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Optically active spin defects in wide bandgap semiconductors serve as a local sensor of multiple degrees of freedom in a variety of hard and soft condensed matter systems. Taking advantage of the recent progress on quantum sensing using van der Waals (vdW) quantum materials, here we report direct measurements of spin waves excited in magnetic insulator Y3Fe5O12 (YIG) by boron vacancy [Formula: see text] spin defects contained in few-layer-thick hexagonal boron nitride nanoflakes. We show that the ferromagnetic resonance and parametric spin excitations can be effectively detected by [Formula: see text] spin defects under various experimental conditions through optically detected magnetic resonance measurements. The off-resonant dipole interaction between YIG magnons and [Formula: see text] spin defects is mediated by multi-magnon scattering processes, which may find relevant applications in a range of emerging quantum sensing, computing, and metrology technologies. Our results also highlight the opportunities offered by quantum spin defects in layered two-dimensional vdW materials for investigating local spin dynamic behaviors in magnetic solid-state matters.

Abstract: The response of a LaCl3:Ce detector has been found to depend upon the hydrogen content of bulk samples in prompt gamma analysis using 14MeV neutron inelastic scattering. The moderation of 14MeV neutrons from hydrogen in the bulk sample produces thermal neutrons around the sample which ultimately excite chlorine capture gamma rays in the LaCl3:Ce detector material. Interference of 6.11MeV chlorine gamma rays from the detector itself with 6.13MeV oxygen gamma rays from the bulk samples makes the intensity of the 6.13MeV oxygen gamma ray peak relatively insensitive to variations in oxygen concentration. The strong dependence of the 1.95MeV doublet chlorine gamma ray yield on hydrogen content of the bulk samples confirms fast neutron moderation from hydrogen in the bulk samples as a major source of production of thermal neutrons and chlorine gamma rays in the LaCl3:Ce detector material. Despite their poor oxygen detection capabilities, these detectors have nonetheless excellent detection capabilities for hydrogen and carbon in benzene, butyl alcohol, propanol, propanic acid, and formic acid bulk samples using 14MeV neutron inelastic scattering. [Copyright &y& Elsevier]

Abstract: Hydrogen, carbon and oxygen concentrations were measured in caffeine, urea, ammonium acetate and melamine bulk samples via 14MeV neutron inelastic scattering using a LaBr3:Ce detector. The samples tested herein represent drugs, explosives and benign materials, respectively. Despite its intrinsic activity, the LaBr3:Ce detector performed well in detecting the hydrogen, carbon and oxygen elements. Because 5.1MeV nitrogen gamma rays interfere with silicon and calcium prompt gamma rays from the room background, the nitrogen peak was not detected in the samples. An excellent agreement was observed between the experimental and theoretical yields of 2.22, 4.43 and 6.13MeV gamma rays from the analyzed samples as a function of H, C and O concentrations, respectively. Within statistical errors, the minimum detectable concentration (MDC) of hydrogen, carbon and oxygen elements in the tested materials were consistent with previously reported MDC values for these elements measured in hydrocarbon samples. [Copyright &y& Elsevier]

Optically active spin defects in wide bandgap semiconductors serve as a local sensor of multiple degrees of freedom in a variety of "hard" and "soft" condensed matter systems. Taking advantage of the recent progress on quantum sensing using van der Waals (vdW) quantum materials, here we report direct measurements of spin waves excited in magnetic insulator Y3Fe5O12 (YIG) by boron vacancy VB- spin defects contained in few-layer-thick hexagonal boron nitride nanoflakes. We show that the ferromagnetic resonance and parametric spin excitations can be effectively detected by VB- spin defects under various experimental conditions through optically detected magnetic resonance measurements. The off-resonant dipole interaction between YIG magnons and VB- spin defects is mediated by multi-magnon scattering processes, which may find relevant applications in a range of emerging quantum sensing, computing, and metrology technologies. Our results also highlight the opportunities offered by quantum spin defects in layered two-dimensional vdW materials for investigating local spin dynamic behaviors in magnetic solid-state matters. [ABSTRACT FROM AUTHOR]

Abstract: The yield of 478 and 558keV gamma-rays have been measured from water samples containing 0.031–0.500wt. % boron and 0.0625–0.500wt. % cadmium, respectively, using a cylindrical 76mm×76mm (height×diameter) LaCl3:Ce detector. Inspite of interferences between detector-associated and the sample-associated prompt gamma rays, the LaCl3:Ce detector has excellent resolution for the low energy prompt gamma-rays. An excellent agreement has been observed between the experimental and calculated yield of boron and cadmium prompt gamma ray from water samples. [Copyright &y& Elsevier]

Abstract: The response of a cylindrical 3in.×3in. (height×diameter) LaBr3:Ce detector was measured for low energy prompt gamma-rays from boron and cadmium contaminated water samples using a newly designed portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. Prompt gamma-rays were measured from water samples contaminated with 0.031, 0.125, 0.250 and 0.5wt% boron and 0.0625, 0.125, 0.250 and 0.500wt% cadmium. The experimental yield of boron and cadmium prompt gamma-rays measured with the LaBr3:Ce detector based PGNAA setup were compared with the results of Monte Carlo calculations. An excellent agreement between the experimental and calculated yields of 478keV gamma-ray from boron and 558keV gamma-rays from cadmium from boron and cadmium contaminated water samples, indicate an excellent response of the LaBr3:Ce detector for the low energy prompt gamma-rays. [Copyright &y& Elsevier]