The NASA SN1987A program

International Nuclear Information System (INIS)

Teegarden, B.J.

1988-01-01

The existing and planned experiments for making gamma-ray observations of SN1987A are reviewed. The main emphasis is on the NASA program which consists primarily of balloon-borne instruments. Some 11--13 experiments are or will be available. Four have already flown from Alice Springs, Australia with null results. Campaigns are planned on nominal six month centers with more possible if gamma-rays are detected. In addition long duration flights from Australia to South America are planned for January 88 and 89

High-energy γ-ray observations of SN 1987A

International Nuclear Information System (INIS)

Sood, R.K.; Thomas, J.A.; Waldron, L.; Manchanda, R.K.; Rochester, G.K.; Sumner, T.J.; Frye, G.; Jenkins, T.; Koga, R.; Ubertini, P.; Bazzano, A.; La Padula, C.; Staubert, R.; Kendziorra, E.

1988-01-01

SN 1987A has been observed with a combined high energy γ-ray (50-500 MeV) and hard X-ray (15-50 keV) payload during a balloon flight on 5 April 1988 from Alice Springs, Australia. The γ-ray observations, along with our earlier ones on 19 April 1987 are the only such observations of the supernova to date. The γ-ray detector characteristics are described. The preliminary results of the recent flight and their implications in terms of the known supernova parameters are discussed. 17 refs., 6 figs

Physics, SN1987A, and the next nearby supernova

International Nuclear Information System (INIS)

Burrows, A.

1989-01-01

The scientific community has extracted quite a bit of information from SN1987A, some of it enduring. I will summarize what I believe we learned, what we did not learn, and what we can learn about supernovae, neutrinos, and particle physics when the next galactic supernova explodes onto the news

Gamma-ray observations of SN1987A

International Nuclear Information System (INIS)

Figueiredo, N.; Villela, T.; Jayanthi, U.B.; Souza, C.A.W.; Neri, J.A.C.F.; Cestal, R.C.; Martinez, M.L.

1990-01-01

This paper reports that on February 23, 1987, a Supernova (SN 1987A) was discovered in the Large Magellanic Cloud, a neighbor irregular galaxy only 55 kpc away. For the first time it was possible to observe a supernova whose progenitor star was known. This may also be the first time that it will be possible to prove the theoretical hypothesis that neutron stars are a consequence of a supernova explosion. The main peculiar characteristic of this supernova is that the progenitor star was a blue supergiant instead of a red supergiant as thy are generally believed to be. It was known as Sk -69 degrees 202, a 15-solar-mass star, spectral type B3I. Two hypothesis were invoked to explain such unexpected progenitor: the low metallicity of the LMC or large mass loss during the stage of red supergiant

Asymmetry of the SN 1987A envelope

International Nuclear Information System (INIS)

Chugaj, N.N.

1991-01-01

The origin of the peculiar structure in the profiles of the emission lines observed in the spectrum of SN 1987A, namely, (1) redshift of maxima, and (2) fine structure of hydrogen lines, is considered. Among the three proposed hypothesis for the redshift, at least two (electron scattering in the spherically-symmetric envelope, and geometrical effects in the fragmented envelope) have serious drawbacks. More favorable is the third hypothesis which invokes asymmetric distribution of 56 Ni and of the iron-peak elements

Rapid ionization of the environment of SN 1987A

International Nuclear Information System (INIS)

Raga, A.C.

1987-01-01

It has been suggested by some authors that IUE observations of the supernova SN 1987A show the presence of a strong component of the interstellar C IV 1550 and Si IV 1393 absorption lines at a velocity that approximately corresponds to the velocity of the LMC. It is possible that this component might come from originally neutral (or at least not very highly ionized) gas which has been photoionized by the initially very strong ionizing radiation field of the supernova. Theoretical considerations of this scenario lead to the study of fast (with velocities of about c) ionization fronts. It is shown that for reasonable model parameters it is possible to obtain considerably large C IV column densities, in agreement with the IUE observations. On the other hand, the models do not so easily predict the large Si IV column densities that are also obtained from the IUE observations. It is found that only models in which the interstellar medium surrounding SN 1987A is initially composed of already ionized hydrogen and helium predict substantial Si IV column densities. This result provides an interesting prediction of the ionization state of the environment of the presupernova star. 9 references

Rapid ionization of the environment of SN 1987A

Science.gov (United States)

Raga, A. C.

1987-01-01

It has been suggested by some authors that IUE observations of the supernova SN 1987A show the presence of a strong component of the interstellar C IV 1550 and Si IV 1393 absorption lines at a velocity that approximately corresponds to the velocity of the LMC. It is possible that this component might come from originally neutral (or at least not very highly ionized) gas which has been photoionized by the initially very strong ionizing radiation field of the supernova. Theoretical considerations of this scenario lead to the study of fast (with velocities of about c) ionization fronts. It is shown that for reasonable model parameters it is possible to obtain considerably large C IV column densities, in agreement with the IUE observations. On the other hand, the models do not so easily predict the large Si IV column densities that are also obtained from the IUE observations. It is found that only models in which the interstellar medium surrounding SN 1987A is initially composed of already ionized hydrogen and helium predict substantial Si IV column densities. This result provides an interesting prediction of the ionization state of the environment of the presupernova star.

Supernova 1987A in the Large Magellanic Cloud

Science.gov (United States)

Kafatos, Minas; Michalitsianos, Andrew G.

2006-11-01

Foreword; Acknowledgements; Workshop participants; 1. Images and spectrograms of Sanduleak - 69º202, the SN 1987a progenitor N. R. Walborn; 2. The progenitor of SN 1987A G. Sonneborn; 3. Another supernova with a blue progenitor C. M. Gaskell and W. C. Keel; 4. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory M. M. Phillips; 5. SN 1987A: observational results obtained at ESO I. J. Danziger, P. Bouchet, R. A. E. Fosbury, C. Gouiffes, L. B. Lucy, A. F. M. Moorwood, E. Oliva and F. Rufener; 6. Observations of SN 1987A at the South African Astronomical Observatory (SAAO) M. W. Feast; 7. Observations of SN 1987A at the Anglo-Australian Telescope W. J. Couch; 8. Linear polarimetric study of SN 1987A A. Clocchiatti, M. Méndez, O. Benvenuto, C. Feinstein, H. Marraco, B. García and N. Morrell; 9. Infrared spectroscopy of SN 1987A from the NASA Kuiper Airborne Observatory H. P. Larson, S. Drapatz, M. J. Mumma and H. A. Weaver; 10. Radio observations of SN 1987A N. Bartel et al.; 11. Ultraviolet observations of SN 1987A: clues to mass loss R. P. Kirshner; 12. On the energetics of SN 1987A N. Panagia; 13. On the nature and apparent uniqueness of SN 1987A A. V. Filippenko; 14. A comparison of the SN 1987A light curve with other type II supernovae, and the detectability of similar supernovae M. F. Schmitz and C. M. Gaskell; 15. P-Cygni features and photospheric velocities L. Bildsten and J. C. L. Wang; 16. The Neutrino burst from SN 1987A detected in the Mont Blanc LSD experiment M. Aglietta et al.; 17. Toward observational neutrino astrophysics M. Koshiba; 18. The discovery of neutrinos from SN 1987A with the IMB detector J. Matthews; 19. Peering into the abyss: the neutrinos from SN 1987A A. Burrows; 20. Phenomenological analysis of neutrino emission from SN 1987A J. N. Bahcall, D. N. Spergel and W. H. Press; 21. Mass determination of neutrinos H. Y. Chiu; 22. Neutrino transport in a type II supernova D. C. Ellison, P. M. Giovanoni

Detection of a Very Bright Source Close to the LMC Supernova SN 1987A: Erratum

Science.gov (United States)

Nisenson, P.; Papaliolios, C.; Karovska, M.; Noyes, R.

1988-01-01

In the Letter "Detection of a Very Bright Source Close to the LMC Supernova SN 1987A" by P. Nisenson, C. Papaliolios, M. Karovska, and R. Noyes (1987 Ap. J. [Letters], 320, L15), two of the figure labels for Figure 1 were inadvertently transposed in the production process. A corrected version of the figure appears as Plate L4. The Journal regrets the error.

A mobile antineutrino detector with plastic scintillators

International Nuclear Information System (INIS)

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

2012-01-01

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

Detection of a very bright source close to the LMC supernova SN 1987A

Science.gov (United States)

Nisenson, P.; Papaliolios, C.; Karovska, M.; Noyes, R.

1987-01-01

High angular resolution observations of the supernova in the Large Magellanic Cloud, SN 1987A, have revealed a bright source separated from the SN by approximately 60 mas with a magnitude difference of 2.7 at 656 nm (H-alpha). Speckle imaging techniques were applied to data recorded with the CfA two-dimensional photon counting detector on the CTIO 4 m telescope on March 25 and April 2 to allow measurements in H-alpha on both nights and at 533 nm and 450 nm on the second night. The nature of this object is as yet unknown, though it is almost certainly a phenomenon related to the SN.

SN 2009E

DEFF Research Database (Denmark)

Pastorello...[], A.; Pumo, M.L.; Navasardyan, H.

2012-01-01

. In this paper we investigate the properties of SN 2009E, which exploded in a relatively nearby spiral galaxy (NGC 4141) and that is probably the faintest 1987A-like supernova discovered so far. We also attempt to characterize this subgroup of core-collapse supernovae with the help of the literature and present...... observations which started about 2 months after the supernova explosion, highlight significant differences between SN 2009E and the prototypical SN 1987A. Modelling the data of SN 2009E allows us to constrain the explosion parameters and the properties of the progenitor star, and compare the inferred estimates...... 2009E ejected about 0.04 M⊙ of 56Ni, which is the smallest 56Ni mass in our sample of 1987A-like events. Modelling the observations with a radiation hydrodynamics code, we infer for SN 2009E a kinetic plus thermal energy of about 0.6 foe, an initial radius of ~7 × 1012 cm and an ejected mass of ~19 M...

Convective instabilities in SN 1987A

Science.gov (United States)

Benz, Willy; Thielemann, Friedrich-Karl

1990-01-01

Following Bandiera (1984), it is shown that the relevant criterion to determine the stability of a blast wave, propagating through the layers of a massive star in a supernova explosion, is the Schwarzschild (or Ledoux) criterion rather than the Rayleigh-Taylor criterion. Both criteria coincide only in the incompressible limit. Results of a linear stability analysis are presented for a one-dimensional (spherical) explosion in a realistic model for the progenitor of SN 1987A. When applying the Schwarzschild criterion, unstable regions get extended considerably. Convection is found to develop behind the shock, with a characteristic growth rate corresponding to a time scale much smaller than the shock traversal time. This ensures that efficient mixing will take place. Since the entire ejected mass is found to be convectively unstable, Ni can be transported outward, even into the hydrogen envelope, while hydrogen can be mixed deep into the helium core.

Primordial lithium abundance from interstellar lithium lines towards SN 1987A

International Nuclear Information System (INIS)

Sahu, K.C.; Pottasch, S.R.; Sahu, M.

1989-01-01

The primoridal lithium abundance is known to be one of the best probes to test the standard as well as the non-standard Big Bang nucleosynthesis theories, and to measure the nucleon abundance in the early universe in the standard Big Bang (SSB) model. We have obtained high-resolution ((λ)/(δλ)congruent 100,000), high signal-to-noise (S/N approx-gt 1,500) spectra of SN 1987A around the Li:I λ6708 A region, using the ESO 1.4m CAT and the Coude Echelle Spectrograph. The non-detection of any lithium feature in our sepctra places an upper limit on the lithium abundance

Study of μ e events produced in antineutrino interactions

Science.gov (United States)

Marage, P.; Gerbier, G.; Guy, J.; Kochowski, C.; Aderholz, M.; Armenise, N.; Azemoon, T.; Bartley, J. H.; Baton, J. P.; Bertrand, D.; Bertrand-Coremans, Gh.; Brisson, V.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper, A. M.; Deck, L.; Erriquez, O.; Faulkener, P.; Fogli-Muciaccia, M. T.; Hulth, P. O.; Iaselli, G.; Jones, G. T.; Kasper, P.; Klein, H.; Lagraa, M.; Leighton-Davis, S.; Middleton, R.; Miller, D. B.; Mobayyen, M. M.; Natali, S.; Neveu, M.; Nuzzo, S.; O'Neale, S.; Parker, A.; Petiau, P.; Sacton, J.; Schmitz, N.; Simopoulou, E.; Talebzadeh, M.; van Doninck, W.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wernhard, K. L.; Wittek, W.; Zevgolatakos, E.

1984-12-01

A study is presented of μ e events from an exposure of BEBC, filed with an heavy H 2/ Ne mixture, to a wide band antineutrino beam at the CERN SPS. The prompt μ + e - rate, based on the observation of 45 events with p μ>4 GeV/c and p e>0.8 GeV/c, is found to be 0.31±0.05±0.02%, in agreement with previous determinations made on much smaller statistics. The differential kinematical variables characterizing the events and the content of strange particles are as expected for the production of charmed hadrons which subsequently decay semi-leptonically. An upper limit of 2.0±10-4 at 90% C.L. is given for the production rate of prompt μ + e + events. No evidence is found for a significant production of Beauty hadrons.

CHANDRA OBSERVATIONS OF SN 1987A: THE SOFT X-RAY LIGHT CURVE REVISITED

Energy Technology Data Exchange (ETDEWEB)

Helder, E. A.; Broos, P. S.; Burrows, D. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Dewey, D. [MIT Kavli Institute, Cambridge, MA 02139 (United States); Dwek, E. [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McCray, R. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Park, S. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019 (United States); Racusin, J. L. [NASA, Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States); Zhekov, S. A. [Space Research and Technology Institute, Akad. G. Bonchev str., bl.1, Sofia 1113 (Bulgaria)

2013-02-10

We report on the present stage of SN 1987A as observed by the Chandra X-Ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by {approx}6 Multiplication-Sign 10{sup -13} erg s{sup -1} cm{sup -2} per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.

Formation of dust grains in the ejecta of SN 1987A

International Nuclear Information System (INIS)

Kozasa, Takashi; Hasegawa, Hiroichi; Nomoto, Kenichi

1989-01-01

Formation of dust grains in the ejecta of SN 1987A is investigated on the basis of a theory of homogeneous nucleation and grain growth. The formation of dust grains in the gas ejected from a heavy element-rich mantle is considered, including the effects of latent heat released during grain growth and of radiation from the photosphere. It is shown that dust grains can condense in the heavy-element-rich mantle, and that the time of formation strongly depends on the temperature structure in the ejecta. Moreover, the formation of dust grains is retarded by the strong SN radiation field and the effect of latent heat deposited during grain growth. 41 refs

Can a Bright and Energetic X-Ray Pulsar Be Hiding Amid the Debris of SN 1987A?

Science.gov (United States)

Esposito, Paolo; Rea, Nanda; Lazzati, Davide; Matsuura, Mikako; Perna, Rosalba; Pons, José A.

2018-04-01

The mass of the stellar precursor of supernova (SN) 1987A and the burst of neutrinos observed at the moment of the explosion are consistent with the core-collapse formation of a neutron star. However, no compelling evidence for the presence of a compact object of any kind in SN 1987A has been found yet in any band of the electromagnetic spectrum, prompting questions on whether the neutron star survived and, if it did, on its properties. Beginning with an analysis of recent Chandra observations, here we appraise the current observational situation. We derived limits on the X-ray luminosity of a compact object with a nonthermal, Crab-pulsar-like spectrum of the order of ≈(1–5) × 1035 erg s‑1, corresponding to limits on the rotational energy loss of a possible X-ray pulsar in SN 1987A of ≈(0.5–1.5) × 1038 erg s‑1. However, a much brighter X-ray source cannot be excluded if, as is likely, it is enshrouded in a cloud of absorbing matter with a metallicity similar to that expected in the outer layers of a massive star toward the end of its life. We found that other limits obtained from various arguments and observations in other energy ranges either are unbinding or allow a similar maximum luminosity of the order of ≈1035 erg s‑1. We conclude that while a pulsar alike the one in the Crab Nebula in both luminosity and spectrum is hardly compatible with the observations, there is ample space for an “ordinary” X-ray-emitting young neutron star, born with normal initial spin period, temperature, and magnetic field, to be hiding inside the evolving remnant of SN 1987A.

Further results on muon-antineutrino-electron scattering

International Nuclear Information System (INIS)

Hasert, F.J.

1975-01-01

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

Airborne spectrophotometry of SN 1987A from 1.7 to 12.6 microns - Time history of the dust continuum and line emission

Science.gov (United States)

Wooden, Diane H.; Rank, David M.; Bregman, Jesse D.; Witteborn, Fred C.; Tielens, A. G. G. M.; Cohen, Martin; Pinto, Philip A.; Axelrod, Timothy S.

1993-01-01

Spectrophotometric observations of SN 1987A from the Kuiper Airborne Observatory are presented for five epochs at 60, 260, 415, 615, and 775 days after the explosion. The low-resolution (lambda/Delta lambda = 50-100) spectra of SN 1987A are combined with data from other wavelengths to model the continuum, subtract the continuum from the spectra to determine line strengths and reveal molecular bands, separate the atomic continuum radiation from the dust continuum, and derive constraints on the grain temperatures and optical depths. A scenario for the evolution of SN 1987A and that of the ejecta from which it arises is obtained on the basis of the analysis of the continuum emission.

Signatures of particle acceleration at SN1987a

Science.gov (United States)

Gaisser, T. K.; Stanev, Todor; Harding, Alice

1988-01-01

Young SNRs may be bright sources of energetic photons and neutrinos generated by the collisions of particles accelerated within the remnant. Due to the large opacity of the shell at these early times, a photon signal may be suppressed; at later times, due to adiabatic losses of the magnetically-trapped particles in the expanding envelope, both neutron and neutrino signals will begin to decrease. There is therefore a window during which the secondary photon signal will be at its maximum. It is presently noted that if the observed decline of the optical light curve of SN1987a is due to Ni-56, Co-56 decay, this may place upper limits on such other sources of light as a central pulsar.

Ti-44 Gamma-Ray Emission Lines from SN1987A Reveal an Asymmetric Explosion

Science.gov (United States)

Boggs, S. E.; Harrison, F. A.; Miyasaka, H.; Grefenstette, B. W.; Zoglauer, A.; Fryer, C. L.; Reynolds, S. P.; Alexander, D. M.; An, H.; Barret, D.;

44Ti gamma-ray emission lines from SN1987A reveal an asymmetric explosion

DEFF Research Database (Denmark)

Boggs, S. E.; Harrison, F. A.; Miyasaka, H.

2015-01-01

In core-collapse supernovae, titanium-44 (44Ti) is produced in the innermost ejecta, in the layer of material directly on top of the newly formed compact object. As such, it provides a direct probe of the supernova engine. Observations of supernova 1987A (SN1987A) have resolved the 67.87- and 78.......32–kilo–electron volt emission lines from decay of 44Ti produced in the supernova explosion. These lines are narrow and redshifted with a Doppler velocity of ~700 kilometers per second, direct evidence of large-scale asymmetry in the explosion....

HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

International Nuclear Information System (INIS)

Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

2009-01-01

The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 ± 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is α = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

Particle acceleration and production of energetic photons in SN1987A

Science.gov (United States)

Gaisser, T. K.; Stanev, Todor; Harding, Alice

1987-01-01

A pulsar wind model for the acceleration of particles in SN1987A is discussed. The expected photon flux is investigated in terms of the spectrum of parent protons and electrons, the nature of the region in which they propagate after acceleration, and the magnetic field and radiation environment which determines the subsequent fate of produced photons. The model is found to produce observable signals if the spin period of the pulsar is 10 ms or less.

Gamma-ray observations of SN 1987A with an array of high-purity germanium detectors

International Nuclear Information System (INIS)

Sandie, W.G.; Nakano, G.H.; Chase, L.F. Jr.; Fishman, G.J.; Meegan, C.A.; Wilson, R.B.; Paciesas, W.

1988-01-01

A balloon borne gamma-ray spectrometer comprising an array of high-purity n-type germanium (HPGe) detectors having geometric area 119 cm 2 , resolution 2.5 keV at 1.0 MeV, surrounded by an active NaI (Tl) collimator and Compton suppressing anticoincidence shield nominally 10 cm thick, was flown from Alice Springs, Northern Territory, Australia, on May 29--30, 1987, 96 days after the observed neutrino pulse. The average column depth of residual atmosphere in the direction of SN 1987A at float altitude was 6.3 g cm-2 during the observation. SN 1987A was within the 22-deg full-width-half-maximum (FWHM) field of view for about 3300 s during May 29.9--30.3 UT. No excess gamma rays were observed at energies appropriate to the Ni(56)-Co(56) decay chain or from other lines in the energy region from 0.1 to 3.0 MeV. With 80% of the data analyzed, the 3-sigma upper limit obtained for the 1238-keV line from Co(56) at the instrument resolution (about 3 keV) is 1.3 x 10-3 photons cm-2 s-1

Non-LTE model calculations for SN 1987A and the extragalactic distance scale

Science.gov (United States)

Schmutz, W.; Abbott, D. C.; Russell, R. S.; Hamann, W.-R.; Wessolowski, U.

1990-01-01

This paper presents model atmospheres for the first week of SN 1987A, based on the luminosity and density/velocity structure from hydrodynamic models of Woosley (1988). The models account for line blanketing, expansion, sphericity, and departures from LTE in hydrogen and helium and differ from previously published efforts because they represent ab initio calculations, i.e., they contain essentially no free parameters. The formation of the UV spectrum is dominated by the effects of line blanketing. In the absorption troughs, the Balmer line profiles were fit well by these models, but the observed emissions are significantly stronger than predicted, perhaps due to clumping. The generally good agreement between the present synthetic spectra and observations provides independent support for the overall accuracy of the hydrodynamic models of Woosley. The question of the accuracy of the Baade-Wesselink method is addressed in a detailed discussion of its approximations. While the application of the standard method produces a distance within an uncertainty of 20 percent in the case of SN 1987A, systematic errors up to a factor of 2 are possible, particularly if the precursor was a red supergiant.

Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles

International Nuclear Information System (INIS)

Payez, Alexandre; Ringwald, Andreas; Evoli, Carmelo; Mirizzi, Alessandro; Fischer, Tobias; Giannotti, Maurizio

2014-10-01

We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: g aγ -12 GeV -1 , for m a -10 eV, and we also give its dependence at larger ALP masses m a . Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.

Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory

International Nuclear Information System (INIS)

Phillips, M.M.

1988-01-01

Results from optical and infrared observations of SN 1987A obtained at Cerro Tololo Inter-American Observatory over the first seven months since core collapse are reviewed. Around 130 days after outburst, the bolometric light curve began to smoothly decline at a rate of ∼ 0.01 mag day-1, providing dramatic confirmation of the prediction that radioactivity had powered the optical display after the first month./ the peculiar color changes are kinks observed beginning on the 25th day probably signaled the initial release of trapped energy from mass 56 material. The bolometric luminosity of SN 1987A was unusually low at first, but reached a value more typical of other type II supernovae by the time that the final exponential decline had begun. Over much of the period covered by these observations, the optical and infrared spectra were characterized by strong absorption lines of Ba II and Sr II. Comparison with the spectra of other type II supernovae at similar stages of evolution supports the suggestion that s-processed elements were enriched in the hydrogen envelope of the progenitor, Sanduleak - 69 degrees 202

Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles

Energy Technology Data Exchange (ETDEWEB)

Payez, Alexandre; Ringwald, Andreas [Theory group, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany); Evoli, Carmelo; Mirizzi, Alessandro [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany); Fischer, Tobias [Institute for Theoretical Physics, University of Wroc\\law, Pl. M. Borna 9, 50-204 Wroc\\law (Poland); Giannotti, Maurizio, E-mail: alexandre.payez@desy.de, E-mail: carmelo.evoli@desy.de, E-mail: fischer@ift.uni.wroc.pl, E-mail: mgiannotti@barry.edu, E-mail: alessandro.mirizzi@desy.de, E-mail: andreas.ringwald@desy.de [Physical Sciences, Barry University, 11300 NE 2nd Ave., Miami Shores, FL 33161 (United States)

2015-02-01

We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: g{sub aγ} ∼< 5.3 × 10{sup -12} GeV{sup -1}, for m{sub a} ∼< 4.4 × 10{sup -10} eV, and we also give its dependence at larger ALP masses m{sub a}. Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.

Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

Energy Technology Data Exchange (ETDEWEB)

Abellán, F. J.; Marcaide, J. M. [Departamento de Astronomía y Astrofísica, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Indebetouw, R.; Chevalier, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Gabler, M.; Janka, H.-Th. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany); Fransson, C.; Lundqvist, P. [Department of Astronomy, The Oskar Klein Centre, Stockholm University, Alba Nova University Centre, SE-106 91 Stockholm (Sweden); Spyromilio, J. [ESO, Karl-Schwarzschild-Straße 2, D-85748 Garching (Germany); Burrows, D. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Cigan, P.; Gomez, H. L.; Matsuura, M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Gaensler, B. M. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Larsson, J. [KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, SE-106 91 Stockholm (Sweden); McCray, R. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Park, S. [Department of Physics, University of Texas at Arlington, 108 Science Hall, Box 19059, Arlington, TX 76019 (United States); Roche, P., E-mail: francisco.abellan@uv.es [Department of Physics, University of Oxford, Oxford OX1 3RH (United Kingdom); and others

2017-06-20

Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks (“nickel heating”). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.

Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

International Nuclear Information System (INIS)

Abellán, F. J.; Marcaide, J. M.; Indebetouw, R.; Chevalier, R.; Gabler, M.; Janka, H.-Th.; Fransson, C.; Lundqvist, P.; Spyromilio, J.; Burrows, D. N.; Cigan, P.; Gomez, H. L.; Matsuura, M.; Gaensler, B. M.; Kirshner, R.; Larsson, J.; McCray, R.; Ng, C.-Y.; Park, S.; Roche, P.

2017-01-01

Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks (“nickel heating”). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.

Measurements of the diameter of the supernova SN 1987A

International Nuclear Information System (INIS)

Karovska, M.; Nisenson, P.; Standley, C.; Heathcote, S.R.

1991-01-01

Speckle interferometric measurements of the angular diameter of SN 1987A in the Large Magellanic Cloud, obtained at 664 days after the outburst are presented. Diameters were estimated with milliarcsec precision at 657 nm and 550 nm by fitting model visibility functions to the data corresponding to different intensity distributions for the supernova disk. Measurements made assuming a uniform intensity distribution were compared to the uniform disk measurements obtained from 30 days after the explosion. Diameter measurements obtained near the center of the H-alpha line are consistent with homologous expansion of the supernova shell with a mean velocity of 2850 km/s. The linear least-squares fit to the measurements obtained at other wavelengths from 260 days after the explosion yielded a somewhat lower mean expansion velocity. 8 refs

Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles

Energy Technology Data Exchange (ETDEWEB)

Payez, Alexandre; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Evoli, Carmelo; Mirizzi, Alessandro [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Fischer, Tobias [Wroclaw Univ. (Poland). Inst. for Theoretical Physics; Giannotti, Maurizio [Barry Univ., Miami Shores, FL (United States). Physical Sciences

2014-10-15

We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: g{sub aγ}a}a}. Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

On the interpretation of rare events recorded by Kamiokande 2. and IMB detectors in association with occurrence of supernova 1987 A

International Nuclear Information System (INIS)

Krivoruchenko, M.I.

1989-01-01

A statistical analysis of angular distribution of neutrino events observed in Kamiokande 2. and IMB detectors from supernova SN 1987 A is carried out. The Neyman-Pearson test is applied to each of the events in testing the hypothesis ν-bar e p→e + n against the alternative one νe→νe. The confidence level of the hypothesis that the recorded events all represent ν-bar e p→e + n inelastic scatterings against possible alternatives is found with the use of the Kolmogorov and Mises tests to be 2% and 0.9%, respectively. The number of νe→νe events is estimated to be from 3 to 11 with probability ≥0.9. The current supernova models fail to give a satisfactory account of the angular distribution data

SN Refsdal

DEFF Research Database (Denmark)

Kelly, P. L.; Brammer, G.; Selsing, J.

2016-01-01

(SNe), and we find strong evidence for a broad H-alpha P-Cygni profile in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show...... in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, SN Refsdal has a blue B-V color and a high luminosity for the assumed range of potential magnifications. If SN Refsdal can be modeled as a scaled version of SN...

Particle acceleration and production of energetic photons in SN1987A

Energy Technology Data Exchange (ETDEWEB)

Gaisser, T.K.; Stanev, Todor; Harding, Alice

1987-09-24

Young supernova remnants are likely to be bright sources of energetic photons and neutrinos through the collision of particles accelerated inside the remnant. Interactions of accelerated particles in the expanding envelope or in ambient radiation fields will also produce secondary photons and neutrinos at some level. If > 10/sup 39/ erg s/sup -1/ in protons above 10 TeV is injected into the target region, TeV photons from SN1987A could be observable with present detectors. Synchrotron X rays and ..gamma..-rays up to 10 MeV, generated by accelerated electrons, may well also be detectable. The authors discuss a pulsar wind model for acceleration of particles, and find that it would produce observable signals if the spin period of the pulsar is <10 ms.

THE DESTRUCTION OF THE CIRCUMSTELLAR RING OF SN 1987A

International Nuclear Information System (INIS)

Fransson, Claes; Migotto, Katia; Lundqvist, Peter; Taddia, Francesco; Sollerman, Jesper; Larsson, Josefin; Pesce, Dominic; Chevalier, Roger A.; Challis, Peter; Kirshner, Robert P.; France, Kevin; Leibundgut, Bruno; Spyromilio, Jason; McCray, Richard; Jerkstrand, Anders; Mattila, Seppo; Smith, Nathan; Wheeler, J. Craig; Crotts, Arlin; Garnavich, Peter

2015-01-01

We present imaging and spectroscopic observations with Hubble Space Telescope and Very Large Telescope of the ring of SN 1987A from 1994 to 2014. After an almost exponential increase of the shocked emission from the hotspots up to day ∼8000 (∼2009), both this and the unshocked emission are now fading. From the radial positions of the hotspots we see an acceleration of these up to 500–1000 km s −1 , consistent with the highest spectroscopic shock velocities from the radiative shocks. In the most recent observations (2013 and 2014), we find several new hotspots outside the inner ring, excited by either X-rays from the shocks or by direct shock interaction. All of these observations indicate that the interaction with the supernova ejecta is now gradually dissolving the hotspots. We predict, based on the observed decay, that the inner ring will be destroyed by ∼2025

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

International Nuclear Information System (INIS)

Schultze, K.

1977-01-01

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

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

Science.gov (United States)

Nikitenko, Ya.

2016-11-01

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

Neutrino helicity flips via electroweak interactions and SN1987a

International Nuclear Information System (INIS)

Gaemers, K.J.F.; Gandhi, R.; Lattimer, J.M.

1988-10-01

Electroweak mechanisms via which neutrinos may flip helicity and become sterile are examined in detail. Exact and approximate expressions for a variety of flip processes relevant in astrophysics and cosmology, mediated by W,Z, and γ exchange, including their interference, are derived. It is shown that within the context of the Standard Model with massive neutrinos, for νe→νe scattering, σ Z flip /σ γ flip ∼ 6 X 10 3 , independent of particle masses and energies to a good approximation. It is also shown that using some general considerations and the fact that the observed anti ν e burst from SN1987a lasted several seconds, these weak interaction flip cross-sections can be used to derive an upper limit on μ and τ neutrino masses of ∼ 40 keV. Finally, some other consequences for astrophysics in general and supernovae in particular are briefly discussed. 29 refs.; 47 schemes

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

International Nuclear Information System (INIS)

Bhattacharya, Debdatta

2009-01-01

This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 10 6 neutrino events and 1.60 x 10 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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-01-01

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

Detector of reactor antineutrinos with plastic scintillation bars

International Nuclear Information System (INIS)

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

2015-01-01

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

Things begin to happen around Supernova 1987A

Science.gov (United States)

1994-01-01

On 23 February 1994, it will be exactly seven years since the explosion of Supernova 1987A in the Large Magellanic Cloud [1] was first observed, at a distance of approx. 160,000 light-years. It was the first naked-eye supernova to be seen in almost four hundred years. Few events in modern astronomy have met with such an enthusiastic response by the scientists and this famous object has been under constant surveillance ever since. After several years of relative quiescence, things are now beginning to happen in the immediate neighbourhood of SN 1987A. Recent observations with the ESO 3.5 m New Technology Telescope (NTT) indicate that interaction between the stellar material which was ejected during the explosion and the surrounding ring-shaped nebulae has started. This signals the beginning of a more active phase during which the supernova is likely to display a number of new and interesting phenomena, never before observed. SEVEN YEARS IN THE LIFE OF A SUPERNOVA After brightening to maximum light at about magnitude 3 a few months after the explosion, the long period of steady fading which is typical for supernovae, set in by mid-1987. The matter ejected by the explosion took the form of an expanding fireball, which began to spread through the nearly empty space around the supernova with a velocity of almost 10,000 km/sec. As it cooled, the temperature and therefore the total brightness decreased and the supernova became fainter and fainter. At the present moment, the magnitude of SN 1987A is about 18.5, that is almost 2 million times fainter than it was at maximum. Various phenomena have been observed around SN 1987A during the past years. Already in early 1988, light echoes were seen as concentric, slowly expanding luminous circles; they represent the reflections of the explosion light flash in interstellar clouds inside the Large Magellanic Cloud, between the supernova and us. In 1989, high-resolution observations with the NTT showed an elliptical ``ring

Circumstellar matter and the nature of the SN1987A progenitor star

International Nuclear Information System (INIS)

Chevalier, R.A.; Fransson, C.

1987-01-01

The radio observations of the supernova SN1987A can be interpreted in terms of its interaction with circumstellar matter. The early turn-on of the radio emission implies a relatively low density circumstellar medium. The optical properties of the supernova imply that the progenitor star had a smaller radius than that of a typical type II supernova progenitor. The mass loss properties are consistent with this hypothesis. The authors predict the thermal X-ray luminosity of the supernova, and note that it is below the current upper limit. A bright infrared dust echo is not expected. Weak ultraviolet emission lines from circumstellar gas may be visible. Although the circumstellar density is low, it is possible that the progenitor star did lose a substantial fraction of its mass prior to the supernova explosion. (author)

SN 1987A gamma-ray line profiles and fluxes

International Nuclear Information System (INIS)

Bussard, R.W.; Burrows, A.; The, L.S.

1989-01-01

Results for the time dependence of the line profiles and integrated fluxes for the 0.847 and 1.238 MeV gamma rays from the decay of cobalt to excited states of iron are presented for several models of the ejectum of SN 1987A. The relatively early detection of these lines has led several workers to propose that some degree of mixing has brought the cobalt closer to the electron-scattering photosphere than standard models predict. Constraints on the amount of mixing from recent observations are discussed using calculations of the energy-integrated line fluxes as a function of time since the explosion. Implications for the line profiles at various times are considered, and it is found that they show strong time dependences and are quite sensitive to the degree of mixing. The two primary effects are Doppler broadening due to the presence of radioactive material at higher velocities and a strong blueshift at early times resulting from optical depth effects. These results have important implications for gamma-ray observations, especially with high-resolution germanium instruments. Finally, the consequences of the fragmentation of the debris for the early emergence of the gamma-ray lines are considered. 32 refs

X-ray emission due to interaction of SN1987A ejecta with its progenitor's stellar-wind matter

International Nuclear Information System (INIS)

Masai, Kuniaki.

1990-06-01

The progenitor of the supernova 1987A, Sk-69 202 probably had lost a considerable amount of mass in its stellar wind in the past evolutionary track through a red supergiant to a blue supergiant. In about 10 years, the expanding ejecta of SN1987A will catch up to collide with the wind matter ejected in the red supergiant phase. Shocks due to the collision will heat up the ejecta and the wind matter to cause an enhancement of thermal X-ray emission lasting for several decades. We predict the X-ray light curve and the spectrum as well as the epoch of the enhancement intending to encourage future X-ray observations, which will give a clue for the study of such peculiar stellar evolution with a blueward transition as Sk-69 202. (author)

SUPERNOVA 1987A: A TEMPLATE TO LINK SUPERNOVAE TO THEIR REMNANTS

Energy Technology Data Exchange (ETDEWEB)

Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana”, Piazza del Parlamento 1, I-90134 Palermo (Italy)

2015-09-10

The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2–1.4 × 10{sup 51} erg and the envelope mass in the range 15–17 M{sub ⊙}. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = −8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

THE PRODUCTION RATE OF SN Ia EVENTS IN GLOBULAR CLUSTERS

International Nuclear Information System (INIS)

Washabaugh, Pearce C.; Bregman, Joel N.

2013-01-01

In globular clusters, dynamical evolution produces luminous X-ray emitting binaries at a rate about 200 times greater than in the field. If globular clusters also produce SN Ia at a high rate, it would account for many of the SN Ia production in early-type galaxies and provide insight into their formation. Here we use archival Hubble Space Telescope (HST) images of nearby galaxies that have hosted an SN Ia to examine the rate at which globular clusters produce these events. The location of the SN Ia is registered on an HST image obtained before the event or after the supernova (SN) faded. Of the 36 nearby galaxies examined, 21 had sufficiently good data to search for globular cluster hosts. None of the 21 SNe have a definite globular cluster counterpart, although there are some ambiguous cases. This places an upper limit to the enhancement rate of SN Ia production in globular clusters of about 42 at the 95% confidence level, which is an order of magnitude lower than the enhancement rate for luminous X-ray binaries. Even if all of the ambiguous cases are considered as having a globular cluster counterpart, the upper bound for the enhancement rate is 82 at the 95% confidence level, still a factor of several below that needed to account for half of the SN Ia events. Barring unforeseen selection effects, we conclude that globular clusters are not responsible for producing a significant fraction of the SN Ia events in early-type galaxies.

Antineutrino Neutral Current Interactions in MiniBooNE

Energy Technology Data Exchange (ETDEWEB)

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

2012-01-01

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

The reactor antineutrino anomalies

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

AGM2015: Antineutrino Global Map 2015.

Science.gov (United States)

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

2015-09-01

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

Antineutrino Oscillations in the Atmospheric Sector

International Nuclear Information System (INIS)

Himmel, Alexander I.

2011-01-01

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

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

Science.gov (United States)

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

2017-04-01

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

Updated constraints on self-interacting dark matter from Supernova 1987A

Science.gov (United States)

Mahoney, Cameron; Leibovich, Adam K.; Zentner, Andrew R.

2017-08-01

We revisit SN1987A constraints on light, hidden sector gauge bosons ("dark photons") that are coupled to the standard model through kinetic mixing with the photon. These constraints are realized because excessive bremsstrahlung radiation of the dark photon can lead to rapid cooling of the SN1987A progenitor core, in contradiction to the observed neutrinos from that event. The models we consider are of interest as phenomenological models of strongly self-interacting dark matter. We clarify several possible ambiguities in the literature and identify errors in prior analyses. We find constraints on the dark photon mixing parameter that are in rough agreement with the early estimates of Dent et al. [arXiv:1201.2683.], but only because significant errors in their analyses fortuitously canceled. Our constraints are in good agreement with subsequent analyses by Rrapaj & Reddy [Phys. Rev. C 94, 045805 (2016)., 10.1103/PhysRevC.94.045805] and Hardy & Lasenby [J. High Energy Phys. 02 (2017) 33., 10.1007/JHEP02(2017)033]. We estimate the dark photon bremsstrahlung rate using one-pion exchange (OPE), while Rrapaj & Reddy use a soft radiation approximation (SRA) to exploit measured nuclear scattering cross sections. We find that the differences between mixing parameter constraints obtained through the OPE approximation or the SRA approximation are roughly a factor of ˜2 - 3 . Hardy & Laseby [J. High Energy Phys. 02 (2017) 33., 10.1007/JHEP02(2017)033] include plasma effects in their calculations finding significantly weaker constraints on dark photon mixing for dark photon masses below ˜10 MeV . We do not consider plasma effects. Lastly, we point out that the properties of the SN1987A progenitor core remain somewhat uncertain and that this uncertainty alone causes uncertainty of at least a factor of ˜2 - 3 in the excluded values of the dark photon mixing parameter. Further refinement of these estimates is unwarranted until either the interior of the SN1987A progenitor is

Experimental results from a reactor monitoring experiment with a cubic meter scale antineutrino detector

International Nuclear Information System (INIS)

Bernstein, A.

2007-01-01

Cubic meter scale antineutrino detectors can stably and no intrusively monitor both plutonium content and reactor power at the few percent level, at a standoff of a few tens of meters. Our Lawrence Livermore National Laboratory/Sandia National Laboratories collaboration has deployed a detector to demonstrate this capability at a 3 GWt pressurized water reactor in Southern California, operating 25 meters from the core center, and acquiring data over an approximate one year period. Such monitoring may be useful for tracking power output and plutonium buildup in nuclear reactors, constraining the fissile content and providing the earliest possible measurement of the amount of plutonium in the reactor core. We present our antineutrino event sample, and show that the observed change in antineutrino rate recorded in our detector over the reactor cycle correlates with plutonium ingrowth according to predictions. We present our current precision and estimate the attainable precision of the method, and discuss the benefits this technology may have for the International Atomic Energy Agency (IAEA) or other safeguards regimes

Antineutrino Oscillations in the Atmospheric Sector

Energy Technology Data Exchange (ETDEWEB)

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

2011-05-01

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

HST Archival Imaging of the Light Echoes of SN 1987A

Science.gov (United States)

Lawrence, S. S.; Hayon, M.; Sugerman, B. E. K.; Crotts, A. P. S.

2002-12-01

We have undertaken a search for light echo signals from Supernova 1987A that have been serendipitously recorded in images taken near the 30 Doradus region of the Large Magellanic Cloud by HST. We used the MAST interface to create a database of the 1282 WF/PC, WFPC2 and STIS images taken within 15 arcminutes of the supernova, between 1992 April and 2002 June. These 1282 images are grouped into 125 distinct epochs and pointings, with each epoch containing between 1 and 42 separate exposures. Sorting this database with various programs, aided by the STScI Visual Target Tuner, we have identified 63 pairs of WFPC2 imaging epochs that are not centered on the supernova but that have a significant amount of spatial overlap between their fields of view. These image data were downloaded from the public archive, cleaned of cosmic rays, and blinked to search for light echoes at radii larger than 2 arcminutes from the supernova. Our search to date has focused on those pairs of epochs with the largest degree of overlap. Of 16 pairs of epochs scanned to date, we have detected 3 strong light echoes and one faint, tentative echo signal. We will present direct and difference images of these and any further echoes, as well as the 3-D geometric, photometric and color properties of the echoing dust structures. In addition, a set of 20 epochs of WF/PC and WFPC2 imaging centered on SN 1987A remain to be searched for echoes within 2 arcminutes of the supernova. We will discuss our plans to integrate the high spatial-resolution HST snapshots of the echoes with our extensive, well-time-sampled, ground-based imaging data. We gratefully acknowledge the support of this undergraduate research project through an HST Archival Research Grant (HST-AR-09209.01-A).

Short gamma ray bursts triggered by neutrino-antineutrino annihilation

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-11-15

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

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

Science.gov (United States)

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

1989-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Scanavini, Scanavini,Giacomo [Yale U.

2017-01-01

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

Towards Compact Antineutrino Detectors for Safeguarding Nuclear Reactors

International Nuclear Information System (INIS)

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

2010-01-01

In 2008 the IAEA Division of Technical Support convened a Workshop on Antineutrino Detection for Safeguards Applications. Two of the recommendations expressed that IAEA should consider antineutrino detection and monitoring in its current R and D program for safeguarding bulk-process reactors, and consider antineutrino detection and monitoring in its Safeguards by Design approaches for power and fissile inventory monitoring of new and next generation reactors. The workshop came to these recommendations after having assessed the results obtained at the San Onofre Nuclear Generator Station (SONGS) in California. A 600 litre, 10% efficiency detector, placed at 25m from the core was shown to record 300 net antineutrino events per day. The 2*2.5*2.5 m 3 footprint of the detector and the required below background operation, prevents an easy deployment at reactors. Moreover it does not provide spatial information of the fissile inventory and, because of the shape of a PBMR reactor, would not be representative for such type of reactor. A solution to this drawback is to develop more efficient detectors that are less bulky and less sensitive to cosmic and natural radiation backgrounds. Antineutrino detection in the SONGS detector is based on the capture of antineutrinos by a proton resulting in a positron and neutron. In the SONGS detector the positron and neutron are detected by secondary gamma-rays. The efficiency of the SONGS detector is largely dominated by the low efficiency for gamma detection high background sensitivity We are investigating two methods to resolve this problem, both leading to more compact detectors, which in a modular set up also will provide spatial information. One is based on detecting the positrons on their slowdown signal and the neutrons by capturing in 10 B or 6 Li, resulting in alpha-emission. The drawback for standard liquid scintillators doped with e.g. B is the low flame point of the solvent and the strong quenching of the alpha signal. Our

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Gamma-Ray Imaging Spectrometer (GRIS) instrument and plans for serving SN 1987A

International Nuclear Information System (INIS)

Tueller, J.; Barthelmy, S.; Gehrels, N.; Teegarden, B.J.; Leventhal, M.; MacCallum, C.J.

1988-01-01

The Gamma-Ray Imaging Spectrometer (GRIS) is a powerful second-generation high-resolution gamma-ray spectrometer. It consists of an array of seven large (typically >200 cm 3 ) n-type Germanium detectors surrounded by a thick (15 m) NaI active shield. Its energy range is 0.02 to 10 MeV. A new detector segmentation technique will be employed to reduce the detector background. The β-decay background component, which is expected to be dominant in the 0.2--2 MeV range, will be suppressed by roughly a factor of 20. The 3σ GRIS sensitivity to a narrow Fe line at 847 keV (expected to be the most intense from a supernova) will be ∼2 x 10 -4 photons/cm 2 -s for an 8 hr observation of the LMC over Alice Springs, Australia with unsegmented detectors. The instrument in simplified form will be ready to observe SN 1987A in early 1988

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

International Nuclear Information System (INIS)

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

1989-01-01

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

High-Velocity Ly(Alpha) Emission from SMR 1987A

Science.gov (United States)

Michael, Eli; McCray, Richard; Borkowski, Kazimierz J.; Pun, Chu S. J.; Sonneborn, George

1998-01-01

The high-velocity Ly(Alpha) emission from SN 1987A observed with the Space Telescope Imaging Spectrograph (STIS) evidently comes from a reverse shock formed where the outer envelope of SN 1987A strikes ionized gas inside the inner circumstellar ring. The observations can be explained by a simple kinematic model, in which the Ly(Alpha) emission comes from hydrogen atoms with radial velocity approximately 15,000 km s(exp -1) crossing a reverse shock in the shape of a slightly prolate ellipsoid with equatorial radius 4.8 x 10(exp 17) cm or approximately 80% of the distance to the inner surface of the inner ring. N v double Lambda 1239, 1243 emission, if present, has a net luminosity approximately less than 30% times that of the Ly(Alpha) emission. Future STIS observations should enable us to predict the time of impact with the inner ring and to determine unambiguously whether or not N v emission is present. These observations will offer a unique opportunity to probe the structure of SN 1987A's circumstellar environment and the hydrodynamics and kinetics of very fast shocks.

EVOLUTION AND HYDRODYNAMICS OF THE VERY BROAD X-RAY LINE EMISSION IN SN 1987A

Energy Technology Data Exchange (ETDEWEB)

Dewey, D.; Canizares, C. R. [MIT Kavli Institute, Cambridge, MA 02139 (United States); Dwarkadas, V. V. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Haberl, F.; Sturm, R., E-mail: dd@space.mit.edu, E-mail: vikram@oddjob.uchicago.edu [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Garching D-85748 (Germany)

2012-06-20

Observations of SN 1987A by the Chandra High Energy Transmission Grating (HETG) in 1999 and the XMM-Newton Reflection Grating Spectrometer (RGS) in 2003 show very broad (v-b) lines with a full width at half-maximum (FWHM) of order 10{sup 4} km s{sup -1}; at these times the blast wave (BW) was primarily interacting with the H II region around the progenitor. Since then, the X-ray emission has been increasingly dominated by narrower components as the BW encounters dense equatorial ring (ER) material. Even so, continuing v-b emission is seen in the grating spectra suggesting that the interaction with H II region material is ongoing. Based on the deep HETG 2007 and 2011 data sets, and confirmed by RGS and other HETG observations, the v-b component has a width of 9300 {+-} 2000 km s{sup -1} FWHM and contributes of order 20% of the current 0.5-2 keV flux. Guided by this result, SN 1987A's X-ray spectra are modeled as the weighted sum of the non-equilibrium-ionization emission from two simple one-dimensional hydrodynamic simulations; this '2 Multiplication-Sign 1D' model reproduces the observed radii, light curves, and spectra with a minimum of free parameters. The interaction with the H II region ({rho}{sub init} Almost-Equal-To 130 amu cm{sup -3}, {+-} 15 Degree-Sign opening angle) produces the very broad emission lines and most of the 3-10 keV flux. Our ER hydrodynamics, admittedly a crude approximation to the multi-D reality, gives ER densities of {approx}10{sup 4} amu cm{sup -3}, requires dense clumps ( Multiplication-Sign 5.5 density enhancement in {approx}30% of the volume), and predicts that the 0.5-2 keV flux will drop at a rate of {approx}17% per year once no new dense ER material is being shocked.

Reactor antineutrino spectra and their application to antineutrino-induced reactions II

International Nuclear Information System (INIS)

Vogel, P.; Schenter, G.K.; Mann, F.M.; Schenter, R.E.

1980-12-01

The antineutrino and electron spectra associated with various nuclear fuels are calculated. There are substantial differences between the spectra of different uranium and plutonium isotopes. On the other hand, the dependence on the energy and flux of the fission inducing neutrons is very weak. The resulting spectra can be used for calculation of the antineutrino and electron spectra of an arbitrary nuclear reactor at various stages of its refueling cycle. The sources of uncertainties in the spectrum are identified and analyzed in detail. The exposure time dependence of the spectrum is also discussed. The resulting anti ν/sub e/ spectra are then used to calculate the averaged cross sections of the inverse neutron β decay, weak charged and neutral current induced deuteron disintegration, and the antineutrino-electron scattering

High energy emission of supernova sn 1987a. Cosmic rays acceleration in mixed shocks

International Nuclear Information System (INIS)

Lehoucq, Roland

1992-01-01

In its first part, this research thesis reports the study of the high energy emission of the sn 1987 supernova, based on a Monte Carlo simulation of the transfer of γ photons emitted during disintegration of radioactive elements (such as "5"6Ni, "5"6Co, "5"7Co and "4"4Ti) produced during the explosion. One of the studied problems is the late evolution (beyond 1200 days) of light curvature which is very different when it is powered by the radiation of a central object or by radioactivity. The second part reports the study of acceleration of cosmic rays in two-fluid shock waves in order to understand the different asymmetries noticed in hot spots of extragalactic radio-sources. This work comprises the resolution of structure equations of a shock made of a conventional fluid and a relativistic one, in presence or absence of a magnetic field [fr

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Far-infrared spectrophotometry of SN 1987A - Days 265 and 267

Science.gov (United States)

Moseley, S. H.; Dwek, E.; Silverberg, R. F.; Glaccum, W.; Graham, J. R.; Loewenstein, R. F.

1989-01-01

The paper presents 16-66-micron spectra of SN 1987A taken on days 266 and 268 after core collapse. The spectrum consists of a nearly flat continuum, strong emission lines of hydrogen, and fine-structure lines of Fe II, Fe III, Co II, S I, and possibly Fe I, Ni II, and S III. From the relative strength of three lines which arise from transitions within the ground and excited states of Fe II, the temperature and a lower limit on the density of the line-emitting region are derived. From the line strengths, the abundances of Fe and S I, the end products of explosive nucleosynthesis in the supernova are estimated. An upper limit is also set to the amount of Co II remaining in the mantle. The low measured mass of Fe suggests that the ejecta are clumpy. The flat continuum is most likely free-free emission from the expanding supernova ejecta. About 35 percent of this emission arises from the ionized metals in the mantle; the rest arises from ionized hydrogen. At the time of these observations, there is no evidence for any emission from dust that may have formed in the supernova ejecta or from preexisting dust in the surrounding medium.

Prospects for Antineutrino Running at MiniBooNE

OpenAIRE

Wascko, M. O.

2006-01-01

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

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.

Daya Bay Antineutrino Detector gas system

Science.gov (United States)

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

2012-11-01

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

Daya Bay Antineutrino Detector Gas System

OpenAIRE

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

2012-01-01

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

Asymmetry of the envelope of supernova 1987A

Energy Technology Data Exchange (ETDEWEB)

Papaliolios, C.; Karovska, M.; Koechlin, L.; Nisenson, P.; Standley, C.; Heathcote, S.

1989-04-13

The supernova SN1987A in the Large Magellanic Cloud has been observed by high-angular-resolution speckle interferometry since 25 March (30 days after the explosion) with the 4-m telescope at the Cerro Tololo Interamerican Observatory. Data obtained on 25 March and 2 April 1987 revealed a second bright 'companion' source separated from the supernova by 60 milliarcseconds and less than three magnitudes fainter than the supernova. Measurements of the average diameter of the supernova envelope have been made from data recorded from March 1987 to April 1988. Here we present a more detailed analysis of these data, which shows that the expanding envelope is asymmetric. (author).

Asymmetry of the envelope of supernova 1987A

International Nuclear Information System (INIS)

Papaliolios, C.; Karovska, M.; Koechlin, L.; Nisenson, P.; Standley, C.; Heathcote, S.

1989-01-01

The supernova SN1987A in the Large Magellanic Cloud has been observed by high-angular-resolution speckle interferometry since 25 March (30 days after the explosion) with the 4-m telescope at the Cerro Tololo Interamerican Observatory. Data obtained on 25 March and 2 April 1987 revealed a second bright 'companion' source separated from the supernova by 60 milliarcseconds and less than three magnitudes fainter than the supernova. Measurements of the average diameter of the supernova envelope have been made from data recorded from March 1987 to April 1988. Here we present a more detailed analysis of these data, which shows that the expanding envelope is asymmetric. (author)

ISM chemical abundances in two intermediate-velocity clouds in the line of sight to SN 1987A

Science.gov (United States)

Morgan, Siobahn; Bohm-Vitense, Erika

1988-01-01

The earliest IUE high-resolution spectra of SN 1987A have been studied and reveal the presence of several clouds in the line of sight to the LMC. In particular, there are two clouds with radial velocities of about 130 km/s and about 180 km/s. These clouds' velocities are between those of Galactic clouds at 0-80 km/s and those of LMC gas at about 270 km/s. Chemical-abundance determinations may help to determine the origin and location of these clouds. Curve-of-growth analysis and 21-cm observations show that they may be underabundant in heavy elements by about a factor of 2 as compared to solar abundances. No depletion indicative of grain formation can be seen.

Recent results on neutrino, antineutrino charged current interactions at NAL

International Nuclear Information System (INIS)

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

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

Statistical properties of reactor antineutrinos

CERN Document Server

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

2002-01-01

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

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

International Nuclear Information System (INIS)

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

1989-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-01-01

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

Dissecting Reactor Antineutrino Flux Calculations

Science.gov (United States)

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

2017-09-01

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

Measurement of the electroweak coupling of neutrinos and antineutrinos on electrons

International Nuclear Information System (INIS)

Jonker, M.

1983-01-01

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

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

International Nuclear Information System (INIS)

Lyubushkin, Vladimir

2009-01-01

We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions (v μ n→μ - p and v-bar μ p→μ + n using a set of experimental data collected by the NOMAD collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly Carbon) normalizing it to the total v μ (v-bar μ ) charged current cross-section. The results for the flux averaged QEL cross-sections in the (anti)neutrino energy interval 3-100 GeV are qel >v μ = (0.92±0.02(stat)±0.06(syst))x10 -38 cm 2 and qel >v-bar μ = (0.81±0.05(stat)±0.09(syst))x10 -38 cm 2 for neutrino and antineutrino, respectively. The axial mass parameter MA was extracted from the measured quasi-elastic neutrino cross-section. The corresponding result is M A = 1.05±0.02(stat)±0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross-section and extracted from the pure Q 2 shape analysis of the high purity sample of v μ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured MA is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M A is lower than those recently published by K2K and MiniBooNE collaborations. However, within the large errors quoted by these experiments on M A , these results are compatible with the more precise NOMAD value.

Anti-neutrino imprint in solar neutrino flare

Science.gov (United States)

Fargion, D.

2006-10-01

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

Assembly and Installation of the Daya Bay Antineutrino Detectors

International Nuclear Information System (INIS)

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

2013-01-01

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

Is there a high-y anomaly in antineutrino interactions

International Nuclear Information System (INIS)

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

1977-01-01

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

Detection of neutrinos, antineutrinos, and neutrino-like particles

Energy Technology Data Exchange (ETDEWEB)

Fischbach, Ephraim

2018-04-24

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

Reactor antineutrino detector iDREAM.

Science.gov (United States)

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

2017-09-01

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

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

OpenAIRE

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

2014-01-01

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

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

Science.gov (United States)

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

2018-01-01

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

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

Directory of Open Access Journals (Sweden)

Mills Robert W

2018-01-01

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

On the event detected by the Mont Blanc underground neutrino detector on February 23, 1987

Energy Technology Data Exchange (ETDEWEB)

Dadykin, V L; Zatsepin, G T; Korchagin, V B

1988-02-01

The event detected by the Mont Balnc Soviet -Italian scintillation detector on February 23, 1987 at 2:52:37 are discussed. The corrected energies of the pulases of the event and the probability of the event imitation by the background are presented.

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...

Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

Science.gov (United States)

Bear, Ealeal; Soker, Noam

2018-04-01

We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.

INFRARED CONTINUUM AND LINE EVOLUTION OF THE EQUATORIAL RING AROUND SN 1987A

Energy Technology Data Exchange (ETDEWEB)

Arendt, Richard G. [CRESST/UMBC (United States); Dwek, Eli [Observational Cosmology Lab, Code 665, NASA/GSFC, Greenbelt, MD 20771 (United States); Bouchet, Patrice [Laboratoire AIM Paris-Saclay, CEA-IRFU/SAp, CNRS, Université Paris Diderot, F-91191 Gif-sur-Yvette (France); Danziger, I. John [INAF-Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Frank, Kari A. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Gehrz, Robert D.; Woodward, Charles E. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street, SE, Minneapolis, MN 55455 (United States); Park, Sangwook, E-mail: richard.g.arendt@nasa.gov [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

2016-03-15

Spitzer observations of SN 1987A have now spanned more than a decade. Since day ∼4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6–24 μm, and low and moderate resolution spectroscopy at 5–35 μm. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 μm. These data show that the 3.6 and 4.5 μm brightness has clearly begun to fade after day ∼8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe ii] and [Si ii] lines show different, peculiar velocity structures.

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

Science.gov (United States)

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

2018-01-01

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

Dilepton and trilepton production by antineutrinos and neutrinos in neon

Science.gov (United States)

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

1985-03-01

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

Dilepton and trilepton production by antineutrinos and neutrinos in neon

International Nuclear Information System (INIS)

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

1985-01-01

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

The reactor antineutrino anomaly and low energy threshold neutrino experiments

Science.gov (United States)

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

2018-01-01

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

DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA

Energy Technology Data Exchange (ETDEWEB)

Indebetouw, R.; Chevalier, R. [Department of Astronomy, University of Virginia, PO Box 400325, Charlottesville, VA 22904 (United States); Matsuura, M.; Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Dwek, E. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Zanardo, G. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, Crawley, WA 6009 (Australia); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bouchet, P. [CEA-Saclay, F-91191 Gif-sur-Yvette (France); Burrows, D. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Clayton, G. C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Fransson, C.; Lundqvist, P. [Department of Astronomy and the Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Gaensler, B. [Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Lakićević, M. [Lennard-Jones Laboratories, Keele University, ST5 5BG (United Kingdom); Long, K. S.; Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Martí-Vidal, I. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Marcaide, J. [Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); McCray, R., E-mail: remy@virginia.edu [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, UCB 391, Boulder, CO 80309 (United States); and others

2014-02-10

Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 μm, 870 μm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M {sub ☉}). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

Reactor Antineutrinos Signal all over the world

OpenAIRE

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

2014-01-01

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

Massive stars dying alone: Extremely remote environments of SN2009ip and SN2010jp

Science.gov (United States)

Smith, Nathan

2014-10-01

We propose an imaging study of the astonishingly remote environments of two recent supernovae (SNe): SN2009ip and SN2010jp. Both were unusual Type IIn explosions that crashed into dense circumstellar material (CSM) ejected by the star shortly before explosion. The favored progenitors of these SNe are very massive luminous blue variable (LBV) stars. In fact, SN2009ip presents an extraordinay case where the LBV-like progenitor was actually detected directly in archival HST data, and where we obtained spectra and photometry for numerous pre-SN eruptions. No other SN has this treasure trove of detailed information about the progenitor (not even SN1987A). SN2010jp represents a possible collapsar-powered event, since it showed evidence of a fast bipolar jet in spectra and a low 56Ni mass; this would be an analog of the black-hole forming explosions that cause gamma ray bursts, but where the relativistic jet is damped by a residual H envelope on the star. In both cases, the only viable models for these SNe involve extremely massive (initial masses of 40-100 Msun) progenitor stars. This seems at odds with their extremely remote environments in the far outskirts of their host galaxies, with no detected evidence for an underlying massive star population in ground-based data (nor in the single shallow WFPC2/F606W image of SN2009ip). Here we propose deep UV HST images to search for any mid/late O-type stars nearby, deep red images to detect any red supergiants, and an H-alpha image to search for any evidence of ongoing star formation in the vicinity. These observations will place important and demanding constraints on the initial masses and ages of these progenitors.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

Science.gov (United States)

Gran, R.; Betancourt, M.; Elkins, M.; Rodrigues, P. A.; Akbar, F.; Aliaga, L.; Andrade, D. A.; Bashyal, A.; Bellantoni, L.; Bercellie, A.; Bodek, A.; Bravar, A.; Budd, H.; Vera, G. F. R. Caceres; Cai, T.; Carneiro, M. F.; Coplowe, D.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gallagher, H.; Ghosh, A.; Haider, H.; Han, J. Y.; Harris, D. A.; Henry, S.; Jena, D.; Kleykamp, J.; Kordosky, M.; Le, T.; Leistico, J. R.; Lovlein, A.; Lu, X.-G.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Nguyen, C.; Norrick, A.; Nuruzzaman, Olivier, A.; Paolone, V.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Ruterbories, D.; Schellman, H.; Salinas, C. J. Solano; Su, H.; Sultana, M.; Falero, S. Sánchez; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Minerva Collaboration

2018-06-01

We report on multinucleon effects in low momentum transfer (<0.8 GeV /c ) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

The rebirth of Supernova 1987A : a study of the ejecta-ring collision

Science.gov (United States)

Gröningsson, Per

Supernovae are some of the most energetic phenomena in the Universe and they have throughout history fascinated people as they appeared as new stars in the sky. Supernova (SN) 1987A exploded in the nearby satellite galaxy, the Large Magellanic Cloud (LMC), at a distance of only 168,000 light years. The proximity of SN 1987A offers a unique opportunity to study the medium surrounding the supernova in great detail. Powered by the dynamical interaction of the ejecta with the inner circumstellar ring, SN 1987A is dramatically evolving at all wavelengths on time scales less than a year. This makes SN 1987A a great ``laboratory'' for studies of shock physics. Repeated observations of the ejecta-ring collision have been carried out using the UVES echelle spectrograph at VLT. This thesis covers seven epochs of high resolution spectra taken between October 1999 and November 2007. Three different emission line components are identified from the spectra. A narrow (~10 km/s) velocity component emerges from the unshocked ring. An intermediate (~250 km/s) component arises in the shocked ring, and a broad component extending to ~15,000 km/s comes from the reverse shock. Thanks to the high spectral resolution of UVES, it has been possible to separate the shocked from the unshocked ring emission. For the unshocked gas, ionization stages from neutral up to Ne V and Fe VII were found. The line fluxes of the low-ionization lines decline during the period of the observations. However, the fluxes of the [O III] and [Ne III] lines appear to increase and this is found to be consistent with the heating of the pre-shock gas by X-rays from the shock interactions. The line emission from the ejecta-ring collision increases rapidly as more gas is swept up by the shocks. This emission comes from ions with a range of ionization stages (e.g., Fe II-XIV). The low-ionization lines show an increase in their line widths which is consistent with that these lines originate from radiative shocks. The

Coherent scattering of neutrinos and antineutrinos by quarks in a crystal

International Nuclear Information System (INIS)

Weber, J.; Wilmot, G.

1988-01-01

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

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

Science.gov (United States)

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

2018-02-01

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

Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

International Nuclear Information System (INIS)

Heeger, Karsten M.

2014-01-01

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

Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

Energy Technology Data Exchange (ETDEWEB)

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

2014-09-13

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

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

International Nuclear Information System (INIS)

Haag, Nils-Holger

2013-01-01

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

Electron Neutrino and Antineutrino Appearance in the MINOS Detector

Energy Technology Data Exchange (ETDEWEB)

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

2013-04-01

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

Improved measurement of electron antineutrino disappearance at Daya Bay

International Nuclear Information System (INIS)

An Fengpeng; Bai Jingzhi; An Qi

2013-01-01

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

Anti-neutrino disintegration of the deuteron

International Nuclear Information System (INIS)

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

1981-01-01

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-03-15

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

Anti-Neutrino Charged-Current Reactions on Scintillator with Low Momentum Transfer

Energy Technology Data Exchange (ETDEWEB)

Gran, R.; et al.

2018-03-25

We report on multi-nucleon effects in low momentum transfer ($< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $\\Delta$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.

Neutrino scattering and the reactor antineutrino anomaly

Science.gov (United States)

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

2017-12-01

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

Study of charged current reactions induced by muon antineutrinos

International Nuclear Information System (INIS)

Huss, D.

1979-07-01

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

Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

Energy Technology Data Exchange (ETDEWEB)

Potter, T. M.; Staveley-Smith, L. [International center for Radio Astronomy Research (ICRAR) M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Reville, B. [Center for Plasma Physics, Queen' s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Bicknell, G. V.; Sutherland, R. S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 0200 (Australia); Wagner, A. Y., E-mail: tobympotter@gmail.com [Center for Computational Sciences, Tsukuba University, Tsukuba, Ibaraki, 305-8577 (Japan)

2014-10-20

The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ☉} and an energy of 1.5 × 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 10{sup 7} m{sup –3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

Improved Measurement of Electron-antineutrino Disappearance at Daya Bay

International Nuclear Information System (INIS)

Dwyer, D.A.

2013-01-01

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

Improved Measurement of Electron-antineutrino Disappearance at Daya Bay

Energy Technology Data Exchange (ETDEWEB)

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

2013-02-15

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

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.

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-15

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Hard x- and gamma-rays from supernova 1987A

International Nuclear Information System (INIS)

Kumagai, S.; Shigeyama, T.; Nomoto, K.; Nishmura, J.; Itoh, M.

1988-01-01

The x-ray light curve and spectrum from SN 1987A due to Compton degradation of γ-rays from the 56 Co decay are calculated and compared with the Ginga and Kvant observations. If mixing of 56 Co into outer layers has taken place, the x-rays emerge much earlier than in the case without mixing and the resulting hard x-rays are in reasonable agreement with observations

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)

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

Science.gov (United States)

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

2018-01-01

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

Gamma-ray observations of supernovae SN1987A

International Nuclear Information System (INIS)

Souza, C.A.W.; Neri, J.A.C.F.; Jayanthi, U.B.

1988-01-01

Theoretical investigations of supernovae explosions predict a high emission of gamma rays (∼ 10 -2 photons.cm -2 .s -1 ) beginning around 300 days after explosion. A balloon-borne experiment was flown in October, 1987, to observe this emission. The payload carried 4 phoswich detectors of BGO/CsI and NaI/CsI with areas 169 cm 2 and 100 cm 2 , respectively. The detectors' sensitivity (for 10000 s at 3g/cm 3 with error bar of 3 σ) is about 10 -3 ∼ 10 -4 photons. cm -2 .s -1 at energies above 200 KeV. The detectors mounted on a stabilized platform observed the supernova for about 2 hours. The data are being analized for pulsations (≥ 0.5 ms) and gamma ray emission. Energy spectra and temporal analysis will be presented and discussed. (author) [pt

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

Science.gov (United States)

de Gouvêa, André; Kelly, Kevin J.

2017-11-01

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

Comparing neutrino and antineutrino scattering

International Nuclear Information System (INIS)

Barish, B.C.

1977-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-01-01

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

The Daya Bay antineutrino detector filling system and liquid mass measurement

Science.gov (United States)

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

2013-09-01

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

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

International Nuclear Information System (INIS)

Rudstam, G.; Aleklett, K.

1979-01-01

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

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

OpenAIRE

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

2007-01-01

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

HIGH-RESOLUTION RADIO OBSERVATIONS OF THE REMNANT OF SN 1987A AT HIGH FREQUENCIES

International Nuclear Information System (INIS)

Zanardo, Giovanna; Staveley-Smith, L.; Potter, T. M.; Ng, C.-Y.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

2013-01-01

We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, which is super-resolved to 0.''25. The flux density is 40 ± 2 mJy at 44 GHz and 81 ± 6 mJy at 18 GHz. At both frequencies, the remnant exhibits a ring-like emission with two prominent lobes, and an east-west brightness asymmetry that peaks on the eastern lobe. A central feature of fainter emission appears at 44 GHz. A comparison with previous ATCA observations at 18 and 36 GHz highlights higher expansion velocities of the remnant's eastern side. The 18-44 GHz spectral index is α = –0.80 (S ν ∝ν α ). The spectral index map suggests slightly steeper values at the brightest sites on the eastern lobe, whereas flatter values are associated with the inner regions. The remnant morphology at 44 GHz generally matches the structure seen with contemporaneous X-ray and Hα observations. Unlike the Hα emission, both the radio and X-ray emission peaks on the eastern lobe. The regions of flatter spectral index align and partially overlap with the optically visible ejecta. Simple free-free absorption models suggest that emission from a pulsar wind nebula or a compact source inside the remnant may now be detectable at high frequencies or at low frequencies if there are holes in the ionized component of the ejecta.

MULTIFREQUENCY RADIO MEASUREMENTS OF SUPERNOVA 1987A OVER 22 YEARS

International Nuclear Information System (INIS)

Zanardo, G.; Staveley-Smith, L.; Potter, T. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.; Gaensler, B. M.; Ng, C.-Y.

2010-01-01

We present extensive observations of the radio emission from the remnant of supernova (SN) 1987A made with the Australia Telescope Compact Array (ATCA), since the first detection of the remnant in 1990. The radio emission has evolved in time providing unique information on the interaction of the SN shock with the circumstellar medium. We particularly focus on the monitoring observations at 1.4, 2.4, 4.8, and 8.6 GHz, which have been made at intervals of 4-6 weeks. The flux density data show that the remnant brightness is now increasing exponentially, while the radio spectrum is flattening. The current spectral index value of -0.68 represents an 18 ± 3% increase over the last eight years. The exponential trend in the flux is also found in the ATCA imaging observations at 9 GHz, which have been made since 1992, approximately twice a year, as well as in the 843 MHz data set from the Molonglo Observatory Synthesis Telescope from 1987 to 2007 March. Comparisons with data at different wavelengths (X-ray, Hα) are made. The rich data set that has been assembled in the last 22 years forms a basis for a better understanding of the evolution of the supernova remnant.

REVIEWS OF TOPICAL PROBLEMS Rotational explosion mechanism for collapsing supernovae and the two-stage neutrino signal from supernova 1987A in the Large Magellanic Cloud

Science.gov (United States)

Imshennik, Vladimir S.

2011-02-01

The two-stage (double) signal produced by the outburst of the close supernova (SN) in the Large Magellanic Cloud, which started on and involved two neutrino signals during the night of 23 February 1987 UT, is theoretically interpreted in terms of a scenario of rotationally exploding collapsing SNs, to whose class the outburst undoubtedly belongs. This scenario consists of a set of hydrodynamic and kinetic models in which key results are obtained by numerically solving non-one-dimensional and nonstationary problems. Of vital importance in this context is the inclusion of rotation effects, their role being particularly significant precisely in terms of the question of the transformation of the original collapse of the presupernova iron core to the explosion of the SN shell, with an energy release on a familiar scale of 1051 erg. The collapse in itself leads to the birth of neutron stars (black holes) emitting neutrino and gravitational radiation signals of gigantic intensity, whose total energy significantly (by a factor of hundreds) exceeds the above-cited SN burst energy. The proposed rotational scenario is described briefly by artificially dividing it into three (or four) characteristic stages. This division is dictated by the physical meaning of the chain of events a rotating iron core of a sufficiently massive (more than 10M) star triggers when it collapses. An attempt is made to quantitatively describe the properties of the associated neutrino and gravitational radiations. The review highlights the interpretation of the two-stage neutrino signal from SN 1987A, a problem which, given the present status of theoretical astrophysics, cannot, in the author's view, be solved without including rotation effects.

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.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Study of single pion production in antineutrino induced charged current interactions

International Nuclear Information System (INIS)

Bolognese, Teresa.

1978-01-01

Results are presented on the exclusive charged current antineutrino production of one pion using the data of the Gargamelle propane experiment at CERN PS. The isospin structure of the charged weak current is studied as well as the energy dependence of the total cross section for π - antineutrino production, which is compared with the prediction of Adler's model [fr

SN 1987 A: A Unique Laboratory for Shock Physics

Science.gov (United States)

Sonneborn, George

2012-01-01

Supernova 1987 A has given us an unprecedented view of the evolution of the explosion debris and its interaction with circumstellar matter. The outer supernova debris, now expanding with velocities approx.8000 km/s, encountered the relatively dense circumstellar ring formed by presupernova mass loss in the early 1990s. The shock interaction is manifested by UV-optical "hotspots", an expanding X-ray ring, an expanding ring of knotty non-thermal radio emission, and a ring of thermal IR emission from silicate dust Recent ultraviolet observations of the emissions from the reverse shock and the ring with the HST/COS reveal new details about the shock interaction. Lyman alpha emission from the reverse shock is much stronger than H alpha and they have different emission morphologies, pointing to different emission mechanisms. The reverse shock was detected for the first time in C IV 1550. The N V to C IV brightness ratio indicates the N/C abundance ratio in the expanding debris is about 100X solar, about 3X N/C in the inner ring.

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

OpenAIRE

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

2012-01-01

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

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

International Nuclear Information System (INIS)

Barlag, S.J.M.

1984-01-01

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

Evidence for higher twist effects in fast π- production by antineutrinos in neon

Science.gov (United States)

Fitch, P. J.; Kasper, P.; Cooper-Sarkar, A. M.; Aderholz, M.; Armenise, N.; Azemoon, T.; Bertrand, D.; Berggren, M.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Gerbier, G.; Guy, J.; Hulth, P. O.; Iaselli, G.; Jones, G. T.; Lagraa, M.; Marage, P.; Middleton, R. P.; Miller, D.; Mobayyen, M. M.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Sansum, R. A.; Simopoulou, E.; Varvell, K.; Vallée, C.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wittek, W.; Wells, J.; Zevgolatakos, E.

1986-03-01

Evidence for a significant higher twist contribution to high z π- production in antineutrino scattering is presented. In events with W>3 GeV and Q 2>1 GeV2 in our data, it accounts for (51 ±8)% of all π- with z above 0.5. It is consistent with the z- Q 2 correlations of Berger's higher twist prediction. The data are inconclusive concerning the predicted y-z correlation and p T dependence. The z - Q 2 correlation is not adequately described by the Lund Monte-Carlo.

Evidence for higher twist effects in fast π- production by antineutrinos in neon

International Nuclear Information System (INIS)

Fitch, P.J.; Azemoon, T.; Bullock, F.W.; Sansum, R.A.; Armenise, N.; Calicchio, M.; Erriquez, O.; Iaselli, G.; Bertrand, D.; Marage, P.; Berggren, M.; Hulth, P.O.; Coghen, T.; Gerbier, G.; Lagraa, M.; Neveu, M.; Parker, M.A.; Wachsmuth, H.; Simopoulo, E.; Vayaki, A.; Zevgolatakos, E.; Varvell, K.; Wells, J.; Vallee, C.

1986-01-01

Evidence for a significant higher twist contribution to high zπ - production in antineutrino scattering is presented. In events with W>3 GeV and Q 2 >1 GeV 2 in our data, it accounts for (51+-8)% of all π - with z above 0.5. It is consistent with the z-Q 2 correlations of Berger's higher twist prediction. The data are inconclusive concerning the predicted y-z correlation and psub(T) dependence. The z-Q 2 correlation is not adequately described by the Lund Monte-Carlo. (orig.)

Highlights from the Daya Bay Neutrino Experiment

Directory of Open Access Journals (Sweden)

Wang Zhe

2014-04-01

Full Text Available With an understanding of the energy response of the anti-neutrino detectors, the Daya Bay collaboration presents new results using gadolinium-neutron capture: sin2 2θ13 = 0.108 ± 0.028 and |Δmee2| = 2.55−0.18+0.21 × 10−3 eV2 with only the distortion information of the neutrino energy spectrum shape, and sin2 2θ13 = 0.090−0.009+0.008 and |Δmee2| = 2.59−0.20+0.19 10−3 eV2 with both the shape and event rate information. It is also demonstrated that a clean inverse beta decay sample can be extracted using hydrogen-neutron capture, which is now being used for neutrino oscillation measurement. The supernova online trigger is designed and implemented, which can provide about 100% efficiency for all SN1987A-scale supernova bursts within the Milky Way.

Supernova 1987A Interpreted through the SLIP Pulsar Model

Science.gov (United States)

Middleditch, John

2010-01-01

The model of pulsar emission through superluminally induced polarization currents (SLIP) predicts that pulsations produced by such currents, induced by a rotating, magnetized body at many light cylinder radii, as would be the case for a neutron star born within any star of >1.5 solar masses, will drive pulsations close to the axis of rotation. Such highly collimated pulsations (), and later, in less collimated form, the bipolarity of SN 1987A itself. The pulsations and jet interacted with circumstellar material (CM), to produce features observed in the very early light curve which correspond to: 1) the entry of the pulsed beam into the CM; 2) the entry of the 0.95 c particles into the CM; 3) the exit of the pulsed beam from the CM (with contributions in the B and I bands -- the same as later inferred/observed for its 2.14 ms pulsations); and 4) the exit of the fastest particles from the CM. Because of the energy requirements of the jet in these early stages, the spindown required of its pulsar could exceed 1e-5 Hz/s at a rotation rate of 500 Hz. There is no reason to suggest that this mechanism is not universally applicable to all SNe with gaseous remnants remaining, and thus SN 1987A is the Rosetta Stone for 99% of SNe, gamma-ray bursts, and millisecond pulsars. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085.

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.

Towards earth AntineutRino TomograpHy (EARTH)

NARCIS (Netherlands)

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

2006-01-01

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

When a major star dies

International Nuclear Information System (INIS)

Joubert, G.

1988-01-01

Astrologers are slowly learning what happens when a star dies. On the night of 23-24 February 1987, the light of an exploding star - a supernova with the name SN 1987A - reached the earth. In this article this astrological event of the century are discussed, and its importance for astrologers

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

International Nuclear Information System (INIS)

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

1993-01-01

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

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

NARCIS (Netherlands)

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

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-11-03

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

The U238 antineutrino spectrum in the Double Chooz experiment

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

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

Science.gov (United States)

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

2017-06-23

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

X-RAY EMISSION FROM SN 2004dj: A TALE OF TWO SHOCKS

Energy Technology Data Exchange (ETDEWEB)

Chakraborti, Sayan; Yadav, Naveen; Ray, Alak [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Smith, Randall [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7K 7B4 (Canada); Pooley, David, E-mail: schakraborti@fas.harvard.edu [Department of Physics, Sam Houston State University, Huntsville, TX (United States)

2012-12-20

Type IIP (Plateau) supernovae are the most commonly observed variety of core-collapse events. They have been detected in a wide range of wavelengths from radio, through optical to X-rays. The standard picture of a Type IIP supernova has the blastwave interacting with the progenitor's circumstellar matter to produce a hot region bounded by a forward and a reverse shock. This region is thought to be responsible for most of the X-ray and radio emission from these objects. Yet the origin of X-rays from these supernovae is not well understood quantitatively. The relative contributions of particle acceleration and magnetic field amplification in generating the X-ray and radio emission need to be determined. In this work, we analyze archival Chandra observations of SN 2004dj, one of the nearest supernovae since SN 1987A, along with published radio and optical information. We determine the pre-explosion mass-loss rate, blastwave velocity, electron acceleration, and magnetic field amplification efficiencies. We find that a greater fraction of the thermal energy goes into accelerating electrons than into amplifying magnetic fields. We conclude that the X-ray emission arises out of a combination of inverse Compton scattering by non-thermal electrons accelerated in the forward shock and thermal emission from supernova ejecta heated by the reverse shock.

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

International Nuclear Information System (INIS)

Le Bas, P.A.

1984-01-01

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

Search for Electron Antineutrino Appearance at the Δm2∼1 eV2 Scale

International Nuclear Information System (INIS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Fleming, B. T.; Linden, S. K.; Spitz, J.; Brice, S. J.; Brown, B. C.; Ford, R.; Garcia, F. G.; Kobilarcik, T.; Marsh, W.; Moore, C. D.; Russell, A. D.; Stefanski, R. J.; Bugel, L.; Djurcic, Z.; Mahn, K. B. M.; Shaevitz, M. H.; Sorel, M.; Conrad, J. M.

2009-01-01

The MiniBooNE Collaboration reports initial results from a search for ν μ →ν e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10 20 protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200 ν QE <3000 MeV: 144 electronlike events have been observed in this energy range, compared to an expectation of 139.2±17.6 events. No significant excess of events has been observed, both at low energy, 200-475 MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect to antineutrino oscillations suggested by data from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

Limits on the electron-antineutrino mass

International Nuclear Information System (INIS)

Wilkerson, J.F.

1987-01-01

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

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

Science.gov (United States)

Hiraki, Takahiro

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

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

International Nuclear Information System (INIS)

Hiraki, Takahiro

2015-01-01

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

Ultraviolet spectroscopy of the blue supergiant SBW1: the remarkably weak wind of a SN 1987A analogue

Science.gov (United States)

Smith, Nathan; Groh, Jose H.; France, Kevin; McCray, Richard

2017-06-01

The Galactic blue supergiant SBW1 with its circumstellar ring nebula represents the best known analogue of the progenitor of SN 1987A. High-resolution imaging has shown Hα and infrared structures arising in an ionized flow that partly fills the ring's interior. To constrain the influence of the stellar wind on this structure, we obtained an ultraviolet (UV) spectrum of the central star of SBW1 with the Hubble Space Telescope Cosmic Origins Spectrograph. The UV spectrum shows none of the typical wind signatures, indicating a very low mass-loss rate. Radiative transfer models suggest an extremely low rate below 10-10 M⊙ yr-1, although we find that cooling time-scales probably become comparable to (or longer than) the flow time below 10-8 M⊙ yr-1. We therefore adopt this latter value as a conservative upper limit. For the central star, the model yields Teff = 21 000 ± 1000 K, log(geff) = 3.0, L ≃ 5 × 104 L⊙, and roughly Solar composition except for enhanced N abundance. SBW1's very low mass-loss rate may hinder the wind's ability to shape its nebula and to shed angular momentum. The spin-down time-scale for magnetic breaking is more than 500 times longer than the age of the ring. This, combined with the star's slow rotation rate, constrains merger scenarios to form ring nebulae. The mass-loss rate is at least 10 times lower than expected from mass-loss recipes, without any account of clumping. The physical explanation for why SBW1's wind is so weak presents an interesting mystery.

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

Science.gov (United States)

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

1986-06-01

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

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

International Nuclear Information System (INIS)

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

1986-01-01

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

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.

The triple-ring nebula around SN 1987A: fingerprint of a binary merger.

Science.gov (United States)

Morris, Thomas; Podsiadlowski, Philipp

2007-02-23

Supernova 1987A, the first naked-eye supernova observed since Kepler's supernova in 1604, defies a number of theoretical expectations. Its anomalies have long been attributed to a merger between two massive stars that occurred some 20,000 years before the explosion, but so far there has been no conclusive proof that this merger took place. Here, we present three-dimensional hydrodynamical simulations of the mass ejection associated with such a merger and the subsequent evolution of the ejecta, and we show that this accurately reproduces the properties of the triple-ring nebula surrounding the supernova.

Determination of neutrino mass hierarchy and θ13 with a remote detector of reactor antineutrinos

International Nuclear Information System (INIS)

Learned, John G.; Pakvasa, Sandip; Dye, Stephen T.; Svoboda, Robert C.

2008-01-01

We describe a method for determining the hierarchy of the neutrino mass spectrum and θ 13 through remote detection of electron antineutrinos from a nuclear reactor. This method utilizing a single, 10-kiloton scintillating liquid detector at a distance of 49-63 kilometers from the reactor complex measures mass-squared differences involving ν 3 with a one(ten)-year exposure provided sin 2 (2θ 13 )>0.05(0.02). Our technique applies the Fourier transform to the event rate as a function of neutrino flight distance over neutrino energy. Sweeping a relevant range of δm 2 resolves separate spectral peaks for δm 2 31 and δm 2 32 . For normal (inverted) hierarchy |δm 2 31 | is greater (lesser) than |δm 2 32 |. This robust determination requires a detector energy resolution of 3.5%/√(E).

Science Potential of a Deep Ocean Antineutrino Observatory

International Nuclear Information System (INIS)

Dye, S.T.

2007-01-01

This paper presents science potential of a deep ocean antineutrino observatory being developed 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 and θ 13 . 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

THIRTY YEARS OF SN 1980K: EVIDENCE FOR LIGHT ECHOES

Energy Technology Data Exchange (ETDEWEB)

Sugerman, Ben E. K. [Department of Physics and Astronomy, Goucher College, 1021 Dulaney Valley Road, Baltimore, MD 21208 (United States); Andrews, Jennifer E. [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Clayton, Geoffrey C. [Department of Physics and Astronomy, Lousiana State University, 202 Nicholson Hall, Baton Roughe, LA 70803 (United States); Ercolano, Barbara [Excellence Cluster ' Universe' , Universitaets-Sternwarte Muenchen, Scheinerstr. 1, 81679 Muenchen (Germany); Ghavamian, Parviz [Department of Physics, Astronomy and Geosciences, Towson University, Smith Hall, Towson, MD 21252 (United States); Kennicutt, Robert C. Jr. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CM3 0HA (United Kingdom); Krause, Oliver [Max Planck Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Meixner, Margaret [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Otsuka, Masaaki, E-mail: ben.sugerman@goucher.edu [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China)

2012-04-20

We report optical and mid-infrared photometry of SN 1980K between 2004 and 2010, which shows slow monotonic fading consistent with previous spectroscopic and photometric observations made 8-17 yr after outburst. The slow rate of change over two decades suggests that this evolution may result from scattered and thermal light echoes off of extended circumstellar material. We present a semi-analytic dust radiative-transfer model that uses an empirically corrected effective optical depth to provide a fast and robust alternative to full Monte Carlo radiative-transfer modeling for homogenous dust at low to intermediate optical depths. We find that unresolved echoes from a thin circumstellar shell 14-15 lt-yr from the progenitor, and containing {approx}< 0.02 M{sub Sun} of carbon-rich dust, can explain the broadband spectral and temporal evolution. The size, mass, and dust composition are in good agreement with the contact discontinuity observed in scattered echoes around SN 1987A. The origin of slowly changing high-velocity [O I] and H{alpha} lines is also considered. We propose an origin in shocked high-velocity metal-rich clumps of ejecta, rather than arising in the impact of ejecta on slowly moving circumstellar material, as is the case with hot spots in SN 1987A.

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.

A statistical analysis of angular distribution of neutrino events observed in Kamiokande II and IMB detectors from supernova SN 1987 A

International Nuclear Information System (INIS)

Krivoruchenko, M.I.

1989-01-01

A detailed statistical analysis of angular distribution of neutrino events observed in Kamiokande II and IMB detectors on UT 07:35, 2/23'87 is carried out. Distribution functions of the mean scattering angles in the reaction anti υ e p→e + n and υe→υe are constructed with account taken of the multiple Coulomb scattering and the experimental angular errors. The Smirnov and Wald-Wolfowitz run tests are used to test the hypothesis that the angular distributions of events from the two detectors agree with each other. We test with the use of the Kolmogorov and Mises statistical criterions the hypothesis that the recorded events all represent anti υ e p→e + n inelastic scatterings. Then the Neyman-Pearson test is applied to each event in testing the hypothesis anti υ e p→e + n against the alternative υe→υe. The hypotheses that the number of elastic events equals s=0, 1, 2, ... against the alternatives s≠0, 1, 2, ... are tested on the basis of the generalized likelihood ratio criterion. The confidence intervals for the number of elastic events are also constructed. The current supernova models fail to give a satisfactory account of the angular distribution data. (orig.)

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.

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

International Nuclear Information System (INIS)

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

1997-01-01

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

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

CERN Multimedia

CERN. Geneva

2016-01-01

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

Experimental spectrum of reactor antineutrinos and spectra of main fissile isotopes

Energy Technology Data Exchange (ETDEWEB)

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

2013-05-15

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

The double chooz experiment: simulation of reactor antineutrino spectra

International Nuclear Information System (INIS)

Mueller, T.

2010-01-01

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

Proposal on electron anti-neutrino mass measurement at INS

International Nuclear Information System (INIS)

Ohshima, Takayoshi.

1981-03-01

Some comment on the proposed experiment, namely the measurement of electron anti-neutrino mass, is described. Various experiments with the measurement of β-ray from tritium have been reported. The precise measurement of the shape of the Kurie plot is required in this kind of experiment. The present experiment aimed at more accurate determination of neutrino mass than any other previous ones. An important point of the present experiment is to reduce the background due to the β-ray from evaporating tritium. The source candidates have low evaporation rate. A double focus √2π air core spectrometer is employed for the measurement of β-ray. The spectrometer was improved to meet the present purpose. The accumulated event rate was expected to be about 10 times higher than Russian experiment. The estimated energy resolution was about 30 eV. The neutrino mass with less than 10 eV accuracy will be obtained. (Kato, T.)

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 ν_μ → ν_e 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 E_ν ~ 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

Science Potential of a Deep Ocean Antineutrino Observatory

Energy Technology Data Exchange (ETDEWEB)

Dye, S.T. [Department of Physics and Astronomy, University of Hawaii, 2505 Correa Road, Honolulu, Hawaii, 96822 (United States); College of Natural Sciences, Hawaii Pacific University, 45-045 Kamehameha Highway, Kaneohe, Hawaii 96744 (United States)

2007-06-15

This paper presents science potential of a deep ocean antineutrino observatory being developed 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 and {theta}{sub 13}. 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.

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

Science.gov (United States)

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

2015-06-01

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

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

International Nuclear Information System (INIS)

Lutz, Anne-Marie.

1975-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-01

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

Optical spectrophotometric atlas of Supernova 1987A in the LMC. I. The first 130 days

International Nuclear Information System (INIS)

Phillips, M.M.; Heathcote, S.R.; Hamuy, M.; Navarrete, M.

1988-01-01

Optical spectrophotometry of SN 1987A in the Large Magellanic Cloud (LMC) covering the first 5 months since outburst is presented. More than 80 spectra were obtained at Cerro Tololo over this period, mostly with the 2D-Frutti two-dimensional photon-counting detector on the 1-m telescope. The spectrophotometric calibration of the 2D-Frutti data is considered in detail. Through a comparison with broadband photometry, it is shown that the accuracy of the 2D-Frutti spectrophotometry is + or - 5 percent in absolute terms, and that the relative calibration for any single spectrum is accurate to + or - 3 percent. CCD spectrophotometry obtained on the first night of observation (Feb. 25, 1987) is also briefly discussed. Radial velocities for several prominent absorption and emission features are measured from these combined data. 13 references

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.

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

OpenAIRE

Tornow W.; Bhike Megha

2015-01-01

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

A study of inclusive antineutrino interactions in propane

International Nuclear Information System (INIS)

Ramzan, F.A.

1979-02-01

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

Development of the reactor antineutrino detection technology within the iDream project

Science.gov (United States)

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

2017-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Tzanov, Martin Mihaylov [Pittsburgh U.

2005-11-01

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

Monitoring of spent nuclear fuel with antineutrino detectors

Science.gov (United States)

Brdar, Vedran

2017-09-01

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

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

Science.gov (United States)

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

2016-12-01

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

Status of Works on A-40-MCI-Activity Tritium Source for the Measurement of the Antineutrino Magnetic Moment

International Nuclear Information System (INIS)

Yukhimchuk, A.A.; Vinogradov, Yu.I.; Golubkov, A.N.; Grishechkin, S.K.; Il'kaev, R.I.; Kuryakin, A.V.; Lebedev, B.L.; Lobanov, V.N.; Mikhailov, V.N.; Tumkin, D.P.; Bogdanova, L.N.

2005-01-01

For the experiment on the measurement of the electron antineutrino magnetic moment we suggest a new approach to the tritium source design, namely, a configuration of annular cells filled with TiT 2 that are stacked into a hollow cylinder. Detectors are mounted in the hole inside.We present results of the optimization of geometrical and physical parameters of the source with respect to its experimental effectiveness and safety guaranty at all stages of its lifecycle. We discuss the choice of the construction materials and specify technological issues relevant to radiation purity of the source, being of the special concern in the experiment on the electron antineutrino magnetic moment measurement

New Monte Carlo-based method to evaluate fission fraction uncertainties for the reactor antineutrino experiment

Energy Technology Data Exchange (ETDEWEB)

Ma, X.B., E-mail: maxb@ncepu.edu.cn; Qiu, R.M.; Chen, Y.X.

2017-02-15

Uncertainties regarding fission fractions are essential in understanding antineutrino flux predictions in reactor antineutrino experiments. A new Monte Carlo-based method to evaluate the covariance coefficients between isotopes is proposed. The covariance coefficients are found to vary with reactor burnup and may change from positive to negative because of balance effects in fissioning. For example, between {sup 235}U and {sup 239}Pu, the covariance coefficient changes from 0.15 to −0.13. Using the equation relating fission fraction and atomic density, consistent uncertainties in the fission fraction and covariance matrix were obtained. The antineutrino flux uncertainty is 0.55%, which does not vary with reactor burnup. The new value is about 8.3% smaller. - Highlights: • The covariance coefficients between isotopes vs reactor burnup may change its sign because of two opposite effects. • The relation between fission fraction uncertainty and atomic density are first studied. • A new MC-based method of evaluating the covariance coefficients between isotopes was proposed.

On neutrino and antineutrino scattering by electrons, and by partons

International Nuclear Information System (INIS)

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

1975-09-01

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

SUPERNOVA 2003ie WAS LIKELY A FAINT TYPE IIP EVENT

Energy Technology Data Exchange (ETDEWEB)

Arcavi, Iair; Gal-Yam, Avishay [Department of Particle Physics and Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Sergeev, Sergey G., E-mail: iair.arcavi@weizmann.ac.il [Crimean Astrophysical Observatory, P/O Nauchny, Crimea 98409 (Ukraine)

2013-04-15

We present new photometric observations of supernova (SN) 2003ie starting one month before discovery, obtained serendipitously while observing its host galaxy. With only a weak upper limit derived on the mass of its progenitor (<25 M{sub Sun }) from previous pre-explosion studies, this event could be a potential exception to the ''red supergiant (RSG) problem'' (the lack of high-mass RSGs exploding as Type IIP SNe). However, this is true only if SN2003ie was a Type IIP event, something which has never been determined. Using recently derived core-collapse SN light-curve templates, as well as by comparison to other known SNe, we find that SN2003ie was indeed a likely Type IIP event. However, with a plateau magnitude of {approx} - 15.5 mag, it is found to be a member of the faint Type IIP class. Previous members of this class have been shown to arise from relatively low-mass progenitors (<12 M{sub Sun }). It therefore seems unlikely that this SN had a massive RSG progenitor. The use of core-collapse SN light-curve templates is shown to be helpful in classifying SNe with sparse coverage. These templates are likely to become more robust as large homogeneous samples of core-collapse events are collected.

On neutrino and antineutrino scattering by electrons, and by partons

CERN Document Server

Bell, J S

1975-01-01

Assuming a non-derivative point interaction, and Born approximation, there are some simple relations between neutrino and antineutrino scattering on electrons or partons. They have been observed already, for some special cases, in the results of explicit calculations. Here they are obtained from simple and general considerations. (8 refs).

Performing a stellar autopsy using the radio-bright remnant of SN 1996cr

Science.gov (United States)

Meunier, C.; Bauer, F. E.; Dwarkadas, V. V.; Koribalski, B.; Emonts, B.; Hunstead, R. W.; Campbell-Wilson, D.; Stockdale, C.; Tingay, S. J.

2013-05-01

We present newly reduced archival radio observations of SN 1996cr in the Circinus Galaxy from the Australia Telescope Compact Array and the Molonglo Observatory Synthesis Telescope, and attempt to model its radio light curves using recent hydrodynamical simulations of the interaction between the supernova (SN) ejecta and the circumstellar material (CSM) at X-ray wavelengths. The radio data within the first 1000 d show clear signs of free-free absorption (FFA), which decreases gradually and is minimal above 1.4 GHz after day ˜3000. Constraints on the FFA optical depth provide estimates of the CSM free electron density, which allows insight into the ionization of SN 1996cr's CSM and offers a test on the density distribution adopted by the hydrodynamical simulation. The intrinsic spectral index of the radiation shows evidence for spectral flattening, which is characterized by α = 0.852 ± 0.002 at day 3000 and a decay rate of Δα = -0.014 ± 0.001 yr-1. The striking similarity in the spectral flattening of SN 1987A, SN 1993J and SN 1996cr suggests this may be a relatively common feature of SNe/CSM shocks. We adopt this spectral index variation to model the synchrotron radio emission of the shock, and consider several scalings that relate the parameters of the hydrodynamical simulation to the magnetic field and electron distribution. The simulated light curves match the large-scale features of the observed light curves, but fail to match certain tightly constraining sections. This suggests that simple energy density scalings may not be able to account for the complexities of the true physical processes at work, or alternatively, that the parameters of the simulation require modification in order to accurately represent the surroundings of SN 1996cr.

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

International Nuclear Information System (INIS)

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

2004-01-01

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

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

Science.gov (United States)

Tornow, W.; Bhike, Megha

2015-05-01

A program is underway at the Triangle Universities Nuclear Laboratory (TUNL) to measure the neutron capture cross section in the 0.5 to 15 MeV energy range on nuclei whose radioactive daughters could potentially create backgrounds in searches for rare events. Here, we refer to neutrino-less double-beta decay and dark-matter searches, and to detectors built for neutrino and/or antineutrino studies. Neutron capture cross-section data obtained by using the activation method are reported for 40Ar, 74,76Ge, 128,130Te and 136Xe and compared to model calculations and evaluations.

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.

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

Directory of Open Access Journals (Sweden)

Yu-Feng Li

2014-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-07-01

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

Acceleration and propagation of cosmic radiation. Production, oscillation and detection of neutrinos

International Nuclear Information System (INIS)

Lagage, P.-O.

1987-06-01

In recent years, the old problem of cosmic-ray acceleration and propagation has become alive again, with the discovery of the diffusive shock acceleration mechanism, and with the first measurements of the cosmic-ray antiproton flux, which appears to be higher than expected. I have shown that the new acceleration mechanism was slow and I have calculated the maximum energy that can be reached by particles accelerated in various astrophysical sites. I have also studied in detail a cosmic-ray propagation model which takes into account the antiproton measurements. Neutrino astronomy is a field much more recent and in rapid expansion, thanks to a convergence of interests between astrophysicists and elementary particle physicists. Several large neutrino detectors already exist; really huge ones are in project. I have studied the possible impact of the high energy (> 1 TeV) neutrino astronomy on models of cosmic-ray sources such as Cygnus X3. Comparing the low energy (∼ 10 MeV) cosmic-ray antineutrinos with other sources of neutrinos and antineutrinos (sun, supernova, earth...), I have pointed out that the antineutrino background resulting from all the nuclear power-stations of the planet was sizeable. This background is a nuisance for some astrophysical applications but could be useful for studies on vacuum or matter neutrino oscillations (MSW effect). I have also examined the MSW effect in another context: the travel through the earth of neutrinos from the supernova explosion SN1987a [fr

Tropical impacts of SST forcing: A case study for 1987 versus 1988

Science.gov (United States)

Druyan, Leonard M.; Hastenrath, Stefan

1994-01-01

The response of the NASA/Goddard Institute for Space Studies general circulation model (GCM) to large tropical sea surface temperature (SST) anomalies is investigated by evaluating model simulations of the particularly contrasting summer monsoon seasons 1987 and 1988. These years are representative of the warm and cold phases, respectively, of a recent El Nino-Southern Oscillation (ENSO) event. An ensemble averaging the results of three simulations was considered for each season, using monthly mean observed SST anomalies for June-August 1987 and 1988 as lower boundary forcing. Consistent with the European Center for Medium Weather Forecast (ECMWF)-analyzed winds, the simulations based on 1988 as compared to 1987 SST exhibit stronger upper-tropospheric irrotational circulation between the monsoon regions and the Southern Hemispheric sub-tropical anticyclones, a stronger Pacific Walker cell and a weaker subtropical westerly jet over the South Pacific. In the same vein, the modeled precipitation, indicating a more northerly position of the Pacific Inter-Tropical Convergence Zone (ITCZ) in 1988 compared with 1987, is supported by satellite observations of outgoing longwave radiation and highly reflective clouds.

Uncertainties in the Anti-neutrino Production at Nuclear Reactors

Energy Technology Data Exchange (ETDEWEB)

Djurcic, Zelimir; Detwiler, Jason A.; Piepke, Andreas; Foster Jr., Vince R.; Miller, Lester; Gratta, Giorgio

2008-08-06

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 {bar {nu}}{sub e} detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties, and their relevance to reactor {bar {nu}}{sub e} experiments.

Reporting of safeguards events

International Nuclear Information System (INIS)

Dwyer, P.A.; Ervin, N.E.

1988-02-01

On June 9, 1987, the Commission published in the Federal Register a final rule revising the reporting requirements for safeguards events. Safeguards events include actual or attempted theft of special nuclear material (SNM); actual or attempted acts or events which interrupt normal operations at power reactors due to unauthorized use of or tampering with machinery, components, or controls; certain threats made against facilities possessing SNM; and safeguards system failures impacting the effectiveness of the system. The revised rule was effective October 8, 1987. On September 14, 1987, the NRC held a workshop in Bethesda, MD, to answer affected licensees' questions on the final rule. This report documents questions discussed at the September 14 meeting, reflects a completed staff review of the answers, and supersedes previous oral comment on the topics covered

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-18

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

SN2015bh: NGC2770's 4th supernova or a luminous blue variable on its way to a Wolf-Rayet star?

DEFF Research Database (Denmark)

Thone, C. C.; de Ugarte Postigo, A.; Leloudas, G.

2017-01-01

yr that experienced a possible terminal explosion as type IIn SN in 2015, named SN 2015bh. This possible SN (or " main event") had a precursor peaking similar to 40 days before maximum. The total energy release of the main event ;is similar to 1.8 X 10(49) erg, consistent with a ... 2015bh lies within a spiral arm of NGC2770 next to several small star-forming regions with a metallicity of similar to 0.5 solar and a stellar population age of 7-10 Myr. SN 2015bh shares many similarities with SN 2009ip and may form a new class of objects that exhibit outbursts a few decades prior...

Correlations between muons and low energy pulses at LSD of the Mont Blanc laboratory near the time of SN1987A explosion

International Nuclear Information System (INIS)

Dadykin, V.L.; Khalchukov, F.F.; Korchagin, P.V.; Korolkova, E.V.; Kudryavtsev, V.A.; Mal'gin, A.S.; Ryasny, V.G.; Ryazhskaya, O.G.; Yakushev, V.F.; Zatsepin, G.T.; Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.; Fulgione, W.; Galeotti, P.; Saavedra, O.; Trinchero, G.; Vernetto, S.; Turin Univ.

1989-01-01

We have analysed the data of LSD from February 10, 1987, to March 7, 1987, in order to search for autocorrelations between all pulses detected by LSD with energy higher than 5 MeV like those occurred at ∼ 3:00 UT on February 23, 1987, between the pulses detected by 3 neutrino telescopes and 2 gravitational wave antennae. We have found 9 pairs of correlated pulses (muon + low energy pulse) from 5:42 UT to 10:13 UT on February 23, 1987. The time differences of pulses in the pairs are less than 2 s, the first pulse in the pair being either muon or low energy pulse. The frequency of such random poissonian fluctuations is ∼1/(10 years). There are no correlations outside statistics between low energy, low energy pulses and muon, muon pulses detected by LSD during the whole time period

Net charge of quark jets in (anti)neutrino interactions

International Nuclear Information System (INIS)

Teper, M.

1981-01-01

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

A study of charm quark production in the NOMAD event generator

International Nuclear Information System (INIS)

Boyd, S.

1995-01-01

Although constructed primarily to aid in the search for neutrino oscillations, NOMAD, a counter experiment exposed to a ν m beam at the CERN SPS, is capable of making significant contributions to the study of charm quark production in ν m Deep Inelastic Scattering (DIS) processes. The analysis of such events, however, is dependent upon Monte Carlo simulations of the event kinematics and hence it is essential to understand the behaviour of such simulations. This talk compares data on charm production in the dimuon channel generated by the NOMAD Event Generator (NEGLIB) for an anti-neutrino beam with data collected in the CDHS experiment which ran at CERN in the period 1977-1980. Overall the two sets of data compare well, although some marked differences are observed. Several possible reasons are proposed and discussed

Toward connecting core-collapse supernova theory with observations. I. Shock revival in a 15 M ☉ blue supergiant progenitor with SN 1987A energetics

International Nuclear Information System (INIS)

Handy, Timothy; Plewa, Tomasz; Odrzywołek, Andrzej

2014-01-01

We study the evolution of the collapsing core of a 15 M ☉ blue supergiant supernova progenitor from the core bounce until 1.5 s later. We present a sample of hydrodynamic models parameterized to match the explosion energetics of SN 1987A. We find the spatial model dimensionality to be an important contributing factor in the explosion process. Compared to two-dimensional (2D) simulations, our three-dimensional (3D) models require lower neutrino luminosities to produce equally energetic explosions. We estimate that the convective engine in our models is 4% more efficient in 3D than in 2D. We propose that the greater efficiency of the convective engine found in 3D simulations might be due to the larger surface-to-volume ratio of convective plumes, which aids in distributing energy deposited by neutrinos. We do not find evidence of the standing accretion shock instability or turbulence being a key factor in powering the explosion in our models. Instead, the analysis of the energy transport in the post-shock region reveals characteristics of penetrative convection. The explosion energy decreases dramatically once the resolution is inadequate to capture the morphology of convection on large scales. This shows that the role of dimensionality is secondary to correctly accounting for the basic physics of the explosion. We also analyze information provided by particle tracers embedded in the flow and find that the unbound material has relatively long residency times in 2D models, while in 3D a significant fraction of the explosion energy is carried by particles with relatively short residency times.

Statistical analysis of experimental multifragmentation events in 64Zn+112Sn at 40 MeV/nucleon

Science.gov (United States)

Lin, W.; Zheng, H.; Ren, P.; Liu, X.; Huang, M.; Wada, R.; Chen, Z.; Wang, J.; Xiao, G. Q.; Qu, G.

2018-04-01

A statistical multifragmentation model (SMM) is applied to the experimentally observed multifragmentation events in an intermediate heavy-ion reaction. Using the temperature and symmetry energy extracted from the isobaric yield ratio (IYR) method based on the modified Fisher model (MFM), SMM is applied to the reaction 64Zn+112Sn at 40 MeV/nucleon. The experimental isotope distribution and mass distribution of the primary reconstructed fragments are compared without afterburner and they are well reproduced. The extracted temperature T and symmetry energy coefficient asym from SMM simulated events, using the IYR method, are also consistent with those from the experiment. These results strongly suggest that in the multifragmentation process there is a freezeout volume, in which the thermal and chemical equilibrium is established before or at the time of the intermediate-mass fragments emission.

PSR1987A: the case for strange-quark stars

International Nuclear Information System (INIS)

Glendenning, N.K.

1989-01-01

The new fast pulsar observed in the remnant of SN1987A, together with other considerations, provide evidence that there are two types of collapsed stars: neutron stars, having moderate central densities and subject to the usual mass constraint, and strange-quark-matter stars. We show that (i) all known pulsar masses and frequencies, with the exception of the new one, can be accounted for by plausible neutron star models; (ii) no known neutron star model can withstand the fast rotation of the new pulsar unless the central energy density is ∼ 15 that of normal nuclei, at which densities hadrons cannot plausibly exist as constituents; and (iii) if strange-quark matter is the true ground state of the strong interactions, strange-quark stars can sustain the high rotation imputed to the new pulsar. In the absence of another plausible structure that can withstand the fast rotation, we provisionally infer that the new pulsar is such a star. (author)

Nuclear status report for Western Europe 1987

International Nuclear Information System (INIS)

Decock, J.P.; Rogghe, L.; Selleslagh, E.; Fynbo, P.B.; Tuura, L.; Gaussens, J.; Cuzzaniti, M.; Hoogenboom, J.E.; Monroy, C.R.; Wikdahl, C.E.; Juillerat, T.; Starr, G.; Afgan, N.; Riznic, J.

1988-01-01

Information about nuclear electricity production and main events in the nuclear sector in 1987 is given for following countries: Belgium, Denmark, Finland, France, F.R. Germany, Italy, Netherlands, Spain, Sweden, Switzerland, United Kingdom and Yugoslavia

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

International Nuclear Information System (INIS)

Volpe, C.; Welzel, J.

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 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 ν e and ν-bar e fluxes and on the number of events for ν e + C 12 , ν e + O 16 , ν e + Ar 40 and ν-bar e + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

Diffractive production of ρ-mesons and of ρπ-systems by neutrinos and antineutrinos on protons

Science.gov (United States)

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

1993-09-01

Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems in vp andbar ν p chargedcurrent interactions. In the (anti-)neutrino energy range 10 GeV< E v <60 GeV the cross sections for diffractive ρ and diffractive ρπ production are found to be (0.64±0.14 (stat.)±0.08 (syst.))% and (0.28±0.08 (stat.)±0.04 (syst.))% of the charged-current cross section. The diffractive ρπ signal is consistent with being entirely due to diffractive a 1 production. However, the data cannot distinguish between diffractive a 1 and diffractive nonresonant ρπ production. The experimental distributions of W, Q 2, x Bj and y Bj for diffractive ρ and ρπ events are consistent with model predictions.

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

International Nuclear Information System (INIS)

Vallee, C.

1984-03-01

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

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

Science.gov (United States)

Collett, B; Bateman, F; Bauder, W K; Byrne, J; Byron, W A; Chen, W; Darius, G; DeAngelis, C; Dewey, M S; Gentile, T R; Hassan, M T; Jones, G L; Komives, A; Laptev, A; Mendenhall, M P; Nico, J S; Noid, G; Park, H; Stephenson, E J; Stern, I; Stockton, K J S; Trull, C; Wietfeldt, F E; Yerozolimsky, B G

2017-08-01

We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Antineutrino science in KamLAND

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Atsuto [KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2014-10-15

The primary goal of KamLAND is a search for the oscillation of anti ν{sub e}'s emitted from distant power reactors. The long baseline, typically 180 km, enables KamLAND to address the oscillation solution of the ''solar neutrino problem'' with anti ν{sub e}'s under laboratory conditions. KamLAND found fewer reactor anti ν{sub e} events than expected from standard assumptions about anti ν{sub e} propagation at more than 9 σ confidence level (C.L.). The observed energy spectrum disagrees with the expected spectral shape at more than 5 σ C.L., and prefers the distortion from neutrino oscillation effects. A three-flavor oscillation analysis of the data from KamLAND and KamLAND + solar neutrino experiments with CPT invariance, yields Δm{sub 21}{sup 2} = [7.54{sub -0.18}{sup +0.19} x 10{sup -5} eV{sup 2}, 7.53{sub -0.18}{sup +0.19} x 10{sup -5} eV{sup 2}], tan{sup 2}θ{sub 12} = [0.481{sub -0.080}{sup +0.092}, 0.437{sub -0.026}{sup +0.029}], and sin{sup 2}θ{sub 13} = [0.010{sub -0.034}{sup +0.033}, 0.023{sub -0.015}{sup +0.015}]. All solutions to the solar neutrino problem except for the large mixing angle region are excluded. KamLAND also demonstrated almost two cycles of the periodic feature expected from neutrino oscillation effects. KamLAND performed the first experimental study of antineutrinos from the Earth's interior so-called geoneutrinos (geo anti ν{sub e}'s), and succeeded in detecting geo anti ν{sub e}'s produced by the decays of {sup 238}U and {sup 232}Th within the Earth. Assuming a chondritic Th/U mass ratio, we obtain 116{sub -27}{sup +28} anti ν{sub e} events from {sup 238}U and {sup 232}Th, corresponding a geo anti ν{sub e} flux of 3.4{sub -0.8}{sup +0.8} x 10{sup 6} cm{sup -2}s{sup -1} at the KamLAND location. We evaluate various bulk silicate Earth composition models using the observed geo anti ν{sub e} rate. (orig.)

INTERACTING SUPERNOVAE AND SUPERNOVA IMPOSTORS: SN 2009ip, IS THIS THE END?

International Nuclear Information System (INIS)

Pastorello, A.; Cappellaro, E.; Benetti, S.; Inserra, C.; Smartt, S. J.; Fraser, M.; Pignata, G.; Takáts, K.; Bufano, F.; Valenti, S.; Benitez, S.; Botticella, M. T.; Brimacombe, J.; Cellier-Holzem, F.; Costado, M. T.; Cupani, G.; Curtis, I.; Elias-Rosa, N.; Ergon, M.; Fynbo, J. P. U.

2013-01-01

We report the results of a three-year-long dedicated monitoring campaign of a restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically in the optical and near-infrared domains. We monitored a number of erupting episodes in the past few years, and increased the density of our observations during eruptive episodes. In this paper, we present the full historical data set from 2009 to 2012 with multi-wavelength dense coverage of the two high-luminosity events between 2012 August and September. We construct bolometric light curves and measure the total luminosities of these eruptive or explosive events. We label them the 2012a event (lasting ∼50 days) with a peak of 3 × 10 41 erg s –1 , and the 2012b event (14 day rise time, still ongoing) with a peak of 8 × 10 42 erg s –1 . The latter event reached an absolute R-band magnitude of about –18, comparable to that of a core-collapse supernova (SN). Our historical monitoring has detected high-velocity spectral features (∼13,000 km s –1 ) in 2011 September, one year before the current SN-like event. This implies that the detection of such high-velocity outflows cannot, conclusively, point to a core-collapse SN origin. We suggest that the initial peak in the 2012a event was unlikely to be due to a faint core-collapse SN. We propose that the high intrinsic luminosity of the latest peak, the variability history of SN 2009ip, and the detection of broad spectral lines indicative of high-velocity ejecta are consistent with a pulsational pair-instability event, and that the star may have survived the last outburst. The question of the survival of the LBV progenitor star and its future fate remain open issues, only to be answered with future monitoring of this historically unique explosion.

Acceleration and propagation of cosmic rays. Production, oscillation and detection of neutrinos

International Nuclear Information System (INIS)

Lagage, P.O.

1987-01-01

This thesis is devoted to studies on cosmic rays and neutrinos, particles astrophysically relevant. In recent years, the old problem of cosmic-ray acceleration and propagation has become alive again, with the discovery of the diffusive shock acceleration mechanism, and with the first measurements of the cosmic-ray antiproton flux, which appears to be higher than expected. I have shown that the new acceleration mechanism was slow and I have calculated the maximum energy that can be reached by particles accelerated in various astrophysical sites. I have also studied in detail a cosmic-ray propagation model which takes into account the antiproton measurements. Neutrino astronomy is a field much more recent and in rapid expansion, thanks to a convergence of interests between astrophysicists and elementary particle physicists. Several large neutrino detectors already exist; really huge ones are in project. I have studied the possible impact of the high energy (> 1 TeV) neutrino astronomy on models of cosmic-ray sources such as Cygnus X3. Comparing the low energy (∼ 10 MeV) cosmic-ray antineutrinos with other sources of neutrinos and antineutrinos (sun, supernova, earth ...), I have pointed out that the antineutrino background resulting from all the nuclear power-stations of the planet was sizeable. This background is a nuisance for some astrophysical applications but could be useful for studies on vacuum or matter neutrino oscillations (MSW effect). I have also examined the MSW effect in another context: the travel through the earth of neutrinos from the supernova explosion SN1987a [fr

Heavy quark production by neutrinos and antineutrinos

International Nuclear Information System (INIS)

Scott, D.M.; Tanaka, K.

1979-01-01

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

AECB staff review of Bruce NGS'A' operation for the year 1987

International Nuclear Information System (INIS)

1988-06-01

This report presents AECB project staff's review of major licensing issues and of the operational performance of the station during 1987. Ontario Hydro reports and official correspondence and observations on AECB staff at site have been taken into consideration. The report is limited to aspects of the station performance that AECB staff considers to have a safety significance. Where significant developments associated with issues addressed in the report occurred in the early part of 1988 (up to the time of writing), these are mentioned where appropriate. Ontario Hydro's Quarterly Reports for 1987 contain detailed technical information on the performance of the station, individual units and unit systems. It is the opinion of AECB project staff that despite a number of commendable actions and achievements which are identified in this report, the performance of the station in 1987 was only marginally satisfactory and less satisfactory than in 1986. This assessment is supported by key performance indicators such as the number of reportable significant events, the number of events caused by or influenced by human error and the reactor trip frequency, all of which exceeded 1986 levels, and also by the lack of satisfactory progress made during the year on actions to address the findings of the Fall '86 AECB Assessment of Operating Practices. AECB staff considers that the outstanding operations and maintenance problems that were identified in the 1986 Assessment are due, in part, to an ineffective quality assurance program, and in part to a shortage of resources

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)

Report to the US Nuclear Regulatory Commission on Analysis and Evaluation of Operational Data, 1987: Nonreactors

International Nuclear Information System (INIS)

1988-10-01

This annual report of the US Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) is devoted to the activities performed during 1987. The report is published in two volumes. NUREG-1272, Vol. 2, No. 1, covers Power Reactors and presents an overview of the operating experience of the nuclear power industry, with comments regarding the trends of some key performance measures. The report also includes the principal findings and issues identified in AEOD studies over the past year, and summarizes information from Licensee Event Reports, the NRC's Operations Center, and Diagnostic Evaluations. NUREG-1272, Vol. 2, No. 2, covers Nonreactors and presents a review of the nonreactor events and misadministration reports that were reported in 1987 and a brief synopsis of AEOD studies published in 1987. Each volume contains a list of the AEOD reports issued for 1980-1987

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

2016-05-27

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{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[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.

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

Energy Technology Data Exchange (ETDEWEB)

Volpe, C.; Welzel, J. [Institut de Physique Nuclueaire, 91 - Orsay (France)

2007-07-01

We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic {nu}{sub e} and {nu}-bar{sub e} fluxes and on the number of events for {nu}{sub e} + C{sup 12}, {nu}{sub e} + O{sup 16}, {nu}{sub e} + Ar{sup 40} and {nu}-bar{sub e} + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

Whisker and Hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits

International Nuclear Information System (INIS)

Boettinger, W.J.; Johnson, C.E.; Bendersky, L.A.; Moon, K.-W.; Williams, M.E.; Stafford, G.R.

2005-01-01

High purity bright Sn, Sn-Cu and Sn-Pb layers, 3, 7 and 16 μm thick were electrodeposited on phosphor bronze cantilever beams in a rotating disk apparatus. Beam deflection measurements within 15 min of plating proved that all electrodeposits had in-plane compressive stress. In several days, the surfaces of the Sn-Cu deposits, which have the highest compressive stress, develop 50 μm contorted hillocks and 200 μm whiskers, pure Sn deposits develop 20 μm compact conical hillocks, and Sn-Pb deposits, which have the lowest compressive stress, remain unchanged. The differences between the initial compressive stresses for each alloy and pure Sn is due to the rapid precipitation of Cu 6 Sn 5 or Pb particles, respectively, within supersaturated Sn grains produced by electrodeposition. Over longer time, analysis of beam deflection measurements indicates that the compressive stress is augmented by the formation of Cu 6 Sn 5 on the bronze/Sn interface, while creep of the electrodeposit tends to decrease the compressive stress. Uniform creep occurs for Sn-Pb because it has an equi-axed grain structure. Localized creep in the form of hillocks and whiskers occurs for Sn and Sn-Cu because both have columnar structures. Compact hillocks form for the Sn deposits because the columnar grain boundaries are mobile. Contorted hillocks and whiskers form for the Sn-Cu deposits because the columnar grain boundary motion is impeded

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-05-12

The reactor neutrino and gallium anomalies can be tested with a 3-4 PBq (75-100 kCi scale) ¹⁴⁴Ce-¹⁴⁴Pr antineutrino beta-source deployed at the center or next to a large low-background liquid scintillator detector. The antineutrino generator will be produced by the Russian reprocessing plant PA Mayak as early as 2014, transported to Japan, and deployed in the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) as early as 2015. KamLAND's 13 m diameter target volume provides a suitable environment to measure the energy and position dependence of the detected neutrino flux. A characteristic oscillation pattern would be visible for a baseline of about 10 m or less, providing a very clean signal of neutrino disappearance into a yet-unknown, sterile neutrino state. This will provide a comprehensive test of the electron dissaperance neutrino anomalies and could lead to the discovery of a 4th neutrino state for Δm$2\\atop{new}$ ≳ 0.1 eV² and sin²(2θ_new) > 0.05.

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

Science.gov (United States)

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

1993-03-01

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

Diffractive production of charmed strange mesons by neutrinos and antineutrinos

International Nuclear Information System (INIS)

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

1993-01-01

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

Lithium converter of reactor neutrinos in antineutrino

International Nuclear Information System (INIS)

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

1989-01-01

The questions of developing lithium converter of the reactor neutrons in antineutrino operating at dynamic regime in the scheme with the cycle circulation of the high-purified lithium (by 7 Li isotope) through the converter are considered. The scheme allows to localize the 8 Li β-decay (T 1/2 =0.84 s) in the reservoir near the detector and so to design the hard-spectrum lithium ν-tilde e -source (E max ≅13 MeV) at the distance from the active zone being the soft-spectrum ν-tilde e -source. The expressions for the lithium ν-tilde e flux from the converter, reservoir and conveyance channel are obtained. 9 refs.; 8 figs.; 1 tab

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

A STUBBORNLY LARGE MASS OF COLD DUST IN THE EJECTA OF SUPERNOVA 1987A

Energy Technology Data Exchange (ETDEWEB)

Matsuura, M.; Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Dwek, E. [Observational Cosmology Laboratory Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Babler, B. [Department of Astronomy, 475 North Charter Street, University of Wisconsin, Madison, WI 53706 (United States); Baes, M.; Fritz, Jacopo [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cernicharo, José [Departamento de Astrofísica, Centro de Astrobiología, CSIC-INTA, Ctra. de Torrejón a Ajalvir km 4, E-28850 Madrid (Spain); Clayton, Geoff C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Dunne, L. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand); Fransson, C.; Lundqvist, P. [The Oskar Klein Centre, Department of Astronomy, Stockholm University, Albanova, SE-10691 Stockholm (Sweden); Gear, Walter; Gomez, H. L. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Groenewegen, M. A. T. [Koninklijke Sterrenwacht van België, Ringlaan 3, 1180 Brussel (Belgium); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Ivison, R. J. [SUPA, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Jerkstrand, A. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Lebouteiller, V. [AIM, CEA/Saclay, L' Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Lim, T. L., E-mail: mikako@star.ucl.ac.uk [RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); and others

2015-02-10

We present new Herschel photometric and spectroscopic observations of Supernova 1987A, carried out in 2012. Our dedicated photometric measurements provide new 70 μm data and improved imaging quality at 100 and 160 μm compared to previous observations in 2010. Our Herschel spectra show only weak CO line emission, and provide an upper limit for the 63 μm [O I] line flux, eliminating the possibility that line contaminations distort the previously estimated dust mass. The far-infrared spectral energy distribution (SED) is well fitted by thermal emission from cold dust. The newly measured 70 μm flux constrains the dust temperature, limiting it to nearly a single temperature. The far-infrared emission can be fitted by 0.5 ± 0.1 M {sub ☉} of amorphous carbon, about a factor of two larger than the current nucleosynthetic mass prediction for carbon. The observation of SiO molecules at early and late phases suggests that silicates may also have formed and we could fit the SED with a combination of 0.3 M {sub ☉} of amorphous carbon and 0.5 M {sub ☉} of silicates, totalling 0.8 M {sub ☉} of dust. Our analysis thus supports the presence of a large dust reservoir in the ejecta of SN 1987A. The inferred dust mass suggests that supernovae can be an important source of dust in the interstellar medium, from local to high-redshift galaxies.

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

Science.gov (United States)

Abreu, Yamiel; SoLid Collaboration

2017-02-01

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

CARBON MONOXIDE IN THE COLD DEBRIS OF SUPERNOVA 1987A

Energy Technology Data Exchange (ETDEWEB)

Kamenetzky, J.; McCray, R.; Glenn, J. [Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, UCB 391, Boulder, CO 80309 (United States); Indebetouw, R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22903 (United States); Barlow, M. J.; Matsuura, M. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Blommaert, J. A. D. L.; Decin, L. [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D BUS 2401, B-2001 Leuven (Belgium); Bolatto, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dunne, L. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8410 (New Zealand); Fransson, C. [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Gomez, H. L. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Groenewegen, M. A. T. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Hopwood, R. [Physics Department, Imperial College London, London SW7 2AZ (United Kingdom); Kirshner, R. P. [Harvard College Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Lakicevic, M. [Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Marcaide, J. [Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Marti-Vidal, I. [Onsala Space Observatory, SE-439 92 Onsala (Sweden); Meixner, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

2013-08-20

We report spectroscopic and imaging observations of rotational transitions of cold CO and SiO in the ejecta of SN1987A, the first such emission detected in a supernova remnant. In addition to line luminosities for the CO J = 1-0, 2-1, 6-5, and 7-6 transitions, we present upper limits for all other transitions up to J = 13-12, collectively measured from the Atacama Large Millimeter Array, the Atacama Pathfinder EXperiment, and the Herschel Spectral and Photometric Imaging REceiver. Simple models show the lines are emitted from at least 0.01 M{sub Sun} of CO at a temperature >14 K, confined within at most 35% of a spherical volume expanding at {approx}2000 km s{sup -1}. Moreover, we locate the emission within 1'' of the central debris. These observations, along with a partial observation of SiO, confirm the presence of cold molecular gas within supernova remnants and provide insight into the physical conditions and chemical processes in the ejecta. Furthermore, we demonstrate the powerful new window into supernova ejecta offered by submillimeter observations.

CARBON MONOXIDE IN THE COLD DEBRIS OF SUPERNOVA 1987A

International Nuclear Information System (INIS)

Kamenetzky, J.; McCray, R.; Glenn, J.; Indebetouw, R.; Barlow, M. J.; Matsuura, M.; Baes, M.; Blommaert, J. A. D. L.; Decin, L.; Bolatto, A.; Dunne, L.; Fransson, C.; Gomez, H. L.; Groenewegen, M. A. T.; Hopwood, R.; Kirshner, R. P.; Lakicevic, M.; Marcaide, J.; Marti-Vidal, I.; Meixner, M.

2013-01-01

We report spectroscopic and imaging observations of rotational transitions of cold CO and SiO in the ejecta of SN1987A, the first such emission detected in a supernova remnant. In addition to line luminosities for the CO J = 1-0, 2-1, 6-5, and 7-6 transitions, we present upper limits for all other transitions up to J = 13-12, collectively measured from the Atacama Large Millimeter Array, the Atacama Pathfinder EXperiment, and the Herschel Spectral and Photometric Imaging REceiver. Simple models show the lines are emitted from at least 0.01 M ☉ of CO at a temperature >14 K, confined within at most 35% of a spherical volume expanding at ∼2000 km s –1 . Moreover, we locate the emission within 1'' of the central debris. These observations, along with a partial observation of SiO, confirm the presence of cold molecular gas within supernova remnants and provide insight into the physical conditions and chemical processes in the ejecta. Furthermore, we demonstrate the powerful new window into supernova ejecta offered by submillimeter observations

Growth of intermetallics between Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layered structures

International Nuclear Information System (INIS)

Horváth, Barbara; Illés, Balázs; Shinohara, Tadashi

2014-01-01

Intermetallic growth mechanisms and rates are investigated in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. An 8–10 μm thick Sn surface finish layer was electroplated onto a Cu substrate with a 1.5–2 μm thick Ni or Ag barrier layer. In order to induce intermetallic layer growth, the samples were aged in elevated temperatures: 50 °C and 125 °C. Intermetallic layer growth was checked by focused ion beam–scanning ion microscope. The microstructures and chemical compositions of the intermetallic layers were observed with a transmission electron microscope. It has been found that Ni barrier layers can effectively block the development of Cu 6 Sn 5 intermetallics. The intermetallic growth characteristics in the Sn/Cu and Sn/Ni/Cu systems are very similar. The intermetallic layer grows towards the Sn layer and forms a discrete layer. Differences were observed only in the growth gradients and surface roughness of the intermetallic layer which may explain the different tin whiskering properties. It was observed that the intermetallic layer growth mechanisms are completely different in the Ag barrier layers compared to the Ni layers. In the case of Sn/Ag/Cu systems, the Sn and Cu diffused through the Ag layer, formed Cu 6 Sn 5 intermetallics mainly at the Sn/Ag interface and consumed the Ag barrier layer. - Highlights: • Intermetallic growth was characterised in Sn/Ni/Cu, Sn/Ag/Cu and Sn/Cu layer systems. • Intermetallic growth rates and roughness are similar in the Sn/Cu and Sn/Ni/Cu systems. • Sn/Ni/Cu system contains the following intermetallic layer structure Sn–Ni3Sn4–Ni3Sn2–Ni3Sn–Ni. • In the case of Sn/Ag/Cu systems the Sn and Cu diffusion consumes the Ag barrier layer. • When Cu reaches the Sn/Ag interface a large amount of Cu 6 Sn 5 forms above the Ag layer

A look at Supernova 1987A

International Nuclear Information System (INIS)

Schramm, D.N.

1987-10-01

Supernova 1987A is reviewed with emphasis on the neutrino observations. It is shown that the results fit well with the expectations for neutrino temperatures (T ∼ 4ε 0 4.5 MeV) and total energy emitted (2ε 0 4 x 10 53 ergs). It is argued that the detection tends to favor collapse models that yield emission for 10 second timescales with a 1ε 0 2 second early accretion phase followed by Kelvin-Helmholtz cooling as opposed to prompt shocks with the immediate onset of cooling. It is also argued that the probable detection of one or more electron scattering event favors a superthermal tail at high energies. Neutrino mass limits and flavor limits are comparable to laboratory experiments. An estimate for future collapse rates in our galaxy of 1/7 year is made based on nucleosynthesis yields. The supernova also has eliminated many axion and majoron models. 69 refs., 3 figs., 27 tabs

Report to the US Nuclear Regulatory Commission on analysis and evaluation of operational data - 1987: Power reactors

Energy Technology Data Exchange (ETDEWEB)

None

1988-10-01

This annual report of the US Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) is devoted to the activities performed during 1987. The report is published in two volumes. NUREG-1272, Vol. 2, No. 1, covers Power Reactors and presents an overview of the operating experience of the nuclear power industry, with comments regarding the trends of some key performance measures. The report also includes the principal findings and issues identified in AEOD studies over the past year, and summarizes information from Licensee Event Reports, the NRC's Operations Center, and Diagnostic Evaluations. NUREG-1272, Vol. 2, No. 2, covers Nonreactors and presents a review of the nonreactors events and misadministration reports that were reported in 1987 and a brief synopsis of AEOD studies published in 1987. Each volume contains a list of the AEOD Reports issued for 1980-1987.

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

International Nuclear Information System (INIS)

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

1990-01-01

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

LOS ALAMOS: Candidate events in a search for neutrino oscillations

International Nuclear Information System (INIS)

Anon.

1995-01-01

In the past several years, a number of experiments have searched for neutrino oscillations,where a neutrino of one type (say muon-antineutrinos) spontaneously transforms into a neutrino of another type (say electron antineutrinos). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. At this time, there is no broadly accepted evidence for neutrino oscillations from a terrestrial experiment. The Liquid Scintillator Neutrino Detector (LSND) experiment (July 1993, page 10) at the Los Alamos Meson Physics facility (LAMPF) is designed to search with high sensitivity for muon-antineutrino electronantineutrino oscillations from positive muon decay at rest. The collaboration consists of groups from the University of California at Riverside, San Diego and Santa Barbara, the University California Intercampus Institute for Research at Particle Accelerators, Embry Riddle Aeronautical University, Linfield College, Los Alamos National Laboratory, Louisiana State University, Louisiana Tech University, the University of New Mexico, Southern University, and Temple University. LAMPF is an intense source of low energy neutrinos due to its 1 mA proton intensity and 800 MeV energy. The neutrino source is well understood because almost all neutrinos arise from positive pion or muon decay; negative muons and pions are readily captured in the iron of the shielding and copper of the beam stop. The production of kaons and heavier mesons is negligible at these energies. The electron-antineutrino rate is calculated to be only 4 x 10 -4 that of muon-antineutrinos in the neutrino energy range between 36 and 52.8 MeV, so that the observation of a significant electronantineutrino rate would be evidence for muon-antineutrino electronantineutrino oscillations. The LSND detector consists of an approximately cylindrical tank 8.3 m long by 5.7 m in diameter. The centre of the detector is 30 m from the neutrino source. On the

Charged current antineutrino reactions from 12C at MiniBooNE energies

International Nuclear Information System (INIS)

Athar, M. Sajjad; Ahmad, Shakeb; Singh, S. K.

2007-01-01

A study of charged current induced antineutrino interactions from nuclei has been done for the intermediate energy antineutrinos and applied to 12 C, 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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-11

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

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.

Workshop applied antineutrino physics 2007

International Nuclear Information System (INIS)

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

2007-01-01

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

Comparison of the electrochemical performance of mesoscopic Cu2Sb, SnSb and Sn/SnSb alloy powders

International Nuclear Information System (INIS)

Zhang Ge; Huang Kelong; Liu Suqin; Zhang Wei; Gong Benli

2006-01-01

Cu 2 Sb, SnSb and Sn/SnSb mesoscopic alloy powders were prepared by chemical reduction, respectively. The crystal structures and particle morphology of Cu 2 Sb, SnSb and Sn/SnSb were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The electrochemical performances of the Cu 2 Sb, SnSb and Sn/SnSb electrodes were investigated by galvanostatic charge and discharge cycling and electrochemical impedance spectroscopy (EIS). The results showed the first charge and discharge capacities of SnSb and Sn/SnSb were higher than Cu 2 Sb, but after 15 cycles, the charge capacity fading rates of Cu 2 Sb, Sn/SnSb and Sn/SnSb were 26.16%, 55.33% and 47.39%, respectively. Cu 2 Sb had a better cycle performance, and Sn/SnSb multiphase alloy was prior to pure SnSb due to the existence of excessive Sn in Sn/SnSb system

Spectral and morphological analysis of the remnant of supernova 1987A with ALMA and ATCA

Energy Technology Data Exchange (ETDEWEB)

Zanardo, Giovanna; Staveley-Smith, Lister [International Centre for Radio Astronomy Research (ICRAR), M468, University of Western Australia, Crawley, WA 6009 (Australia); Indebetouw, Remy; Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Matsuura, Mikako; Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Gaensler, Bryan M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Fransson, Claes; Lundqvist, Peter [Department of Astronomy, Oskar Klein Center, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Kamenetzky, Julia R. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Lakićević, Maša [Institute for the Environment, Physical Sciences and Applied Mathematics, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Marcaide, Jon M. [Departamento de Astronomía, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Martí-Vidal, Ivan [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Meixner, Margaret [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ng, C.-Y. [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (China); Park, Sangwook, E-mail: giovanna.zanardo@gmail.com [Department of Physics, University of Texas at Arlington, 108 Science Hall, Box 19059, Arlington, TX 76019 (United States); and others

2014-12-01

We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 μm), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S {sub ν}∝ν{sup –0.73}) and the thermal component originating from dust grains at T ∼ 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields –0.4 ≲ α ≲ –0.1 across the western regions, with α ∼ 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.

De verkeersonveiligheid in 1987 : een kwantitatieve beschrijving van de verkeersonveiligheid in 1987.

NARCIS (Netherlands)

Blokpoel, A.

1989-01-01

Traffic safety in 1987 is described and quantitative description and analysis are given. 1987 is compared to the period 1982- 1986. In 1987 42.655 accidents with injuries were registered, out of which 1485 fatalities, and 35, 230 hospitalizations resulted. This is a slight decrease compared to 1986.

Neutral strange particle production in antineutrino-neon charged current interactions

Science.gov (United States)

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

1992-06-01

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

Supernova 1987a: One year later: A summary of the La Thuile symposium

International Nuclear Information System (INIS)

Schramm, D.N.

1988-04-01

The Conference reviewed what we have learned after one year from SN 1987a. In particular, new information continues to come in daily on the evolving spectra, including x-rays and γ-rays. We now know the light curve was indeed powered by 56 Co decay. The neutrino data from IMB and Kamioka continues to be analyzed. It is fit very well by a standard collapse to a neutron star although some nagging problems with the angular distribution remain. Constraints on neutrino and other weakly interacting particle properties have been developed that rival or exceed terrestrial laboratory results. The question of the counts detected by the Mt. Blanc neutrino detector had new mysteries added at this meeting as reports of multiple coincidences with gravitational wave detectors at Maryland and Rome were presented. Future supernova rates were also discussed. It was argued that neutrino detection from a future supernova in our Galaxy might be the only way to prove that the ν/sub /tau// was the dominant matter of the Universe

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

Science.gov (United States)

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

1984-05-01

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

Review of speckle observations of Supernova 1987A

International Nuclear Information System (INIS)

Meikle, W.P.S.

1988-01-01

SN 1987A is sufficiently close to allow a unique examination of the morphology of a supernova, using speckle interferometry. Several groups [Center for Astrophysics (CfA); Imperial College (IC); Mount Stromlo and Siding Spring Observatories/Anglo-Australian Observatory (M/A)] have reported optical speckle observations. At Hα, both CfA and M/A have determined the angular extent of the emission, and reasonable agreement is obtained. The speckle-derived values are consistent with those obtained from line profiles. IC has also succeeded in resolving the supernova at Hα. At wavelengths other than Hα, at early epochs, angular diameters obtained by CfA are larger than those derived from photometric and spectroscopic measurements, possibly due to scattering effects. At later epochs, the diameters exhibit little variation between the wavelengths examined. CfA reports significant asymmetry in the late epoch data. Several attempts have been made to re-observe (at optical wavelengths) the companion object, but none have succeeded. The nature of this phenomenon is still controversial, but the evidence indicates that the companion was real, with emission from dust apparently being the least problematic explanation. Support for this may lie in IR speckle observations (Haute Provence/Lyon) which, on about day 115, indicated the presence of one or more resolved components at an angular displacement comparable to that of the optical companion. 39 refs., 1 fig., 1 tab

Annual report 1986-1987

International Nuclear Information System (INIS)

1988-01-01

The Australian Nuclear Science and Technology Organisation (ANSTO) is a statutory body constituted by the ANSTO Act, 1987. The Act, which came into force on Monday, 27 April 1987, established ANSTO as the successor organisation to the Australian Atomic Energy Commission (AAEC) originally established under the Atomic Energy Act, 1953. The AAEC was abolished under the provisions of the Atomic Energy Amendment Act, 1987. This report covers the operations of the two statutory bodies for the financial year ended 30 June 1987

Monitoring the Thermal Power of Nuclear Reactors with a Prototype Cubic Meter Antineutrino Detector

Energy Technology Data Exchange (ETDEWEB)

Bernstein, A; Bowden, N; Misner, A; Palmer, T

2007-06-27

In this paper, we estimate how quickly and how precisely a reactor's operational status and thermal power can be monitored over hour to month time scales, using the antineutrino rate as measured by a cubic meter scale detector. Our results are obtained from a detector we have deployed and operated at 25 meter standoff from a reactor core. This prototype can detect a prompt reactor shutdown within five hours, and monitor relative thermal power to 3.5% within 7 days. Monitoring of short-term power changes in this way may be useful in the context of International Atomic Energy Agency's (IAEA) Reactor Safeguards Regime, or other cooperative monitoring regimes.

STRESS a SN survey at ESO

Science.gov (United States)

Botticella, M. T.

We performed the Southern inTermediate Redshift ESO Supernova Search (STRESS), a survey specifically designed to measure the rate of both SNe Ia and CC SNe, in order to obtain a direct comparison of the high redshift and local rates and to investigate the dependence of the rates on specific galaxy properties, most notably their colour. We found that the type Ia SN rate, at mean redshift z = 0.3, is 0.22+0.10+0.16-0.08-0.14 h270 SNu, while the CC SN rate, at z = 0.21, is 0.82+0.31+0.300.24-0.26 h270 SNu. The quoted errors are the statistical and systematic uncertainties. With respect to the local value, the CC SN rate at z = 0.2 is higher by a factor of ˜ 2, whereas the type Ia SN rate remains almost constant. We also measured the SN rates in the red and blue galaxies and found that the SN Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe. Finally we exploited the link between SFH and SN rates to predict the evolutionary behaviour of the SN rates and compare it with the path indicated by observations.

SN 2012au: A GOLDEN LINK BETWEEN SUPERLUMINOUS SUPERNOVAE AND THEIR LOWER-LUMINOSITY COUNTERPARTS

International Nuclear Information System (INIS)

Milisavljevic, Dan; Soderberg, Alicia M.; Margutti, Raffaella; Drout, Maria R.; Marion, G. Howie; Sanders, Nathan E.; Lunnan, Ragnhild; Chornock, Ryan; Berger, Edo; Foley, Ryan J.; Challis, Pete; Kirshner, Robert P.; Dittmann, Jason; Bieryla, Allyson; Kamble, Atish; Chakraborti, Sayan; Hsiao, Eric Y.; Fesen, Robert A.; Parrent, Jerod T.; Levesque, Emily M.

2013-01-01

We present optical and near-infrared observations of SN 2012au, a slow-evolving supernova (SN) with properties that suggest a link between subsets of energetic and H-poor SNe and superluminous SNe. SN 2012au exhibited conspicuous Type-Ib-like He I lines and other absorption features at velocities reaching ≈2 × 10 4 km s –1 in its early spectra, and a broad light curve that peaked at M B = –18.1 mag. Models of these data indicate a large explosion kinetic energy of ∼10 52 erg and 56 Ni mass ejection of M Ni ≈ 0.3 M ☉ on par with SN 1998bw. SN 2012au's spectra almost one year after explosion show a blend of persistent Fe II P-Cyg absorptions and nebular emissions originating from two distinct velocity regions. These late-time emissions include strong [Fe II], [Ca II], [O I], Mg I], and Na I lines at velocities ∼> 4500 km s –1 , as well as O I and Mg I lines at noticeably smaller velocities ∼ –1 . Many of the late-time properties of SN 2012au are similar to the slow-evolving hypernovae SN 1997dq and SN 1997ef, and the superluminous SN 2007bi. Our observations suggest that a single explosion mechanism may unify all of these events that span –21 ∼ B ∼< –17 mag. The aspherical and possibly jetted explosion was most likely initiated by the core collapse of a massive progenitor star and created substantial high-density, low-velocity Ni-rich material.

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

International Nuclear Information System (INIS)

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

1984-01-01

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

SN 1987A and companion

International Nuclear Information System (INIS)

Papaliolios, C.; Karovska, M.; Nisenson, P.; Standley, C.

1988-01-01

To determine the position of the supernova relative to the Sanduleak star the authors have recorded data with a 400 nm filter which would reduce the large magnitude difference between the supernova and Sanduleak - 69 degrees 202. In the search for light echoes they have recorded supernova data again in our usual mode of operation except for the addition of neutral density filters that were needed to make the count rates manageable. They have used several different 10 nm wide spectral filters (in H alpha and in the continuum around it) to look at the supernova and at a few nearby stars which serve as unresolved references. They discuss their findings in this paper

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

Energy Technology Data Exchange (ETDEWEB)

Wietfeldt, F.E., E-mail: few@tulane.ed [Department of Physics, Tulane University, New Orleans, LA 70118 (United States); Byrne, J. [University of Sussex (United Kingdom); Collett, B. [Physics Department, Hamilton College, Clinton, NY 13323 (United States); Dewey, M.S. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Jones, G.L. [Physics Department, Hamilton College, Clinton, NY 13323 (United States); Komives, A. [Physics Department, DePauw University, Greencastle, IN 46135 (United States); Laptev, A. [Department of Physics, Tulane University, New Orleans, LA 70118 (United States); Nico, J.S. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Noid, G.; Stephenson, E.J. [Indiana University Cyclotron Facility, Bloomington, IN 47408 (United States); Stern, I.; Trull, C. [Department of Physics, Tulane University, New Orleans, LA 70118 (United States); Yerozolimsky, B.G. [Physics Department, Harvard University, Cambridge, MA 02139 (United States)

2009-12-11

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.

Solar-Geophysical Data Number 521, January 1988. Part 2 (comprehensive reports). Data for July 1987, and miscellanea

International Nuclear Information System (INIS)

Coffey, H.E.; McKinnon, J.A.

1988-01-01

Contents include: Detailed index for 1987; Data for July 1987--(Meudon Carte Synoptique, Solar flares, Solar radio bursts at fixed frequencies, Solar x-ray radiation from GOES satellite, Mass ejections from the sun, Active prominences and filaments); Miscellaneous data--Solar x-ray flare events May-December 1984

A facile inexpensive route for SnS thin film solar cells with SnS{sub 2} buffer

Energy Technology Data Exchange (ETDEWEB)

Gedi, Sreedevi [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Minna Reddy, Vasudeva Reddy, E-mail: drmvasudr9@gmail.com [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Pejjai, Babu [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Park, Chinho, E-mail: chpark@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Ramakrishna Reddy, K.T., E-mail: ktrkreddy@gmail.com [Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India)

2016-05-30

Graphical abstract: PYS spectra of SnS/SnS{sub 2} interface and the related band diagram. - Highlights: • A low cost SnS solar cell is developed using chemical bath deposition. • We found E{sub I} & χ of SnS (5.3 eV & 4.0 eV) and SnS{sub 2} (6.9 eV & 4.1 eV) films from PYS. • Band offsets of 0.1 eV (E{sub c}) and 1.6 eV (E{sub v}) are estimated for SnS/SnS{sub 2} junction. • SnS based solar cell showed a conversion efficiency of 0.51%. - Abstract: Environment-friendly SnS based thin film solar cells with SnS{sub 2} as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS{sub 2} films were polycrystalline; (1 1 1)/(0 0 1) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS{sub 2} films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS{sub 2} films. The band alignment of SnS/SnS{sub 2} junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density–voltage (J–V) measurements of the cell showed open circuit voltage (V{sub oc}) of 0.12 V, short circuit current density (J{sub sc}) of 10.87 mA cm{sup −2}, fill factor (FF) of 39% and conversion efficiency of 0.51%.

SN 2012au: A GOLDEN LINK BETWEEN SUPERLUMINOUS SUPERNOVAE AND THEIR LOWER-LUMINOSITY COUNTERPARTS

Energy Technology Data Exchange (ETDEWEB)

Milisavljevic, Dan; Soderberg, Alicia M.; Margutti, Raffaella; Drout, Maria R.; Marion, G. Howie; Sanders, Nathan E.; Lunnan, Ragnhild; Chornock, Ryan; Berger, Edo; Foley, Ryan J.; Challis, Pete; Kirshner, Robert P.; Dittmann, Jason; Bieryla, Allyson; Kamble, Atish; Chakraborti, Sayan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Fesen, Robert A.; Parrent, Jerod T. [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Levesque, Emily M., E-mail: dmilisav@cfa.harvard.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); and others

2013-06-20

We present optical and near-infrared observations of SN 2012au, a slow-evolving supernova (SN) with properties that suggest a link between subsets of energetic and H-poor SNe and superluminous SNe. SN 2012au exhibited conspicuous Type-Ib-like He I lines and other absorption features at velocities reaching Almost-Equal-To 2 Multiplication-Sign 10{sup 4} km s{sup -1} in its early spectra, and a broad light curve that peaked at M{sub B} = -18.1 mag. Models of these data indicate a large explosion kinetic energy of {approx}10{sup 52} erg and {sup 56}Ni mass ejection of M{sub Ni} Almost-Equal-To 0.3 M{sub Sun} on par with SN 1998bw. SN 2012au's spectra almost one year after explosion show a blend of persistent Fe II P-Cyg absorptions and nebular emissions originating from two distinct velocity regions. These late-time emissions include strong [Fe II], [Ca II], [O I], Mg I], and Na I lines at velocities {approx}> 4500 km s{sup -1}, as well as O I and Mg I lines at noticeably smaller velocities {approx}< 2000 km s{sup -1}. Many of the late-time properties of SN 2012au are similar to the slow-evolving hypernovae SN 1997dq and SN 1997ef, and the superluminous SN 2007bi. Our observations suggest that a single explosion mechanism may unify all of these events that span -21 {approx}< M{sub B} {approx}< -17 mag. The aspherical and possibly jetted explosion was most likely initiated by the core collapse of a massive progenitor star and created substantial high-density, low-velocity Ni-rich material.

The GRB 060218/SN 2006aj event in the context of other gamma-ray burst supernovae

DEFF Research Database (Denmark)

Ferrero, P.; Kann, D. A.; Zeh, A.

2006-01-01

Gamma rays: bursts: X-rays: individuals: GRB 060218, supernovae: individual: SN 2006aj Udgivelsesdato: Oct.......Gamma rays: bursts: X-rays: individuals: GRB 060218, supernovae: individual: SN 2006aj Udgivelsesdato: Oct....

The high-temperature modification of LuAgSn and high-pressure high-temperature experiments on DyAgSn, HoAgSn, and YbAgSn

Energy Technology Data Exchange (ETDEWEB)

Heying, B.; Rodewald, U.C.; Hermes, W.; Schappacher, F.M.; Riecken, J.F.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Muenchen Univ. (Germany). Dept. fuer Chemie und Biochemie; Sebastian, C.P. [Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany)

2008-02-15

The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P6{sub 3}mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F{sup 2}, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag{sub 3}Sn{sub 3}] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag{sub 3}Sn{sub 3}] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F{sup 2}, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F{sup 2}, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with {mu}{sub eff} = 7.53(1) {mu}{sub B}/Tm atom and {theta}P = -15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature {sup 119}Sn Moessbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively. (orig.)

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

International Nuclear Information System (INIS)

Dass, G.V.

1976-01-01

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

Automated calibration system for a high-precision measurement of neutrino mixing angle θ13 with the Daya Bay antineutrino detectors

International Nuclear Information System (INIS)

Liu, J.; Cai, B.; Carr, R.; Dwyer, D.A.; Gu, W.Q.; Li, G.S.; Qian, X.; McKeown, R.D.; Tsang, R.H.M.; Wang, W.; Wu, F.F.; Zhang, C.

2014-01-01

We describe the automated calibration system for the antineutrino detectors in the Daya Bay Neutrino Experiment. This system consists of 24 identical units instrumented on 8 identical 20-ton liquid scintillator detectors. Each unit is a fully automated robotic system capable of deploying an LED and various radioactive sources into the detector along given vertical axes. Selected results from performance studies of the calibration system are reported

Daresbury 1987/8

International Nuclear Information System (INIS)

1988-01-01

1987 was the twenty fifth anniversary of the Daresbury Laboratory and special events were held to celebrate this. Over the twenty five years the projects have changed but the role of the laboratory, which is to provide and operate facilities too large for a single University to operate on its own and to collaborate with the Universities using them, has not changed. The report covers the main facilities at Daresbury. The main events and progress throughout the year are highlighted. For the Nuclear Structure facility highlights included collaboration on the largest array of high resolution germanium gamma-ray detectors ever assembled, work on super deformed nuclei at high angular momentum and the use of the polarised heavy ion source. At the Synchrotron Radiation Source a High Brightness Lattice has been installed and this has resulted in improved imaging and diffraction. Protein molecules, semiconductor materials, very small crystals and muscle structure have been studied using the high brightness lattice facility. A review of the computational science support for projects is included. Facts and figures about Daresbury are presented and a list of publications resulting from work done at the Laboratory during the year is given. (U.K.)

Texas A and M University, Nuclear Science Center: Twenty-fourth progress report, January 1, 1987-December 31, 1987

International Nuclear Information System (INIS)

Crawford, K.C.; Davis, J.W.; Krohn, J.L.; Meyer, C.M.; Petesch, J.E.; Stasny, G.S.

1988-03-01

Utilization of the reactor (NSCR Reactor) during 1987 increased slightly over that in 1986. The main activity is shifting from isotope tracer production to testing and exposure irradiations. Core VIII-A, operational since March 1986, was used throughout 1987

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

Science.gov (United States)

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

1986-01-01

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

A study of the EMC effect using neutrino and antineutrino interactions in neon and deuterium

International Nuclear Information System (INIS)

Guy, J.; Cooper-Sarkar, A.M.; Venus, W.; Apeldoorn, G. van; Jongejans, B.; Tenner, A.; Eijndhoven, N. van; Berggren, M.; Hulth, P.O.; Simopoulou, E.; Vayaki, A.; Bobisut, F.; Sconza, A.; Brisson, V.; Petiau, P.; Vallee, C.; Capiluppi, P.; Giacomelli, G.; Mandrioli, G.; Rossi, A.M.; Cirio, R.; Marzari-Chiesa, A.; Romero, A.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Coghen, T.; Frodesen, A.G.; Gerbier, G.; Kasper, P.; Neveu, M.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Faccini-Turluer, M.L.; Vignaud, D.

1987-01-01

Nearly 40000 neutrino and antineutrino interactions in BEBC are compared to measure the differences between neon and deuterium in the quark and antiquark distributions and in the nucleon structure functions. The ratio of Ne to D cross sections indicates some decrease between x ≅ 0.2 and x ≅ 0.6. The y distributions show there is no significant increase in the neon sea, but prefer a small decrease. Taken altogether the x and y distributions and the measured total cross-sections indicate some change in the shape of the valence distributions. No significant dependence on A is observed for either the shape of the sea or the ratio of longitudinal to transverse cross-sections. (orig.)

A study of the EMC effect using neutrino and antineutrino interactions in neon and deuterium

Science.gov (United States)

Guy, J.; Saitta, B.; van Apeldoorn, G.; Allport, P.; Angelini, C.; Armenise, N.; Baldini, A.; Berggren, M.; Bertrand, D.; Bobisut, F.; Brisson, V.; Bullock, F.; Calicchio, M.; Capiluppi, P.; Cirio, R.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Faccini-Turluer, M. L.; Fitch, P.; Frodesen, A. G.; Gerbier, G.; Giacomelli, G.; Hulth, P. O.; Jones, G. T.; Jongejans, B.; Kasper, P.; Klein, H.; Mandrioli, G.; Marage, P.; Marzari-Chiesa, A.; Middleton, R. P.; Miller, D. B.; Morrison, D. R. O.; Mobayyen, M. M.; O'Neale, S. W.; Neveu, M.; Parker, M. A.; Petiau, P.; Romero, A.; Rossi, A. M.; Sacton, J.; Sansum, A.; Sconza, A.; Simopoulou, E.; Schmitz, N.; Tenner, A.; Vallee, C.; van Eijndhoven, N.; Varvell, K.; Vayaki, A.; Venus, W.; Vignaud, D.; Wachsmuth, H.; Wittek, W.

1987-09-01

Nearly 40000 neutrino and antineutrino interactions in BEBC are compared to measure the differences between neon and deuterium in the quark and antiquark distributions and in the nucleon structure functions. The ratio of Ne to D cross sections indicates some decrease between x˜0.2 and x˜0.6. The y distributions show there is no significant increase in the neon sea, but prefer a small decrease. Taken altogether, the x and y distributions and the measured total cross-sections indicate some change in the shape of the valence distributions. No significant dependence on A is observed for either the shape of the sea or the ratio of longitudinal to transverse cross-sections.

Reference Data for the Density, Viscosity, and Surface Tension of Liquid Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn Eutectic Alloys

Science.gov (United States)

Dobosz, Alexandra; Gancarz, Tomasz

2018-03-01

The data for the physicochemical properties viscosity, density, and surface tension obtained by different experimental techniques have been analyzed for liquid Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn eutectic alloys. All experimental data sets have been categorized and described by the year of publication, the technique used to obtain the data, the purity of the samples and their compositions, the quoted uncertainty, the number of data in the data set, the form of data, and the temperature range. The proposed standard deviations of liquid eutectic Al-Zn, Ag-Sn, Bi-Sn, Cu-Sn, and Sn-Zn alloys are 0.8%, 0.1%, 0.5%, 0.2%, and 0.1% for the density, 8.7%, 4.1%, 3.6%, 5.1%, and 4.0% for viscosity, and 1.0%, 0.5%, 0.3%, N/A, and 0.4% for surface tension, respectively, at a confidence level of 95%.

Rooted in symmetry: Yang reflects on a life of physics

CERN Multimedia

2007-01-01

"During his latest visit to CERN, Nobel laureate Chen Ning Yang talked to CERN Courier about some of his early work, his impressions of the LHC and his thoughts about the future of physics."; 2006 Nobel laureate George Smoot talked about his quest to explore the early universe; Masayuki Nakahata, who ofundthe signal of a neutrino pulse emitted by SN1987A, looks at the ongoing legacy of this event; (9 pages with photos)

Non-accelerator particle physics: Progress report, February 1, 1987-January 31, 1988

International Nuclear Information System (INIS)

Steinberg, R.I.

1988-01-01

The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are currently engaged in construction of the MACRO detector, an Italian-American collaborative research instrument with a total particle acceptance of 12,000 m 2 sr, which will perform a sensitive search for magnetic monopoles using excitation-ionization methods. Other major objectives of the MACRO experiment are to search for astrophysical high energy neutrinos expected to be emitted by such objects as Vela X-1, LMC X-4 and SN-1987A and to search for low energy neutrino bursts from gravitational stellar collapse. The past year has seen major progress in our program of liquid scintillator development. We now have an advanced scintillator formulation whose figure-of-merit for use in long counters (such as the MACRO counters) is double that of the previous best scintillator. The new formulation promises to enhance substantially the physics potential of the MACRO detector. Dr. Charles Lane (Ph.D. 1987, Caltech)l has now joined our group, resulting in significant expansion of our responsibilities on the MACRO experiment. We are now leaders of the American effort to develop the off-line data analysis for MACRO

Automated calibration system for a high-precision measurement of neutrino mixing angle θ{sub 13} with the Daya Bay antineutrino detectors

Energy Technology Data Exchange (ETDEWEB)

Liu, J., E-mail: jianglai.liu@sjtu.edu.cn [Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Cai, B.; Carr, R. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Dwyer, D.A. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Gu, W.Q.; Li, G.S. [Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Qian, X. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Brookhaven National Laboratory, Upton, NY (United States); McKeown, R.D. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Department of Physics, College of William and Mary, Williamsburg, VA (United States); Tsang, R.H.M. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Wang, W. [Department of Physics, College of William and Mary, Williamsburg, VA (United States); Wu, F.F. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Zhang, C. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA (United States); Brookhaven National Laboratory, Upton, NY (United States)

2014-06-01

We describe the automated calibration system for the antineutrino detectors in the Daya Bay Neutrino Experiment. This system consists of 24 identical units instrumented on 8 identical 20-ton liquid scintillator detectors. Each unit is a fully automated robotic system capable of deploying an LED and various radioactive sources into the detector along given vertical axes. Selected results from performance studies of the calibration system are reported.

Licensee contractor and vendor inspection status report: Quarterly report, October 1987-December 1987

International Nuclear Information System (INIS)

1988-02-01

This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from October 1987 thru December 1987. Also, included in this issue are the results of certain inspections performed prior to October 1987 that were not included in previous issues of NUREG-0040

Licensee contractor and vendor inspection status report: Quarterly report, July 1987-September 1987

International Nuclear Information System (INIS)

1987-10-01

This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from July 1987 through September 1987. Also included in this issue are the results of certain inspections performed prior to July 1987 that were not included in previous issues of NUREG-0040

Earthquake measurements in southern Sweden Oct 1, 1986 - Mar 31, 1987

International Nuclear Information System (INIS)

Slunga, R.; Nordgren, L.

1987-12-01

A network of four stations covering southeastern Sweden has been operated for the period Oct 1, 1986 - Mar 31, 1987. Three events were aftershocks to the strong Skoevde event, 860714, ML=4.5. This made it necessary to include the Skoevde main event together with a couple of earlier aftershocks in the analysis presented in this report. Thus the present study gives 10 new earthquake mechanisms. Three of these events are in the range ML=3.5-4.5. Of the earlier about 170 earthquake mechanisms available for southern Sweden the largest is ML=3.2. The earthquakes of the present study thus give significant new information about Swedish seismic activity. (orig./DG)

HPLC method for determination of SN-38 content and SN-38 entrapment efficiency in a novel liposome-based formulation, LE-SN38.

Science.gov (United States)

Xuan, Tong; Zhang, J Allen; Ahmad, Imran

2006-05-03

A simple HPLC method was developed for quantification of SN-38, 7-ethyl-10-hydroxycamptothecin, in a novel liposome-based formulation (LE-SN38). The chromatographic separation was achieved on an Agilent Zorbax SB-C18 (4.6 mmx250 mm, 5 microm) analytical column using a mobile phase consisting of a mixture of NaH2PO4 (pH 3.1, 25 mM) and acetonitrile (50:50, v/v). SN-38 was detected at UV wavelength of 265 nm and quantitatively determined using an external calibration method. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.05 and 0.25 microg/mL, respectively. The individual spike recovery of SN-38 ranged from 100 to 101%. The percent of relative standard deviation (%R.S.D.) of intra-day and inter-day analyses were less than 1.6%. The method validation results confirmed that the method is specific, linear, accurate, precise, robust and sensitive for its intended use. The current method was successfully applied to the determination of SN-38 content and drug entrapment efficiency in liposome-based formulation, LE-SN38 during early stage formulation development.

Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac

International Nuclear Information System (INIS)

Garavini, G.; Aldering, G.; Amadon, A.; Amanullah, R.; Astier, P.; Balland, C.; Blanc, G.; Conley, A.; Dahlen, T.; Deustua, S.E.; Ellis, R.; Fabbro, S.; Fadeyev, V.; Fan, X.; Folatelli, G.; Frye, B.; Gates, E.L.; Gibbons, R.; Goldhaber, G.; Goldman, B.; Goobar, A.; Groom, D.E.; Haissinski, J.; Hardin, D.; Hook, I.; Howell, D.A.; Kent, S.; Kim, A.G.; Knop, R.A.; Kowalski, M.; Kuznetsova, N.; Lee, B.C.; Lidman, C.; Mendez, J.; Miller, G.J.; Moniez, M.; Mouchet, M.; Mourao, A.; Newberg, H.; Nobili, S.; Nugent, P.E.; Pain, R.; Perdereau, O.; Perlmutter, S.; Quimby, R.; Regnault, N.; Rich, J.; Richards, G.T.; Ruiz-Lapuente, P.; Schaefer, B.E.; Schahmaneche, K.; Smith, E.; Spadafora, A.L.; Stanishev, V.; Thomas, R.C.; Walton, N.A.; Wang, L.; Wood-Vasey, W.M.

2005-01-01

The authors present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after B-band maximum appear more normal. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, though SN 1999ac is not particularly dim. The analysis of the parameters v 10 (Si II), R(Si II), v, and Δm 15 further underlines the unique characteristics of SN 1999ac. They find convincing evidence of C II λ6580 in the day -15 spectrum with ejection velocity v > 16,000 km s -1 , but this signature disappears by day -9. This rapid evolution at early times highlights the importance of extremely early-time spectroscopy

Pseudomorphic GeSiSn, SiSn and Ge layers in strained heterostructures

Science.gov (United States)

Timofeev, V. A.; Nikiforov, A. I.; Tuktamyshev, A. R.; Mashanov, V. I.; Loshkarev, I. D.; Bloshkin, A. A.; Gutakovskii, A. K.

2018-04-01

The GeSiSn, SiSn layer growth mechanisms on Si(100) were investigated and the kinetic diagrams of the morphological GeSiSn, SiSn film states in the temperature range of 150 °C-450 °C at the tin content from 0% to 35% were built. The phase diagram of the superstructural change on the surface of Sn grown on Si(100) in the annealing temperature range of 0 °C-850 °C was established. The specular beam oscillations were first obtained during the SiSn film growth from 150 °C to 300 °C at the Sn content up to 35%. The transmission electron microscopy and x-ray diffractometry data confirm the crystal perfection and the pseudomorphic GeSiSn, SiSn film state, and also the presence of smooth heterointerfaces between GeSiSn or SiSn and Si. The photoluminescence for the multilayer periodic GeSiSn/Si structures in the range of 0.6-0.8 eV was detected. The blue shift with the excitation power increase is observed suggesting the presence of a type II heterostructure. The creation of tensile strained Ge films, which are pseudomorphic to the underlying GeSn layer, is confirmed by the results of the formation and analysis of the reciprocal space map in the x-ray diffractometry. The tensile strain in the Ge films reached the value in the range of 0.86%-1.5%. The GeSn buffer layer growth in the Sn content range from 8% to 12% was studied. The band structure of heterosystems based on pseudomorphic GeSiSn, SiSn and Ge layers was calculated and the valence and conduction band subband position dependences on the Sn content were built. Based on the calculation, the Sn content range in the GeSiSn, SiSn, and GeSn layers, which corresponds to the direct bandgap GeSiSn, SiSn, and Ge material, was obtained.

Review of nuclear air treatment system related License Event Reports for the period 1985 - 1987

International Nuclear Information System (INIS)

Jacox, J.W.

1989-01-01

This paper will continue the review of HVAC/NATS related LERS presented at past Air Cleaning Conferences by Dr. D. W. Moeller and his associates. The general approach and format are similar. LER abstracts from mid 1985 through 1987 were reviewed and those related to HVAC/NATS classified and analyzed. The categories were jointly developed by Dr. Moeller, Dr. Casper Sun and myself. In appropriate cases both primary and secondary categories fora problem are given. A basic listing by category and brief statistical review are presented. Additionally a number of categories are discussed in some detail. The categories chosen for specific review are intended to highlight particular problem areas. NUREG/CR-2000 License Event Report (LER) Compilation is the basis for the initial review and coding. In essentially all cases where an LER is classified as of interest the complete LER was obtained and reviewed in full. The intent of this paper is to provide a basis for the industry to document and analyze problem areas that require additional attention. It appears that about 15% of all LERS in the subject period are HVAC/NATS related. This figure is generally consistent with those reported at the 17th DOE Nuclear Air Cleaning Conference. It is hoped that such attention will allow additional resources to be allocated to upgrade systems, procedures and training as well as in some cases government regulation

Social and Economic Consequences of the 1987 Earthquakes in Ecuador

Directory of Open Access Journals (Sweden)

Vicente Albornoz

2014-10-01

Full Text Available El 5 de marzo de 1987, dos terremotos de 6,1 y 6,9 grados en la escala Richter sacudieron en noreste del Ecuador. Si bien el país había vivido terremotos más fuertes, el de 1987 representa uno de los que más golpearon su economía. Para entender la gravedad de las consecuencias económicas y sociales que este fenómeno natural tuvo, es necesario revisar la realidad ecuatoriana previa al desastre. En particular tres factores habrían hecho más vulnerable al país frente a los terremotos de ese año: condiciones climáticas desfavorables, infraestructura vulnerable y malas políticas económicas. El resultado de esta vulnerabilidad fue que un terremoto causó una crisis económica que duró alrededor de cinco años. Abstract On March 5, 1987, northeastern Ecuador was shaken by two earthquakes, which registered 6.1 and 6.9 degrees, respectively, on the Richter scale. Even though the country had experienced stronger earthquakes, the ones that occurred in 1987 hit the economy harder than most. In order to understand how serious the economic and social consequences of this natural disaster were, it is necessary to examine Ecuador’s reality prior to these events. Three factors in particular made the country more susceptible to repercussions from the 1987 earthquakes: unfavorable climatic conditions, vulnerable infrastructure and ill-conceived economic policies. This meant that the earthquakes gave rise to an economic crisis that lasted approximately five years.

Energy spectrum of reactor antineutrinos and searches for new physics (Resent developments)

International Nuclear Information System (INIS)

Kopejkin, V.I.; Sinev, V.V.

2001-01-01

The study of the electron neutrino properties - its mass, mixing, magnetic moment - is the main goal of the present reactor antineutrino experiments. We consider the time evolution of the reactor ν bar e spectrum during reactor ON and reactor OFF periods. An important role of the time variations of the reactor ν bar e spectrum in searches for neutrino magnetic moment is discussed. Corrections to the predicted earlier theoretical and precise measured inverse beta-decay cross sections are calculated. We found that the residual ν bar e emission during the reactor OFF period can play a non-negligible role in oscillation experiments

Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

KAUST Repository

Zhu, Haibo

2014-12-01

A new one pot, surfactant-free, synthetic route based on the surface organometallic chemistry (SOMC) concept has been developed for the synthesis of Sn surface-enriched Pt-Sn nanoparticles. Bu3SnH selectively reacts with [Pt]-H formed in situ at the surface of Pt nanoparticles, Pt NPs, obtained by reduction of K2PtCl4 by LiB(C2H5)3H. Chemical analysis, 1H MAS and 13C CP/MAS solid-state NMR as well as two-dimensional double-quantum (DQ) and triple-quantum (TQ) experiments show that organo-tin moieties Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as-synthesized Pt-Sn NPs, enabling the bimetallic NPs to be well dispersed in THF. Additionally, the Pt-Sn nanoparticles can be supported on MgAl2O4 during the synthesis of the nanoparticles. Some of the Pt-Sn/MgAl2O4 catalyst thus prepared exhibits high activity in PROX of CO and an extremely high selectivity and stability in propane dehydrogenation to propylene. The enhanced activity in propane dehydrogenation is associated with the high concentration of inactive Sn at the surface of Pt nanoparticles which ”isolates” the active Pt atoms. This conclusion is confirmed by XRD, NMR, TEM, and XPS analysis.

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

International Nuclear Information System (INIS)

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

1986-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-04-01

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

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

Science.gov (United States)

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

1986-10-01

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

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

Science.gov (United States)

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

1993-04-01

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

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

Science.gov (United States)

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

1987-09-01

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

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

International Nuclear Information System (INIS)

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

1987-01-01

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

States in 118Sn from 117Sn(d,p) 118Sn at 12 MeV

International Nuclear Information System (INIS)

Frota-Pessoa, E.

1983-01-01

118 Sn energy levels up to = 5.2 MeV excitation energy are studied in the reaction 117 Sn (d,p) 118 Sn. Deuterons had a bombarding energy of 12 MeV. The protons were analized by a magnetic spectrograph. The detector was nuclear emulsion and the resolution in energy about 10 KeV. The distorted-wave analysis was used to determine l values and spectroscopic strengths. Centers of gravity and the sums of reduced spectroscopic factors are presented for the levels when it was possible to determine the S' value. 66 levels of excitation energy were found which did not appear in previous 117 Sn (d,p) reactions. 40 levels were not found previously in any reaction giving 118 Sn. The results are compared with the known ones. (Author) [pt

Solid Liquid Interdiffusion Bonding of (Pb, Sn)Te Thermoelectric Modules with Cu Electrodes Using a Thin-Film Sn Interlayer

Science.gov (United States)

Chuang, T. H.; Lin, H. J.; Chuang, C. H.; Yeh, W. T.; Hwang, J. D.; Chu, H. S.

2014-12-01

A (Pb, Sn)Te thermoelectric element plated with a Ni barrier layer and a Ag reaction layer has been joined with a Cu electrode coated with Ag and Sn thin films using a solid-liquid interdiffusion bonding method. This method allows the interfacial reaction between Ag and Sn such that Ag3Sn intermetallic compounds form at low temperature and are stable at high temperature. In this study, the bonding strength was about 6.6 MPa, and the specimens fractured along the interface between the (Pb, Sn)Te thermoelectric element and the Ni barrier layer. Pre-electroplating a film of Sn with a thickness of about 1 μm on the thermoelectric element and pre-heating at 250°C for 3 min ensures the adhesion between the thermoelectric material and the Ni barrier layer. The bonding strength is thus increased to a maximal value of 12.2 MPa, and most of the fractures occur inside the thermoelectric material. During the bonding process, not only the Ag3Sn intermetallics but also Cu6Sn5 forms at the Ag3Sn/Cu interface, which transforms into Cu3Sn with increases in the bonding temperature or bonding time.

The Great Chinese fire of 1987: A view from space

International Nuclear Information System (INIS)

Cahoon, D.R. Jr.; Levine, J.S.; Cofer, W.R. III; Miller, J.E.; Minnis, P.; Tennille, G.M.; Yip, T.W.; Stocks, B.J.; Heck, P.W.

1991-01-01

On May 6, 1987, three fires were started in the boreal forest of the Helongjing Province of the Peoples' Republic of China. The Helongjing Province borders the Soviet Union along the Amur River. Over 200 images spanning a period of six months were examined in the study of this event. The Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-9 spacecraft produced all the imaging. This chapter reviews the methodology employed in determining the extent of the burning. An important reservation made after comparison with Landsat imagery is that small burned areas may be missed and hence some uncertainty exists with estimations of burned area using AVHRR Global Area Coverage measurements

HOST GALAXY PROPERTIES OF THE SUBLUMINOUS GRB 120422A/SN 2012bz

Energy Technology Data Exchange (ETDEWEB)

Levesque, Emily M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado 389-UCB, Boulder, CO 80309 (United States); Chornock, Ryan; Soderberg, Alicia M.; Berger, Edo; Lunnan, Ragnhild, E-mail: Emily.Levesque@colorado.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-10-20

GRB 120422A is a nearby (z = 0.283) long-duration gamma-ray burst (LGRB) detected by Swift with E {sub {gamma},iso} {approx} 4.5 Multiplication-Sign 10{sup 49} erg. It is also associated with the spectroscopically confirmed broad-lined Type Ic SN 2012bz. These properties establish GRB 120422A/SN 2012bz as the sixth and newest member of the class of subluminous GRBs supernovae (SNe). Observations also show that GRB 120422A/SN 2012bz occurred at an unusually large offset ({approx}8 kpc) from the host galaxy nucleus, setting it apart from other nearby LGRBs and leading to speculation that the host environment may have undergone prior interaction activity. Here, we present spectroscopic observations using the 6.5 m Magellan telescope at Las Campanas. We extract spectra at three specific locations within the GRB/SN host galaxy, including the host nucleus, the explosion site, and the 'bridge' of diffuse emission connecting these two regions. We measure a metallicity of log(O/H) + 12 = 8.3 {+-} 0.1 and a star formation rate (SFR) per unit area of 0.08 M {sub Sun} yr{sup -1} kpc{sup -2} at the host nucleus. At the GRB/SN explosion site we measure a comparable metallicity of log(O/H) + 12 = 8.2 {+-} 0.1 but find a much lower SFR per unit area of 0.01 M {sub Sun} yr{sup -1} kpc{sup -2}. We also compare the host galaxy of this event to the hosts of other LGRBs, including samples of subluminous LGRBs and cosmological LGRBs, and find no systematic metallicity difference between the environments of these different subtypes.

Rod-like hierarchical Sn/SnOx@C nanostructures with enhanced lithium storage properties

Science.gov (United States)

Yang, Juan; Chen, Sanmei; Tang, Jingjing; Tian, Hangyu; Bai, Tao; Zhou, Xiangyang

2018-03-01

Rod-like hierarchical Sn/SnOx@C nanostructures have been designed and synthesized via calcining resorcinol-formaldehyde (RF) resin coated Sn-based metal-organic frameworks. The rod-like hierarchical Sn/SnOx@C nanostructures are made of a great number of carbon-wrapped primary Sn/SnOx nanospheres of 100-200 nm in diameter. The as-prepared hierarchical Sn/SnOx@C nanocomposite manifests a high initial reversible capacity of 1177 mAh g-1 and remains 1001 mAh g-1 after 240 cycles at a current density of 200 mA g-1. It delivers outstanding high-rate performance with a reversible capacity of 823 mAh g-1 even at a high current density of 1000 mA g-1. The enhanced electrochemical performances of the Sn/SnOx@C electrode are mainly attributed to the synergistic effect of the unique hierarchical micro/nanostructures and the protective carbon layer.

Analyses of the Sn IX-Sn XII spectra in the EUV region

International Nuclear Information System (INIS)

Churilov, S S; Ryabtsev, A N

2006-01-01

The Sn IX-Sn XII spectra excited in a vacuum spark have been analysed in the 130-160 A wavelength region. The analysis was based on the energy parameter extrapolation in the isonuclear Sn VI-VIII and Sn XIII-XIV sequence. 266 spectral lines belonging to the 4d m -(4d m-1 4f+4p 5 4d m+1 ) (m=6-3) transition arrays were classified in the Sn IX-Sn XII spectra for the first time. All 18 level energies of the 4d 3 configuration and 39 level energies of the strongly interacting 4d 2 4f and 4p 5 4d 4 configurations were established in the Sn XII spectrum. The energy differences between the majority of the 4d m levels and about 40 levels of the 4d m-1 4f+4p 5 4d m+1 configurations were determined in each of the Sn IX, Sn X and Sn XI spectra (m=6-4). As a result, all intense lines were classified in the 130-140 A region relevant to the extreme ultraviolet (EUV) lithography. It was shown that the most of the intense lines in the 2% bandwidth at 135 A belong to the transitions in the Sn XI-Sn XIII spectra

Supernovae 2016bdu and 2005gl, and their link with SN 2009ip-like transients: another piece of the puzzle

DEFF Research Database (Denmark)

Pastorello, A.; Kochanek, C. S.; Fraser, M.

2018-01-01

Supernova (SN) 2016bdu is an unusual transient resembling SN 2009ip. SN 2009ip-like events are characterized by a long-lasting phase of erratic variability which ends with two luminous outbursts a few weeks apart. The second outburst is significantly more luminous (about 3 mag) than the first. In...

Multiepoch Spectropolarimetry of SN 2011fe

International Nuclear Information System (INIS)

Milne, Peter A.; Williams, G. Grant; Smith, Paul S.; Smith, Nathan; Jannuzi, Buell T.; Green, E. M.; Porter, Amber; Leising, Mark D.

2017-01-01

We present multiple spectropolarimetric observations of the nearby Type Ia supernova (SN) 2011fe in M101, obtained before, during, and after the time of maximum apparent visual brightness. The excellent time coverage of our spectropolarimetry has allowed better monitoring of the evolution of polarization features than is typical, which has allowed us new insight into the nature of normal SNe Ia. SN 2011fe exhibits time-dependent polarization in both the continuum and strong absorption lines. At early epochs, red wavelengths exhibit a degree of continuum polarization of up to 0.4%, likely indicative of a mild asymmetry in the electron-scattering photosphere. This behavior is more common in subluminous SNe Ia than in normal events, such as SN 2011fe. The degree of polarization across a collection of absorption lines varies dramatically from epoch to epoch. During the earliest epoch, a λ 4600–5000 Å complex of absorption lines shows enhanced polarization at a different position angle than the continuum. We explore the origin of these features, presenting a few possible interpretations, without arriving at a single favored ion. During two epochs near maximum, the dominant polarization feature is associated with the Si ii λ 6355 Å absorption line. This is common for SNe Ia, but for SN 2011fe the polarization of this feature increases after maximum light, whereas for other SNe Ia, that polarization feature was strongest before maximum light.

Multiepoch Spectropolarimetry of SN 2011fe

Energy Technology Data Exchange (ETDEWEB)

Milne, Peter A.; Williams, G. Grant; Smith, Paul S.; Smith, Nathan; Jannuzi, Buell T.; Green, E. M. [University of Arizona, Steward Observatory, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Porter, Amber; Leising, Mark D. [118 Kinard Laboratory, Clemson University, Clemson, SC 29634 (United States)

2017-01-20

We present multiple spectropolarimetric observations of the nearby Type Ia supernova (SN) 2011fe in M101, obtained before, during, and after the time of maximum apparent visual brightness. The excellent time coverage of our spectropolarimetry has allowed better monitoring of the evolution of polarization features than is typical, which has allowed us new insight into the nature of normal SNe Ia. SN 2011fe exhibits time-dependent polarization in both the continuum and strong absorption lines. At early epochs, red wavelengths exhibit a degree of continuum polarization of up to 0.4%, likely indicative of a mild asymmetry in the electron-scattering photosphere. This behavior is more common in subluminous SNe Ia than in normal events, such as SN 2011fe. The degree of polarization across a collection of absorption lines varies dramatically from epoch to epoch. During the earliest epoch, a λ 4600–5000 Å complex of absorption lines shows enhanced polarization at a different position angle than the continuum. We explore the origin of these features, presenting a few possible interpretations, without arriving at a single favored ion. During two epochs near maximum, the dominant polarization feature is associated with the Si ii λ 6355 Å absorption line. This is common for SNe Ia, but for SN 2011fe the polarization of this feature increases after maximum light, whereas for other SNe Ia, that polarization feature was strongest before maximum light.

A robust neural network-based approach for microseismic event detection

KAUST Repository

Akram, Jubran; Ovcharenko, Oleg; Peter, Daniel

2017-01-01

We present an artificial neural network based approach for robust event detection from low S/N waveforms. We use a feed-forward network with a single hidden layer that is tuned on a training dataset and later applied on the entire example dataset

Status of the experiment on the laboratory search for the electron antineutrino magnetic moment at the level mu subnu <= 3 x 10 sup - sup 1 sup 2 mu sub B

CERN Document Server

Neganov, B S; Yukhimchuk, A A; Bogdanova, L N; Beda, A G; Starostin, A S

2001-01-01

The experiment on the direct detection of antineutrino-electron scattering using a 40 MCi tritium beta-active source will allow to lower the present-day laboratory limit for the neutrino magnetic moment by two orders of magnitude. The experiment brings together novel unique technologies in studies of rare processes of neutrino-electron scattering: 1) and artificial source of antineutrinos from tritium decay of 40-MCi activity with the antineutrino flux density approx = 6 x 10 sup 1 sup 4 cm sup - sup 2 s sup - sup 1; 2) new types of detectors capable of detecting electrons with energy down to approx 10 eV, namely, a silicon cryogenic detector based on the ionization-into-heat conversion effect, a high-pure germanium detector with the internal signal amplification in the electric field. A compact installation located in a specially equipped laboratory underground (<= 100 water equivalent meters) will provide favorable background conditions for running the experiment. With the background level about 0.1 even...

Oxidation of Pb-Sn and Pb-Sn-In alloys

International Nuclear Information System (INIS)

Sluzewski, D.A.; Chang, Y.A.; Marcotte, V.C.

1990-01-01

Air oxidized Pb-Sn and Pb-Sn-In single phase alloys have been studied with scanning Auger microscopy. Line scans across grain boundaries combined with argon ion sputter etching revealed grain boundary oxidation. In the Pb-Sn samples, tin is preferentially oxidized with the grain boundary regions having a much higher percentage of tin oxide than the bulk surface oxide. In the Pb-Sn-In alloys, both tin and indium are preferentially oxidized with the grain boundary regions being enriched with tin and indium oxides

Development of a 117mSn preparation method

International Nuclear Information System (INIS)

Moraes, Vanessa; Osso Junior, Joao Alberto

2000-01-01

117m Sn is a radioisotope with suitable characteristics to be used in nuclear medicine as radiotherapy, when labeled with DTPA. The aim of this work is the preparation of 117m Sn from irradiation of the natural tin with proton beam at the cyclotron CV-28 of IPEN-CNEN/SP via the nuclear reaction nat Sn (p, xn) 117 Sb to 117m Sn. Due to the formation of the Sb precursor it is necessary to perform a chemical separation for Sb-Sn. The separation method used was the ion exchange, due to its utilization facilities for radioactive material. Chemical, radiochemical and radionuclidic methods were also developed for the quality control of the final product, the 117m Sn. (author)

Effects of interlayer Sn-Sn lone pair interaction on the band gap of bulk and nanosheet SnO

Science.gov (United States)

Umezawa, Naoto; Zhou, Wei

2015-03-01

Effects of interlayer lone-pair interactions on the electronic structure of SnO are firstly explored by the density-functional theory. Our comprehensive study reveals that the band gap of SnO opens as increase in the interlayer Sn-Sn distance. The effect is rationalized by the character of band edges which consists of bonding and anti-bonding states from interlayer lone pair interactions. The band edges for several nanosheets and strained double-layer SnO are estimated. We conclude that the double-layer SnO is a promising material for visible-light driven photocatalyst for hydrogen evolution. This work is supported by the Japan Science and Technology Agency (JST) Precursory Research for Embryonic Science and Technology (PRESTO) program.

Host Galaxy Spectra and Consequences for SN Typing from the SDSS SN Survey

Energy Technology Data Exchange (ETDEWEB)

Olmstead, Matthew D.; Brown, Peter J.; Sako, Masao; Bassett, Bruce; Bizyaev, Dmitry; Brinkmann, J.; Brownstein, Joel R.; Brewington, Howard; Campbell, Heather; D’Andrea, Chris B.; Dawson, Kyle S.; Ebelke, Garrett L.; Frieman, Joshua A.; Galbany, Lluís; Garnavich, Peter; Gupta, Ravi R.; Hlozek, Renee; Jha, Saurabh W.; Kunz, Martin; Lampeitl, Hubert; Malanushenko, Elena; Malanushenko, Viktor; Marriner, John; Miquel, Ramon; Montero-Dorta, Antonio D.; Nichol, Robert C.; Oravetz, Daniel J.; Pan, Kaike; Schneider, Donald P.; Simmons, Audrey E.; Smith, Mathew; Snedden, Stephanie A.

2014-03-06

We present the spectroscopy from 5254 galaxies that hosted supernovae (SNe) or other transient events in the Sloan Digital Sky Survey II (SDSS-II). Obtained during SDSS-I, SDSS-II, and the Baryon Oscillation Spectroscopic Survey (BOSS), this sample represents the largest systematic, unbiased, magnitude limited spectroscopic survey of supernova (SN) host galaxies. Using the host galaxy redshifts, we test the impact of photometric SN classification based on SDSS imaging data with and without using spectroscopic redshifts of the host galaxies. Following our suggested scheme, there are a total of 1166 photometrically classified SNe Ia when using a flat redshift prior and 1126 SNe Ia when the host spectroscopic redshift is assumed. For 1024 (87.8%) candidates classified as likely SNe Ia without redshift information, we find that the classification is unchanged when adding the host galaxy redshift. Using photometry from SDSS imaging data and the host galaxy spectra, we also report host galaxy properties for use in future nalysis of SN astrophysics. Finally, we investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. When using the SALT2 light curve fitter, we find a 21% increase in the number of fits that converge when using the spectroscopic redshift. Without host galaxy redshifts, we find that SALT2 light curve fits are systematically biased towards lower photometric redshift estimates and redder colors in the limit of low signal-to-noise data. The general improvements in performance of the light curve fitter and the increased diversity of the host galaxy sample highlights the importance of host galaxy spectroscopy for current photometric SN surveys such as the Dark Energy Survey and future surveys such as the Large Synoptic Survey Telescope.

The Fast Evolution of SN 2010bh Associated with XRF 100316D

Science.gov (United States)

Olivares E., F.; Greiner, J.; Schady, P.; Rau, A.; Klose, S.; Kruhler, T.; Afonso, P. M. J.; Updike, A. C.; Nardini, M.; Filgas, R.;

A Comparative Study on SN II Progenitors for the Synthesis of Li and ...

Indian Academy of Sciences (India)

these two elements for SN II progenitors with 8, 10 and 20 solar masses. The process considered ... explain their origin. Interaction of ... universe expansion rate either due to cosmological term or due to increased 'grav- itational constant' ..... elevate Li production or to suppress B production in early solar system events. The.

α-Eleostearic acid-containing triglycerides for a continuous assay to determine lipase sn-1 and sn-3 regio-preference.

Science.gov (United States)

El Alaoui, Meddy; Soulère, Laurent; Noiriel, Alexandre; Queneau, Yves; Abousalham, Abdelkarim

2017-08-01

Lipases are essentially described as sn-1 and sn-3 regio-selective. Actually few methods are available to measure this lipase regio-selectivity, moreover they require chiral chromatography analysis or specific derivations which are discontinuous and time consuming. In this study we describe a new, convenient, sensitive and continuous spectrophotometric method to screen lipases regio-selectivity using synthetic triglycerides (TG) containing α-eleostearic acid (9Z, 11E, 13E-octadecatrienoic acid) either at the sn-1 position [1-α-eleostearoyl-2,3-octadecyl-sn-glycerol (sn-EOO)] or at the sn-3 position [1,2-octadecyl-3-α-eleostearoyl-sn-glycerol (sn-OOE)] and coated onto the wells of microtiter plates. A non-hydrolysable ether bond, with a non UV-absorbing alkyl chain, was introduced at the other sn positions to prevent acyl chain migration during TG synthesis or lipolysis. The synthesis of TG containing α-eleostearic acid was performed from S-glycidol in six steps to obtain sn-EOO and in five steps to sn-OOE. The α-eleostearic acid conjugated triene constitutes an intrinsic chromophore and, consequently, confers the strong UV absorption properties of this free fatty acid as well as of the TG harboring it. The lipase activity on coated sn-EOO or sn-OOE was measured by the increase in the absorbance at 272nm due to the transition of α-eleostearic acid from the adsorbed to the soluble state. Human and porcine pancreatic lipases, guinea pig pancreatic lipase related protein 2, Thermomyces lanuginosus lipase, Candida antarctica lipase A and Candida antarctica lipase B were all used to validate the assay. This continuous high-throughput screening method could determine directly without any processes after lipolysis the regio-selectivity of various lipases. Copyright © 2017 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Magnetic behaviour of cerium in Ce2 Sn5 and Ce3 Sn7, surstructures of Ce Sn3

International Nuclear Information System (INIS)

Stunault, A.

1988-07-01

The compound studied, Ce 2 Sn 5 and Ce 3 Sn 7 are both orthorhombic, surstructure of cubic Ce Sn 3 . Magnetic susceptibility measurements show in both compounds an antiferromagnetic order at low temperature and magnetization shows a high anisotropy. Magnetization densities are determined by polarized neutron diffraction. The cerium site which has two Ce atoms as nearest neighbourgs carries all the magnetism in both structures. For Ce 2 Sn 5 moments are directed as the high magnetization axis and structure is modulated. Ce 3 Sn 7 presents a simple antiferromagnetic order but moment are directed as low magnetization axis. Various transitions towards a ferromagnetic order are presented. Results are interpreted by measuring the difference between energy levels of crystalline field. A model of crystalline field and isotrope exchange agrees well with Ce 3 Sn 7 , but for Ce 2 Sn 7 it is necessary to reduce the magnetic moment which is typical of the Kondo effect [fr

Relative excitation of the seismic shear waves Sn and Lg as a function of source depth and their propagation from Melanesia and Banda arcs to Australia

Directory of Open Access Journals (Sweden)

J. OLIVER

1977-06-01

Full Text Available SUMMARY. - Seismic activity associated with the collision of the continental
part of the Australian plate with the oceanic Melanesian arcs along Papua New
Guinea and the Banda arc provides an unusual opportunity to study the relative
excitation of the seismic shear waves Sn and Lg. These waves are produced by
earthquakes located along the arcs in the upper 200 km of the earth and are
recorded by the Australian WWSSN Stations at Charters Towers (CTA and Alice
Springs (ASP. The paths to these stations are predominantly continental. The data
clearly show that for events located at crustal depths, Lg is the predominant phase
on the records and Sn is either absent or very weak. For events deeper than about
50-70 km, Sn becomes the predominant phase on the records. These observations
arc in qualitative agreement with the explanations of Sn and Lg as higher
modes of surface waves, for the particle displacement amplitudes are maximum
within the crust for Lg and maximum within the lid of the lithospheric mantle
for Sn. The data suggest that either the crustal wave guide for Lg is more
efficient than that for Sn, or that Lg is more easily excited than Sn. No clear
Lg is observed from shallow earthquakes when the length of the segment of the
path crossing oceanic structure is greater than about 200 km. Also, widespread
Quaternary volcanism within the « stable » area of central Papua New Guinea
to the south of the mobile belt does not seem to affect the efficient transmission
of high-frequency (1 Hz shear energy.
The paths from events located along the New Hebrides, Solomon, and New
Britain arcs to Australia traverse oceanic structure, and no Lg is observed from
these paths. The inefficient propagation of Sn along these paths from both
shallow and intermediate-depth events can be explained as follows: 1 For
the New Hebrides case, the

Isomer shifts and chemical bonding in crystalline Sn(II) and Sn(IV) compounds

International Nuclear Information System (INIS)

Terra, J.; Guenzburger, D.

1991-01-01

First-principles self-consistent Local Density calculations of the electronic structure of clusters representing Sn(II) (SnO, SnF 2 , SnS, SnSe) and Sn(IV) (SnO 2 , SnF 4 ) crystalline compounds were performed. Values of the electron density at the Sn nucleus were obtained and related to measured values of the Moessbauer Isomer Shifts reported in the literature. The nuclear parameter of 119 Sn derived was ΔR/R=(1.58±0.14)x10 -4 . The chemical bonding in the solids was analysed and related to the electron densities obtained. (author)

A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

Science.gov (United States)

Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

2017-05-01

The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

SUPERLUMINOUS SUPERNOVA SN 2015bn IN THE NEBULAR PHASE: EVIDENCE FOR THE ENGINE-POWERED EXPLOSION OF A STRIPPED MASSIVE STAR

Energy Technology Data Exchange (ETDEWEB)

Nicholl, M.; Berger, E.; Blanchard, P. K.; Challis, P.; Cowperthwaite, P. S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Margutti, R. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Chornock, R. [Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701 (United States); Jerkstrand, A.; Smartt, S. J.; Inserra, C.; Kankare, E.; Maguire, K. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Arcavi, I.; Hosseinzadeh, G.; Howell, D. A. [Las Cumbres Observatory Global Telescope, 6740 Cortona Drive, Suite 102, Goleta, CA 93111 (United States); Chambers, K. C.; Magnier, E. A. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Chen, T.-W. [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße 1, D-85748, Garching (Germany); Gal-Yam, A. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Mazzali, P. A., E-mail: matt.nicholl@cfa.harvard.edu [Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); and others

2016-09-10

We present nebular-phase imaging and spectroscopy for the hydrogen-poor superluminous supernova (SLSN) SN 2015bn, at redshift z = 0.1136, spanning +250–400 days after maximum light. The light curve exhibits a steepening in the decline rate from 1.4 mag (100 days){sup −1} to 1.7 mag (100 days){sup −1}, suggestive of a significant decrease in the opacity. This change is accompanied by a transition from a blue continuum superposed with photospheric absorption lines to a nebular spectrum dominated by emission lines of oxygen, calcium, and magnesium. There are no obvious signatures of circumstellar interaction or large {sup 56}Ni mass. We show that the spectrum at +400 days is virtually identical to a number of energetic SNe Ic such as SN 1997dq, SN 2012au, and SN 1998bw, indicating similar core conditions and strengthening the link between “hypernovae”/long gamma-ray bursts and SLSNe. A single explosion mechanism may unify these events that span absolute magnitudes of −22 < M {sub B} < −17. Both the light curve and spectrum of SN 2015bn are consistent with an engine-driven explosion ejecting 7–30 M {sub ⊙} of oxygen-dominated ejecta (for reasonable choices in temperature and opacity). A strong and relatively narrow O i λ 7774 line, seen in a number of these energetic events but not in normal supernovae, may point to an inner shell that is the signature of a central engine.

70 °C synthesis of high-Sn content (25%) GeSn on insulator by Sn-induced crystallization of amorphous Ge

Energy Technology Data Exchange (ETDEWEB)

Toko, K., E-mail: toko@bk.tsukuba.ac.jp; Oya, N.; Suemasu, T. [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Saitoh, N.; Yoshizawa, N. [Electron Microscope Facility, TIA, AIST, 16-1 Onogawa, Tsukuba 305-8569 (Japan)

2015-02-23

Polycrystalline GeSn thin films are fabricated on insulating substrates at low temperatures by using Sn-induced crystallization of amorphous Ge (a-Ge). The Sn layer stacked on the a-Ge layer (100-nm thickness each) had two roles: lowering the crystallization temperature of a-Ge and composing GeSn. Slow annealing at an extremely low temperature of 70 °C allowed for a large-grained (350 nm) GeSn layer with a lattice constant of 0.590 nm, corresponding to a Sn composition exceeding 25%. The present investigation paves the way for advanced electronic optical devices integrated on a flexible plastic substrate as well as on a Si platform.

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

International Nuclear Information System (INIS)

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

1987-01-01

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

U6 snRNA expression prevents toxicity in TDP-43-knockdown cells.

Directory of Open Access Journals (Sweden)

Masao Yahara

Full Text Available Depletion of amyotrophic lateral sclerosis (ALS-associated transactivation response (TAR RNA/DNA-binding protein 43 kDa (TDP-43 alters splicing efficiency of multiple transcripts and results in neuronal cell death. TDP-43 depletion can also disturb expression levels of small nuclear RNAs (snRNAs as spliceosomal components. Despite this knowledge, the relationship between cell death and alteration of snRNA expression during TDP-43 depletion remains unclear. Here, we knocked down TDP-43 in murine neuroblastoma Neuro2A cells and found a time lag between efficient TDP-43 depletion and appearance of cell death, suggesting that several mechanisms mediate between these two events. The amount of U6 snRNA was significantly decreased during TDP-43 depletion prior to increase of cell death, whereas that of U1, U2, and U4 snRNAs was not. Downregulation of U6 snRNA led to cell death, whereas transient exogenous expression of U6 snRNA counteracted the effect of TDP-43 knockdown on cell death, and slightly decreased the mis-splicing rate of Dnajc5 and Sortilin 1 transcripts, which are assisted by TDP-43. These results suggest that regulation of the U6 snRNA expression level by TDP-43 is a key factor in the increase in cell death upon TDP-43 loss-of-function.

SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU

International Nuclear Information System (INIS)

Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P.; Cenko, S. B.; Filippenko, A. V.; Silverman, J. M.; Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N.; Jha, S. W.; McCully, C.; Anderson, J. P.; De Jaeger, T.; Forster, F.; Benetti, S.; Bufano, F.

2013-01-01

We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II λ6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II λ6355 HVF fades by phase –5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of ∼12,000 km s –1 until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v ≈ 12,000 km s –1 with narrow line width and long velocity plateau, as well as an HVF beginning at v ≈ 31,000 km s –1 two weeks before maximum. SN 2012fr resides on the border between the ''shallow silicon'' and ''core-normal'' subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the ''low velocity gradient'' group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

Ethanol electrooxidation on Pt-Sn and Pt-Sn-W bulk alloys

Energy Technology Data Exchange (ETDEWEB)

Anjos, D.M. dos; Hahn, F.; Leger, J.M.; Kokoh, K.B. [Universite de Poitiers, Poitiers Cedex (France). Centre National de la Recherche Scientifique (CNRS). Equipe Electrocatalyse; Tremiliosi-Filho, G. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica

2008-07-01

Ethanol oxidation has been studied on Pt-Sn and Pt-Sn-W electrodes prepared in an arc-melting furnace. Different electrochemical techniques like cyclic voltammetry and chronoamperometry were used to evaluate the catalytic activity of these materials. The electro-oxidation process was also investigated by in situ infrared reflectance spectroscopy in order to determine adsorbed intermediates and reaction products. Experimental results indicated that Pt-Sn and Pt-Sn-W alloys are able to oxidize ethanol mainly to acetaldehyde and acetic acid. Adsorbed CO was also detected, demonstrating the viability of splitting the C-C bond in the ethanol molecule during the oxidation process. The adsorbed CO was further oxidized to CO{sub 2}.This reaction product was clearly detected by SNIFTIRS. Pt-Sn-W catalyst showed a better electrochemical performance than Pt-Sn that, in it turn, is better than Pt-alone. (author)

Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

KAUST Repository

Zhu, Haibo; Anjum, Dalaver H.; Wang, Qingxiao; Abou-Hamad, Edy; Emsley, Lyndon; Dong, Hailin; Laveille, Paco; Li, Lidong; Samal, Akshaya Kumar; Basset, Jean-Marie

2014-01-01

Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as

Fabrication of textured SnO2 transparent conductive films using self-assembled Sn nanospheres

Science.gov (United States)

Fukumoto, Michitaka; Nakao, Shoichiro; Hirose, Yasushi; Hasegawa, Tetsuya

2018-06-01

We present a novel method to fabricate textured surfaces on transparent conductive SnO2 films by processing substrates through a bottom-up technique with potential for industrially scalable production. The substrate processing consists of three steps: deposition of precursor Sn films on glass substrates, formation of a self-assembled Sn nanosphere layer with reductive annealing, and conversion of Sn to SnO2 by oxidative annealing. Ta-doped SnO2 films conformally deposited on the self-assembled nanospherical SnO2 templates exhibited attractive optical and electrical properties, namely, enhanced haze values and low sheet resistances, for applications as transparent electrodes in photovoltaics.

Phase diagram of SnTe-CdSe cross-section of SnTe+CdSe reversible SnSe+CdTe ternary reciprocal system

International Nuclear Information System (INIS)

Dubrovin, I.V.; Budennaya, L.D.; Mizetskaya, I.B.; Sharkina, Eh.V.

1986-01-01

Phase equilibrium diagram of SnTe-CdSe cross-section of Sn, Cd long Te, Se ternary reciprocal system is investigated using the methods of differential thermal, X-ray phase, and microstructural analyses. Maximum length of solid solutions on the base of SnTe corresponds to approximately 14 mol.% at 1050 K and approximately 3 mol.% of CdSe at 670 K. Region of solid solutions on the base of CdSe corresponds to less than 1 mol.% of SnTe at room temperature. SnTe-CdSe cross-section is not a quasibinar one. Equilibrium is shifted to the left in the SnTe+CdSe reversible SnSe+CdTe reciprocal system

SN 2008D: A WOLF-RAYET EXPLOSION THROUGH A THICK WIND

International Nuclear Information System (INIS)

Svirski, Gilad; Nakar, Ehud

2014-01-01

Supernova (SN) 2008D/XRT 080109 is considered to be the only direct detection of a shock breakout from a regular SN to date. While a breakout interpretation was favored by several papers, inconsistencies remain between the observations and current SN shock breakout theory. Most notably, the duration of the luminous X-ray pulse is considerably longer than expected for a spherical breakout through the surface of a type Ibc SN progenitor, and the X-ray radiation features, mainly its flat spectrum and its luminosity evolution, are enigmatic. We apply a recently developed theoretical model for the observed radiation from a Wolf-Rayet SN exploding through a thick wind and show that it naturally explains all of the observed features of SN 2008D X-ray emission, including the energetics, the spectrum, and the detailed luminosity evolution. We find that the inferred progenitor and SN parameters are typical for an exploding Wolf-Rayet. A comparison of the wind density found at the breakout radius and the density at much larger radii, as inferred by late radio observations, suggests an enhanced mass-loss rate taking effect about 10 days prior to the SN explosion. This finding joins accumulating evidence for a possible late phase in the stellar evolution of massive stars, involving vigorous mass loss a short time before the SN explosion

SN 2008D: A WOLF-RAYET EXPLOSION THROUGH A THICK WIND

Energy Technology Data Exchange (ETDEWEB)

Svirski, Gilad; Nakar, Ehud [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

2014-06-10

Supernova (SN) 2008D/XRT 080109 is considered to be the only direct detection of a shock breakout from a regular SN to date. While a breakout interpretation was favored by several papers, inconsistencies remain between the observations and current SN shock breakout theory. Most notably, the duration of the luminous X-ray pulse is considerably longer than expected for a spherical breakout through the surface of a type Ibc SN progenitor, and the X-ray radiation features, mainly its flat spectrum and its luminosity evolution, are enigmatic. We apply a recently developed theoretical model for the observed radiation from a Wolf-Rayet SN exploding through a thick wind and show that it naturally explains all of the observed features of SN 2008D X-ray emission, including the energetics, the spectrum, and the detailed luminosity evolution. We find that the inferred progenitor and SN parameters are typical for an exploding Wolf-Rayet. A comparison of the wind density found at the breakout radius and the density at much larger radii, as inferred by late radio observations, suggests an enhanced mass-loss rate taking effect about 10 days prior to the SN explosion. This finding joins accumulating evidence for a possible late phase in the stellar evolution of massive stars, involving vigorous mass loss a short time before the SN explosion.

Annual report 1987-1988

International Nuclear Information System (INIS)

1988-01-01

The paper presents: the annual report 1987/8 of the University Research Reactor, Risley, United Kingdom. The report contains a description of the current research programme using reactor produced isotopes and other reactor facilities. A summary of the work carried out by the Activation Analysis Service during 1987/8 is also given, along with the Reactor Teaching Programme, and the reactor operation and site safety arrangements. (U.K.)

The role of Tre6P and SnRK1 in maize early kernel development and events leading to stress-induced kernel abortion.

Science.gov (United States)

Bledsoe, Samuel W; Henry, Clémence; Griffiths, Cara A; Paul, Matthew J; Feil, Regina; Lunn, John E; Stitt, Mark; Lagrimini, L Mark

2017-04-12

of kernel excision from the ear triggers a cascade of events starting with the precipitous drop in Tre6P levels. It is proposed that the removal of Tre6P suppression of SnRK1 activity results in transcription of putative SnRK1 target genes, and the metabolic transition from biosynthesis to catabolism. This highlights the importance of Tre6P in the metabolic response to starvation. We also present evidence that sugars can mediate the activation of SnRK1. The precipitous drop in Tre6P corresponds to a large increase in transcription of ZmTPPA.3, indicating that this specific enzyme may be responsible for the de-phosphorylation of Tre6P. The high levels of Tre6P in the immature embryo are likely important for preventing kernel abortion.

Report to Congress on abnormal occurrences, October-December 1987

International Nuclear Information System (INIS)

1988-03-01

Section 208 of the Energy Reorganization Act of 1974 identifies an abnormal occurrence as an unscheduled incident or event which the Nuclear Regulatory Commission determines to be significant from the standpoint of public health or safety and requires a quarterly report of such events to be made to Congress. This report covers the period from October 1 to December 31, 1987. The report states that for this reporting period, these was one abnormal occurrence at the NRC licensees; the item involved the suspension of license of an oil and gas well tracer company for noncompliance with NRC regulatory requirements. There were no abnormal occurrences report by the Agreement States. The report also contains information updating some previously reported abnormal occurrences

Exports of petroleum products, 1987

International Nuclear Information System (INIS)

1988-04-01

A summary is presented of exports of motor gasoline, middle distillate, aviation turbine fuel, heavy fuel oil, and partially processed oil from Canada for the 1987 calendar year. A discussion of petroleum product imports is included in order to put exports in the context of the overall trade. Exports of the above petroleum products averaged 22,200 m 3 /d in 1987, up 15% from 1986 levels. Exports of middle distillates and aviation fuel had the largest gains in 1987. Export prices for light petroleum products stayed relatively close to USA spot prices. The heavy fuel oil price was below the New York spot price in the beginning of 1987 but remained close for the rest of the year. Canada's petroleum products exports were made to 5 countries while imports came from at least 13 countries. The USA remained Canada's largest trading partner in petroleum products. Exports to Japan and the Far East rose ca 60% over 1986. Product outturns for export were 9% of total Canadian refinery throughput. Exports of aviation turbine fuel from Ontario began in April 1987. The top single exporter in Canada was Irving Oil Ltd. with 2,485,000 m 3 . Irving was also the top exporter in 1986. 11 figs., 4 tabs

Spectral and ion emission features of laser-produced Sn and SnO2 plasmas

Science.gov (United States)

Hui, Lan; Xin-Bing, Wang; Du-Luo, Zuo

2016-03-01

We have made a detailed comparison of the atomic and ionic debris, as well as the emission features of Sn and SnO2 plasmas under identical experimental conditions. Planar slabs of pure metal Sn and ceramic SnO2 are irradiated with 1.06 μm, 8 ns Nd:YAG laser pulses. Fast photography employing an intensified charge coupled device (ICCD), optical emission spectroscopy (OES), and optical time of flight emission spectroscopy are used as diagnostic tools. Our results show that the Sn plasma provides a higher extreme ultraviolet (EUV) conversion efficiency (CE) than the SnO2 plasma. However, the kinetic energies of Sn ions are relatively low compared with those of SnO2. OES studies show that the Sn plasma parameters (electron temperature and density) are lower compared to those of the SnO2 plasma. Furthermore, we also give the effects of the vacuum degree and the laser pulse energy on the plasma parameters. Project supported by the National Natural Science Foundation of China (Grant No. 11304235) and the Director Fund of WNLO, China.

PHOTOMETRIC TYPE Ia SUPERNOVA CANDIDATES FROM THE THREE-YEAR SDSS-II SN SURVEY DATA

International Nuclear Information System (INIS)

Sako, Masao; Connolly, Brian; Gladney, Larry; Bassett, Bruce; Dilday, Benjamin; Cambell, Heather; Lampeitl, Hubert; Nichol, Robert C.; Frieman, Joshua A.; Kessler, Richard; Marriner, John; Miquel, Ramon; Schneider, Donald P.; Smith, Mathew; Sollerman, Jesper

2011-01-01

We analyze the three-year Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey data and identify a sample of 1070 photometric Type Ia supernova (SN Ia) candidates based on their multiband light curve data. This sample consists of SN candidates with no spectroscopic confirmation, with a subset of 210 candidates having spectroscopic redshifts of their host galaxies measured while the remaining 860 candidates are purely photometric in their identification. We describe a method for estimating the efficiency and purity of photometric SN Ia classification when spectroscopic confirmation of only a limited sample is available, and demonstrate that SN Ia candidates from SDSS-II can be identified photometrically with ∼91% efficiency and with a contamination of ∼6%. Although this is the largest uniform sample of SN candidates to date for studying photometric identification, we find that a larger spectroscopic sample of contaminating sources is required to obtain a better characterization of the background events. A Hubble diagram using SN candidates with no spectroscopic confirmation, but with host galaxy spectroscopic redshifts, yields a distance modulus dispersion that is only ∼20%-40% larger than that of the spectroscopically confirmed SN Ia sample alone with no significant bias. A Hubble diagram with purely photometric classification and redshift-distance measurements, however, exhibits biases that require further investigation for precision cosmology.

Photometric type Ia supernova candidates from the three-year SDSS-II SN survey data

Energy Technology Data Exchange (ETDEWEB)

Sako, Masao; /Pennsylvania U.; Bassett, Bruce; /South African Astron. Observ. /Cape Town U., Dept. Math.; Connolly, Brian; /Pennsylvania U.; Dilday, Benjamin; /Las Cumbres Observ. /UC, Santa Barbara /Rutgers U., Piscataway; Cambell, Heather; /Portsmouth U., ICG; Frieman, Joshua A.; /Chicago U. /Chicago U., KICP /Fermilab; Gladney, Larry; /Pennsylvania U.; Kessler, Richard; /Chicago U. /Chicago U., KICP; Lampeitl, Hubert; /Portsmouth U., ICG; Marriner, John; /Fermilab; Miquel, Ramon; /Barcelona, IFAE /ICREA, Barcelona /Portsmouth U., ICG

2011-07-01

We analyze the three-year Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey data and identify a sample of 1070 photometric Type Ia supernova (SN Ia) candidates based on their multiband light curve data. This sample consists of SN candidates with no spectroscopic confirmation, with a subset of 210 candidates having spectroscopic redshifts of their host galaxies measured while the remaining 860 candidates are purely photometric in their identification. We describe a method for estimating the efficiency and purity of photometric SN Ia classification when spectroscopic confirmation of only a limited sample is available, and demonstrate that SN Ia candidates from SDSS-II can be identified photometrically with {approx}91% efficiency and with a contamination of {approx}6%. Although this is the largest uniform sample of SN candidates to date for studying photometric identification, we find that a larger spectroscopic sample of contaminating sources is required to obtain a better characterization of the background events. A Hubble diagram using SN candidates with no spectroscopic confirmation, but with host galaxy spectroscopic redshifts, yields a distance modulus dispersion that is only {approx}20%-40% larger than that of the spectroscopically confirmed SN Ia sample alone with no significant bias. A Hubble diagram with purely photometric classification and redshift-distance measurements, however, exhibits biases that require further investigation for precision cosmology.

Gadolinium-loaded gel scintillators for neutron and antineutrino detection

Science.gov (United States)

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

2016-11-29

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

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

Science.gov (United States)

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

1987-03-01

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

The Type II supernovae 2006V and 2006au

DEFF Research Database (Denmark)

Taddia, F.; Stritzinger, M. D.; Sollerman, J.

2012-01-01

curve evolution similar to that of SN 1987A. At the earliest epochs, SN 2006au also displays an initial dip which we interpret as the signature of the adiabatic cooling phase that ensues shock break-out. SNe 2006V and 2006au are both found to be bluer, hotter and brighter than SN 1987A. Spectra of SNe...

Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

DEFF Research Database (Denmark)

Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.

1998-01-01

: (1) SnPb; (2) InSn; (3) AuSn. The studies of the oxidation kinetics show that the growth of the native oxide, which covers the solder surfaces from the start of all soldering operations is self-limiting. The rate of oxidation on the molten, metallic solder surfaces is significantly reduced...... and reduction kinetics, are applied to flip-chip (FC) bonding experiments in vacuum with and without the injection of H2. Wetting in vacuum is excellent but the self-alignment during flip-chip soldering is restricted. The desired, perfectly self-aligned FC-bonds have been only achieved, using evaporated...

Synthesis, characterization and photocatalytic performance of SnS nanofibers and SnSe nanofibers derived from the electrospinning-made SnO{sub 2} nanofibers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Li; Li, Dan; Dong, Xiangting; Ma, Qianli; Yu, Wensheng; Wang, Xinlu; Yu, Hui; Wang, Jinxian; Liu, Guixia, E-mail: dongxiangting888@163.com [Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun (China)

2017-11-15

SnO{sub 2} nanofibers were fabricated by calcination of the electrospun PVP/SnCl{sub 4} composite nanofibers. For the first time, SnS nanofibers and SnSe nanofibers were successfully synthesized by double crucible sulfurization and selenidation methods via inheriting the morphology of SnO{sub 2} nanofibers used as precursors, respectively. X-ray diffraction (XRD) analysis shows SnS nanofibers and SnSe nanofibers are respectively pure orthorhombic phase with space group of Pbnm and Cmcm. Scanning electron microscope (SEM) observation indicates that the diameters of SnS nanofibers and SnSe nanofibers are respectively 140.54±12.80 nm and 96.52±14.17 nm under the 95 % confidence level. The photocatalytic activities of samples were studied by using rhodamine B (Rh B) as degradation agent. When SnS or SnSe nanofibers are employed as the photocatalysts, the respective degradation rates of Rh B solution under the ultraviolet light irradiation after 200 min irradiation are 92.55 % and 92.86 %. The photocatalytic mechanism and formation process of SnS and SnSe nanofibers are also provided. More importantly, this preparation technique is of universal significance to prepare other metal chalcogenides nanofibers. (author)

SKB annual report 1987

International Nuclear Information System (INIS)

1988-05-01

The annual report on the activities of the Swedish Nuclear Fuel and Waste Management contains in part I an overview of SKB activities in different fields. Part II gives a description of the research and development work on nuclear waste disposal performed during 1987. Lectures and publications during 1987 as well as reports issued in the SKB technical report series are listed in part III. Part IV contains the summaries of all technical reports issued during 1987. At Forsmark the first construction phase for the final repository for radioactive waste - SFR - is now completed. The repository is situated in crystalline rock under the Baltic Sea. The first construction phase includes rock caverns for 60 000 m 3 of waste. A second phase for additional 30 000 m 3 is planned to be built and commissioned around the year 2000. (orig./DG)

Supernova will continue to glow

International Nuclear Information System (INIS)

Anon.

1987-01-01

On the night of 23/24 February 1987 a new supernova called SN 1987A, was discovered. Within a few hours of the announcement of the discovery, the South African Astronomical Observatory (SAAO) began a series of observations. In this article, the importance of supernovae-exploding stars, and what the SAAO has discovered so far from SN 1987A are discussed

Observational and theoretical spectra of supernovae

Science.gov (United States)

Wheeler, J. Craig; Swartz, Douglas A.; Harkness, Robert P.

1993-05-01

Progress in nuclear astrophysics by means of quantitative supernova spectroscopy is discussed with special concentration on type Ia, Ib and Ic and on SN 1987A. Spectral calculations continue to support an exploding C/O white dwarf as the best model of a SN Ia. Deflagration model W7 produces good maximum light spectra of SN Ia and seems to have a better composition distribution compared to delayed detonation models, but proper treatment of opacity remains a problem and the physical basis of SN Ia explosions is still not completely understood. All models for SN Ia predict large quantities of 56Co in the ejecta, but it is not clear that observations confirm this. Although the evolutionary origin of SN Ia remains uncertain, there is recent evidence that transfer of hydrogen in a binary system may be involved, as long suspected. There has been progress in comparing dynamical models with the optical/IR spectra of SN 1987A. The evolution of the [OI] λλ6300, 6364 feature and the presence of strong persistent HeI λ10 830 indicate that both the envelope and core material contribute substantially to the formation of emission lines in the nebular phase and that neither the core nor the envelope can be neglected. Blending with nearby hydrogen lines may affect both of these spectral features, thereby complicating the analysis of the lines. The effects of continuum transfer and photoionization have been included and are under study. The discrepancies between theoretical and observed spectra are due primarily to the one-dimensional hydrodynamic models. The spectral data are not consistent with the high density ``spike'' (in radial coordinate) of the core material that is predicted by all such models. Analysis of the light curves of SN Ib and SN Ic supernovae implies that there are significant differences in their physical properties. Some SN Ib have considerably more ejecta mass than SN Ic events. SN Ib require He-rich atmospheres to produce the observed strong optical lines of

Sn-In-Ag phase equilibria and Sn-In-(Ag)/Ag interfacial reactions

International Nuclear Information System (INIS)

Chen Sinnwen; Lee Wanyu; Hsu Chiaming; Yang Chingfeng; Hsu Hsinyun; Wu Hsinjay

2011-01-01

Research highlights: → Thermodynamic models of Sn-In and Sn-In-Ag are developed using the CALPHAD approach. → Reaction layer in the Sn-In-(Ag)/Ag couples at 100 deg. C is thinner than those at 25 deg. C, 50 deg. C, and 75 deg. C. → Reactions in the Sn-20 wt%In-2.8 wt%Ag/Ag couples are faster than those in the Sn-20 wt%In/Ag couples. - Abstract: Experimental verifications of the Sn-In and Sn-In-Ag phase equilibria have been conducted. The experimental measurements of phase equilibria and thermodynamic properties are used for thermodynamic modeling by the CALPHAD approach. The calculated results are in good agreement with experimental results. Interfacial reactions in the Sn-In-(Ag)/Ag couples have been examined. Both Ag 2 In and AgIn 2 phases are formed in the Sn-51.0 wt%In/Ag couples reacted at 100 and 150 deg. C, and only the Ag 2 In phase is formed when reacted at 25, 50 and 75 deg. C. Due to the different growth rates of different reaction phases, the reaction layer at 100 deg. C is thinner than those at 25 deg. C, 50 deg. C, and 75 deg. C. In the Sn-20.0 wt%In/Ag couples, the ζ phase is formed at 250 deg. C and ζ/AgIn 2 phases are formed at 125 deg. C. Compared with the Sn-20 wt%In/Ag couples, faster interfacial reactions are observed in the Sn-20.0 wt%In-2.8 wt%Ag/Ag couples, and minor Ag addition to Sn-20 wt%In solder increases the growth rates of the reaction phases.

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

CERN Multimedia

Université de Genève

2012-01-01

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

Growth of highly textured SnS on mica using an SnSe buffer layer

International Nuclear Information System (INIS)

Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C.

2014-01-01

We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer

Controlling the antibacterial activity of CuSn thin films by varying the contents of Sn

Energy Technology Data Exchange (ETDEWEB)

Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol, E-mail: yckang@pknu.ac.kr

2016-12-15

Highlights: • We deposit CuSn thin films on a Si substrate with various Cu/Sn ratio. • Antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time increased. • XPS was utilized to assign the chemical environment of CuSn thin films before and after antibacterial test. - Abstract: We investigated antibacterial activity of CuSn thin films against Gram positive Staphylococcus aureus (S. aureus). CuSn thin films with different Cu to Sn ratios were deposited on Si(100) by radio frequency (RF) magnetron sputtering method using Cu and Sn metal anodes. The film thickness was fixed at 200 nm by varying the sputtering time and RF power on the metal targets. The antibacterial test was conducted in various conditions such as different contact times and Cu to Sn ratios in the CuSn films. The antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time between the film and bacteria suspension increased execpt in the case of CuSn-83. The oxidation states of Cu and Sn and the chemical composition of CuSn thin films before and after the antibacterial test were investigated by X-ray photoelectron spectroscopy (XPS). When the contact time was fixed, the Cu species was further oxidized as the RF power on Cu target increased. The intensity of Sn 3d decreased with increasing Cu ratio. When the sample was fixed, the peak intensity of Sn 3d decreased as the contact time increased due to the permeation of Sn into the cell.

Recovery of the coral Montastrea annularis in the Florida Keys after the 1987 Caribbean ``bleaching event''

Science.gov (United States)

Fitt, William K.; Spero, Howard J.; Halas, John; White, Michael W.; Porter, James W.

1993-07-01

Many reef-building corals and other cnidarians lost photosynthetic pigments and symbiotic algae (zooxanthellae) during the coral bleaching event in the Caribbean in 1987. The Florida Reef Tract included some of the first documented cases, with widespread bleaching of the massive coral Montastrea annularis beginning in late August. Phototransects at Carysfort Reef showed discoloration of >90% of colonies of this species in March 1988 compared to 0% in July 1986; however no mortality was observed between 1986 and 1988. Samples of corals collected in February and June 1988 had zooxanthellae densities ranging from 0.1 in the most lightly colored corals, to 1.6x106 cells/cm2 in the darker corals. Minimum densities increased to 0.5x106 cells/cm2 by August 1989. Chlorophyll- a content of zooxanthellae and zooxanthellar mitotic indices were significantly higher in corals with lower densities of zooxanthellae, suggesting that zooxanthellar at low densities may be more nutrientsufficient than those in unbleached corals. Ash-free dry weight of coral tissue was positively correlated with zooxanthellae density at all sample times and was significantly lower in June 1988 compared to August 1989. Proteins and lipids per cm2 were significantly higher in August 1989 than in February or June, 1988. Although recovery of zooxanthellae density and coral pigmentation to normal levels may occur in less than one year, regrowth of tissue biomass and energy stores lost during the period of low symbiont densities may take significantly longer.

A review and prospects for Nb3Sn superconductor development

Science.gov (United States)

Xu, Xingchen

2017-09-01

Nb3Sn superconductors have significant applications in constructing high-field (>10 T) magnets. This article briefly reviews development of Nb3Sn superconductor and proposes prospects for further improvement. It is shown that significant improvement of critical current density (J c) is needed for future accelerator magnets. After a brief review of the development of Nb3Sn superconductors, the factors controlling J c are summarized and correlated with their microstructure and chemistry. The non-matrix J c of Nb3Sn conductors is mainly determined by three factors: the fraction of current-carrying Nb3Sn phase in the non-matrix area, the upper critical field B c2, and the flux line pinning capacity. Then prospects to improve the three factors are discussed respectively. An analytic model was developed to show how the ratios of precursors determine the phase fractions after heat treatment, based on which it is predicted that the limit of current-carrying Nb3Sn fraction in subelements is ∼65%. Then, since B c2 is largely determined by the Nb3Sn stoichiometry, a thermodynamic/kinetic theory is presented to show what essentially determines the Sn content of Nb3Sn conductors. This theory explains the influences of Sn sources and Ti addition on stoichiometry and growth rate of Nb3Sn layers. Next, to improve flux pinning, previous efforts in this community to introduce additional pinning centers to Nb3Sn wires are reviewed, and an internal oxidation technique is described. Finally, prospects for further improvement of non-matrix J c of Nb3Sn conductors are discussed, and it is seen that the only opportunity for further significantly improving J c lies in improving flux pinning.

LED Die-Bonded on the Ag/Cu Substrate by a Sn-BiZn-Sn Bonding System

Science.gov (United States)

Tang, Y. K.; Hsu, Y. C.; Lin, E. J.; Hu, Y. J.; Liu, C. Y.

2016-12-01

In this study, light emitting diode (LED) chips were die-bonded on a Ag/Cu substrate by a Sn-BixZn-Sn bonding system. A high die-bonding strength is successfully achieved by using a Sn-BixZn-Sn ternary system. At the bonding interface, there is observed a Bi-segregation phenomenon. This Bi-segregation phenomenon solves the problems of the brittle layer-type Bi at the joint interface. Our shear test results show that the bonding interface with Bi-segregation enhances the shear strength of the LED die-bonding joints. The Bi-0.3Zn and Bi-0.5Zn die-bonding cases have the best shear strength among all die-bonding systems. In addition, we investigate the atomic depth profile of the deposited Bi-xZn layer by evaporating Bi-xZn E-gun alloy sources. The initial Zn content of the deposited Bi-Zn alloy layers are much higher than the average Zn content in the deposited Bi-Zn layers.

Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

Science.gov (United States)

Takahashi, Junichi; Nakahara, Sumio; Hisada, Shigeyoshi; Fujita, Takeyoshi

2004-10-01

It has reported that a waste of an electronics substrate including lead and its compound such as 63Sn-37Pb has polluted the environment with acid rain. For that environment problem the development of lead-free solder alloys has been promoted in order to find out the substitute for Sn-Pb solders in the United States, Europe, and Japan. In a present electronics industry, typical alloys have narrowed down to Sn-Ag-Cu and Sn-Zn lead-free solder. In this study, solderability of Pb-free solder that are Sn-Ag-Cu and Sn-Zn-Bi alloy was studied on soldering using YAG (yttrium aluminum garnet) laser and diode laser. Experiments were peformed in order to determine the range of soldering parameters for obtaining an appropriate wettability based on a visual inspection. Joining strength of surface mounting chip components soldered on PCB (printed circuit board) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics of eutectic Sn-Pb alloy and under different power density were examined. As a result, solderability of Sn-Ag-Cu (Pb-free) solder paste are equivalent to that of coventional Sn-Pb solder paste, and are superior to that of Sn-Zn-Bi solder paste in the laser soldering method.

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

International Nuclear Information System (INIS)

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

1981-01-01

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

Risoe annual report 1987

International Nuclear Information System (INIS)

1988-06-01

An explanation of Risoe National Laboratory's function within the Danish research system is followed by brief accounts of research activities at Risoe during 1987. Energy resources, technology and policy are discussed, the annual accounts are presented, a guide to the National Laboratory and a list of its publications are given. Some of the research activities that took place in 1987 described in more detail are within the fields of chemistry and the environment, superconductivity, new aspects of powdery mildew, polymers and robotics. (AB)

Annealing of RF-magnetron sputtered SnS{sub 2} precursors as a new route for single phase SnS thin films

Energy Technology Data Exchange (ETDEWEB)

Sousa, M.G., E-mail: martasousa@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Cunha, A.F. da, E-mail: antonio.cunha@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Fernandes, P.A., E-mail: pafernandes@ua.pt [AIN, I3N and Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Física, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida 431, 4200-072 Porto (Portugal)

2014-04-01

Tin sulphide thin films have been grown on soda-lime glass substrates through the annealing of RF-magnetron sputtered SnS{sub 2} precursors. Three different approaches to the annealing were compared and the resulting films thoroughly studied. One series of precursors was annealed in a tubular furnace directly exposed to a flux of sulphur vapour plus forming gas, N{sub 2} + 5%H{sub 2}, and at a constant pressure of 500 mbar. The other two series of identical precursors were annealed in the same furnace but inside a graphite box with and without elemental sulphur evaporation again in the presence of N{sub 2} + 5%H{sub 2} and at the same pressure as for the sulphur flux experiments. Different maximum annealing temperatures for each set of samples, in the range of 300–570 °C, were tested to study their effects on the properties of the final films. The resulting phases were structurally investigated by X-Ray Diffraction (XRD) and Raman spectroscopy. Annealing of SnS{sub 2} precursors in sulphur flux produced films where SnS{sub 2} was dominant for temperatures up to 480 °C. Increasing the temperature to 530 °C and 570 °C led to films where the dominant phase became Sn{sub 2}S{sub 3}. Annealing of SnS{sub 2} precursors in a graphite box with sulphur vapour at temperatures in the range between 300 °C and 480 °C the films are multi-phase, containing Sn{sub 2}S{sub 3}, SnS{sub 2} and SnS. For high annealing temperatures of 530 °C and 570 °C the films have SnS as the dominant phase. Annealing of SnS{sub 2} precursors in a graphite box without sulphur vapour at 300 °C and 360 °C the films are essentially amorphous, at 420 °C SnS{sub 2} is the dominant phase. For temperatures of 480 °C and 530 °C SnS is the dominant phase but also same residual SnS{sub 2} and Sn{sub 2}S{sub 3} phases are observed. For annealing at 570 °C, according to the XRD results the films appear to be single phase SnS. The composition was studied using energy dispersive spectroscopy being

RED AND DEAD: THE PROGENITOR OF SN 2012aw IN M95

International Nuclear Information System (INIS)

Fraser, M.; Maund, J. R.; Smartt, S. J.; Inserra, C.; Kotak, R.; Reilly, E.; Botticella, M.-T.; Dall'Ora, M.; Tomasella, L.; Benetti, S.; Ciroi, S.; Ochner, P.; Pastorello, A.; Valenti, S.; Eldridge, J. J.; Ergon, M.; Sollerman, J.; Taddia, F.; Mattila, S.; Stephens, A.

2012-01-01

Core-collapse supernovae (SNe) are the spectacular finale to massive stellar evolution. In this Letter, we identify a progenitor for the nearby core-collapse SN 2012aw in both ground-based near-infrared and space-based optical pre-explosion imaging. The SN itself appears to be a normal Type II Plateau event, reaching a bolometric luminosity of 10 42 erg s –1 and photospheric velocities of ∼11,000 km s –1 from the position of the Hβ P-Cygni minimum in the early SN spectra. We use an adaptive optics image to show that the SN is coincident to within 27 mas with a faint, red source in pre-explosion HST+WFPC2, VLT+ISAAC, and NTT+SOFI images. The source has magnitudes F555W = 26.70 ± 0.06, F814W = 23.39 ± 0.02, J = 21.1 ± 0.2, K = 19.1 ± 0.4, which, when compared to a grid of stellar models, best matches a red supergiant. Interestingly, the spectral energy distribution of the progenitor also implies an extinction of A V > 1.2 mag, whereas the SN itself does not appear to be significantly extinguished. We interpret this as evidence for the destruction of dust in the SN explosion. The progenitor candidate has a luminosity between 5.0 and 5.6 log L/L ☉ , corresponding to a zero-age main-sequence mass between 14 and 26 M ☉ (depending on A V ), which would make this one of the most massive progenitors found for a core-collapse SN to date.