The PROSPECT physics program Ashenfelter, J; Balantekin, A B; Band, H R ...
Journal of physics. G, Nuclear and particle physics,
10/2016, Letnik:
43, Številka:
11
Journal Article
Recenzirano
Odprti dostop
The precision reactor oscillation and spectrum experiment, PROSPECT, is designed to make a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and probe eV-scale ...sterile neutrinos by searching for neutrino oscillations over a distance of several meters. PROSPECT is conceived as a 2-phase experiment utilizing segmented 6Li-doped liquid scintillator detectors for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT Phase I consists of a movable 3 ton antineutrino detector at distances of 7-12 m from the reactor core. It will probe the best-fit point of the e disappearance experiments at 4 in 1 year and the favored region of the sterile neutrino parameter space at > 3 in 3 years. With a second antineutrino detector at 15-19 m from the reactor, Phase II of PROSPECT can probe the entire allowed parameter space below 10 eV2 at 5 in 3 additional years. The measurement of the reactor antineutrino spectrum and the search for short-baseline oscillations with PROSPECT will test the origin of the spectral deviations observed in recent θ 13 experiments, search for sterile neutrinos, and conclusively address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly.
The PROSPECT reactor antineutrino experiment Ashenfelter, J.; Balantekin, A.B.; Baldenegro, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
922
Journal Article
Recenzirano
Odprti dostop
The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe ...eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented6Li-doped liquid scintillator detector for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT is a movable 4-ton antineutrino detector covering distances of 7m to 13m from the High Flux Isotope Reactor core. It will probe the best-fit point of the ν̄e disappearance experiments at 4σ in 1 year and the favored regions of the sterile neutrino parameter space at more than 3σ in 3 years. PROSPECT will test the origin of spectral deviations observed in recent θ13 experiments, search for sterile neutrinos, and address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly. This paper describes the design, construction, and commissioning of PROSPECT and reports first data characterizing the performance of the PROSPECT antineutrino detector.
Higher order Bessel functions are prevalent in physics and engineering and there exist different methods to evaluate them quickly and efficiently. Two of these methods are Miller's algorithm and the ...continued fractions algorithm. Miller's algorithm uses arbitrary starting values and normalization constants to evaluate Bessel functions. The continued fractions algorithm directly computes each value, keeping the error as small as possible. Both methods respect the stability of the Bessel function recurrence relations. Here we outline both methods and explain why the continued fractions algorithm is more efficient. The goal of this paper is both (1) to introduce the continued fractions algorithm to physics and engineering students and (2) to present a MATLAB GUI (Graphic User Interface) where this method has been used for computing the Semi-integer Bessel Functions and their zeros.
Funções de Bessel de ordem mais alta são recorrentes em física e nas engenharias, sendo que há diferentes métodos para calculá-las de maneira rápida e eficiente. Dois destes métodos são o algoritmo de Miller e o algoritmo de frações continuadas. O primeiro faz uso de valores iniciais e constantes de normalização arbitrários, enquanto o segundo o faz calculando cada valor diretamente, minimizando tanto quanto possível o erro. Ambos respeitam a estabilidade das relações de recorrência das funções de Bessel. Neste trabalho descrevemos ambos os métodos e explicamos a razão pela qual o algoritmo das frações continuadas é mais eficiente. O objetivo do artigo é (1) introduzir o algoritmo de frações continuadas para estudantes de física e das engenharias e (2) apresentar um GUI (Graphic User Interface) em Matlab no qual este método foi utilizado para calcular funções de Bessel semi-inteiras e seus zeros.
A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the ...PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron-gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified.
We determine the trajectories of vortex singularities that arise after a single vortex is broken by a discretely symmetric impulse in the context of Bose-Einstein condensates in a harmonic trap. The ...dynamics of these singularities are analyzed to determine the form of the imprinted motion. We find that the symmetry-breaking process introduces two effective forces: a repulsive harmonic force that causes the daughter trajectories to be ejected from the parent singularity, and a Magnus force that introduces a torque about the axis of symmetry. For the analytical non-interacting case we find that the parent singularity is reconstructed from the daughter singularities after one period of the trapping frequency. The interactions between singularities in the weakly interacting system do not allow the parent vortex to be reconstructed. Analytic trajectories were compared to the actual minima of the wavefunction, showing less 0.5% error for impulse strength of (v=0.00005). We show that these solutions are valid within the impulse regime for various impulse strengths using numerical integration of the Gross-Pitaevskii equation. We also show that the actual duration of the symmetry breaking potential does not significantly change the dynamics of the system as long as the strength is below (v=0.0005).
The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe ...eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented \(^6\)Li-doped liquid scintillator detector for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT is a movable 4-ton antineutrino detector covering distances of 7m to 13m from the High Flux Isotope Reactor core. It will probe the best-fit point of the \(\bar\nu_e\) disappearance experiments at 4\(\sigma\) in 1 year and the favored regions of the sterile neutrino parameter space at more than 3\(\sigma\) in 3 years. PROSPECT will test the origin of spectral deviations observed in recent \(\theta_{13}\) experiments, search for sterile neutrinos, and address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly. This paper describes the design, construction, and commissioning of PROSPECT and reports first data characterizing the performance of the PROSPECT antineutrino detector.
This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of \(^{235}\)U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor ...Oscillation and Spectrum Experiment, consists of a segmented 4 ton \(^6\)Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 meter water equivalent overburden. Data collected during 33 live-days of reactor operation at a nominal power of 85 MW yields a detection of 25461 \(\pm\) 283 (stat.) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5\(\sigma\) statistical significance within two hours of on-surface reactor-on data-taking. A reactor-model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the Reactor Antineutrino Anomaly at 2.2\(\sigma\) confidence level.
This paper describes the design and performance of a 50 liter, two-segment \(^{6}\)Li-loaded liquid scintillator detector that was designed and operated as prototype for the PROSPECT (Precision ...Reactor Oscillation and Spectrum) Experiment. The two-segment detector was constructed according to the design specifications of the experiment. It features low-mass optical separators, an integrated source and optical calibration system, and materials that are compatible with the \(^{6}\)Li-doped scintillator developed by PROSPECT. We demonstrate a high light collection of 850\(\pm\)20 PE/MeV, an energy resolution of \(\sigma\) = 4.0\(\pm\)0.2% at 1 MeV, and efficient pulse-shape discrimination of low \(dE/dx\) (electronic recoil) and high \(dE/dx\) (nuclear recoil) energy depositions. An effective scintillation attenuation length of 85\(\pm\)3 cm is measured in each segment. The 0.1% by mass concentration of \(^{6}\)Li in the scintillator results in a measured neutron capture time of \(\tau\) = 42.8\(\pm\)0.2 \(\mu s\). The long-term stability of the scintillator is also discussed. The detector response meets the criteria necessary for achieving the PROSPECT physics goals and demonstrates features that may find application in fast neutron detection.
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