A5103277237- Particle Detector Development and Performance
- Microstructure and mechanical properties
- CCD and CMOS Imaging Sensors
- Metal and Thin Film Mechanics
- High-pressure geophysics and materials
- Thin-Film Transistor Technologies
- Boron and Carbon Nanomaterials Research
- Astro and Planetary Science
- Advanced Semiconductor Detectors and Materials
- Microstructure and Mechanical Properties of Steels
- Advancements in Semiconductor Devices and Circuit Design
- Radiation Detection and Scintillator Technologies
- Medical Imaging Techniques and Applications
- Nuclear Physics and Applications
- High Temperature Alloys and Creep
- Advanced X-ray and CT Imaging
- Electron and X-Ray Spectroscopy Techniques
- Pulsars and Gravitational Waves Research
- Nonlocal and gradient elasticity in micro/nano structures
- High-Velocity Impact and Material Behavior
- Advanced Thermodynamics and Statistical Mechanics
- Advanced ceramic materials synthesis
- Intermetallics and Advanced Alloy Properties
- Advanced Optical Sensing Technologies
- Thermal properties of materials
Brno University of Technology
2011-2023
Central European Institute of Technology
2015-2023
Czech Academy of Sciences, Institute of Physics of Materials
2015-2019
Central European Institute of Technology – Masaryk University
2015-2016
Masaryk University
2015
Brookhaven National Laboratory
2000-2010
European Organization for Nuclear Research
1976
Karlsruhe Institute of Technology
1974
Scuola Normale Superiore
1973
A statistical model for atoms in a very strong magnetic field (${10}^{12}$-${10}^{14}$ G) may be built, starting from the assumption that Coulomb motion of atomic electrons is adiabatically slow with respect to their motion. Within this framework, binding energies and radii, as well ionization singly doubly ionized atoms, are computed numbers $5\ensuremath{\le}Z\ensuremath{\le}100$ Thomas-Fermi case, $5\ensuremath{\le}Z\ensuremath{\le}70$ Thomas-Fermi-Dirac case. Possible astrophysical...
The drift time measurement and the charge division can be performed simultaneously on same electrode (resistive anode) without affecting accuracy of either measurement. It is shown that for shortest there an optimum value anode wire resistance. signal requirement a position uncertainty σ≤ 0.5% length only 2.7 x 106 electron charges. chamber operated in linear mode with negligible space effects, so it also used ΔE/ΔX measurements. A simple preamplifier optimized both measurements using...
A low-noise, fast, charge-sensitive preamplifier was designed on high-resistivity, detector-grade silicon. It is built at the surface of a fully depleted region n-type silicon, allowing it to be placed very close detector anode. The uses classical input-cascode configuration with capacitor and high-value resistor in feedback loop. output stage can drive load up 20 pF. power dissipation 13 mW. amplifying elements are single-sided gate JFETs developed for this application. Preamplifiers...
Four different models (corresponding to loading conditions) of first principles tensile tests are employed determine cohesion and strength several interfaces, namely coherent interfaces two fcc metals (Ni/Ag Ni/Cu) symmetrical tilted Σ5(210) grain boundary in nickel (clean as well sulfur-decorated). The purpose this study is compare the selected critically discuss their advantages limitations. Particular attention paid differences predictions, ability identify weakest link studied system...
The concept of X-ray active matrix pixel sensor (XAMPS) is introduced. XAMPSs are direct illumination, position sensitive detectors with the possibility containing 1000 000 pixels. They count number diffracted X-rays in each by measuring total charge released converted body sensor. Readout accomplished a relatively small channels equal to square root estimated readout time can be about 1 ms. Noise electronics so low that practically no additional fluctuations incident per added and,...
The response of three covalent crystals with a diamond lattice (C, Si and Ge) to uniaxial special triaxial (generally nonhydrostatic) loading is calculated from first principles. deformations are described in terms variations bond lengths angles. stress state simulated as superposition axial tension or compression transverse (both tensile compressive) biaxial stresses. stresses considered be adjustable parameters the theoretical strengths along 〈100〉, 〈110〉, 〈111〉 crystallographic directions...
Two fcc crystals, Ni and Ir, are subjected to simulated isotropic uniaxial tension along the direction. Their structural stability is assessed by analyzing phonon spectra that calculated from first principles for different values of strain. A relevant analysis elastic conditions also performed. Predicted instabilities correspond well those associated with soft phonons vanishing wavevectors. Although most previous studies predicted in crystals macroscopic (elastic) instabilities, we found...
X-ray Active Matrix Pixel Sensors (XAMPS) were designed and fabricated at Brookhaven National Laboratory. Devices based on J-FET technology produced 100 mm high-resistivity silicon, typically 400 μm-thick. The prototypes are square matrices with n rows columns = 16, 32, 64, 128, 256, 512. Each pixel of the matrix is 90 × μm2 contains a JFET switch to control charge readout. XAMPS position sensitive ionization detector made high resistivity silicon. It consists array integrated switches....
Lattice dynamics and stability of four fcc crystals (Al, Ir, Pt Au) under isotropic (hydrostatic) tensile loading are studied from first principles using the linear response method harmonic approximation. The results reveal that, contrary to former expectations, strengths all limited by instabilities related soft phonons with finite or vanishing wavevectors. critical strains associated such remarkably lower than those volumetric instability. On other hand, corresponding reduction strength is...
Abstract Principles and advantages of a new concept based on the ab initio aided strain gradient elasticity theory are shown in comparison with classical Barenblatt cohesive model. The method is applied to theoretical prediction critical energy release rate crack tip opening displacement at instability nanopanels made germanium molybdenum crystals. necessary length scale parameter l 1 determined for by best fits computed screw dislocation displacements phonon dispersions. Values rates...
Controlled-drift detectors are fully depleted silicon for X-ray imaging that combine good position resolution with very fast frame readout. The basic feature of the controlled-drift detector is transport charge packets stored in each pixel column to output electrode by means a uniform drift field. time packet identifies incidence. Images an source obtained up 100-kHz rate presented and discussed. achievable energy as function operating temperature analyzed.
In superstrong magnetic fields, of the order magnitude supposed to exist in neutron stars, atoms are characterized by enormous binding energies, small dimensions, and a very elongated distribution charge having approximately shape concave-ended cylinder. Their ionization energies have monotonic dependence on atomic number, tend level off at high $Z$; peculiar favors formation negative ions. When field increases, nuclei align share their electrons, forming linear molecules. These features...
Two methods to produce a thin-junction sensor are reported here. The first method consists of regular boron implantation with energies 2 keV (dose 1 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> /cm xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and 5 xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> into silicon directly, (1 X ), 45 Si through thin oxide layer (500 A 1000 respectively) form junction. An aluminum was...
Stability of ideal bcc tungsten crystal under triaxial tensile loading was explored from first principles using an analysis both elastic and dynamic stability. The stress state considered as a superposition axial biaxial transverse stresses. region attainable stresses which delimited the computed maxima marginally reduced by occurrence soft phonons in lattice. While, purely hydrostatic tension, predicted stable up to 48 GPa, greater magnitude differential value mean (hydrostatic) associated...
This paper presents a method for the measurement of doping fluctuations in high resistivity silicon wafers. Spatial are derived from knowledge electrostatic potential completely depleted semiconductor bulk. The variations indirectly measured through analysis trajectories majority carriers drifting within material. Regions semiconductors up to full wafer can be investigated. An example mapping along parallel lines floating zone 2 K Ω cm over an area 0.4×0.8 cm2 is presented. relative...