The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n_TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 ...(EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam pro↓le and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash.
We point out that hard exclusive production of tensor mesons
f
2(1270) with helicity
λ=±2 is dominated by the gluon component in the meson wave function and can be used to determine gluon admixture ...in tensor mesons in a theoretically clean manner. We present a detailed analysis of the tensor meson distribution amplitudes and calculate the transition form factor
γ+γ
∗→f
2(1270)
for one real and one virtual photon.
Online NobleChem is a technology to mitigate stress corrosion cracking in reactor internals and recirculation pipes of boiling water reactors (BWRs). For a more efficient reduction of the ...electrochemical corrosion potential (ECP) under hydrogen water chemistry conditions, noble metals (e.g. Pt) are injected into the feed water during power operation. They are claimed to deposit as very fine metallic particles on all water wetted surfaces and to stay electrocatalytic over long periods. To study the deposition and (re)distribution behaviour of Pt, a sophisticated high temperature water loop has been constructed, in which specimens can be exposed to simulated BWR water and Pt can be deposited in situ. The specimens are analysed by laser ablation-inductively coupled plasma-mass spectrometry and electron microscopy after the experiments. Results from two experiments with different Pt injection rates but similar total Pt amounts revealed a faster and more pronounced reduction of the ECP and slightly larger average Pt particle size using the higher Pt injection rate. A longer preoxidation of the specimens seems to increase the average Pt concentration on the specimen surface.
Rifalazil is a new antibiotic structurally related to rifampin but devoid of the metabolic liabilities typically associated with the rifamycin class of antibiotics. A randomized, 3‐way crossover ...study in healthy male volunteers (n = 12) investigated the safety and pharmacokinetics of a single 25‐mg oral rifalazil dose administered under a standard breakfast containing fat as 30% of calories, a high‐fat breakfast containing fat as 60% of calories, and an overnight fast of 10 hours with a 21‐ to 28‐day washout between doses. Systemic exposure to rifalazil based on Cmax, AUC0‐Tlast, and AUC0‐∞ was increased progressively as the fat content of the test breakfast was increased from 30% to 60% compared with fasting. The confidence intervals for both fat‐containing breakfasts are outside the limits of 80% to 125% allowed for food effect bioequivalence based on Cmax, AUC0‐Tlast, and AUC0‐∞. This food effect may be a result of increased fractional absorption with increasing dietary fat content. Another striking finding was the large reduction of the pharmacokinetic intersubject variability after rifalazil administration with food. Rifalazil was safe and well tolerated under fed and fasted conditions.
Monte Carlo (MC) simulations are an essential tool to determine fundamental features of a neutron beam, such as the neutron flux or the γ-ray background, that sometimes can not be measured or at ...least not in every position or energy range. Until recently, the most widely used MC codes in this field had been MCNPX and FLUKA. However, the Geant4 toolkit has also become a competitive code for the transport of neutrons after the development of the native Geant4 format for neutron data libraries, G4NDL. In this context, we present the Geant4 simulations of the neutron spallation target of the n_TOF facility at CERN, done with version 10.1.1 of the toolkit. The first goal was the validation of the intra-nuclear cascade models implemented in the code using, as benchmark, the characteristics of the neutron beam measured at the first experimental area (EAR1), especially the neutron flux and energy distribution, and the time distribution of neutrons of equal kinetic energy, the so-called Resolution Function. The second goal was the development of a Monte Carlo tool aimed to provide useful calculations for both the analysis and planning of the upcoming measurements at the new experimental area (EAR2) of the facility.
The amplitude of the deeply virtual Compton scattering off nucleon is computed to the twist-3 accuracy in the Wandzura–Wilczek (WW) approximation. The result is presented in the form which can be ...easily used for analysis of DVCS observables.
We computed the twist-4 part of the photon spin-flip amplitude in deeply virtual Compton scattering on a nucleon in the Wandzura–Wilczek approximation. We found a factorizable contribution, which ...arises from photon scattering on quarks with non-zero angular momentum along the collision axis. As the genuine twist-2 amplitude arises at the NLO, for moderate virtualities of the hard photon, \(Q^2 \le 10\) GeV\(^2\), a kinematical twist-4 correction can give a numerically important contribution to the photon helicity-flip amplitude.
The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such ...as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n_TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n_TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented.
Using the available cross-section and polarization data for elastic electron-proton scattering, we provide an extraction of the two-photon exchange amplitudes at a common value of four-momentum ...transfer, around
Q
2
= 2.5 GeV^2. This analysis also predicts the
e
+
p
/
e
-
p
elastic-scattering cross-section ratio, which will be measured by forthcoming experiments.
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