measurements of the neutron antineutrino spin asymmetry coefficient B in the beta decay of polarized neutrons are considered. The measurements were carried out on the polarized neutron vertical channel of the WWR-M-Gatchina reactor. Basing on the combination of the results of measurements of the observed asymmetry P · B 0.6617 ± 0.0044 with those of the measurements on the neutron beam polarization P = (66.88 ± 0.22)% the value B = 0.9894 ± 0.0083 is obtained. This value implies that the mass of a hypothetical right-handed charged gauge boson in the left-right symmetric model of the weak interaction is greater than 281 GeV/c2 (90% CL). The conclusion on the agreement of this value with restrictions from muon decay and direct searches for an additional vector boson W is made. 9 refs., 1 tab., 5 figs

  20. Determination of the nucleon structure functions in the study of the inclusive charged current interactions of neutrinos and antineutrinos in iron between 30 and 200 GeV

    International Nuclear Information System (INIS)

    In the deep inelastic neutrino scattering experiment of the CERN-Dortmund-Heidelberg-Saclay collaboration realized on the CERN SPS narrow band beam, we have measured 23000 charged current neutrino and 6200 antineutrino interactions. The structure functions of the nucleon have been extracted from the differential cross sections on iron and compared with parton model predictions. The total cross sections and the fraction of momentum carried by the antiquarks in the nucleon have been measured as function of the neutrino energy. The structure functions obtained for different Q2 bins show significant deviations from scale invariance. The data are in agreement with QCD predictions for a value of the scale parameter Λ between 300 and 700 MeV

  1. 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)

    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 sin2Osub(w)(msub(w))=0.226+-0.012 is obtained, where the error represents the experimental uncertainty. The theoretical uncertainty is estimated to be Δ sind2Osub(w)=+-0.006. (orig.)

  2. Electron antineutrino disappearance at KamLAND and JUNO as decisive tests of the short baseline ν stretchy="false">¯μ→ν stretchy="false">¯e appearance anomaly

    Science.gov (United States)

    Conrad, J. M.; Shaevitz, M. H.

    2014-03-01

    The IsoDAR antineutrino source, which produces a flux from Li8 isotope decay at rest, when paired with the proposed Jiangmen Underground Neutrino Observatory detector, has unprecedented sensitivity to ν ¯e disappearance for oscillations at high Δm2. Assuming charge conjugation, parity transformation, and time reversal (CPT) invariance, the sensitive region for ν ¯e disappearance can be used to restrict the allowed parameter space of a ν ¯μ→ν ¯e appearance signal. The 5σ sensitivity of this experiment covers the entire ν ¯μ→ν ¯e allowed parameter space from a combined fit to short-baseline experiments. This represents a decisive test of the LSND neutrino experiment and MiniBooNE antineutrino appearance signals within all models that are CPT invariant. Running IsoDAR at KamLAND restricts a large part of the appearance signal region in a similar way.

  3. Piezonuclear Reactions

    CERN Document Server

    Cardone, Fabio; Petrucci, Andrea

    2010-01-01

    In this paper, we deal with the subject of piezonuclear reactions, namely nuclear reactions (of new type) triggered by pressure waves. We discuss the experimental evidences obtained in the last two decades, which can be summarized essentially as follows: experiments in cavitation of liquids, where transmutation of elements, creation of elements and emission of neutrons have been observed; emission of neutrons in brittle failure of solids subjected to mechanical pressure; alteration of the lifetime of un unstable element (thorium) subjected to cavitation. A theoretical model to explain these facts is proposed. Future perspectives of these experimental and theoretical investigations are also underlined.

  4. Reaction mechanisms

    International Nuclear Information System (INIS)

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported

  5. Gamow-Teller strength functions of superfluid odd nuclei and neutrino capture reactions

    International Nuclear Information System (INIS)

    The charge-exchange excitations of superfluid odd-A nuclei are studied within the framework of the self-consistent finite Fermi-system theory. The pairing blocking effect due to the odd quasiparticle, the effective NN-interactions both in the particle-hole (ph) and particle-particle (pp) channel, and also the ph-continuum are taken into account. Gamow-Teller strength functions of 71Ga, 115In and 19F nuclei are calculated and compared with those extracted from experimental spectra of (p,n) reactions. The total capture cross sections of the reactor electron antineutrinos are calculated (assuming complete μe-bar→μe conversion), as well as the solar neutrino capture rates for the 71Ga and 115In+19F detectors. Uncertainties regarding nuclear structure information involved in these calculations are discussed. (authors) 55 refs., 4 figs., 3 tabs

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

    International Nuclear Information System (INIS)

    The coherent production of π and ρ mesons in νμ(bar νμ)--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 (bar νμ) 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±πminus-plus coherent events and (19±7) μ±πminus-plusπ0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2±0.7)x10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1±0.8)x10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at |t|2 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

  7. Cross sections for neutrino and antineutrino induced pion production on hydrocarbon in the few-GeV region using MINERvA

    CERN Document Server

    McGivern, C L; Eberly, B; Aliaga, L; Altinok, O; Bellantoni, L; Bercellie, A; Betancourt, M; Bodek, A; Bravar, A; Budd, H; Cai, T; Carneiro, M F; Christy, M E; da Motta, H; Dytman, S A; Diaz, G A; Endress, E; Felix, J; Fields, L; Fine, R; Galindo, R; Gallagher, H; Golan, T; Gran, R; Harris, D A; Higuera, A; Hurtado, K; Kiveni, M; Kleykamp, J; Kordosky, M; Maher, E; Manly, S; Mann, W A; Marshall, C M; Caicedo, D A Martinez; McFarland, K S; McGowan, A M; Messerly, B; Miller, J; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Norrick, A; Nuruzzaman,; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Rakotondravohitra, L; Ramirez, M A; Ransome, R D; Ray, H; Ren, L; Rimal, D; Rodrigues, P A; Ruterbories, D; Schellman, H; Schmitz, D W; Simon, C; Salinas, C J Solano; Falero, S Sanchez; Tice, B G; Valencia, E; Walton, T; Wolcott, J; Wospakrik, M; Zhang, D

    2016-01-01

    Separate samples of charged-current pion production events representing two semi-inclusive channels nu_mu-CC(pi+) and anu_mu-CC(pi0) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon muon-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q2, are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the Delta(1232) and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the nu_mu-CC(pi+) (anu_mu-CC(pi0)) sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to-2 sigma. However the generators are able to reproduce the shapes of the differential cross ...

  8. 3-flavor and 4-flavor implications of the latest T2K and NOνA electron (anti-)neutrino appearance results

    Science.gov (United States)

    Palazzo, Antonio

    2016-06-01

    The two long-baseline experiments T2K and NO νA have recently presented new findings. T2K has shown the first νbare appearance data while NO νA has released the first νe appearance results. These data are of particular importance because they allow us to probe for the first time in a direct (or manifest) way the leptonic CP-violation. In fact, it is the first time that a hint of CP-violation arises from the comparison of the observations of neutrinos and antineutrinos. We consider the implications of such new results both for the standard 3-flavor framework and for the non-standard 3 + 1 scheme involving one sterile neutrino species. The 3-flavor analysis shows a consolidation of the previous trends, namely a slight preference for sin ⁡ δ statistical significance close to 90% C.L., and a mild preference (at more than 68% C.L.) for the normal hierarchy. In a 3 + 1 framework, the data constrain two CP-phases (δ13 ≡ δ and δ14), which exhibit a slight preference for the common value δ13 ≃δ14 ≃ - π / 2. Interestingly, in the enlarged four neutrino scheme the preference for the normal hierarchy found within the 3-flavor framework completely disappears. This indicates that light sterile neutrinos may constitute a potential source of fragility in the capability of the two LBL experiments of discriminating the neutrino mass hierarchy.

  9. The electron antineutrino angular correlation coefficient a in free neutron decay. Testing the standard model with the aSPECT-spectrometer

    International Nuclear Information System (INIS)

    The β-decay of free neutrons is a strongly over-determined process in the Standard Model (SM) of Particle Physics and is described by a multitude of observables. Some of those observables are sensitive to physics beyond the SM. For example, the correlation coefficients of the involved particles belong to them. The spectrometer aSPECT was designed to measure precisely the shape of the proton energy spectrum and to extract from it the electron anti-neutrino angular correlation coefficient a. A first test period (2005/2006) showed the ''proof-of-principles''. The limiting influence of uncontrollable background conditions in the spectrometer made it impossible to extract a reliable value for the coefficient a (published in 2008). A second measurement cycle (2007/2008) aimed to under-run the relative accuracy of previous experiments (δa)/(a)=5%. I performed the analysis of the data taken there which is the emphasis of this doctoral thesis. A central point are background studies. The systematic impact of background on a was reduced to (δa(syst.))/(a)=0.61 %. The statistical accuracy of the analyzed measurements is (δa(stat.))/(a)∼1.4 %. Besides, saturation effects of the detector electronics were investigated which were initially observed. These turned out not to be correctable on a sufficient level. An applicable idea how to avoid the saturation effects is discussed in the last chapter. (orig.)

  10. Nuclear reactions

    International Nuclear Information System (INIS)

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  11. Chain reaction

    International Nuclear Information System (INIS)

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  12. Measurement of the angular correlation coefficient a between electron and antineutrino in neutron β-decay with the spectrometer aSPECT

    International Nuclear Information System (INIS)

    Neutron β-decay is parametrized by several measurable correlation coefficients which are used to determine parameters of the Standard Model and to search for new physics. The aim of the retardation spectrometer aSPECT is to measure the electron-antineutrino angular correlation coefficient a with an unprecedented accuracy of well below 1%. The coefficient is extracted from a high precision measurement of the proton energy spectrum. A central point of this PhD thesis is the analysis of the background, motivated by the observations of discharges during the beam time of 2011, and an earlier indication for a dependence on the retardation potential. During this thesis, several measurements were conducted off-line, without ionizing particles from neutron decay. An 'internal' background (X-rays and ions) was identified. It has an influence of 10-5 to 10-4 on Δa/a depending on the vacuum level (∼10-9 mbar) and the spectrometer settings. Within the analysis of the data from the beam time in 2013, a model was built to correct for backgrounds present in neutron decay experiment, taking into account its time dependence. The correction is about 3% on the coefficient for standard settings and vacuum but it can reach 7% for unfavorable settings. To reduce the background, a drift electric field was applied close to the maximum of the retardation potential. Additional measurements performed during this beam time included tests of systematics, in particular the edge effect (beam profile) and different electrode settings. In order to obtain the final result, the analysis has to be extended by including the different corrections and by comparing with simulations of the systematic effects. (author)

  13. Background for Terrestrial Antineutrino Investigations: Radionuclide Distribution, Georeactor Fission Events, and Boundary Conditions on Fission Power Production

    CERN Document Server

    Herndon, J M; Edgerley, Dennis A.

    2005-01-01

    Estimated masses of fissioning and non-fissioning radioactive elements and their respective distributions within the Earth are presented, based upon the fundamental identity of the components of the interior 82% of the Earth, the endo-Earth, with corresponding components of the Abee enstatite chondrite meteorite. Within limits of existing data, the following generalizations concerning the endo-Earth radionuclides can be made: (1) Most of the K-40 may be expected to exist in combination with oxygen in the silicates of the lower mantle, perhaps being confined to the upper region of the lower mantle where it transitions to the upper mantle; (2) Uranium may be expected to exist at the center of the Earth where it may undergo self-sustaining nuclear fission chain reactions, but there is a possibility that some non-fissioning uranium may be found scattered diffusely within the core floaters which are composed of CaS and MgS; and, (3) Thorium may be expected to occur within the core floaters at the core-mantle bound...

  14. Neutrino-driven nuclear reactions of cold fusion and transmutation

    International Nuclear Information System (INIS)

    The term 'neutrino-driven nuclear reactions' is usually attributed to some reactions of direct or reverse β-decay having, as a rule, an extremely small interaction cross section and is applied for detection of neutrino (antineutrino). The author considers that a great majority of intense reactions of β-decay, nuclear fission and partly of fusion, formerly described without participation of neutrinos as an input, are neutrino-driven ones. The facts listed below demonstrate that the reactions of direct and reverse β-decay, including nuclear fission and partly nuclear fusion, are driven from the outside. Significance of a radioactive decay rate variation and its correlation with the solar activity variation is demonstrated after some decades long observations. Variation of decay rate after variation of crystalline and chemical environment was observed since the 40. years of the 20. century. Variation of nuclear transmutation rates is even more significant after low energy non-nuclear actions on media (cold fusion and transmutation of nuclei). It was also stated that the Chernobyl accident produced radioisotopes (in particular, 137Cs) for some years after their fallout had reduced half-life periods (3.5 and 17 years for 1988 and 1992 years' samples, respectively), hereinafter asymptotically increasing incrementally up to the conventional values (30.6 years). And, last but not least: there are some data on an opportunity of radioisotopes decay and other nuclear transformations initiating by means of so-called torsion radiation (scalar fields, non-hertzian energy and so on). We suggest the hypothesis of neutrino-driven nuclear reactions for explication of abnormally fast nuclear reactions surveyed above and conformities to natural laws observed under the noted reactions proceeding. The not-high energy neutrino (NNN) is abundant in Nature, which is a solid fact. The author suggests that correct interpretation by many other authors of experimental data allow the

  15. On thermonuclear reaction rates

    OpenAIRE

    Hans J. Haubold; Mathai, Arak Mathai

    1996-01-01

    Nuclear reactions govern major aspects of the chemical evolution of galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the cases of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are als...

  16. The Glyoxal Clock Reaction

    Science.gov (United States)

    Ealy, Julie B.; Negron, Alexandra Rodriguez; Stephens, Jessica; Stauffer, Rebecca; Furrow, Stanley D.

    2007-01-01

    Research on the glyoxal clock reaction has led to adaptation of the clock reaction to a general chemistry experiment. This particular reaction is just one of many that used formaldehyde in the past. The kinetics of the glyoxal clock makes the reaction suitable as a general chemistry lab using a Calculator Based Laboratory (CBL) or a LabPro. The…

  17. Étude du potentiel de la détection des antineutrinos pour la surveillance des réacteurs nucléaires à des fins de lutte contre la prolifération.

    OpenAIRE

    Cormon, Sandrine

    2012-01-01

    Ces dernières années, la physique des neutrinos a présenté de nouvelles perspectives de physique appliquée. En effet, les antineutrinos (ne) émis par une centrale nucléaire dépendent du combustible : leur détection constituerait donc une sonde permettant de déterminer la composition isotopique du coeur. L'Agence Internationale de l'Énergie Atomique (AIEA) a montré son intérêt pour le potentiel de cette détection comme nouvel outil au profit de son département des Garanties et a créé un groupe...

  18. Practice Gaps: Drug Reactions.

    Science.gov (United States)

    Wolverton, Stephen E

    2016-07-01

    The term "drug reactions" is relevant to dermatology in three categories of reactions: cutaneous drug reactions without systemic features, cutaneous drug reactions with systemic features, and systemic drugs prescribed by the dermatologist with systematic adverse effects. This article uses examples from each of these categories to illustrate several important principles central to drug reaction diagnosis and management. The information presented will help clinicians attain the highest possible level of certainty before making clinical decisions. PMID:27363888

  19. Nuclear reaction rates and their influence on nucleosynthesis in the neutrino-p-process

    Science.gov (United States)

    Hatcher, Daniel; Frohlich, Carla; Perdikakis, Georgios

    2015-10-01

    The synthesis of elements heavier than iron in the early stages of galactic evolution is commonly attributed to Type II (core collapse) supernova explosions. However, the currently accepted mechanisms of heavy element synthesis through neutron capture processes (r-process and s-process) cannot explain the abundance patterns seen in very old galactic halo stars. A proposed solution to this problem is the neutrino-p-process, which takes place in the strong neutrino winds of core-collapse supernovae. In the neutrino-p-process, antineutrinos absorbed by protons yield neutrons that are quickly captured by the surrounding, proton-rich nuclei through (n,p) reactions. Such interactions allow for the nucleosynthesis of elements with atomic mass numbers greater than 64 (this includes Sr, Y, Zr and others possibly up to Sn). We study the sensitivity of the νp-process abundance pattern to (n,p), (p, γ), and (n, γ) rates for nuclei between Ni and Sn. We illustrate our findings for three different initial electron fractions and two representative trajectories. We discuss how these rates influence the abundance pattern and the nuclear flow. We observe the effects of predicted reaction rates on the abundance pattern and nuclear flow.

  20. Incomplete fusion reactions

    International Nuclear Information System (INIS)

    Various aspects of the mechanism of heavy-ion induced reactions in the range of bombarding energies from a few to about 20 MeV/A are reviewed with special emphasis on the reactions for very asymmetric systems. Results of the experimental studies of binary reactions and particularly of the incomplete fusion reactions (selected by means of various coincidence techniques)are discussed. A model of generalized critical angular momentum is formulated. The model explains essential features of the incomplete fusion reactions and predicts that particular reaction channels are localized in well defined regions of angular momenta. An extension of this model (the sum-rule model) is also proposed in attempt to consistently describe the complete fusion reactions, incomplete fusion reactions and multibody reactions in the framework of statistical competition constrained by the angular momentum limitations. (author)

  1. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng; Sui, Guodong; Elizarov, Arkadij; Kolb, Hartmuth C.; Huang, Jiang; Heath, James R.; Phelps, Michael E.; Quake, Stephen R.; Tseng, Hsian-rong; Wyatt, Paul; Daridon, Antoine

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  2. Microscale Thermite Reactions.

    Science.gov (United States)

    Arnaiz, Francisco J.; Aguado, Rafael; Arnaiz, Susana

    1998-01-01

    Describes the adaptation of thermite (aluminum with metal oxides) reactions from whole-class demonstrations to student-run micro-reactions. Lists detailed directions and possible variations of the experiment. (WRM)

  3. Anaphylaxis-Like Reactions

    Science.gov (United States)

    ... be "primed" by previous exposure to cause anaphylaxis, anaphylactoid reactions can occur with no previous exposure at all. ... an X-ray. Although the mechanism of an anaphylactoid reaction is different, the treatment is the same as ...

  4. Common Reactions After Trauma

    Science.gov (United States)

    ... here Enter ZIP code here Common Reactions After Trauma Public This section is for Veterans, General Public, Family, & Friends Common Reactions After Trauma Available in Spanish: Reacciones Comunes Después de un ...

  5. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  6. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  7. Anaphylactoid reactions to paracetamol

    OpenAIRE

    Ayonrinde, O.; Saker, B.

    2000-01-01

    The toxic effects of paracetamol in overdose quantities are well recognised but the occurrence of anaphylactoid reactions to paracetamol is infrequently identified by consumers and health care professionals. Nevertheless adverse reactions to this drug, even in therapeutic doses, can have fatal or near fatal consequences. A case of an anaphylactoid reaction to paracetamol is described.


Keywords: paracetamol; anaphylaxis; allergy; hypersensitivity

  8. Sodium concrete reactions

    International Nuclear Information System (INIS)

    The data from an extensive series of sodium/concrete reaction tests are presented and mechanisms by which the reactions proceed are analyzed. The results indicate water transport and the resulting sodium/water reaction dominate both the chemical energy release and H2 generation. A mechanism which explains the limited penetration of concrete observed in most of these tests is proposed

  9. Noncanonical Reactions of Flavoenzymes

    Directory of Open Access Journals (Sweden)

    Pablo Sobrado

    2012-11-01

    Full Text Available Enzymes containing flavin cofactors are predominantly involved in redox reactions in numerous cellular processes where the protein environment modulates the chemical reactivity of the flavin to either transfer one or two electrons. Some flavoenzymes catalyze reactions with no net redox change. In these reactions, the protein environment modulates the reactivity of the flavin to perform novel chemistries. Recent mechanistic and structural data supporting novel flavin functionalities in reactions catalyzed by chorismate synthase, type II isopentenyl diphosphate isomerase, UDP-galactopyranose mutase, and alkyl-dihydroxyacetonephosphate synthase are presented in this review. In these enzymes, the flavin plays either a direct role in acid/base reactions or as a nucleophile or electrophile. In addition, the flavin cofactor is proposed to function as a “molecular scaffold” in the formation of UDP-galactofuranose and alkyl-dihydroxyacetonephosphate by forming a covalent adduct with reaction intermediates.

  10. Backward emitted high-energy neutrons in hard reactions of p and π+ on carbon

    Science.gov (United States)

    Malki, A.; Alster, J.; Asryan, G.; Averichev, Y.; Barton, D.; Baturin, V.; Bukhtoyarova, N.; Carroll, A.; Heppelmann, S.; Kawabata, T.; Leksanov, A.; Makdisi, Y.; Minina, E.; Navon, I.; Nicholson, H.; Ogawa, A.; Panebratsev, Yu.; Piasetzky, E.; Schetkovsky, A.; Shimanskiy, S.; Tang, A.; Watson, J. W.; Yoshida, H.; Zhalov, D.

    2002-01-01

    Beams of protons and pions of 5.9 GeV/c were incident on a C target. Neutrons emitted into the backward hemisphere, in the laboratory system, were detected in (triple) coincidence with two emerging particles of tranverse momenta pt>0.6 GeV/c. We determined that for (46.5+/-3.7)% of the proton-induced events and for (40.8+/-4.5)% of the pion-induced events with the two high-pt particles, there is also at least one backward emitted neutron with momentum greater than 0.32 GeV/c. This observation is in sharp contrast to a well- established universal pattern from a large variety of earlier inclusive measurements with hadrons, electrons, photons, neutrinos, and antineutrinos where the probability for backward nucleon emission was in the 5 to 10 % range. We present also a measurement of the momentum spectra for the backward going neutrons. The spectra have the same universal shape observed in the inclusive reactions. We speculate that the enhanced backward neutron emission in this semi-inclusive region could be an indication for a strong dependence of the cross section on the squared total center-of-mass energy (s) and for the importance of short-range nucleon-nucleon correlations.

  11. Cosmetic tattoo pigment reaction

    OpenAIRE

    Greywal, Tanya; Cohen, Philip R

    2016-01-01

    BackgroundCutaneous reactions to tattoos are most commonly granulomatous or lichenoid. PurposeWe describe a woman who developed a lymphocytic reaction following a cosmetic tattoo procedure with black dye. The reaction occurred not only at the site of the tattoos (eyebrows and eyelash lines), but also in non-tattooed skin (bilateral malar cheeks). Methods and MaterialsWe reviewed PubMed for the following terms: cosmetic, dye, granuloma, granulomatous, lichenoid, lymphocytic, ...

  12. Anaphylactic reactions to cinoxacin.

    OpenAIRE

    Stricker, B H; Slagboom, G.; Demaeseneer, R.; Slootmaekers, V.; Thijs, I.; Olsson, S

    1988-01-01

    During 1981 to mid-1988 three cases of anaphylactic shock after treatment with the quinolone derivative cinoxacin were reviewed by the Netherlands Centre for Monitoring of Adverse Reactions to Drugs and 17 cases of an anaphylactic type of reaction notified to the World Health Organisation Collaborating Centre for International Drug Monitoring. In five out of six patients for whom data were available the reaction began shortly after taking a single capsule of a second or next course of treatme...

  13. Reaction kinetics of polybutylene terephthalate polycondensation reaction

    NARCIS (Netherlands)

    Darda, P. J.; Hogendoorn, J. A.; Versteeg, G. F.; Souren, F.

    2005-01-01

    The kinetics of the forward polycondensation reaction of polybutylene terephthalate (PBT) has been investigated using thermogravimetric analysis (TGA). PBT - prepolymer with an initial degree of polymerization of 5.5 was used as starting material. The PBT prepolymer was prepared from dimethyl tereph

  14. Reactions at Solid Surfaces

    CERN Document Server

    Ertl, Gerhard

    2009-01-01

    Expanding on the ideas first presented in Gerhard Ertl's acclaimed Baker Lectures at Cornell University, Reactions at Solid Surfaces comprises an authoritative, self-contained, book-length introduction to surface reactions for both professional chemists and students alike. Outlining our present understanding of the fundamental processes underlying reactions at solid surfaces, the book provides the reader with a complete view of how chemistry works at surfaces, and how to understand and probe the dynamics of surface reactions. Comparing traditional surface probes with more modern ones, and brin

  15. Desosamine in multicomponent reactions

    NARCIS (Netherlands)

    Achatz, Sepp; Dömling, Alexander

    2006-01-01

    Desosamine occurring ubiquitously in natural products is introduced into isocyanide based multicomponent reaction chemistry. Corresponding products are of potential interest for the design of novel antibiotics. © 2006.

  16. Chemical reaction and separation method

    NARCIS (Netherlands)

    Jansen, J.C.; Kapteijn, F.; Strous, S.A.

    2005-01-01

    The invention is directed to process for performing a chemical reaction in a reaction mixture, which reaction produces water as by-product, wherein the reaction mixture is in contact with a hydroxy sodalite membrane, through which water produced during the reaction is removed from the reaction mixtu

  17. Clock Reaction: Outreach Attraction

    Science.gov (United States)

    Carpenter, Yuen-ying; Phillips, Heather A.; Jakubinek, Michael B.

    2010-01-01

    Chemistry students are often introduced to the concept of reaction rates through demonstrations or laboratory activities involving the well-known iodine clock reaction. For example, a laboratory experiment involving thiosulfate as an iodine scavenger is part of the first-year general chemistry laboratory curriculum at Dalhousie University. With…

  18. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  19. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  20. Experimental study of the high-energy reactions antiνμe- #-> # antiνμe-, antiνμN #-> # μ+X in the Gargamelle bubble chamber

    International Nuclear Information System (INIS)

    This thesis presents the results obtained from interactions of muon antineutrinos at the CERN SPS, in the Gargamelle bubble chamber. Two types of interactions have been studied: (a) ''neutral-current'' leptonic interactions antiνμe- #-> # antiνμe- and (b) ''charged-current'' lepton-hadron interactions antiνμN #-> # μ+X. For each reaction, the experimental study provided an estimation of the upper limit of the cross section in the case (a), and of the variation of the total cross section with the incident antiνμ energy in the case (b). These results have been discussed with the model of unification of electromagnetic and weak interactions of Weinberg-Salam (case(a)), and with the parton model in the case (b). 57 refs

  1. Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

    CERN Document Server

    Mosteiro, P; Benziger, J; Bick, D; Bonfini, G; Bravo, D; Caccianiga, B; Cadonati, L; Calaprice, F; Caminata, A; Cavalcante, P; Chavarria, A; Chepurnov, A; D'Angelo, D; Davini, S; Derbin, A; Empl, A; Etenko, A; Fomenko, K; Franco, D; Gabriele, F; Galbiati, C; Gazzana, S; Ghiano, C; Giammarchi, M; Goeger-Neff, M; Goretti, A; Gromov, M; Hagner, C; Hungerford, E; Ianni, Al; Ianni, An; Kobychev, V; Korablev, D; Korga, G; Kryn, D; Laubenstein, M; Lehnert, B; Lewke, T; Litvinovich, E; Lombardi, F; Lombardi, P; Ludhova, L; Lukyanchenko, G; Machulin, I; Manecki, S; Maneschg, W; Marcocci, S; Meindl, Q; Meroni, E; Meyer, M; Miramonti, L; Misiaszek, M; Montuschi, M; Muratova, V; Oberauer, L; Obolensky, M; Ortica, F; Otis, K; Pallavicini, M; Papp, L; Perasso, L; Pocar, A; Ranucci, G; Razeto, A; Re, A; Romani, A; Rossi, N; Saldanha, R; Salvo, C; Schoenert, S; Simgen, H; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Testera, G; Vignaud, D; Vogelaar, R B; von Feilitzsch, F; Wang, H; Winter, J; Wojcik, M; Wright, A; Wurm, M; Zaimidoroga, O; Zavatarelli, S; Zuber, K; Zuzel, G

    2015-01-01

    The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.

  2. Evolved Models for Elementary Particles and Atoms Require Alternating Neutrino/Antineutrino Pairs Along Interlocked or Looped Strings. Traveling Waves, TW, and Standing Waves, SW, Alternate at Nodal Notches

    Science.gov (United States)

    McLeod, Roger David; McLeod, David Matthew

    2009-05-01

    Our hydrogen atom interacts with a neutron star. Its stringy TW/SW electron is cut by a neutrino scissor that instantly becomes its end anti-node. The string has one extra neutrino in 100,000. Antimatter remains concealed. Our Dumbo Proton of a TW state is similarly cut. Inside the star, electron string/spring compresses 100,000 and 1836 times more, to proton's linear mass density. Electrostatics encourages that caboose, stringy electron, to couple with a cut proton. Linear charge densities neutralize while composite length contracts 20%. The writhing string evicts an antineutrino at closure on Pauli's authority, becoming Mickey Neutron, with looped quarks. Unstable Mickey Neutron has his ear notch forced into an ear notch of stable Dumbo Proton, achieving immortality in this deuteron marriage. Tritium is in a m'enage a trois. Alpha Nucleus has a # grid. Meta state Ne-20 predicts alpha eviction to O-16. Schr"odinger finally prevails, so string theory and Wave Mechanics can prosper.

  3. Reactions of oriented molecules.

    Science.gov (United States)

    Brooks, P R

    1976-07-01

    Beams of oriented molecules have been used to directly study geometrical requirements in chemical reactions. These studies have shown that reactivity is much greater in some orientations than others and demonstrated the existence of steric effects. For some reactions portions of the orientation results are in good accord with traditional views of steric hindrance, but for others it is clear that our chemical intuition needs recalibrating. Indeed, the information gained from simultaneously orienting the reactants and observing the scattering angle of the products may lead to new insights about the detailed mechanism of certain reactions. Further work must be done to extend the scope and detail of the studies described here. More detailed information is needed on the CH(3)I reaction and the CF(3)I reaction. The effects of alkyl groups of various sizes and alkali metals of various sizes are of interest. In addition, reactions where a long-lived complex is formed should be studied to see if orientation is important. Finally, it would be of interest to apply the technique to the sort of reactions that led to our interest in the first place: the S(N)2 displacements in alkyl halides where the fascinating Walden inversion occurs. PMID:17793988

  4. Hypersensitivity reactions to corticosteroids.

    Science.gov (United States)

    Vatti, Rani R; Ali, Fatima; Teuber, Suzanne; Chang, Christopher; Gershwin, M Eric

    2014-08-01

    Hypersensitivity reactions to corticosteroids (CS) are rare in the general population, but they are not uncommon in high-risk groups such as patients who receive repeated doses of CS. Hypersensitivity reactions to steroids are broadly divided into two categories: immediate reactions, typically occurring within 1 h of drug administration, and non-immediate reactions, which manifest more than an hour after drug administration. The latter group is more common. We reviewed the literature using the search terms "hypersensitivity to steroids, adverse effects of steroids, steroid allergy, allergic contact dermatitis, corticosteroid side effects, and type I hypersensitivity" to identify studies or clinical reports of steroid hypersensitivity. We discuss the prevalence, mechanism, presentation, evaluation, and therapeutic options in corticosteroid hypersensitivity reactions. There is a paucity of literature on corticosteroid allergy, with most reports being case reports. Most reports involve non-systemic application of corticosteroids. Steroid hypersensitivity has been associated with type I IgE-mediated allergy including anaphylaxis. The overall prevalence of type I steroid hypersensitivity is estimated to be 0.3-0.5%. Allergic contact dermatitis (ACD) is the most commonly reported non-immediate hypersensitivity reaction and usually follows topical CS application. Atopic dermatitis and stasis dermatitis of the lower extremities are risk factors for the development of ACD from topical CS. Patients can also develop hypersensitivity reactions to nasal, inhaled, oral, and parenteral CS. A close and detailed evaluation is required for the clinician to confirm the presence of a true hypersensitivity reaction to the suspected drug and choose the safest alternative. Choosing an alternative CS is not only paramount to the patient's safety but also ameliorates the worry of developing an allergic, and potentially fatal, steroid hypersensitivity reaction. This evaluation becomes

  5. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  6. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  7. Autocatalysis in reaction networks.

    Science.gov (United States)

    Deshpande, Abhishek; Gopalkrishnan, Manoj

    2014-10-01

    The persistence conjecture is a long-standing open problem in chemical reaction network theory. It concerns the behavior of solutions to coupled ODE systems that arise from applying mass-action kinetics to a network of chemical reactions. The idea is that if all reactions are reversible in a weak sense, then no species can go extinct. A notion that has been found useful in thinking about persistence is that of "critical siphon." We explore the combinatorics of critical siphons, with a view toward the persistence conjecture. We introduce the notions of "drainable" and "self-replicable" (or autocatalytic) siphons. We show that: Every minimal critical siphon is either drainable or self-replicable; reaction networks without drainable siphons are persistent; and nonautocatalytic weakly reversible networks are persistent. Our results clarify that the difficulties in proving the persistence conjecture are essentially due to competition between drainable and self-replicable siphons. PMID:25245394

  8. Chemisorption And Precipitation Reactions

    Science.gov (United States)

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  9. Nucleon induced reactions

    International Nuclear Information System (INIS)

    The collection contains full texts of 37 contributions; all fall within the INIS Subject Scope. The topics treated include some unsolved problems of nuclear reactions and relevant problems of nuclear structure at low and intermediate energies. (Z.S.)

  10. Allergic reactions in anaesthesia

    DEFF Research Database (Denmark)

    Krøigaard, M; Garvey, L H; Menné, T;

    2005-01-01

    BACKGROUND: The aim of this retrospective survey of possible allergic reactions during anaesthesia was to investigate whether the cause suspected by anaesthetists involved corresponded with the cause found on subsequent investigation in the Danish Anaesthesia Allergy Centre (DAAC). METHODS: Case...... notes and anaesthetic charts from 111 reactions in 107 patients investigated in the DAAC were scrutinized for either suspicions of or warnings against specific substances stated to be the cause of the supposed allergic reaction. RESULTS: In 67 cases, one or more substances were suspected. In 49 of these...... match, the right substance being suspected, but investigations showed an additional allergen or several substances, including the right substance being suspected. CONCLUSIONS: An informed guess is not a reliable way of determining the cause of a supposed allergic reaction during anaesthesia and may put...

  11. Ofloxacin induced hypersensitivity reaction

    Directory of Open Access Journals (Sweden)

    Hari Babu Ramineni

    2015-01-01

    Full Text Available Ofloxacin is a commonly used antimicrobial agent to combat various infections. The adverse profile of quinolones includes gastrointestinal symptoms, which are the most frequent, neuropsychiatric symptoms, hematologic abnormalities are less common. We report a rare case of ofloxacin induced hypersensitivity reaction in a 57 year old female patient with complaints of rashes over the axilla, upper limb and back, abdomen, thorax associated with exfoliation of skin all over the axilla associated with severe itching. Based on history and clinical examination patient was diagnosed as ofloxacin induced hypersensitivity reaction and was successfully treated with antihistamines and corticosteroids. Pharmacovigilance should be a part of patient care in order to reduce occurrence of adverse drug reaction and also encourage practitioners in reporting so as to gather more and more data regarding adverse drug reactions. [Int J Res Med Sci 2015; 3(1.000: 349-351

  12. Adverse reactions to radiopharmaceuticals

    International Nuclear Information System (INIS)

    Full text. An adverse reaction can occur following administration of a radio pharmaceutical, but fortunately reactions are uncommon. They are usually mild and do not require intensive treatment. This is probably related to the fact that only small chemical quantities of material are administered to patients and that only one or a small number of doses are administered. Since symptoms are unrelated to any known pharmacology of the agents, they can be described as Type B reactions according to the classification of Rawlings and Thompson. Types of reaction that occur and possible mechanisms will be described. The reactions most commonly observed are skin rashes and vasomotor symptoms. It is important that, as far as possible, a cause - effect relationship can be established between the administration of the radio pharmaceutical and the symptoms caused. Some classification schemes therefore exclude vasomotor reactions such as hypotension and slow pulse, since such events can arise in a variety of clinical situations unrelated to radio pharmaceutical administration. It is important for nuclear medicine departments to be aware of the nature of reactions such that they can be recognized and appropriate re-assurance and/or prompt treatment can be given to their patients. Radio pharmaceuticals most frequently mentioned in reporting schemes are di phosphonates used for bone imaging. This probably reflect the fact that these agents are the most frequently used in current practice rather than that they cause more reactions. Problems in establishing the overall frequency of adverse reactions to radio pharmaceuticals include the fact that events may not be recognized if they occur after the patient has left the Nuclear Medicine Department and that reactions are never reported. Two recent studies have attempted to obtain more definitive information by performing prospective studies in a large number of departments. A study in the USA found that there was a rate of 2.3 events per

  13. Adverse reactions to cosmetics

    OpenAIRE

    Dogra A; Minocha Y; Kaur S

    2003-01-01

    Adverse reaction to cosmetics constitute a small but significant number of cases of contact dermatitis with varied appearances. These can present as contact allergic dermatitis, photodermatitis, contact irritant dermatitis, contact urticaria, hypopigmentation, hyperpigmentotion or depigmentation, hair and nail breakage. Fifty patients were included for the study to assess the role of commonly used cosmetics in causing adverse reactions. It was found that hair dyes, lipsticks and surprisingly ...

  14. Meson production in + reactions

    Indian Academy of Sciences (India)

    H Machner; M Betigeri; J Bojowald; A Budzanowski; A Chatterjee; J Ernst; L Freindl; D Frekers; W Garske; K Grewer; A Hamacher; J Ilieva; L Jarczyk; K Kilian; S Kliczewski; W Klimala; D Kolev; T Kutsarova; J Lieb; H Machner; A Magiera; H Nann; L Pentchev; H S Plendl; D Protić; B Razen; P Von Rossen; B J Roy; R Siudak; J Smyrski; R V Srikantiah; A Strzałkowski; R Tsenov; K Zwoll

    2001-08-01

    Total and differential cross sections for the reactions $p+d → 3He + 0 with = ; and + → 3H + + were measured with the GEM detector at COSY for beam momenta between threshold and the maximum of the corresponding baryon resonance. For both reactions a strong forward–backward asymmetry was found. The data were compared with model calculations. The aspect of isospin symmetry breaking is studied.

  15. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  16. EXERCISE AND REACTION TIMES

    OpenAIRE

    Varun; Neeraj; Ushadhar; Yogesh; Rinku

    2015-01-01

    OBJECTIVES: Physical exercise provides multiple benefits to an individual. It is known that exercising regularly can prevent coronary heart disease, hypertension and obesity and improve flexibility. The effect of exercise on visual reaction time needs to be studied, a s the existing data on the benefit of aerobic exercise on psychomotor functions is insufficient. MATERIALS AND METHODS: Online Visual reaction time is measured before and after exercise. Subjects were ...

  17. The power-law reaction rate coefficient for barrierless reactions

    OpenAIRE

    Yin, Cangtao; Du, Jiulin

    2014-01-01

    The power-law reaction rate coefficient for the barrierless reactions is studied if the reactions take place in systems with power-law distributions, and a generalized rate formula for the barrierless reactions in Gorin model is derived. We show that due to barrierless, different from those for bimolecular and unimolcular reactions, the power-law rate coefficient for the barrierless reactions does not have the factor of power-law distribution function and thus it is not very strongly dependen...

  18. Chemical kinetics of gas reactions

    CERN Document Server

    Kondrat'Ev, V N

    2013-01-01

    Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

  19. Marketing Mix Reactions to Entry

    OpenAIRE

    Robinson, William T.

    1988-01-01

    Initial product, distribution, marketing expenditure, and price reactions by incumbents are examined for 115 entrants into oligopolistic markets. The most common reaction pattern is either no reaction or only a single reaction. It is very unusual for entrants to face reactions across the entire marketing mix. Reactions in the first two years after entry are explained as a function of the entrant's strategy, incumbent characteristics, and industry characteristics. The explanation provides insi...

  20. Introduction to chemical reaction engineering

    International Nuclear Information System (INIS)

    This deals with chemical reaction engineering with thirteen chapters. The contents of this book are introduction on reaction engineering, chemical kinetics, thermodynamics and chemical reaction, abnormal reactor, non-isothermal reactor, nonideal reactor, catalysis in nonuniform system, diffusion and reaction in porosity catalyst, design catalyst heterogeneous reactor in solid bed, a high molecule polymerization, bio reaction engineering, reaction engineering in material process, control multi-variable reactor process using digital computer.

  1. Adverse reactions to cosmetics

    Directory of Open Access Journals (Sweden)

    Dogra A

    2003-03-01

    Full Text Available Adverse reaction to cosmetics constitute a small but significant number of cases of contact dermatitis with varied appearances. These can present as contact allergic dermatitis, photodermatitis, contact irritant dermatitis, contact urticaria, hypopigmentation, hyperpigmentotion or depigmentation, hair and nail breakage. Fifty patients were included for the study to assess the role of commonly used cosmetics in causing adverse reactions. It was found that hair dyes, lipsticks and surprisingly shaving creams caused more reaction as compared to other cosmetics. Overall incidence of contact allergic dermatitis seen was 3.3% with patients own cosmetics. Patch testing was also done with the basic ingredients and showed positive results in few cases where casual link could be established. It is recommended that labeling of the cosmetics should be done to help the dermatologists and the patients to identify the causative allergen in cosmetic preparation.

  2. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

      When, in a competitive sphere, people are selected on the basis of qualifications only, their chances of acquiring positions of advantage may seem to depend entirely upon their abilities, not discriminatory bias. However, if reaction qualifications - i.e. characteristics which contribute...... of merit. Specifically, it preserves symmetry between negative evaluations of antimeritocratic bases of selection and negative evaluations of qualifications rooted in comparable antimeritocratic reactions. So if employers should not select among applicants on the basis of their (the employers') racial...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...

  3. Interfacial Reaction Kinetics

    OpenAIRE

    O'Shaughnessy, Ben; Vavylonis, Dimitrios

    1998-01-01

    We study irreversible A-B reaction kinetics at a fixed interface separating two immiscible bulk phases, A and B. We consider general dynamical exponent $z$, where $x_t\\sim t^{1/z}$ is the rms diffusion distance after time $t$. At short times the number of reactions per unit area, $R_t$, is {\\em 2nd order} in the far-field reactant densities $n_A^{\\infty},n_B^{\\infty}$. For spatial dimensions $d$ above a critical value $d_c=z-1$, simple mean field (MF) kinetics pertain, $R_t\\sim Q_b t n_A^{\\in...

  4. Nuclear reactions and structure

    International Nuclear Information System (INIS)

    A more complete data base for deriving level parameters for specific nuclei is provided by using charged-particle induced reactions. (α,pγ) reactions on 40Ca, 52Cr, 19F, 26Mg, 48Ti and 51V at Eα = 12 MeV have been used to excite levels in 43Sc, 55Mn, 22Ne, 29Al, 51V and 54Cr. Gamma rays were observed in coincidence with associated protons using a multiparameter data acquisition system. 5 figs., 9 refs., 1 tab

  5. Nuclear structure, nuclear reaction

    OpenAIRE

    Etchegoyen, Maria Cristina Berisso de.; Sinclair, D.; Dr. D. Sinclair

    1982-01-01

    In this thesis, particle- particle angular correlations for reactions in non-zero degree geometry and with non-zero spin nuclei are performed and found to be a valuable tool for spin determination, (d-α) angular correlations in the reaction process 14N(6Li,d)18F* (α)14N are measured for three high excited states in 18F with a 6Li beam of 36MeV. Spins and parities for two of the observed states are determined, and in agreement with theoretical predictions, these states are s...

  6. Multinucleon transfer reactions

    International Nuclear Information System (INIS)

    Nuclear reactions induced by complex nuclei are studied. The description of the single neutron transfer is used to show some aspect of the theoretical treatment of transfer reactions and rules concerning the dependence of cross sections on quantum numbers of the initial and final channels are deduced. Strongly excited states of 20Ne, 19F, sup(16,17)0, 15N were studied experimentally by using different projectile-target combinations in the four-particle, eight-particle and ten-particle transfer reactions, leading to the some final nuclei. Obtained results are discussed. In addition, studies of the projectile break-up phenomenon were performed. The dissociation of 6Li and 7Li projectiles was investigated in reactions on Pb, Sn and Ni nuclei. These nuclei were chosen to allow measurements at one incident energy below, above and at the Coulomb barrier. The observed spectra indicate that the process proceeds primarily via the resonance level but the shape deviates from the shape which was calculated assuming isotropic decay of the excited 6Li in its center of mass system. The investigations of the elastic scattering turned out to be more fruitful and allowed to define better the Coulomb barrier for the 6Li-target system. (S.B.)

  7. Managing Your Emotional Reactions

    Science.gov (United States)

    ... takes a bit more practice for some people. Learning to React Well Managing emotional reactions means choosing how and when to express ... easier to make choices that work out well. Learning to react well takes ... at taking emotional situations in stride and expressing emotions in healthy ...

  8. Azlactone Reaction Developments.

    Science.gov (United States)

    de Castro, Pedro P; Carpanez, Arthur G; Amarante, Giovanni W

    2016-07-18

    Azlactones (also known as oxazolones) are heterocycles usually employed in the stereoselective synthesis of α,α-amino acids, heterocycles and natural products. The versatility of the azlactone scaffold arises from the numerous reactive sites, allowing its application in a diversity of transformations. This review aims to cover classical and recent applications of oxazolones, especially those involving stereoselective processes. After a short introduction on their structures and intrinsic reactivities, dynamic kinetic resolution (DKR) processes as well as reactions involving stereoselective formation of a new σ C-C bond, such as alkylation/allylation/arylation, aldol, ene, Michael and Mannich reactions will be exposed. Additionally, cycloadditions, Steglich rearrangement and sulfenylation reactions will also be discussed. Recent developments of the well-known Erlenmeyer azlactones will be described. For the most examples, the proposed mechanism, activation modes and/or key reaction intermediates will be exposed to rationalize both the final product and the observed stereochemistry. Finally, this review gives an overview of the synthetic utility of oxazolones. PMID:27245128

  9. Chain Reaction Polymerization.

    Science.gov (United States)

    McGrath, James E.

    1981-01-01

    The salient features and importance of chain-reaction polymerization are discussed, including such topics as the thermodynamics of polymerization, free-radical polymerization kinetics, radical polymerization processes, copolymers, and free-radical chain, anionic, cationic, coordination, and ring-opening polymerizations. (JN)

  10. The Gewald multicomponent reaction

    NARCIS (Netherlands)

    Huang, Yijun; Doemling, Alexander

    2011-01-01

    The Gewald reaction of sulfur, cyanoacetic acid derivatives, and oxo-component (G-3CR) yielding highly substituted 2-aminothiophene derivatives has seen diverse applications in combinatorial and medicinal chemistry. Its products are of great use in pharmaceutical industry mainly as small molecular w

  11. Explaining competitive reaction effects

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Wittink, D.R.

    2001-01-01

    Changes in promotional expenditure decisions for a brand, as in other marketing decisions, should be based on the expected impact on purchase and consumption behavior as well as on the likely reactions by competitors. Purchase behavior may be predicted from estimated demand functions. Competitive re

  12. Cluster knockout reactions

    Indian Academy of Sciences (India)

    Arun K Jain; B N Joshi

    2014-04-01

    Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it were existing as a free entity. Theoretically, the relatively softer interactions of the two outgoing particles with the residual nucleus lead to optical distortions and are treated in terms of distorted wave (DW) formalism. The long-range projectile–cluster interaction is accounted for, in terms of the finite range (FR) direct reaction formalism, as against the more commonly adopted zero-range (ZR) distorted wave impulse approximation (DWIA) formalism. Comparison of the DWIA calculations with the observed data provide information about the momentum distribution and the clustering spectroscopic factor of the target nucleus. Interesting results and some recent advancements in the area of (, 2) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out.

  13. Relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Relativistic heavy ion reactions are reviewed in terms of our present understanding of some selected experimental results from the LBL Bevalac and the CERN ISR. The Lund Model for nucleus-nucleus collisions is presented and its power of predictivity is illustrated. (authors)

  14. EXERCISE AND REACTION TIMES

    Directory of Open Access Journals (Sweden)

    Varun

    2015-03-01

    Full Text Available OBJECTIVES: Physical exercise provides multiple benefits to an individual. It is known that exercising regularly can prevent coronary heart disease, hypertension and obesity and improve flexibility. The effect of exercise on visual reaction time needs to be studied, a s the existing data on the benefit of aerobic exercise on psychomotor functions is insufficient. MATERIALS AND METHODS: Online Visual reaction time is measured before and after exercise. Subjects were instructed to run on the spot with a springy step in ex aggerated motion for 50 to 60 counts at 2 counts per second, maintaining a constant rhythm. RESULTS: We observed that reaction time was significantly lower after performance of exercise. Individuals reported improved mental alertness, feel good factor, bet ter mood and increase circulation. CONCLUSION: Improving reaction times in sports can help the athlete to optimize his performance in making decisions and increasing attention span for example getting off the starting blocks sooner or successfully making c ontact with the ball. In addition this study shows that use of physical exercise helps improve cognitive function. Exercise proves to be a cheap non pharmacological alternative to improve cognitive performance.

  15. Reaction Formulation: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    Reaction formation was studied by Sigmund Freud. This defense mechanism may be related to repression, substitution, reversal, and compensation (or over-compensation). Alfred Adler considered compensation a basic process in his individual psychology. Anna Freud discussed some defense mechanisms, and Bibring, Dwyer, Huntington, and Valenstein…

  16. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  17. Oral Hypersensitivity Reactions

    Science.gov (United States)

    ... and ulcers. Affected individuals may complain of a burning sensation and mouth sensitivity to cold, hot, and spicy foods. Lichenoid ... melon, and pineapple, are all associated with this syndrome. You should inform your ... reaction in the mouth, though some are more common than others. If ...

  18. Photoneutron reactions in astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Varlamov, V. V., E-mail: Varlamov@depni.sinp.msu.ru; Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2014-12-15

    Among key problems in nuclear astrophysics, that of obtaining deeper insight into the mechanism of synthesis of chemical elements is of paramount importance. The majority of heavy elements existing in nature are produced in stars via radiative neutron capture in so-called s- and r processes, which are, respectively, slow and fast, in relation to competing β{sup −}-decay processes. At the same time, we know 35 neutron-deficient so-called bypassed p-nuclei that lie between {sup 74}Se and {sup 196}Hg and which cannot originate from the aforementioned s- and r-processes. Their production is possible in (γ, n), (γ, p), or (γ, α) photonuclear reactions. In view of this, data on photoneutron reactions play an important role in predicting and describing processes leading to the production of p-nuclei. Interest in determining cross sections for photoneutron reactions in the threshold energy region, which is of particular importance for astrophysics, has grown substantially in recent years. The use of modern sources of quasimonoenergetic photons obtained in processes of inverse Compton laser-radiation scattering on relativistic electronsmakes it possible to reveal rather interesting special features of respective cross sections, manifestations of pygmy E1 and M1 resonances, or the production of nuclei in isomeric states, on one hand, and to revisit the problem of systematic discrepancies between data on reaction cross sections from experiments of different types, on the other hand. Data obtained on the basis of our new experimental-theoretical approach to evaluating cross sections for partial photoneutron reactions are invoked in considering these problems.

  19. The human acrosome reaction

    Institute of Scientific and Technical Information of China (English)

    H.W.G.Baker; D.Y.Liu; C.Garrett; M.Martic

    2000-01-01

    We developed tests of sperm-oocyte interaction: sperm-zona binding, zona-induced acrosome reaction, spermzona penetration and sperm-oolemma binding, using oocytes which failed to fertilise in clinical in vitro fertilization (IVF). Although oocyte defects contribute to failure of sperm oocyte interaction, rarely are all oocytes from one woman affected. Low or zero fertilization in standard IVFwas usually caused by sperm abnormalities. Poor sperm-zona pellucida binding was frequently associated with failure of standard IVF and obvious defects of sperm motility or morphology. The size and shape of the acrosome is particularly important for sperm binding to the oocyte. The proportion of acrosome intact sperm in the insemination medium was related to the IVF rate. Inducing the acrosome reaction with a calcium ionophore reduced sperm-zona binding. Blocking acrosome dispersal with an acrosin inhibitor prevented spermzona penetration. Sperm-zona penetration was even more highly related to IVF rates than was sperm-zona binding. Some patients had low or zero fertilization rates with standard IVF but normal sperm by conventional tests and normal sperm-zona binding. Few of their sperm underwent the acrosome reaction on the surface of the zona and none penetrated the zona. In contrast, fertilization and pregnancy rates were high with intracytoplasmic sperm injection. We call thiscondition defective zona pellucida induced acrosome reaction. Discovery of the nature of the abnormalities in the signal transduction and effector pathways of the human zona pellucida induced acrosome reaction should result in simpler tests and treatments for the patients and also provide new leads for contraceptive development.

  20. Parameters influencing the pyrotechnic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Beat [Swiss Department of Defence, Civil Protection and Sports, armasuisse, Science and Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland)

    2005-02-01

    Phenomena (reaction effects) such as varied light emissions, sound, varied burning rates, varied heats of reaction and reaction products occur during the reaction of inorganic redox systems used for pyrotechnics. The peculiarity of these redox reactions is, that they take place as solid-solid, solid-liquid or solid-gaseous state reactions. In opposite the theoretical redox reaction normally postulated in inorganic chemistry takes place in a solvent. By variation of different parameters as for example the reducing agent, the oxidizer, the oxygen balance and the particle size, it is possible to create the above-mentioned effects in a wide range. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  1. Reaction chemistry of cerium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

  2. Neutrons from Piezonuclear Reactions

    CERN Document Server

    Cardone, F; Mignani, R; Perconti, W; Petrucci, A; Rosetto, F; Spera, G

    2007-01-01

    We report the results obtained by cavitating water solutions of iron salts (iron chloride and iron nitrate) with different concentrations at different ultrasound powers. In all cases we detected a neutron radiation well higher than the background level. The neutron production is perfectly reproducible and can at some extent be controlled. These evidences for neutron emission generated by cavitation support some preliminary clues for the possibility of piezonuclear reactions (namely nuclear reactions induced by pressure and shock waves) obtained in the last ten years. We have been able for the first time to state some basic features of such a neutron emission induced by cavitation, namely: 1) a marked threshold behavior in power, energy and time; 2) its occurring without a concomitant production of gamma radiation.

  3. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  4. Photooxidative reactions of psoralens

    International Nuclear Information System (INIS)

    The mechanism and biological significance of photooxidative reactions of psoralens are reviewed. Skin-photosensitizing activities of bifunctional and monofunctional psoralens are compared. Antioxidants tocopherols and butilated hydroxytoluene inhibit photochemical reactions of psoralens responsible for induction of erythema. The same antioxidants do not inhibit PUVA-therapy of psriasis. Though psoralens can generate singlet oxygen under UVA-irradiation (315 - 400 nm), nevertheless singlet oxygen does not play significant role in 8-methoxypsoralen (8-MOP) sensitized photooxidation of tocopherol or dihydroxyphenylalanine (DOPA). SH-compounds enhance the rate of 8-MOP sensitized photooxidation of DOPA by a factor of four, simultaneously the rate of oxidation of SH-groups is enhanced many fold in the presence of DOPA. Under UVA-irradiation in organic solvents psoralens are photooxidized. Dimeric photooxidized psoralens are easily destructed in water medium, their destruction induce oxidation of unsaturated lipids and DOPA. (author)

  5. On Reaction Coordinate Optimality.

    Science.gov (United States)

    Krivov, Sergei V

    2013-01-01

    The following question is addressed: how to establish that a constructed reaction coordinate is optimal, i.e., that it provides an accurate description of dynamics. It is shown that the reaction coordinate is optimal if its cut free energy profile, determined using length-weighted transitions, is constant, i.e., it is position and sampling interval independent. The observation leads to a number of interesting results. In particular, the equilibrium flux between two boundary states can be computed exactly as diffusion on a free energy profile associated with the coordinate. The mean square displacement, for the trajectory projected onto the coordinate, grows linear with time. That for the same trajectory projected onto a suboptimal coordinate grows slower than linear with time. The results are illustrated on a number of model systems, Sierpinski gasket, FIP35 protein, and beta3s peptide. PMID:26589017

  6. Two photon reactions

    International Nuclear Information System (INIS)

    Some recent results from the field of photon-photon interaction are presented. After a brief general introduction author discusses resonance production, exclusive processes with the four pion final state (γγ→π+π-π+π-), exclusive reaction γγ→psi psi, γγ - 2 body final state and jet production. Total hadronic cross sections for γγ - interactions and the photon structure function are also considered. (M.F.W.)

  7. Polymerase chain reaction

    OpenAIRE

    Gaurav Solanki

    2015-01-01

    The polymerase chain reaction (PCR) is a technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications. There are three major steps involved in the PCR technique: denaturation, annealing and extension. PCR is useful in the investigation...

  8. Photochemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

    1993-12-01

    The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

  9. Astrophysical Reaction Rates as a Challenge for Nuclear Reaction Theory

    OpenAIRE

    Rauscher, T.

    2010-01-01

    The relevant energy ranges for stellar nuclear reactions are introduced. Low-energy compound and direct reactions are discussed. Stellar modifications of the cross sections are presented. Implications for experiments are outlined.

  10. Compound-nuclear reaction cross sections via surrogate reactions

    International Nuclear Information System (INIS)

    The surrogate reaction method is an indirect technique for determining cross sections for nuclear reactions that proceed through a well-defined compound nucleus. In this method, the same compound nucleus is produced by an alternate ('surrogate') reaction and its decay products measured. The assumptions underlying the method are examined for the special case of 235U(n, f)

  11. Insect bite reactions

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    2013-01-01

    Full Text Available Insects are a class of living creatures within the arthropods. Insect bite reactions are commonly seen in clinical practice. The present review touches upon the medically important insects and their places in the classification, the sparse literature on the epidemiology of insect bites in India, and different variables influencing the susceptibility of an individual to insect bites. Clinical features of mosquito bites, hypersensitivity to mosquito bites Epstein-Barr virus NK (HMB-EBV-NK disease, eruptive pseudoangiomatosis, Skeeter syndrome, papular pruritic eruption of HIV/AIDS, and clinical features produced by bed bugs, Mexican chicken bugs, assassin bugs, kissing bugs, fleas, black flies, Blandford flies, louse flies, tsetse flies, midges, and thrips are discussed. Brief account is presented of the immunogenic components of mosquito and bed bug saliva. Papular urticaria is discussed including its epidemiology, the 5 stages of skin reaction, the SCRATCH principle as an aid in diagnosis, and the recent evidence supporting participation of types I, III, and IV hypersensitivity reactions in its causation is summarized. Recent developments in the treatment of pediculosis capitis including spinosad 0.9% suspension, benzyl alcohol 5% lotion, dimethicone 4% lotion, isopropyl myristate 50% rinse, and other suffocants are discussed within the context of evidence derived from randomized controlled trials and key findings of a recent systematic review. We also touch upon a non-chemical treatment of head lice and the ineffectiveness of egg-loosening products. Knockdown resistance (kdr as the genetic mechanism making the lice nerves insensitive to permethrin is discussed along with the surprising contrary clinical evidence from Europe about efficacy of permethrin in children with head lice carrying kdr-like gene. The review also presents a brief account of insects as vectors of diseases and ends with discussion of prevention of insect bites and some

  12. Chernobyl - the government reaction

    International Nuclear Information System (INIS)

    The Farmers' Union of Wales submitted this memorandum to the Agriculture Committee of the House of Commons giving its interpretation of the Government's reaction to the Chernobyl disaster. The primary aim of the paper is to provide an objective assessment of the impact of the disaster and the Government's handling of it, for future reference. The subject is dealt with under the following headings:- Chernobyl nuclear fallout in Wales, monitoring of milk and fresh vegetables, silage contamination, the North Wales Sheep Sector, soil, herbage and genetic implications, recommendations for the future. (UK)

  13. Nuclear reactions. An introduction

    International Nuclear Information System (INIS)

    Modern, self-contained introduction to the subject matter. Emphasizes the interplay between theory and experiment. Course-tested tutorial style, contains many derivations. Nuclei and nuclear reactions offer a unique setting for investigating three (and in some cases even all four) of the fundamental forces in nature. Nuclei have been shown - mainly by performing scattering experiments with electrons, muons, and neutrinos - to be extended objects with complex internal structures: constituent quarks; gluons, whose exchange binds the quarks together; sea-quarks, the ubiquitous virtual quark-antiquark pairs and, last but not least, clouds of virtual mesons, surrounding an inner nuclear region, their exchange being the source of the nucleon-nucleon interaction. The interplay between the (mostly attractive) hadronic nucleon-nucleon interaction and the repulsive Coulomb force is responsible for the existence of nuclei; their degree of stability, expressed in the details and limits of the chart of nuclides; their rich structure and the variety of their interactions. Despite the impressive successes of the classical nuclear models and of ab-initio approaches, there is clearly no end in sight for either theoretical or experimental developments as shown e.g. by the recent need to introduce more sophisticated three-body interactions to account for an improved picture of nuclear structure and reactions. Yet, it turns out that the internal structure of the nucleons has comparatively little influence on the behavior of the nucleons in nuclei, and nuclear physics - especially nuclear structure and reactions - is thus a field of science in its own right, without much recourse to subnuclear degrees of freedom. This book collects essential material that was presented in the form of lectures notes in nuclear physics courses for graduate students at the University of Cologne. It follows the course's approach, conveying the subject matter by combining experimental facts and experimental

  14. (d,pγ) Reactions and the surrogate reaction technique

    International Nuclear Information System (INIS)

    Neutron-capture reactions on neutron-rich nuclei are important to understand r-process nucleosynthesis, as well as applied needs such as stewardship science and nuclear energy. Because of the short half-lives of these species, it is not possible to measure these reactions directly with neutron beams on unstable targets. The (d,pγ) reaction with radioactive ion beams has been proposed as a surrogate reaction for (n,γ). Experiments to develop (d,pγ) techniques with radioactive ion beams and to demonstrate the efficacy of the (d,pγ) reaction as a surrogate for (n,γ) are discussed

  15. Zeolite Catalyzed Aldol Condensation Reactions

    OpenAIRE

    Adedayo I. Inegbenebor; Raphael C. Mordi; Oluwakayode M. Ogunwole

    2015-01-01

    The review is based on the description of zeolite structure, uses, synthesis, and catalytic aldol reaction in aldol condensation. An internal aldolcondensation reaction has been achieved over ZSM-5 zeolite with high silica-alumina ratio at 350oC. It therefore follows that zeolite canfunction as a catalyst in aldol type condensation reactions and that weak acid sites as well as a small number of active sites favor the aldolcondensation reaction of carbonyl compounds. However, the mixed condens...

  16. Reaction spreading on percolating clusters

    OpenAIRE

    Bianco, Federico; Chibbaro, Sergio; Vergni, Davide; Vulpiani, Angelo

    2013-01-01

    Reaction-diffusion processes in two-dimensional percolating structures are investigated. Two different problems are addressed: reaction spreading on a percolating cluster and front propagation through a percolating channel. For reaction spreading, numerical data and analytical estimates show a power-law behavior of the reaction product as M(t) \\sim t^dl, where dl is the connectivity dimension. In a percolating channel, a statistically stationary traveling wave develops. The speed and the widt...

  17. Hydrogen isotope exchange reactions

    International Nuclear Information System (INIS)

    The two most widely used methods for following hydrogen isotope exchange reactions, namely dedeuteriation and detritiation, involve in the first place the synthesis of an appropriately labelled compound. Rates of dedeuteriation are usually followed by measuring changes in the 1H n.m.r. spectrum of the substrate (examples are given); the method not only gives the rate but also the site(s) of exchange. It is limited to rather slow reactions and is not as accurate as some of the other methods. The development of deuterium n.m.r. spectroscopy means that changes in the 2H n.m.r. spectrum can also be used to measure rates of dedeuteriation. The development of liquid scintillation counting greatly eased the problem of how to detect weak β emitters; the attractions of tritium as a tracer were thereby much enhanced. Nowadays the study of rates of detritiation constitutes one of the most versatile and accurate methods of following hydrogen isotope exchange. Examples of the technique are given. (U.K.)

  18. Status of breakup reaction theory

    International Nuclear Information System (INIS)

    Recent studies on breakup reactions with the continuum-discretized coupled-channels method are reviewed. The topics covered are: four-body breakup processes for 6He induced reaction, dynamical relativistic effects on Coulomb breakup, microscopic description of projectile breakup processes, description of ternary processes (new triple-α reaction rate) and new approach to inclusive breakup processes.

  19. Medications and Drug Allergic Reactions

    Science.gov (United States)

    ... breathing. This is most common in adults with asthma and in people with nasal polyps (benign growths). Other reactions to NSAIDs can result in hives or in rare instances, severe reactions can result in shock. A number of factors influence your chances of having an adverse reaction ...

  20. The power-law reaction rate coefficient for barrierless reactions

    International Nuclear Information System (INIS)

    We study the power-law reaction rate coefficient for barrierless reactions, when the reactions take place in systems with power-law distributions, and derive a generalized rate formula for the barrierless reactions in the Gorin model. We show that, unlike those for bimolecular and unimolcular reactions, due to the lack of barriers, the power-law rate coefficient for barrierless reactions does not have a power-law function, and thus is not very strongly dependent on the ν-parameter. Four barrierless reactions are taken as application examples to calculate the new rate coefficients, which with larger fitting ν-parameters can be exactly in agreement with measurements in the experimental studies. (paper)

  1. Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2012-10-01

    Full Text Available The polymerase chain reaction (PCR is a technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. PCR is now a common and often indispensable technique used in medical and biological research labs for a variety of applications. There are three major steps involved in the PCR technique: denaturation, annealing and extension. PCR is useful in the investigation and diagnosis of a growing number of diseases. PCR is also used in forensics laboratories. PCR can identify genes that have been implicated in the development of cancer. The present paper is an attempt to review basics of PCR in relation to its methods, application and use.

  2. Kinetics of Bio-Reactions

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    his chapter predicts the specific rates of reaction by means of a mathematical expression, the kinetics of the reaction. This expression can be derived through a mechanistic interpretation of an enzymatically catalyzed reaction, but it is essentially of empirical nature for cell reactions. The...... models can be used in mass balances for design of processes under process conditions not yet studied experimentally. The value of the predictive kinetic model depends on the quality of the experimental data on which the model is based, and well-founded kinetic models for enzyme reactions have a...... considerable predictive power. This is also true for cell reaction models, when the model is used in its proper context. The chapter first discusses the kinetics for enzymatically catalyzed reactions (“enzyme reactions”). The kinetics can be derived from a mechanistic model. Then, the chapter derives empirical...

  3. Resonance Reaction in Diffusion-Influenced Bimolecular Reactions

    OpenAIRE

    Kolb, Jakob J.; Angioletti-Uberti, Stefano; Dzubiella, Joachim

    2016-01-01

    We investigate the influence of a stochastically fluctuating step-barrier potential on bimolecular reaction rates by exact analytical theory and stochastic simulations. We demonstrate that the system exhibits a new resonant reaction behavior with rate enhancement if an appropriately defined fluctuation decay length is of the order of the system size. Importantly, we find that in the proximity of resonance the standard reciprocal additivity law for diffusion and surface reaction rates is viola...

  4. Dechlorinating reaction of organic chlorides

    International Nuclear Information System (INIS)

    Dechlorination has been examined by the reaction between iron, aluminum powder or CaO and organic chlorides such as C2HCl3 and CH2Cl2. Progress of the reaction was analyzed with mass spectrometer. The reaction between iron and organic chloride was rapidly occurred at the temperature between 350 and 440degC in an atmosphere of argon. Above 380degC, more than 99.5% of C2HCl3 was decomposed within approximately 100 minutes. At 440degC, approximately 60% of C2HCl3 was decomposed by the reaction with aluminium powder within approximately 100 minutes. At 440degC, reaction between C2HCl3 and CaO powder were occurred rapidly in an atmosphere of argon to form CaCl2 and free carbon. Also in an atmosphere of air, nearly the same result was obtained. In this reaction, CaCl2, CO and CO2 were formed. CH2Cl2 was also decomposed by the reaction with iron at the temperature between 380 and 440degC. In the reaction, FeCl2, carbon and hydrogen were formed. CH3+ and CH4 were observed during the dechlorinating reaction of CH2Cl2. Variation in particle size of iron powder such as 100, 150 and 250 mesh did not affect the reaction rate. (author)

  5. Resonance Reaction in Diffusion-Influenced Bimolecular Reactions

    CERN Document Server

    Kolb, Jakob J; Dzubiella, Joachim

    2016-01-01

    We investigate the influence of a stochastically fluctuating step-barrier potential on bimolecular reaction rates by exact analytical theory and stochastic simulations. We demonstrate that the system exhibits a new resonant reaction behavior with rate enhancement if an appropriately defined fluctuation decay length is of the order of the system size. Importantly, we find that in the proximity of resonance the standard reciprocal additivity law for diffusion and surface reaction rates is violated due to the dynamical coupling of multiple kinetic processes. Together, these findings may have important repercussions on the correct interpretation of various kinetic reaction problems in complex systems, as, e.g., in biomolecular association or catalysis.

  6. Communication: Resonance reaction in diffusion-influenced bimolecular reactions

    Science.gov (United States)

    Kolb, Jakob J.; Angioletti-Uberti, Stefano; Dzubiella, Joachim

    2016-02-01

    We investigate the influence of a stochastically fluctuating step-barrier potential on bimolecular reaction rates by exact analytical theory and stochastic simulations. We demonstrate that the system exhibits a new "resonant reaction" behavior with rate enhancement if an appropriately defined fluctuation decay length is of the order of the system size. Importantly, we find that in the proximity of resonance, the standard reciprocal additivity law for diffusion and surface reaction rates is violated due to the dynamical coupling of multiple kinetic processes. Together, these findings may have important repercussions on the correct interpretation of various kinetic reaction problems in complex systems, as, e.g., in biomolecular association or catalysis.

  7. Neutrino and Antineutrino Interactions in Deuterium

    CERN Multimedia

    2002-01-01

    This experiment uses BEBC filled with deuterium and exposed to the wide-band neutrino beam N1. The use of deuterium as the target material allows to study interactions on both neutrons and protons. The charge of the target nucleon can be inferred from the number of positive and negative particles in the final state. \\\\ \\\\ Some of the physics aims of this experiment are to measure separately the cross sections @s^n and @s^p on neutrons and protons to determine the structure functions F|n(x,Q|2) and F|p(x,Q|2), the fragmentation functions D(z,Q|2) and the ratio of neutral to charged current interactions. \\\\ \\\\ Additional problems under investigation are the production of nucleon isobars, and of resonances in general, the production of strange and of charmed particles, and the problems of deuterium structure.

  8. Microwave-Accelerated Organic Reactions

    Institute of Scientific and Technical Information of China (English)

    LU; TaJung

    2001-01-01

    The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.  ……

  9. Limits for Stochastic Reaction Networks

    DEFF Research Database (Denmark)

    Cappelletti, Daniele

    Reaction systems have been introduced in the 70s to model biochemical systems. Nowadays their range of applications has increased and they are fruitfully used in dierent elds. The concept is simple: some chemical species react, the set of chemical reactions form a graph and a rate function is...... associated with each reaction. Such functions describe the speed of the dierent reactions, or their propensities. Two modelling regimes are then available: the evolution of the dierent species concentrations can be deterministically modelled through a system of ODE, while the counts of the dierent species at...... a certain time are stochastically modelled by means of a continuous-time Markov chain. Our work concerns primarily stochastic reaction systems, and their asymptotic properties. In Paper I, we consider a reaction system with intermediate species, i.e. species that are produced and fast degraded along...

  10. The Glaser–Hay reaction

    DEFF Research Database (Denmark)

    Vilhelmsen, Mie Højer; Jensen, Jonas; Tortzen, Christian;

    2013-01-01

    The oxidative Glaser–Hay coupling of two terminal alkynes to furnish a butadiyne is a key reaction for acetylenic scaffolding. Although the reaction is performed under rather simple conditions [CuCl/TMEDA/O2 (air)], the mechanism is still under debate. Herein we present detailed studies on the...... scope of this reaction by using both 13C NMR and UV/Vis spectroscopic methods. The former method was used to study the kinetics of the coupling of aryl-substituted alkynes as the aryl carbon resonances of the reactants and products have similar NOEs and relaxation times. The reaction was found to be...... zero-order with respect to the terminal alkyne reactant under standard preparative conditions. Moreover, as the reaction proceeded, a clear change to slower reaction kinetics was observed, but it was still apparently zero-order. The onset of this change was found to depend on the catalyst loading. This...

  11. Microwave-Accelerated Organic Reactions

    Institute of Scientific and Technical Information of China (English)

    LU TaJung

    2001-01-01

    @@ The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.

  12. The Paterno-Buchi reaction

    DEFF Research Database (Denmark)

    Brogaard, Rasmus Yding; Schalk, Oliver; Boguslavskiy, Andrey E.;

    2012-01-01

    The Paternò-Büchi (PB) reaction between an excited carbonyl compound and an alkene has been widely studied, but so far little is known about the excited-state dynamics of the reaction. In this investigation, we used a compound in which a formyl and a vinyl group are attached to a [2.......2]paracyclophane in order to obtain a model system in pre-reactive conformation for the PB reaction. We studied the excited-state dynamics of the isolated molecule in a molecular beam using femtosecond time-resolved photoelectron spectroscopy and ab initio calculations. The results show that inter-system crossing...... within two picoseconds competes efficiently with the reaction in the singlet manifold. Thus, the PB reaction in this model system takes place in the triplet state on a time scale of nanoseconds. This result stresses the importance of triplet states in the excited-state pathway of the PB reaction...

  13. Electrochemical reactions and ionization processes

    OpenAIRE

    Girault, Hubert; Liu, Baohong; Qiao, Liang; Bi, Hongyan; Prudent, Michel; Lion, Niels; Abonnenc, Mélanie

    2010-01-01

    Electrochemical or photo-electrochemical reactions in both electrospray ionization and laser desorption ionization are discussed stressing the role of the electrode reaction in influencing the ionization process. In particular, upon application of a high voltage during electrospray ionization, the emitter includes a working electrode, where redox reactions are observed, such as electro-generation of benzoquinone and metal ions. In contrast, the target plate in laser-induced desorption ionizat...

  14. Nuclear astrophysics from direct reactions

    OpenAIRE

    2008-01-01

    Accurate nuclear reaction rates are needed for primordial nucleosynthesis and hydrostatic burning in stars. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies. In recent years direct reactions have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental techniques and theoretical efforts, which are the subject of this presentation.

  15. Influences of Reaction Parameters on the Product of a Geothermite Reaction: A Multi-Component Oxidation-Reduction Reaction Study

    OpenAIRE

    Faierson, Eric J.

    2009-01-01

    This study investigated an oxidation-reduction reaction involving a mixture of minerals, glass, and aluminum that exhibited thermite-type reaction behavior. Thermite reactions are a class of Self-propagating High-temperature Synthesis (SHS) reactions. Chemical reactions between raw minerals and a reducing agent, which exhibit thermite-type reaction behavior, are termed geothermite reactions by the author. Geothermite reactions have the potential for use in In-Situ Resource Utilization (ISRU...

  16. Speeding chemical reactions by focusing

    Science.gov (United States)

    Lacasta, A. M.; Ramírez-Piscina, L.; Sancho, J. M.; Lindenberg, K.

    2013-04-01

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, and obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate ˜t-1/2 to very close to the perfect mixing rate, ˜t-1.

  17. Speeding chemical reactions by focusing

    CERN Document Server

    Lacasta, A M; Sancho, J M; Lindenberg, K

    2012-01-01

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate (t to the power -1/2) to very close to the perfect mixing rate, (t to the power -1).

  18. Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical Reactions

    Science.gov (United States)

    Schultz, Emeric

    2008-01-01

    A highly flexible learning tool, referred to as a dynamic reaction figure, is described. Application of these figures can (i) yield the correct chemical equation by simply following a set of menu driven directions; (ii) present the underlying "mechanism" in chemical reactions; and (iii) help to solve quantitative problems in a number of different…

  19. [Reaction mechanism studies of heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    This report contains papers that discuss: Target Dependence of Complex Fragment Emission in 47-MeV/u La-Induced Reactions; Deconvolution of Time-of-Flight Data to Improve Mass Identification; and Study of the Reaction of La + Al at E/A = 50 MeV with Landau-Vlasov Dynamics

  20. Progress in microscopic direct reaction modeling of nucleon induced reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M.; Bauge, E.; Hilaire, S.; Lechaftois, F.; Peru, S.; Pillet, N.; Robin, C. [CEA, DAM, DIF, Arpajon (France)

    2015-12-15

    A microscopic nuclear reaction model is applied to neutron elastic and direct inelastic scatterings, and pre-equilibrium reaction. The JLM folding model is used with nuclear structure information calculated within the quasi-particle random phase approximation implemented with the Gogny D1S interaction. The folding model for direct inelastic scattering is extended to include rearrangement corrections stemming from both isoscalar and isovector density variations occurring during a transition. The quality of the predicted (n,n), (n,n{sup '}), (n,xn) and (n,n{sup '}γ) cross sections, as well as the generality of the present microscopic approach, shows that it is a powerful tool that can help improving nuclear reactions data quality. Short- and long-term perspectives are drawn to extend the present approach to more systems, to include missing reactions mechanisms, and to consistently treat both structure and reaction problems. (orig.)

  1. Progress in microscopic direct reaction modeling of nucleon induced reactions

    International Nuclear Information System (INIS)

    A microscopic nuclear reaction model is applied to neutron elastic and direct inelastic scatterings, and pre-equilibrium reaction. The JLM folding model is used with nuclear structure information calculated within the quasi-particle random phase approximation implemented with the Gogny D1S interaction. The folding model for direct inelastic scattering is extended to include rearrangement corrections stemming from both isoscalar and isovector density variations occurring during a transition. The quality of the predicted (n,n), (n,n'), (n,xn) and (n,n'γ) cross sections, as well as the generality of the present microscopic approach, shows that it is a powerful tool that can help improving nuclear reactions data quality. Short- and long-term perspectives are drawn to extend the present approach to more systems, to include missing reactions mechanisms, and to consistently treat both structure and reaction problems. (orig.)

  2. Microscopic effective reaction theory for deuteron-induced reactions

    CERN Document Server

    Neoh, Yuen Sim; Minomo, Kosho; Ogata, Kazuyuki

    2016-01-01

    The microscopic effective reaction theory is applied to deuteron-induced reactions. A reaction model-space characterized by a $p+n+{\\rm A}$ three-body model is adopted, where A is the target nucleus, and the nucleon-target potential is described by a microscopic folding model based on an effective nucleon-nucleon interaction in nuclear medium and a one-body nuclear density of A. The three-body scattering wave function in the model space is obtained with the continuum-discretized coupled-channels method (CDCC), and the eikonal reaction theory (ERT), an extension of CDCC, is applied to the calculation of neutron removal cross sections. Elastic scattering cross sections of deuteron on $^{58}$Ni and $^{208}$Pb target nuclei at several energies are compared with experimental data. The total reaction cross sections and the neutron removal cross sections at 56 MeV on 14 target nuclei are calculated and compared with experimental values.

  3. Astronomy with Radioactivities: Chapter 9, Nuclear Reactions

    OpenAIRE

    Wiescher, M.; Rauscher, T.

    2010-01-01

    Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are determined by laboratory experiments supplemented by nuclear reaction and structure theory. We will discuss the experimental approach as well as the theoretical tools for obtaining the stellar reaction rates. A detailed analysis of a reaction is only possible fo...

  4. Chemistry of heavy ion reactions

    International Nuclear Information System (INIS)

    The use of heavy ions to induce nuclear reactions was reported as early as 1950. Since that time it has been one of the most active areas of nuclear research. Intense beams of ions as heavy as uranium with energies high enough to overcome the Coulomb barriers of even the heaviest elements are available. The wide variety of possible reactions gives rise to a multitude of products which have been studied by many ingenious chemical and physical techniques. Chemical techniques have been of special value for the separation and unequivocal identification of low yield species from the plethora of other nuclides present. Heavy ion reactions have been essential for the production of the trans-Md elements and a host of new isotopes. The systematics of compound nucleus reactions, transfer reactions, and deeply inelastic reactions have been elucidated using chemical techniques. A review of the variety of chemical procedures and techniques which have been developed for the study of heavy ion reactions and their products is given. Determination of the chemical properties of the trans-Md elements, which are very short-lived and can only be produced an ''atom-at-a-time'' via heavy ion reactions, is discussed. 53 refs., 19 figs

  5. Entropy Effects in Chelation Reactions.

    Science.gov (United States)

    Chung, Chung-Sun

    1984-01-01

    The entropy change for a reaction in aqueous solution can be evaluated as a combination of entropy factors. Valuable insight or understanding can be obtained from a detailed examination of these factors. Several entropy effects of inorganic chemical reactions are discussed as examples. (Author/JN)

  6. Symmetry violation in nuclear reactions

    International Nuclear Information System (INIS)

    Precision studies of nuclear reactions can be used to search for small violations of the discrete symmetries. Recent and proposed experimental work using nuclear reactions to study the breakdown of three symmetries - isospin (I), parity (P) and time-reversal (T) is reviewed. 44 references

  7. Free Radical Reactions in Food.

    Science.gov (United States)

    Taub, Irwin A.

    1984-01-01

    Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

  8. Zeolite Catalyzed Aldol Condensation Reactions

    Directory of Open Access Journals (Sweden)

    Adedayo I. Inegbenebor

    2015-03-01

    Full Text Available The review is based on the description of zeolite structure, uses, synthesis, and catalytic aldol reaction in aldol condensation. An internal aldolcondensation reaction has been achieved over ZSM-5 zeolite with high silica-alumina ratio at 350oC. It therefore follows that zeolite canfunction as a catalyst in aldol type condensation reactions and that weak acid sites as well as a small number of active sites favor the aldolcondensation reaction of carbonyl compounds. However, the mixed condensation product was found to be favored at temperatures above 300oCand the self-condensation of ethanal to crotonaldehyde was favored at temperatures below 300oC. It has also been suggested that both Brønstedand Lewis acids are involved in aldol reactions with Lewis acid sites the most probable catalytic sites. The zeolite group of minerals has founduse in many chemical and allied industries.

  9. Enzymatic reactions in confined environments

    Science.gov (United States)

    Küchler, Andreas; Yoshimoto, Makoto; Luginbühl, Sandra; Mavelli, Fabio; Walde, Peter

    2016-05-01

    Within each biological cell, surface- and volume-confined enzymes control a highly complex network of chemical reactions. These reactions are efficient, timely, and spatially defined. Efforts to transfer such appealing features to in vitro systems have led to several successful examples of chemical reactions catalysed by isolated and immobilized enzymes. In most cases, these enzymes are either bound or adsorbed to an insoluble support, physically trapped in a macromolecular network, or encapsulated within compartments. Advanced applications of enzymatic cascade reactions with immobilized enzymes include enzymatic fuel cells and enzymatic nanoreactors, both for in vitro and possible in vivo applications. In this Review, we discuss some of the general principles of enzymatic reactions confined on surfaces, at interfaces, and inside small volumes. We also highlight the similarities and differences between the in vivo and in vitro cases and attempt to critically evaluate some of the necessary future steps to improve our fundamental understanding of these systems.

  10. Sodium concrete reaction: structural considerations

    International Nuclear Information System (INIS)

    An overview of the sodium concrete reaction phenomenon, with emphasis on structural considerations, is presented. Available test results for limestone, basalt, and magnetite concrete with various test article configurations are reviewed. Generally, tests indicate reaction is self limiting before all sodium is used. Uncertainties, however, concerning the mechanism for penetration of sodium into concrete have resulted in different theories about a reaction model. Structural behavior may be significant in the progression of the reaction due to thermal-structural-chemical interactions involving tensile cracking, compressive crushing, or general deterioration of concrete and the exposure of fresh concrete surfaces to react with sodium. Structural behavior of test articles and potential factors that could enhance the progression of the reaction are discussed

  11. Integrated Microreactors for Reaction Automation: New Approaches to Reaction Development

    Science.gov (United States)

    McMullen, Jonathan P.; Jensen, Klavs F.

    2010-07-01

    Applications of microsystems (microreactors) in continuous-flow chemistry have expanded rapidly over the past two decades, with numerous reports of higher conversions and yields compared to conventional batch benchtop equipment. Synthesis applications are enhanced by chemical information gained from integrating microreactor components with sensors, actuators, and automated fluid handling. Moreover, miniaturized systems allow experiments on well-defined samples at conditions not easily accessed by conventional means, such as reactions at high pressure and temperatures. The wealth of synthesis information that could potentially be acquired through use of microreactors integrated with physical sensors and analytical chemistry techniques for online reaction monitoring has not yet been well explored. The increased efficiency resulting from use of continuous-flow microreactor platforms to automate reaction screening and optimization encourages a shift from current batchwise chemical reaction development to this new approach. We review advances in this new area and provide application examples of online monitoring and automation.

  12. Nuclear Reactions at Intermediate Energies

    CERN Document Server

    Shyam, Radhey

    2015-01-01

    In the domain of Nuclear reactions at intermediate energies, the QCD coupling constant $\\alpha_s$ is large enough ($\\sim$ 0.3 - 0.5) to render the perturbative calculational techniques inapplicable. In this regime the quarks are confined into colorless hadrons and it is expected that effective field theories of hadron interactions via exchange of hadrons, provide useful tools to describe such reactions. In this contribution we discuss applications of one such theory, the effective Lagrangian model, in describing the hadronic reactions at intermediate energies whose measurements are the focus of a vast international experimental program.

  13. Palladium-catalyzed coupling reactions

    CERN Document Server

    Molnár, Árpád

    2013-01-01

    This handbook and ready reference brings together all significant issues of practical importance for interested readers in one single volume. While covering homogeneous and heterogeneous catalysis, the text is unique in focusing on such important aspects as using different reaction media, microwave techniques or catalyst recycling. It also provides a comprehensive treatment of modern-day coupling reactions and emphasizes those topics that show potential for future development, such as continuous flow systems, water as a reaction medium, and catalyst immobilization, among others. With i

  14. Hypersensitivity reaction associated with phenytoin.

    Science.gov (United States)

    Indu, T H; Basutkar, Roopa Satyanarayan

    2015-09-01

    Hypersensitivity reactions with antiepileptic drugs (AEDs) are generally associated with aromatic AEDs. We present a case of hypersensitivity reactions followed by administration of phenytoin with diazepam and ranitidine in a patient with generalized tonic-clonic seizures. Antigen-antibody reactions or decreased levels of epoxide hydrolase are well known with phenytoin. Increased level of serum phenytoin causing toxicities due to competitive inhibition with diazepam on co-administration was also reported in the literature. Prevention of the adverse effects with AEDs is a multi-stage process, which requires implementation of preventive measures through careful monitoring and prompts interventions. PMID:26692739

  15. Reactions with light exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenthäler, R.; Faria, P.N. de; Pires, K.C.C.; Lepine-Szily, A.; Guimaraes, V.; Mendes Junior, D.R.; Assuncao, M.; Barioni, A.; Morcelle, V.; Morais, M.C.; Camargo Junior, O.; Alcantara Nuñez, J. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica; Moro, A.M. [Departamento de FAMN, Universidad de Sevilla, Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Rodriguez-Gallardo, M. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)

    2014-07-01

    Experimental cross sections for the {sup 6}He+{sup 120}Sn are analysed. Elastic scattering angular distributions and alpha particle production cross sections have been measured and are compared with the total reaction cross sections. (author)

  16. Bulk Nuclear Properties from Reactions

    OpenAIRE

    Danielewicz, P.

    2002-01-01

    Extraction of bulk nuclear properties by comparing reaction observables to results from semiclassical transport-model simulations is discussed. Specific properties include the nuclear viscosity, incompressibility and constraints on the nuclear pressure at supranormal densities.

  17. Transfer reactions in nuclear astrophysics

    Science.gov (United States)

    Bardayan, D. W.

    2016-08-01

    To a high degree many aspects of the large-scale behavior of objects in the Universe are governed by the underlying nuclear physics. In fact the shell structure of nuclear physics is directly imprinted into the chemical abundances of the elements. The tranquility of the night sky is a direct result of the relatively slow rate of nuclear reactions that control and determines a star’s fate. Understanding the nuclear structure and reaction rates between nuclei is vital to understanding our Universe. Nuclear-transfer reactions make accessible a wealth of knowledge from which we can extract much of the required nuclear physics information. A review of transfer reactions for nuclear astrophysics is presented with an emphasis on the experimental challenges and opportunities for future development.

  18. Reaction-bonded silicon nitride

    International Nuclear Information System (INIS)

    Reaction-bonded silicon nitride (RBSN) has been characterized. The oxidation behaviour in air up to 15000C and 3000 h and the effects of static and cyclic oxidation on room-temperature strength have been studied. (orig./IHOE)

  19. Statistical emission in nuclear reactions

    International Nuclear Information System (INIS)

    Statistical model in nuclear reactions has been extensively developed in the past decades, mainly by V. Weisskopf. However, a clear understanding of the experimental situation regarding low- and medium- energy nuclear reaction is not yet settled. The interpretation is complicated by the fact that often the reactions proceed via other mechanisms, for instance direct effects. The purpose 'of the present paper is to show how a great number of experiments can be put in agreement with the statistical formulas, and particularly the resonance measurements for slow neutrons, the evaporation spectra from medium-energy (n, n'), (p, n) and (n, p) reactions and the (n, p) cross-sections at 14 MeV. From the set of experiments discussed it is possible to obtain a consistent table of a, the parameter of the level density formula. (author)

  20. Fluctuations in catalytic surface reactions

    CERN Document Server

    Imbihl, R

    2003-01-01

    The internal reaction-induced fluctuations which occur in catalytic CO oxidation on a Pt field emitter tip have been studied using field electron microscopy (FEM) as a spatially resolving method. The structurally heterogeneous Pt tip consists of facets of different orientations with nanoscale dimensions. The FEM resolution of roughly 2 nm corresponds to a few hundred reacting adsorbed particles whose variations in the density are imaged as brightness fluctuations. In the bistable range of the reaction one finds fluctuation-induced transitions between the two stable branches of the reaction kinetics. The fluctuations exhibit a behaviour similar to that of an equilibrium phase transition, i.e. the amplitude diverges upon approaching the bifurcation point terminating the bistable range of the reaction. Simulations with a hybrid Monte Carlo/mean-field model reproduce the experimental observations. Fluctuations on different facets are typically uncorrelated but within a single facet a high degree of spatial cohere...

  1. Microreactors for Studying Enantioselective Reactions

    Czech Academy of Sciences Publication Activity Database

    Pavlorková, Jana

    Prague: Faculty of Chemical Technology, ICT, 2014. [Conference of Post-graduate Students. Prague (CZ), 26.06.2014] Institutional support: RVO:67985858 Keywords : enantioselective reactions * microreactors * molecular chirality Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  2. Solar-thermal reaction processing

    Energy Technology Data Exchange (ETDEWEB)

    Weimer, Alan W; Dahl, Jaimee K; Lewandowski, Allan A; Bingham, Carl; Raska Buechler, Karen J; Grothe, Willy

    2014-03-18

    In an embodiment, a method of conducting a high temperature chemical reaction that produces hydrogen or synthesis gas is described. The high temperature chemical reaction is conducted in a reactor having at least two reactor shells, including an inner shell and an outer shell. Heat absorbing particles are included in a gas stream flowing in the inner shell. The reactor is heated at least in part by a source of concentrated sunlight. The inner shell is heated by the concentrated sunlight. The inner shell re-radiates from the inner wall and heats the heat absorbing particles in the gas stream flowing through the inner shell, and heat transfers from the heat absorbing particles to the first gas stream, thereby heating the reactants in the gas stream to a sufficiently high temperature so that the first gas stream undergoes the desired reaction(s), thereby producing hydrogen or synthesis gas in the gas stream.

  3. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    Vivek V Ranade

    2014-03-01

    Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.

  4. Enzymatic reactions in dense gases

    OpenAIRE

    Knez, Željko

    2012-01-01

    The developments on applications of supercritical fluids as alternative solvents for biocatalytic processes that have taken place over the past two decades have been reviewed. An overview of process parameters influencing enzyme activity and stability, the influence of process parameters on reaction rates and productivity are presented. Applications of various types of reactors for enzymatic reaction in dense fluids, limitations of using enzymes as biocatalyst in supercritical fluids as well ...

  5. Psychosocial reactions to physical illness.

    OpenAIRE

    Lipowski, Z J

    1983-01-01

    Recently medical educators have emphasized the need for physicians to acquire the skills to deal with psychologic aspects of patient care. To facilitate this task a descriptive schema is presented for use in evaluating patients' psychosocial reactions to physical illness. Three core components of such reactions are: the personal meaning of illness, emotional responses to illness and modes of coping with illness. Clinical application of this schema may help with patient management and prevent ...

  6. Drug Reactions in Oral Mucosa

    Directory of Open Access Journals (Sweden)

    Emine Derviş

    2012-12-01

    Full Text Available Both immunologic and nonimmunologic drug reactions can be seen in oral mucosa. Since considerable number of these reactions heals spontaneously without being noticed by the patients, exact frequency of the lesions is unknown. Most common lesions are xerostomia, taste disorders, mucosal ulcerations and edema. In this article, oral lesions resulting from drug intake similar to those from oral lesions of local and systemic diseases, and diagnostic problems caused by these similarities, have been reviewed.

  7. Spatial model of autocatalytic reactions

    OpenAIRE

    De Anna, Pietro; Di Patti, Francesca; Fanelli, Duccio; McKane, Alan J.; Dauxois, Thierry

    2010-01-01

    Biological cells with all of their surface structure and complex interior stripped away are essentially vesicles - membranes composed of lipid bilayers which form closed sacs. Vesicles are thought to be relevant as models of primitive protocells, and they could have provided the ideal environment for pre-biotic reactions to occur. In this paper, we investigate the stochastic dynamics of a set of autocatalytic reactions, within a spatially bounded domain, so as to mimic a primordial cell. The ...

  8. Polarization phenomena in collinear reactions

    Science.gov (United States)

    Moravcsik, Michael J.; Arash, Firooz

    1985-06-01

    It is shown for a collinear reaction containing four particles with arbitrary spins which amplitudes remain nonzero and how they are related to the observables. In terms of primary observables all submatrices relating products of amplitudes to observables either vanish or turn into one-by-one submatrices, except the 8i types which may turn into three-by-three submatrices, but these latter submatrices are mostly avoidable when determining amplitudes. In terms of the secondary observables the 1M and 2i submatrices are slightly larger. Specifically, it is shown that in collinear reactions all observables in which only one particle is polarized (no matter how) vanish. Since reactions at very high energies are expected to be predominantly very close to being collinear, the smallness of such observables in such reactions can be expected on general grounds but polarization effects involving observables with more than one polarized particle can very well be very large. An iterative approximation method for the polarization analysis of reactions at very high energies is suggested. The results of this paper are also applicable to all models in which helicity conservation holds, since they are, for all t values, formally identical with collinear reactions.

  9. Polarization phenomena in collinear reactions

    International Nuclear Information System (INIS)

    It is shown for a collinear reaction containing four particles with arbitrary spins which amplitudes remain nonzero and how they are related to the observables. In terms of primary observables all submatrices relating products of amplitudes to observables either vanish or turn into one-by-one submatrices, except the 8/sub i/ types which may turn into three-by-three submatrices, but these latter submatrices are mostly avoidable when determining amplitudes. In terms of the secondary observables the 1/sub M/ and 2/sub i/ submatrices are slightly larger. Specifically, it is shown that in collinear reactions all observables in which only one particle is polarized (no matter how) vanish. Since reactions at very high energies are expected to be predominantly very close to being collinear, the smallness of such observables in such reactions can be expected on general grounds but polarization effects involving observables with more than one polarized particle can very well be very large. An iterative approximation method for the polarization analysis of reactions at very high energies is suggested. The results of this paper are also applicable to all models in which helicity conservation holds, since they are, for all t values, formally identical with collinear reactions

  10. Kinetics of actinide complexation reactions

    International Nuclear Information System (INIS)

    Though the literature records extensive compilations of the thermodynamics of actinide complexation reactions, the kinetics of complex formation and dissociation reactions of actinide ions in aqueous solutions have not been extensively investigated. In light of the central role played by such reactions in actinide process and environmental chemistry, this situation is somewhat surprising. The authors report herein a summary of what is known about actinide complexation kinetics. The systems include actinide ions in the four principal oxidation states (III, IV, V, and VI) and complex formation and dissociation rates with both simple and complex ligands. Most of the work reported was conducted in acidic media, but a few address reactions in neutral and alkaline solutions. Complex formation reactions tend in general to be rapid, accessible only to rapid-scan and equilibrium perturbation techniques. Complex dissociation reactions exhibit a wider range of rates and are generally more accessible using standard analytical methods. Literature results are described and correlated with the known properties of the individual ions

  11. Nuclear Reactions for Astrophysics and Other Applications

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Scielzo, N D; Ressler, J J

    2011-03-01

    Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  12. Reaction rates for a generalized reaction-diffusion master equation

    Science.gov (United States)

    Hellander, Stefan; Petzold, Linda

    2016-01-01

    It has been established that there is an inherent limit to the accuracy of the reaction-diffusion master equation. Specifically, there exists a fundamental lower bound on the mesh size, below which the accuracy deteriorates as the mesh is refined further. In this paper we extend the standard reaction-diffusion master equation to allow molecules occupying neighboring voxels to react, in contrast to the traditional approach, in which molecules react only when occupying the same voxel. We derive reaction rates, in two dimensions as well as three dimensions, to obtain an optimal match to the more fine-grained Smoluchowski model and show in two numerical examples that the extended algorithm is accurate for a wide range of mesh sizes, allowing us to simulate systems that are intractable with the standard reaction-diffusion master equation. In addition, we show that for mesh sizes above the fundamental lower limit of the standard algorithm, the generalized algorithm reduces to the standard algorithm. We derive a lower limit for the generalized algorithm which, in both two dimensions and three dimensions, is of the order of the reaction radius of a reacting pair of molecules.

  13. Reaction pathways of propene pyrolysis.

    Science.gov (United States)

    Qu, Yena; Su, Kehe; Wang, Xin; Liu, Yan; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2010-05-01

    The gas-phase reaction pathways in preparing pyrolytic carbon with propene pyrolysis have been investigated in detail with a total number of 110 transition states and 50 intermediates. The structure of the species was determined with density functional theory at B3PW91/6-311G(d,p) level. The transition states and their linked intermediates were confirmed with frequency and the intrinsic reaction coordinates analyses. The elementary reactions were explored in the pathways of both direct and the radical attacking decompositions. The energy barriers and the reaction energies were determined with accurate model chemistry method at G3(MP2) level after an examination of the nondynamic electronic correlations. The heat capacities and entropies were obtained with statistical thermodynamics. The Gibbs free energies at 298.15 K for all the reaction steps were reported. Those at any temperature can be developed with classical thermodynamics by using the fitted (as a function of temperature) heat capacities. It was found that the most favorable paths are mainly in the radical attacking chain reactions. The chain was proposed with 26 reaction steps including two steps of the initialization of the chain to produce H and CH(3) radicals. For a typical temperature (1200 K) adopted in the experiments, the highest energy barriers were found in the production of C(3) to be 203.4 and 193.7 kJ/mol. The highest energy barriers for the production of C(2) and C were found 174.1 and 181.4 kJ/mol, respectively. These results are comparable with the most recent experimental observation of the apparent activation energy 201.9 +/- 0.6 or 137 +/- 25 kJ/mol. PMID:20082392

  14. Capture reactions at low energies

    International Nuclear Information System (INIS)

    Some few body capture reaction studies at low energies are reviewed. The emphasis is on the use of polarized beams. New calculations of n+d and p+d capture had just recently been completed by the Los Alamos group (Friar, Gibson, and Payne). Their results are in good agreement with existing data, and emphasize the importance of meson exchange current effects in these processes at thermal energies. The effects of M1 radiation can be seen in the vector analyzing power of the p+d radiative capture reaction from its interference with E1 radiation. The vector analyzing powers of the rvec p+T → 4He + γ reaction can be used to search for M1 radiation in 4He. Low energy data show a substantial b1 coefficient which can only be accounted for with a substantial M1 contribution. The author is also working on studying the rvec d+T and rvec d+3He capture reactions in the region of the fusion resonance. His (published) rvec d+T capture data indicate that the reaction goes via ∼95% S = 3/2, E1 capture with small S = 1/2, E1 and small M1 admixtures. In the course of obtaining the d+T and d+3He data, he realized that he could use his spectra to obtain the ground state widths of 5He and 5Li. Finally, he will discuss the d+d reaction at very low energies. The simplest picture of this reaction dominated by S wave capture to the D-state below 1 MeV

  15. Exchange Reactions. Proceedings of the Symposium on Exchange Reactions

    International Nuclear Information System (INIS)

    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

  16. Carbonitriding reactions of diatomaceous earth: phase evolution and reaction mechanisms

    Directory of Open Access Journals (Sweden)

    BRANKO MATOVIC

    2006-06-01

    Full Text Available The possibility of using diatomaceous earth as Si precursor for low temperature synthesis of non-oxide powders by carbothermal reduction-nitridation was studied. It was found that carbonitriding reactions produce phases of the Si–Al–O–N system. Already at 1300 °C, nanosized, non-oxide powders were obtained. The comparatively low reaction temperatures is attributred to the nano-porous nature of the raw material. The evolution of crystalline phases proceeded via many intermediate stages. The powders were characterized by X-ray and SEM investigations. The results showed that diatomaceous earth can be a very effective source for obtaining non-oxide powders.

  17. A comprehensive survey of nuclear reactions; Panorama des reactions nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cugnon, J. [Liege Univ., IFPA, AGO Dept. (Belgium)

    2007-07-01

    The various mechanisms of nuclear reactions are surveyed and classified in different regimes, based on the notions of coherent mechanisms and hard versus soft processes. The emphasis is put on the concepts at the basis of the understanding of these regimes and on the elements of nuclear structure which are involved in these different regimes, as well as the on the possibility of extracting this information. Due to lack of space and for pedagogical reasons, the discussion is limited to nucleon-induced and light-ion-induced reactions. However, a few remarks are given concerning some specific probes, such as weakly bound projectiles or neutron-rich nuclei. (author)

  18. Modeling of fluctuating reaction networks

    International Nuclear Information System (INIS)

    Full Text:Various dynamical systems are organized as reaction networks, where the population size of one component affects the populations of all its neighbors. Such networks can be found in interstellar surface chemistry, cell biology, thin film growth and other systems. I cases where the populations of reactive species are large, the network can be modeled by rate equations which provide all reaction rates within mean field approximation. However, in small systems that are partitioned into sub-micron size, these populations strongly fluctuate. Under these conditions rate equations fail and the master equation is needed for modeling these reactions. However, the number of equations in the master equation grows exponentially with the number of reactive species, severely limiting its feasibility for complex networks. Here we present a method which dramatically reduces the number of equations, thus enabling the incorporation of the master equation in complex reaction networks. The method is examplified in the context of reaction network on dust grains. Its applicability for genetic networks will be discussed. 1. Efficient simulations of gas-grain chemistry in interstellar clouds. Azi Lipshtat and Ofer Biham, Phys. Rev. Lett. 93 (2004), 170601. 2. Modeling of negative autoregulated genetic networks in single cells. Azi Lipshtat, Hagai B. Perets, Nathalie Q. Balaban and Ofer Biham, Gene: evolutionary genomics (2004), In press

  19. Combustion kinetics and reaction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

    1993-12-01

    This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

  20. Optimization of Reaction Conditions for Preparing Carboxymethylcellulose

    OpenAIRE

    S. Nilus; L.M. Chng; Bono, A; A.C.R. Valintinus; N.M. Ismail

    2010-01-01

    The cellulose powder was converted to carboxymethylcellulose (CMC) by etherification process using sodium monochloroacetate and sodium hydroxide. There are two reaction occur simultaneously during carboxymethylation that are the primary reaction which produces pure CMC and side reaction that produces undesired sodium glycolate. The carboxymethylation reaction was optimized against the reaction temperature, reaction time, SMCA concentration, NaOH concentration and the ratio solvent of ethanol:...

  1. Adverse Reactions to Radiographic Contrast Material

    OpenAIRE

    Bush, William H.; Mullarkey, Michael F.; Webb, D. Robert

    1980-01-01

    Major adverse reactions to radiographic contrast media will occur more often as contrast material is now also administered during computerized tomographic (CT) scanning. Differentiation of the two major contrast reactions, the vagus reaction and the anaphylactoid reaction, is essential. Bradycardia is the key finding for identifying the vagus reaction. The vagus reaction involving hypotension and bradycardia requires treatment with large doses of atropine given intravenously. The immediate ge...

  2. The Reaction of Acenaphthene with Nitrobenzene

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The reaction of acenaphthene with nitrobenzene was investigated in the presence of AlCl3 . The results showed that the reaction proceeded via carboncation-electrophilic substitution reaction and free radical substitution reaction pathway. The products of acenaphthenyl phenylamine and biacenaphthyl could be synthesized by this reaction. The influence of the amount of AlCl3 and the temperature on the components of products were also studied in this reaction.

  3. Anaphylactoid reactions to radiocontrast media.

    Science.gov (United States)

    Canter, Lauren M

    2005-01-01

    As the role for diagnostic and therapeutic contrast-enhanced imaging increases, review of the epidemiology, mechanisms, risk factors, and pretreatment for radiocontrast-mediated anaphylactoid reactions becomes more and more pertinent. Ongoing research has failed to elucidate the precise mechanisms of both early and late reactions, though the current data point to a multifactorial pathogenesis. The risk of reactions has decreased over time as contrast media have evolved from ionic, high-osmolality to nonionic, low-osmolality formulations; however, the expense of the low-osmolality agents limit their universal use. Today, 1-12% of patients exhibit adverse responses ranging from mild to severe, with individual risk depending on the type of contrast administered and certain baseline patient characteristics. For those high-risk patients who must receive contrast, effective pretreatment guidelines have been established. PMID:16119034

  4. Postcolumn reaction detectors for HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Frei, R.W.; Jansen, H.; Brinkman, U.A.T.

    1985-12-01

    Currently, the best and most reliable HPLC (high-performance liquid chromatography) detectors are UV-VIS absorbance, fluorescence, and electrochemical detectors. It is attractive to try to expand their range of application by using suitable chemical derivatization techniques to convert the analytes of interest with their originally poor detection properties into compounds that can be detected with high sensitivity with these detectors. Besides an improvement of the detection properties, the chemical reaction can also enhance the selectivity of the total analytical method. The derivatization can be carried out either prior to the HPLC separation or by doing the reaction in an on-line postcolumn mode. Comparative advantages and disadvantages of these two approaches have been discussed previously. This paper will discuss on-line postcolumn derivatization. A general scheme of an HPLC system equipped with an on-line postcolumn reaction detector is given. 40 references, 6 figures, 2 tables.

  5. Photonuclear reactions on titanium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Belyshev, S. S. [Moscow State University (Russian Federation); Dzhilavyan, L. Z. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Ishkhanov, B. S.; Kapitonov, I. M. [Moscow State University (Russian Federation); Kuznetsov, A. A., E-mail: kuznets@depni.sinp.msu.ru; Orlin, V. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2015-03-15

    The photodisintegration of titanium isotopes in the giant-dipole-resonance energy region is studied by the photon-activation method. Bremsstrahlung photons whose spectrum has the endpoint energy of 55 MeV is used. The yields and integrated cross sections are determined for photoproton reactions on the titanium isotopes {sup 47,48,49,50}Ti. The respective experimental results are compared with their counterparts calculated on the basis of the TALYS code and a combined photonucleon-reaction model. The TALYS code disregards the isospin structure of the giant dipole resonance and is therefore unable to describe the yield of photoproton reactions on the heavy titanium isotopes {sup 49,50}Ti.

  6. Catalytic, enantioselective, vinylogous aldol reactions.

    Science.gov (United States)

    Denmark, Scott E; Heemstra, John R; Beutner, Gregory L

    2005-07-25

    In 1935, R. C. Fuson formulated the principle of vinylogy to explain how the influence of a functional group may be felt at a distant point in the molecule when this position is connected by conjugated double-bond linkages to the group. In polar reactions, this concept allows the extension of the electrophilic or nucleophilic character of a functional group through the pi system of a carbon-carbon double bond. This vinylogous extension has been applied to the aldol reaction by employing "extended" dienol ethers derived from gamma-enolizable alpha,beta-unsaturated carbonyl compounds. Since 1994, several methods for the catalytic, enantioselective, vinylogous aldol reaction have appeared, with which varying degrees of regio- (site), enantio-, and diastereoselectivity can be attained. In this Review, the current scope and limitations of this transformation, as well as its application in natural product synthesis, are discussed. PMID:15940727

  7. Spatial model of autocatalytic reactions

    Science.gov (United States)

    de Anna, Pietro; di Patti, Francesca; Fanelli, Duccio; McKane, Alan J.; Dauxois, Thierry

    2010-05-01

    Biological cells with all of their surface structure and complex interior stripped away are essentially vesicles—membranes composed of lipid bilayers which form closed sacs. Vesicles are thought to be relevant as models of primitive protocells, and they could have provided the ideal environment for prebiotic reactions to occur. In this paper, we investigate the stochastic dynamics of a set of autocatalytic reactions, within a spatially bounded domain, so as to mimic a primordial cell. The discreteness of the constituents of the autocatalytic reactions gives rise to large sustained oscillations even when the number of constituents is quite large. These oscillations are spatiotemporal in nature, unlike those found in previous studies, which consisted only of temporal oscillations. We speculate that these oscillations may have a role in seeding membrane instabilities which lead to vesicle division. In this way synchronization could be achieved between protocell growth and the reproduction rate of the constituents (the protogenetic material) in simple protocells.

  8. Direct-reaction and isospin symmetries in d + d reactions

    International Nuclear Information System (INIS)

    We have measured angular distributions of the analyzing powers A/sub y/, A/sub x/x, A/sub y/y, and A/sub x/z for the 2H(d,p)3H reaction at deuteron lab energies E/sub d/ of 13.39 and 17.00 MeV. These distributions do not show the symmetry or antisymmetry about 900 (c.m.) expected on the basis of a simple direct-neutron-transfer reaction mechanism. In a companion experiment, we have measured the same four analyzing powers for both the 2H(d,p)3H reaction and its charge-symmetric partner 2H(d,n)3He at E/sub d/ = 15.50 and 17.00 MeV in a restricted angular range. These latter data were obtained by simultaneously detecting the tritons and helions. Only small differences were observed in the respective analyzing powers for the two reactions, which suggests a weakening of the mechanism responsible for the larger differences found by others at lower energies

  9. Fundamentals of chemical reaction engineering

    CERN Document Server

    Davis, Mark E

    2012-01-01

    Appropriate for a one-semester undergraduate or first-year graduate course, this text introduces the quantitative treatment of chemical reaction engineering. It covers both homogeneous and heterogeneous reacting systems and examines chemical reaction engineering as well as chemical reactor engineering. The authors take a chemical approach, helping students develop an intuitive feeling for concepts, rather than an engineering approach, which tends to overlook the inner workings of systems and objects.Each chapter contains numerous worked-out problems and real-world vignettes involving commercia

  10. Interface reactions in film materials

    Institute of Scientific and Technical Information of China (English)

    Fengwu Zhu; Zhonghai Zhai; Guanghua Yu

    2003-01-01

    Interface reaction (IR) is a frequently observed phenomenon in the study of advanced thin film materials. It is very important to study the reaction conditions at which IR happens and then to suppress or make use of it, the necessary conditions, including both thermodynamical and dynamical conditions of IR were discussed in detail. IRs in various systems, including oxide/silicon,oxide/metal, metal/metal, metal/semiconductor and semiconductor/semiconductor, were reviewed. Methods to suppress and make use of IR were also introduced.

  11. Vision 2020. Reaction Engineering Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Klipstein, David H. [Reaction Design, San Diego, CA (United States); Robinson, Sharon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2001-01-01

    The Reaction Engineering Roadmap is a part of an industry- wide effort to create a blueprint of the research and technology milestones that are necessary to achieve longterm industry goals. This report documents the results of a workshop focused on the research needs, technology barriers, and priorities of the chemical industry as they relate to reaction engineering viewed first by industrial use (basic chemicals; specialty chemicals; pharmaceuticals; and polymers) and then by technology segment (reactor system selection, design, and scale-up; chemical mechanism development and property estimation; dealing with catalysis; and new, nonstandard reactor types).

  12. Tests of Lorentz violation in muon antineutrino to electron antineutrino oscillations

    CERN Document Server

    Auerbach, L B; Caldwell, D O; Church, E D; Cochran, A K; Donahue, J B; Fazely, A R; Garvey, G T; Gunasingha, R M; Imlay, R L; Katori, T; Louis, W C; McIlhany, K L; Metcalf, W J; Mills, G B; Sandberg, V D; Smith, D; Stancu, I; Strossman, W H; Tayloe, R; Sung, M; Vernon, W; White, D H; Yellin, S

    2005-01-01

    A recently developed Standard-Model Extension (SME) formalism for neutrino oscillations that includes Lorentz and CPT violation is used to analyze the sidereal time variation of the neutrino event excess measured by the Liquid Scintillator Neutrino Detector (LSND) experiment. The LSND experiment, performed at Los Alamos National Laboratory, observed an excess, consistent with neutrino oscillations, of ${\\bar\

  13. Reactions

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    2011-01-01

    ) museum. Augmentation, in this expanding digital field, is part of a production of new public spaces, as well as a new reality that affects and traverses art and institutions immanently and througout. The expanding digital field is transforming art and the art museum in a number of fundamental ways, a few......; It is in this negotiation, I would claim, that the foundation of a possible critique of the role of the (art) museum in the age of post-bourgeois public space and experience-based culture should be located....

  14. Reduction of chemical reaction models

    Science.gov (United States)

    Frenklach, Michael

    1991-01-01

    An attempt is made to reconcile the different terminologies pertaining to reduction of chemical reaction models. The approaches considered include global modeling, response modeling, detailed reduction, chemical lumping, and statistical lumping. The advantages and drawbacks of each of these methods are pointed out.

  15. Reactions of ethanol on Ru

    NARCIS (Netherlands)

    Sturm, J. M.; Lee, C. J.; F. Bijkerk,

    2013-01-01

    The adsorption and reactions of ethanol on Ru(0001) were studied with temperature-programmed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. From 175 K to 200 K, ethanol is converted into ethoxy groups, which und

  16. Exchange effects in direct reactions

    International Nuclear Information System (INIS)

    The effect of antisymmetrization in direct reactions is examined by studying the properties of the coupling-normalization kernel function occurring in a resonating-group formulation. From this study, one obtains useful information concerning the general behavior of direct-reactiion processes and some justification for the use of three-body models in phenomenological analyses

  17. Recyclization reactions leading to benzimidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Mamedov, Vakhid A; Murtazina, Anna M [A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences, Kazan (Russian Federation)

    2011-05-31

    The published data on the recyclization reactions that afford benzimidazoles are generalized and systematized. Both classical and new methods of benzimidazole synthesis are considered. Attention is focused on the publications over the recent 10-15 years; of the earlier publications, only those unknown to the wide circle of chemists are analyzed.

  18. Multispecies reaction-diffusion systems

    OpenAIRE

    Aghamohammadi, A.; Fatollahi, A. H.; Khorrami, M.; Shariati, A.

    2000-01-01

    Multispecies reaction-diffusion systems, for which the time evolution equation of correlation functions become a closed set, are considered. A formal solution for the average densities is found. Some special interactions and the exact time dependence of the average densities in these cases are also studied. For the general case, the large time behaviour of the average densities has also been obtained.

  19. Apparent tunneling in chemical reactions

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    2000-01-01

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however...

  20. Apparent tunneling in chemical reactions

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however...

  1. Knoevenagel Reaction of Unprotected Sugars

    Science.gov (United States)

    Scherrmann, Marie-Christine

    The Knoevenagel reaction of unprotected sugars was investigated in the 1950s using zinc chloride as promoter. The so-called Garcia Gonzalez reaction had been almost forgotten for 50 years, until the emergence of new water tolerant catalysts having Lewis acid behavior. The reaction was thus reinvestigated and optimal conditions have been found to prepare trihydroxylated furan derivatives from pentose or β-tetrahydrofuranylfuran from hexoses with non-cyclic β-keto ester or β-diketones. Other valuable compounds such as β-linked tetrahydrobenzofuranyl glycosides or hydroxyalkyl-3,3,6,6,-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione can be obtained using cyclic β-dicarbonylic derivatives. Apart from one report in the 1950s, the Knoevenagel reaction of unprotected carbohydrate in basic condition has been studied only in the mid-1980s to prepare C-glycosyl barbiturates from barbituric acids and, later on, from non-cyclic β-diketones, β-C-glycosidic ketones. The efficient method exploited to prepare such compounds has found an industrial development in cosmetics.

  2. Reactants encapsulation and Maillard Reaction

    NARCIS (Netherlands)

    Troise, A.D.; Fogliano, V.

    2013-01-01

    In the last decades many efforts have been addressed to the control of Maillard Reaction products in different foods with the aim to promote the formation of compounds having the desired color and flavor and to reduce the concentration of several potential toxic molecules. Encapsulation, already app

  3. Quantum Tunneling and Back Reaction

    OpenAIRE

    Banerjee, Rabin; Majhi, Bibhas Ranjan

    2007-01-01

    We give a correction to the tunneling probability by taking into account the back reaction effect to the metric of the black hole spacetime. We then show how this gives rise to the modifications in the semiclassical black hole entropy and Hawking temperature. Finally, we reproduce the familiar logarithmic correction to the Bekenstein-Hawking area law.

  4. Detecting deception through reaction times

    NARCIS (Netherlands)

    B. Verschuere; K. Suchotzki; E. Debey

    2015-01-01

    Reaction times (RTs) are among the oldest measures in psychology, and remain popular in several psychology disciplines. However, they have been largely neglected as a cue for deception, reflecting the sceptic's view that RTs fall under voluntary control and are easily manipulated. From our review of

  5. Strangeness exchange reactions and hypernuclei

    International Nuclear Information System (INIS)

    Recent progress in the spectroscopy of Λ and Σ hypernuclei is reviewed. Prospects for the production of doubly strange hypernuclei at a future kaon factory are assessed. It is suggested that the (K-,K+) reaction on a nuclear target may afford an optimal way of producing the H dibaryon, a stable six quark object with J/sup π/ = O+, S = -2

  6. Reaction of alkylcobalamins with thiols

    International Nuclear Information System (INIS)

    Carbon-13 NMR spectroscopy and phosphorus-31 NMR spectroscopy have been used to study the reaction of several alkylcobalamins with 2-mercaptoethanol. At alkaline pH, when the thiol is deprotonated, the alkyl-transfer reactions involve a nucleophilic attack of the thiolate anion on the Co-methylene carbon of the cobalamins, yielding alkyl thioethers and cob(II)alamin. In these nucleophilic displacement reactions cob(I)alamin is presumably formed as an intermediate. The higher alkylcobalamins react more slowly than methylcobalamin. The lower reactivity of ethyl- and propylcobalamin is probably the basis of the inhibition of the corrinoid-dependent methyl-transfer systems by propyl iodide. The transfer of the upper nucleoside ligand of adenosylcobalamin to 2-mercaptoethanol is a very slow process; S-adenosylmercaptoethanol and cob(II)alamin are the final products of the reaction. The dealkylation of (carboxymethyl)cobalamin is a much more facile reaction. At alkaline pH S-(carboxymethyl)mercaptoethanol and cob(II)alamin are produced, while at pH values below 8 the carbon-cobalt bond is cleaved reductively to acetate and cob(II)alamin. The reductive cleavage of the carbon-cobalt bond of (carboxymethyl)cobalamin by 2-mercaptoethanol is extremely fast when the cobalamin is in the base-off form. Because the authors have been unable to detect trans coordination of 2-mercaptoethanol, they favor a mechanism that involves a hydride attack on the Co-methylene carbon of (carboxymethyl) rather than a trans attack of the thiol on the cobalt atom

  7. Experimental Demonstrations in Teaching Chemical Reactions.

    Science.gov (United States)

    Hugerat, Muhamad; Basheer, Sobhi

    2001-01-01

    Presents demonstrations of chemical reactions by employing different features of various compounds that can be altered after a chemical change occurs. Experimental activities include para- and dia-magnetism in chemical reactions, aluminum reaction with base, reaction of acid with carbonates, use of electrochemical cells for demonstrating chemical…

  8. Exact Results for Kinetics of Catalytic Reactions

    OpenAIRE

    Frachebourg, L.; Krapivsky, P. L.

    1995-01-01

    The kinetics of an irreversible catalytic reaction on substrate of arbitrary dimension is examined. In the limit of infinitesimal reaction rate (reaction-controlled limit), we solve the dimer-dimer surface reaction model (or voter model) exactly in arbitrary dimension $D$. The density of reactive interfaces is found to exhibit a power law decay for $D

  9. GREENER REACTIONS UNDER SOLVENT FREE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Hiren M. Marvaniya

    2011-06-01

    Full Text Available The toxicity and volatile nature of many organic solvents, particularly chlorinated hydrocarbons that are widely used in huge amounts for organic reactions have posed a serious threat to the environment. Thus, design of solventless catalytic reaction has received tremendous attention in recent times in the area of green synthesis. A solvent-free or solid state reaction may be carried out using the reactants alone or incorporating them in clays, zeolites, silica, alumina or other matrices to achieve high degree of stereoselectivity in the products, to reduce byproducts, to maximize rate of reaction. We illustrate the environmentally benign approach to 1,2-Oxazine-2- oxides, Michael addition, Wohl–Ziegler reaction, Acylation, Heck reaction, Tishchenko reaction, Diels– Alder reaction, Reformatsky and Luche Reaction, Oxidative coupling Reaction, Synthesis of chalcones, Synthesis of Dihydropyrimidinones

  10. Thermodynamics of Enzyme-Catalyzed Reactions Database

    Science.gov (United States)

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  11. Investigating Reaction-Driven Cracking

    Science.gov (United States)

    Kelemen, P. B.; Hirth, G.; Savage, H. M.

    2013-12-01

    Many metamorphic reactions lead to large volume changes, and potentially to reaction-driven cracking [1,2]. Large-scale hydration of mantle peridotite to produce serpentine or talc is invoked to explain the rheology of plate boundaries, the nature of earthquakes, and the seismic properties of slow-spread ocean crust and the 'mantle wedge' above subduction zones. Carbonation of peridotite may be an important sink in the global carbon cycle. Zones of 100% magnesite + quartz replacing peridotite, up to 200 m thick, formed where oceanic mantle was thrust over carbonate-bearing metasediments in Oman. Talc + carbonate is an important component of the matrix in subduction mélanges at Santa Catalina Island , California, and the Sanbagawa metamorphic belt, Japan. Engineered systems to emulate natural mineral carbonation could provide relatively inexpensive CO2 capture and storage [3]. More generally, engineered reaction-driven cracking could supplement or replace hydraulic fracture in geothermal systems, solution mining, and extraction of tight oil and gas. The controls on reaction-driven cracking are poorly understood. Hydration and carbonation reactions can be self-limiting, since they potentially reduce permeability and armor reactive surfaces [4]. Also, in some cases, hydration or carbonation may take place at constant volume. Small changes in volume due to precipitation of solid products increases stress, destabilizing solid reactants, until precipitation and dissolution rates become equal at a steady state stress [5]. In a third case, volume change due to precipitation of solid products causes brittle failure. This has been invoked on qualitative grounds to explain, e.g., complete serpentinization of mantle peridotite [6]. Below ~ 300°C, the available potential energy for hydration and carbonation of olivine could produce stresses of 100's of MPa [2], sufficient to fracture rocks to 10 km depth or more, causing brittle failure below the steady state stress required

  12. Relativistic Formulation of Reaction Theory

    CERN Document Server

    Polyzou, W N

    2014-01-01

    A relativistic formulation of reaction theory for nuclei with a dynamics given by a unitary representations of the Poincar\\'e group is developed. Relativistic dynamics is introduced by starting from a relativistic theory of free particles to which rotationally invariant interactions are added to the invariant mass operator. Poincar\\'e invariance is realized by requiring that simultaneous eigenstates of the mass and spin transform as irreducible representations of the Poincar\\'e group. A relativistic formulation of scattering theory is presented and approximations emphasizing dominant degrees of freedom that preserve unitarity, exact Poincar\\'e invariance and exchange symmetry are discussed. A Poincar\\'e invariant formulation of a (d,p) reaction as a three-body problem is given as an explicit example.

  13. Programmability of Chemical Reaction Networks

    Science.gov (United States)

    Cook, Matthew; Soloveichik, David; Winfree, Erik; Bruck, Jehoshua

    Motivated by the intriguing complexity of biochemical circuitry within individual cells we study Stochastic Chemical Reaction Networks (SCRNs), a formal model that considers a set of chemical reactions acting on a finite number of molecules in a well-stirred solution according to standard chemical kinetics equations. SCRNs have been widely used for describing naturally occurring (bio)chemical systems, and with the advent of synthetic biology they become a promising language for the design of artificial biochemical circuits. Our interest here is the computational power of SCRNs and how they relate to more conventional models of computation. We survey known connections and give new connections between SCRNs and Boolean Logic Circuits, Vector Addition Systems, Petri nets, Gate Implementability, Primitive Recursive Functions, Register Machines, Fractran, and Turing Machines. A theme to these investigations is the thin line between decidable and undecidable questions about SCRN behavior.

  14. Nuclear Reactions from Lattice QCD

    CERN Document Server

    Briceño, Raúl A; Luu, Thomas C

    2014-01-01

    One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path ...

  15. Radiation Reaction on Brownian Motions

    CERN Document Server

    Seto, Keita

    2016-01-01

    Tracking the real trajectory of a quantum particle is one of the interpretation problem and it is expressed by the Brownian (stochastic) motion suggested by E. Nelson. Especially the dynamics of a radiating electron, namely, radiation reaction which requires us to track its trajectory becomes important in the high-intensity physics by PW-class lasers at present. It has been normally treated by the Furry picture in non-linear QED, but it is difficult to draw the real trajectory of a quantum particle. For the improvement of this, I propose the representation of a stochastic particle interacting with fields and show the way to describe radiation reaction on its Brownian motion.

  16. Electrochemical promotion of catalytic reactions

    Science.gov (United States)

    Imbihl, R.

    2010-05-01

    The electrochemical promotion of heterogeneously catalyzed reactions (EPOC) became feasible through the use of porous metal electrodes interfaced to a solid electrolyte. With the O 2- conducting yttrium stabilized zirconia (YSZ), the Na + conducting β″-Al 2O 3 (β-alumina), and several other types of solid electrolytes the EPOC effect has been demonstrated for about 100 reaction systems in studies conducted mainly in the mbar range. Surface science investigations showed that the physical basis for the EPOC effect lies in the electrochemically induced spillover of oxygen and alkali metal, respectively, onto the surface of the metal electrodes. For the catalytic promotion effect general concepts and mechanistic schemes were proposed but these concepts and schemes are largely speculative. Applying surface analytical tools to EPOC systems the proposed mechanistic schemes can be verified or invalidated. This report summarizes the progress which has been achieved in the mechanistic understanding of the EPOC effect.

  17. Modelling of biochemical reaction networks

    OpenAIRE

    Gloppen Jørgensen, Arne Gunnar

    2011-01-01

    This report investigates signalling in reaction kinetic networks. The main topic is signalling between a substance being controlled by another substance and how this can be related to control theory. Different types of so-called natural controllers are compared and certain properties are investigated. Natural controllers are models on how a catalyst enzyme controls, for example the concentration, of a substance. There are sixteen different combinations of signalling between these substanc...

  18. Pion production reaction near threshold

    International Nuclear Information System (INIS)

    The differential cross section of the 40Ca(p,π+)41Ca reaction has been measured. The energy dependence of pion production near threshold has been studied at constant transferred momentum. The cross-section decreases by a factor 7, for proton energies varying from 154 to 149MeV (E(π) varies from 17.4 to 12.4MeV). The results are analyzed in the framework of the one nucleon mechanism

  19. Anaphylactic reaction to intravenous diclofenac

    Directory of Open Access Journals (Sweden)

    Ranju Singh

    2011-01-01

    Full Text Available Diclofenac sodium is a non-steroidal anti-inflammatory drug widely used as an opioid sparing agent for postoperative analgesia. Anaphylaxis due to intravenous diclofenac sodium is very rare. We report a case of anaphylactic reaction to IV diclofenac sodium, occurring postoperatively in a 25-year-old primigravida, the clinical features of which mimicked pulmonary embolism. The rarity, clinical importance and the diagnostic dilemma associated prompted us to report this case.

  20. Laser-induced chemical reactions

    International Nuclear Information System (INIS)

    A classical model for the interaction of laser radiation with a molecular system is derived. This model is used to study the enhancement of a chemical reaction via a collision induced absorption. It was found that an infrared laser will in general enhance the rate of a chemical reaction, even if the reactants are infrared inactive. Results for an illustrative analytically solvable model are presented, as well as results from classical trajectory studies on a number of systems. The collision induced absorption spectrum in these systems can be written as the Fourier transform of a particular dipole correlation function. This is used to obtain the collision induced absorption spectrum for a state-selected, mono-energetic reactive collision system. Examples treated are a one-dimensional barrier problem, reactive and nonreactive collisions of H + H2, and a modified H + H2 potential energy surface which leads to a collision intermediate. An extension of the classical model to treat laser-induced electronically nonadiabatic collision processes is constructed. The model treats all degrees of freedom, molecular, electronic and radiation, in a dynamically consistent framework within classical mechanics. Application is made to several systems. Several interesting phenomena are discovered including a Franck-Condon-like effect causing maxima in the reaction probability at energies much below the classical threshold, laser de-enhancement of chemical reactions and an isotope effect. In order to assess the validity of the classical model for electronically nonadiabatic process (without a laser field), a model problem involving energy transfer in a collinear atom-diatom system is studied, and the results compared to the available quantum mechanical calculation. The calculations are in qualitative agreement