Eingereichte Dokumente

We present a versatile optical setup for high-resolution neutron imaging with an adaptable field of view and magnification that can resolve individual neutron absorption events with an image intensifier and a CMOS camera. Its imaging performance is characterized by evaluating the resolution limits of the individual optical components and resulting design aspects are discussed. [...]

We present a concept for an indirect geometry crystal time-of-flight spectrometer, whichwe propose for a source similar to the FRM-II reactor in Garching. Recently, crystal analyzerspectrometers at modern spallation sources have been proposed and are under construction. [...]

A detector based on Timepix3 readout of image- intensified light from a scintillator has been applied and tested in neutron reflectometry for the first time. The detector has been characterized at a monochromatic beamline with λ = 4.2A ̊ at HFIR reactor at ORNL. [...]

A new type of position-sensitive detectors is gaining attention in the neutron community. They are scintillator based detectors that detect the scintillation light on an individual photon basis via an image intensifier and a fast image sensor. [...]

Taillefer is a versatile Python tool for carrying out Sensitivity Analysis (SA) and uncertainty propagation (UP) studies based on Monte Carlo sampling. Developed with the primary goal of investigating sensitivities and uncertainties of steady-state thermal-hydraulic (SSTH) safety parameters of the high-performance research reactors Forschungs Neutronenquelle Heinz Maier-Leibnitz (FRM II) in Garching, Germany, and the Réacteur à Haut Flux (RHF) in Grenoble, France, it can also be used for a large variety of other modeling problems.The work presented here aims to explain the underlying mathematical background of SA and UP studies with Taillefer and to show some steps to verify these routines. [...]

Nanopowders of the magnetite–maghemite series have been synthesized by coprecipitation from aqueous solutions and by the sol–gel method, and a comparative comprehensive study of their structure has been carried out using X-ray diffraction analysis, scanning electron microscopy, low-temperature nitrogen adsorption, and small-angle polarized neutron scattering. It has been established that the resulting iron oxide nanopowders are porous systems that, depending on the synthesis method, have a one-level, two-level (for powders obtained by aqueous synthesis), or three-level (for powders obtained by the sol–gel method) hierarchical structure organization with different scales and different types of aggregation for each of the structural levels, and the characteristic size for the larger level in both cases is >45 nm [...]

Prompt Gamma Activation Analysis (PGAA) is apowerful non-destructive assay for toxic elementssuch as Cd, Hg or Pb in radioactive packages [1,2]. Inparticular, for long-lived actinides, e.g [...]