S. Redford
A5026875463- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Advanced X-ray Imaging Techniques
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- X-ray Diffraction in Crystallography
- Advanced Electron Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- Electron and X-Ray Spectroscopy Techniques
- Enzyme Structure and Function
- Nuclear Physics and Applications
- Crystallization and Solubility Studies
- Advanced X-ray and CT Imaging
- Advanced Semiconductor Detectors and Materials
- CCD and CMOS Imaging Sensors
- Advancements in Photolithography Techniques
- Black Holes and Theoretical Physics
- Radioactive element chemistry and processing
Sensirion (Switzerland)
2023
Paul Scherrer Institute
2016-2022
Max Planck Society
2019
European Organization for Nuclear Research
2014-2019
Swiss Light Source
2019
University of Oxford
2010-2018
Centro Brasileiro de Pesquisas Físicas
2013-2014
University of Cincinnati
2013-2014
Max Planck Institute for Nuclear Physics
2011
Aix-Marseille Université
2011
The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in LHCb experiment. performance of during first years its physics operation reviewed. system operated vacuum, uses bi-phase CO2 cooling system, and sensors are moved to 7 mm from LHC beam for data taking. stability these characteristic features described, details material budget given. calibration timing processing algorithms implemented FPGAs described. fully characterised. have...
The SwissFEL X-ray Free Electron Laser (XFEL) facility started construction at the Paul Scherrer Institute (Villigen, Switzerland) in 2013 and will be ready to accept its first users 2018 on Aramis hard branch. In following sections we summarize various aspects of project, including design soft branches accelerator, results performance simulations, details photon beamlines experimental stations, our commissioning results.
In future measurements of the dilepton (Z/γ ∗) transverse momentum, Q T , at both Tevatron and LHC, achievable bin widths ultimate precision will be limited by experimental resolution rather than available event statistics. a recent paper variable which corresponds to component that is thrust axis, has been studied in this regard. region, < 30 GeV, shown less susceptible efficiency effects . Extending over all we now demonstrate dividing (or ) measured invariant mass further improves...
A bstract The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies $$ \sqrt{s} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 380 GeV, 1 . 5 TeV, and 3 TeV. Its aim to explore the frontier, providing sensitivity physics beyond Standard Model (BSM) precision measurements of processes an emphasis on Higgs...
JUNGFRAU is the pixel detector developed at PSI for SwissFEL [1]. Although development was driven by requirements, it soon realized that such a could also be ...
Abstract One of the main challenges in ultrafast material science is to trigger phase transitions with short pulses light. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a coherent macroscopic transformation pathway for semiconducting-to-metal transition bistable Ti 3 O 5 nanocrystals. Employing femtosecond powder X-ray diffraction, measure lattice deformation as function time. We monitor early intra-cell distortion around light absorbing...
MÖNCH is a 25 µm-pitch charge-integrating detector aimed at exploring the limits of current hybrid silicon technology. The small pixel size makes it ideal for high-resolution imaging. With an electronic noise about 110 eV r.m.s., opens new perspectives many synchrotron applications where currently limiting factor, e.g. inelastic X-ray scattering, Laue diffraction and soft or color Due to pitch, charge cloud generated by absorbed X-rays shared between neighboring pixels most photons....
MÖNCH is a hybrid silicon pixel detector based on charge integration and with analog readout, featuring size of 25×25 μm2. The latest working prototype consists an array 400×400 identical pixels for total active area 1×1 cm2. Its design optimized the single photon regime. An exhaustive characterization this large has been carried out in past months, it confirms ENC order 35 electrons RMS dynamic range ∼4×12 keV photons high gain mode, which increases to ∼100×12 lowest setting. low noise...
Reliable sample delivery and efficient use of limited beam time have remained bottlenecks for serial crystallography (SX). Using a high-intensity polychromatic X-ray in combination with newly developed charge-integrating JUNGFRAU detector, we applied the method fixed-target SX to collect data at rate 1 kHz synchrotron-radiation facility. According our analysis given experimental conditions, only about 3 000 diffraction patterns are required high-quality dataset. With indexing rates up 25%,...
In this paper, we present a data workflow developed to operate the adJUstiNg Gain detector FoR Aramis User station (JUNGFRAU) adaptive gain charge integrating pixel-array detectors at macromolecular crystallography beamlines. We summarize current achievements for operating 9 GB/s data-rate JUNGFRAU with 4 Mpixel 1.1 kHz frame-rate and preparations 46 10 2.2 in future. context, highlight challenges computer architecture how these can be addressed innovative hardware including IBM POWER9...
Long-wavelength pulses from the Swiss X-ray free-electron laser (XFEL) have been used for de novo protein structure determination by native single-wavelength anomalous diffraction (native-SAD) phasing of serial femtosecond crystallography (SFX) data. In this work, sensitive data-quality indicators and model proteins were to quantify improvements in native-SAD at XFELs such as utilization longer wavelengths, careful experimental geometry optimization, better post-refinement partiality...
The JUNGFRAU detector is a charge integrating hybrid silicon pixel developed at the Paul Scherrer Institut for photon science applications, in particular upcoming free electron laser SwissFEL. With high dynamic range, analogue readout, low noise and three automatically switching gains, promises excellent performance not only XFELs but also synchrotrons areas such as protein crystallography, ptychography, pump-probe time resolved measurements. To achieve its full potential, must be calibrated...
Recent advances in segmented low-gain avalanche detectors (LGADs) make them promising for the position-sensitive detection of low-energy X-ray photons thanks to their internal gain. LGAD microstrip sensors fabricated by Fondazione Bruno Kessler have been investigated using X-rays with both charge-integrating and single-photon-counting readout chips developed at Paul Scherrer Institut. In this work it is shown that charge multiplication occurring sensor allows improved signal-to-noise ratio...
Chromium compensated GaAs or GaAs:Cr sensors provided by the Tomsk State University (Russia) were characterized using low noise, charge integrating readout chip JUNGFRAU with a pixel pitch of 75 × µm2 regarding its application as an X-ray detector at synchrotrons sources FELs. Sensor properties such dark current, resistivity, noise performance, spectral resolution capability and transport measured compared results from previous batch which produced wafers obtained different supplier. The...
The LHCb Vertex Locator (VELO) is a silicon strip detector designed to reconstruct charged particle trajectories and vertices produced at the interaction region. During first two years of data collection, 84 VELO sensors have been exposed range fluences up maximum value approximately 45 × 1012 1 MeV neutron equivalent (1 neq). At operational sensor temperature −7 °C, average rate current increase 18 μA per fb−1, in excellent agreement with predictions. effective bandgap has determined using...
The vertex detector at the proposed CLIC multi-TeV linear e+e− collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope expected rate of beam-induced backgrounds. One options being considered is use active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled hybrid pixel ASICs. A prototype such an assembly, using two custom designed chips (CCPDv3 as sensor glued CLICpix readout chip), has been...
JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional hybrid pixel under development for photon science applications at free electron laser and synchrotron facilities. In particular, detectors will equip end stations of SwissFEL, an X-ray currently construction Paul Scherrer Institut in Villigen, Switzerland. has been designed specifically to meet challenges XFELs, including high frame rates, single sensitivity combination with dynamic range, vacuum...
Chromium compensated GaAs sensors have been characterized using the charge-integrating readout chip JUNGFRAU. Due to its low noise performance and 75 × μm2 pixel size, JUNGFRAU enables a precise measurement of charge (of either polarity) with high spatial resolution. Several sensor parameters like dark current, spectral as well transport properties electrons determined. The short lifetime holes in GaAs:Cr gives rise an effect where pixels adjacent photon hit show strong negative signal when...
Precise knowledge of the location material in LHCb vertex locator (VELO) is essential to reducing background searches for long-lived exotic particles, and identifying jets that originate from beauty charm quarks. Secondary interactions hadrons produced beam-gas collisions are used map VELO. Using this map, along with properties a reconstructed secondary its constituent tracks, $p$-value can be assigned hypothesis originates interaction. A validation procedure presented using photon...
The Compact Linear Collider (CLIC) is a high-energy high-luminosity linear electron-positron collider under development. It foreseen to be built and operated in three stages, at centre-of-mass energies of 380 GeV, 1.5 TeV 3 TeV, respectively. offers rich physics program including direct searches as well the probing new through broad set precision measurements Standard Model processes, particularly Higgs-boson top-quark sectors. required for such specific conditions imposed by beam dimensions...
EIGER is a single-photon-counting hybrid pixel detector developed at the Paul Scherrer Institut, Switzerland. It designed for applications synchrotron light sources with photon energies above 5 keV. Features of include small size (75 µm × 75 µm), high frame rate (up to 23 kHz), dead-time between frames (down 3 µs) and dynamic range up 32-bit. In this article, use as electrons in low-energy electron microscopy (LEEM) photoemission (PEEM) reported. demonstrated that, only minimal modification...