![]() ![]() In the paper, the scientists assess the current and projected readiness of various antineutrino-based monitoring technologies. The study was initiated as part of an ongoing research effort led by LLNL and supported by the National Nuclear Security Administration’s (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN). The article is co-authored by two LLNL physicists - Adam Bernstein and Nathaniel Bowden - along with four university colleagues: Bethany Goldblum of the University of California, Berkeley, Patrick Huber of Virginia Tech, Igor Jovanovic of the University of Michigan and John Mattingly of North Carolina State University. Reviews of Modern Physics has published an article that describes the potential uses and limitations of antineutrino detectors for nuclear security applications related to reactor, spent fuel and explosion monitoring. It also could help with verification of existing and planned treaties that seek to limit nuclear weapons materials production worldwide. Such a breakthrough would allow them to warn international authorities about the illicit production of plutonium, a key material for nuclear weapons. With advances by scientists at Lawrence Livermore National Laboratory (LLNL) and other institutions, researchers are moving closer to the day when they can deploy technology to remotely monitor these subatomic particles from nuclear power plants at long distances. Antineutrinos are emitted in vast quantities by nuclear reactors, and since the 1970s, scientists have considered turning antineutrino detection into a tool for nuclear security. Nuclear, Chemical and Isotopic Science and TechnologyĪ tiny, invisible particle could offer help for a big problem - the threat of nuclear proliferation.įor more than six decades, scientists have been developing instruments for fundamental physics that can detect antineutrinos, particles that have no electric charge, almost no mass and easily pass through matter.Lasers and Optical Science and Technology. ![]() We briefly speculate on the possibility that hadronic cosmic rays originate from the subset of supernovae that collapse to form relativistic outflows and GRBs. This is sufficient to account for UHECR generation by GRBs. The luminosity of sources of GRBs and relativistic outflows in L* galaxies such as the Milky Way is at the level of ~10 40☑ ergs s -1. Stronger neutrino fluxes and neutron decay halos can be produced by external shocks in clumpy external media and in scenarios involving internal shock scenarios, so detection of neutrinos associated with smooth profile GRBs could rule out an impulsive GRB central engine and an external shock model for the prompt phase. The decay halo from a single GRB can persist for ≳0.1-1 Myr. The peak luminosity emitted by the diffuse β electron halo from a single GRB with ≳2 × 10 53 ergs isotropic energy release is ~10 35 ergs s -1, with a potentially much brighter signal from the neutron decay protons. Galaxies with GRB activity should be surrounded by radiation halos of ~100 kpc extent from the outflowing neutrons, consisting of a nonthermal optical/X-ray synchrotron component and a high-energy gamma-ray component from Compton-scattered microwave background radiation. The radiative characteristics of the neutron β-decay electrons from the GRB "neutron bomb" are solved in a special case. GRBs provide an intense flux of high-energy neutrons, with neutron production efficiencies exceeding ~1% of the total energy release. The diffuse high-energy GRB neutrino background and the distribution of high-energy GRB neutrino events are calculated for specific parameter sets, and a scaling relation for the photomeson production efficiency in surroundings with different densities is derived. Decay characteristics and radiative efficiencies of the neutral particles that escape from the blast wave are calculated. The evolving synchrotron radiation spectrum in GRB blast waves provides target photons for the photomeson production of neutrinos and neutrons. Implications of this assumption are then derived for the external shock model of GRBs. The hypothesis that ultrahigh-energy (≳10 19 eV) cosmic rays (UHECRs) are accelerated by gamma-ray burst (GRB) blast waves is assumed to be correct. ![]()
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