Search results for "Neutron"
showing 10 items of 2330 documents
Lifetime measurement of neutron-rich even-even molybdenum isotopes
2017
D. Ralet et al. -- 11 pags., 10 figs., 3 tabs.
Target Cooling Options for Neutron Sources at High Power Densities
2014
Abstract Compact neutron sources in many cases beat large ones when it comes to power density; thus, many issues concerning cooling are shared, and each party can learn a lot from the other facilities. Starting from accrued experience with water cooling at moderate power densities in SINQ over the last 15 years, a brief overview will be attempted showing the relevant parameters and specific approaches at several existing and planned neutron (spallation) sources. Extensions from the established ground of cooling with water will be sketched in two directions. An outline of an experiment planned for freshly determining in a representative geometry the hard limit for water cooling, i.e. full bo…
Applied neutron tomography in modern archaelogy
2007
The use of neutron tomography for archaeometric purposes is quite a new technique. The property of neutron to transmit easily large, dense samples is of great importance in modern archaeology. The three-dimensional visualisation of the inner structure of samples of archaeological interest helps to make suggestions about the technological process of manufacturing or reveals information about the origins of delivering of noble materials used in ancient masterpieces. Another application field in modern archaeology is the non-destructive inspection of the quality of specimen conservation where the neutron tomography allows visualization of impregnation solutions in wood or metal matrices. The h…
Protein/Hydration Water Dynamics in Hard Confinement: Dielectric Relaxations and Picoseconds Hydrogen Fluctuations
2011
In this review we report on some experimental studies on the dynamics of Myoglobin in a confined geometry, obtained by encapsulation in a porous silica matrix, at low hydration levels. After formation through the solgel method, the samples were left aging/drying in order to reach a condition where only one or two water layers surround the proteins. In order to put in evidence the specific effect of confinement in the silica host, we compared this system with another one (i.e. hydrated powder) where proteins are confined by other proteins. Using elastic neutron scattering we investigate the temperature dependence of the mean square displacements of non-exchangeable hydrogen atoms of sol-gel …
The pion single-event latch-up cross-section enhancement : mechanisms and consequences for accelerator hardness assurance
2021
Pions make up a large part of the hadronic environment typical of accelerator mixed-fields. Characterizing device cross-sections against pions is usually disregarded in favour of tests with protons, whose single-event latch-up cross-section is, nonetheless, experimentally found to be lower than that of pions for all energies below 250 MeV. While Monte-Carlo simulations are capable of reproducing such behavior, the reason of the observed pion cross-section enhancement can only be explained by a deeper analysis of the underlying mechanisms dominating proton-silicon and pion-silicon reactions. The mechanisms dominating the single-event latchup response are found to vary with the energy under c…
Physics reach of the XENON1T dark matter experiment.
2016
The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in $1$ tonne fiducial volume and ($1$, $12$) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is $(1.80 \pm 0.15) \cdot 10^{-4}$ ($\rm{kg} \cdot day \cdot keV)^{-1}$, mainly due to the decay of $^{222}\rm{Rn}$ daughters inside the xenon target. The nu…
Measurement of θ13 in Double Chooz using neutron captures on hydrogen with novel background rejection techniques
2016
The Double Chooz collaboration presents a measurement of the neutrino mixing angle θ[subscript 13] using reactor [bar over ν[subscript e]] observed via the inverse beta decay reaction in which the neutron is captured on hydrogen. This measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respec…
Time-domain effective-one-body gravitational waveforms for coalescing compact binaries with nonprecessing spins, tides and self-spin effects
2018
We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spin-aligned) and tidally interacting compact binaries.Spin-orbit and spin-spin effects are blended together by making use of the concept of centrifugal EOB radius. The point-mass sector through merger and ringdown is informed by numerical relativity (NR) simulations of binary black holes (BBH) computed with the SpEC and BAM codes. An improved, NR-based phenomenological description of the postmerger waveform is developed.The tidal sector of TEOBResumS describes the dynamics of neutron star binaries up to merger and incorporates a resummed attractive potential motivated by recent advances in the post-Newt…
Liquid structure of a choline chloride-water natural deep eutectic solvent: A molecular dynamics characterization
2021
The liquid structure of a representative of the first water-in-salt (WiS) Natural Deep Eutectic Solvents (NADES), hereinafter indicated as aquoline, a mixture of choline chloride (ChCl) and water with molar ratio 1:3.33, is ex- plored at ambient conditions. Using Molecular Dynamics (MD) simulation tools, we extract structural informa- tion at atomistic level on the nature of inter-correlations between the different moieties. Despite being a very fluid liquid, with much lower viscosity than other common ChCl-based DES, aquoline turns out to be very struc- tured. Computed X-ray and neutron weighted scattering patterns (the latter also on selectively deuterated mix- tures) highlight the existe…
High Current Proton and Deuteron Beams for Accelerators and Neutron Generators
2014
This paper presents the latest results of high current proton and deuteron beam production at SMIS 37 facility at the Institute of Applied Physics (IAP RAS). In this experimental setup the plasma is created and the electrons are heated by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap fulfilling the ECR condition. High microwave power and frequency allow sustaining higher density hydrogen plasma (ne up to 2·1013 cm-3) in comparison to conventional ECRIS’s or microwave sources. The low ion temperature, on the order of a few eV, is beneficial to produce proton beams with low emittance. Latest experiments at SMIS 37 were performed using a single-aperture two-electr…