A. S. Howard
A5105788604- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Distributed and Parallel Computing Systems
- Medical Imaging Techniques and Applications
- Radiation Effects in Electronics
- CCD and CMOS Imaging Sensors
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Superconducting Materials and Applications
- Scientific Research and Discoveries
- Advanced Semiconductor Detectors and Materials
- Advanced Data Storage Technologies
- Astrophysics and Cosmic Phenomena
- Big Data Technologies and Applications
- Enzyme Structure and Function
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
Jožef Stefan International Postgraduate School
2022-2025
Jožef Stefan Institute
2020-2025
University of Ljubljana
2022-2025
Imperial Valley College
2006-2025
Imperial College London
2002-2024
Institute for High Energy Physics
2023-2024
Institute of Science and Technology
2023-2024
Atlas Scientific (United States)
2024
A. Alikhanyan National Laboratory
2024
The University of Adelaide
2023
The ZEPLIN-III experiment in the Palmer Underground Laboratory at Boulby uses a 12 kg two-phase xenon time-projection chamber to search for weakly interacting massive particles (WIMPs) that may account dark matter of our Galaxy. detector measures both scintillation and ionization produced by radiation liquid differentiate between nuclear recoils expected from WIMPs electron-recoil background signals down $\ensuremath{\sim}10\text{ }\text{ }\mathrm{keV}$ nuclear-recoil energy. An analysis...
Results of observations low energy nuclear and electron recoil events in liquid xenon scintillator detectors are given. The relative scintillation efficiency for recoils is 0.22±0.01 the range 40–70 keV. Under assumption a single dominant decay component to pulse shape log-normal mean parameter T0 maximum likelihood estimator time constant 6 keV <Eee<30 equal 21.0±0.5 ns. It observed that rises slowly with energy, having value ∼30 ns at Eee∼15 Electron shapes found be well fitted by...
A flat, relatively thin (9 mm) xenon-filled multiwire proportional counter with two-dimensional, 2 μs delay line readout of a 270 × 300 mm active area has been developed for use as position-sensitive X-ray detector in the 8 keV energy region (Cu Kα) used crystallographic structure work large biological molecules. Its quantum detection efficiency photons is about 0.5, value which spatially uniform to within ± 2%. dead-time loss fraction at typical data collection rate 30000 s−1 12%. The...
We present limits on the WIMP-nucleon cross section for inelastic dark matter derived from 2008 run of ZEPLIN-III. Cuts, notably scintillation pulse shape and scintillation-to-ionisation ratio, give a net exposure 63 kg.days in range 20-80keV nuclear recoil energy, which 6 events are observed. Upper signal rate maximum empty patch data. Under standard halo assumptions small region parameter space consistent, at 99% CL, with causing 1.17 ton.year DAMA modulation is allowed 90% CL: it mass...
Cerebral blood flow (CBF) dysregulation is correlated with pathologies including ischemic stroke and Alzheimer's disease. Portable real-time CBF monitoring, spatial specificity, would aid neuroscience research clinical decision-making. Recently, speckle contrast optical spectroscopy (SCOS) enabled non-invasive human measurement, demonstrating a higher signal-to-noise ratio (SNR) compared to traditional methods. This work advances the SCOS state-of-the-art by developing high-density,...
A table-top plasma focus device is shown to be an ideal neutron source for the calibration and characterization of dark matter detectors has been optimized produce a maximum yield 2.0×107 neutrons per shot. The interaction energetic similar that expected from weakly interacting massive particles (WIMPs)—a favored candidate dominant component in universe. weak with liquid xenon gas was measured prototype two-phase detector. We have developed detector system which both primary scintillation...
Abstract This paper presents the design and characterisation of a front-end prototype ASIC for ATLAS High Granularity Timing Detector, which is planned High-Luminosity phase LHC. prototype, called ALTIROC1, consists 5 × 5-pad matrix contains analog part single-channel readout (preamplifier, discriminator, two TDCs SRAM). Two preamplifier architectures (transimpedance voltage) were implemented tested. The was characterised both alone as module when connected to array LGAD sensors. In...
A Monte Carlo simulation of electrostatic charging the LISA test masses by cosmic-ray protons and alpha particles has been developed using Geant4 toolkit. positive rate 58±17 +e/s (elementary charges per second) was obtained with a 250 eV threshold for production secondary particles. This is five times larger than that found in previous simulations. The difference mainly explained mass investigated this study, tracking lower energy electrons wider range energies considered. We examine...
Several thin Low Gain Avalanche Detectors from Hamamatsu Photonics were irradiated with neutrons to different equivalent fluences up Φeq=3⋅1015 cm−2. After the irradiation they annealed at 60oC in steps times 0>2000 minutes. Their properties, mainly full depletion voltage, gain layer generation and leakage current, as well their performance terms of collected charge time resolution, determined between steps. It was found that effect annealing on timing resolution is not very large occurs...
Abstract The High Granularity Timing Detector (HGTD) will be installed in the ATLAS detector to mitigate pile-up effects during Luminosity (HL) upgrade of Large Hadron Collider (LHC) at CERN. design HGTD is based on use Low Gain Avalanche Detectors (LGADs), with an active thickness 50 μm, that allow measure high-precision time arrival particles. improve particle-vertex assignment by measuring track a resolution ranging from approximately 30 ps beginning HL-LHC operations end. Performances...
Abstract The Serenity-S1 is a production-optimised Advanced Telecommunications Computing Architecture (ATCA) processing blade based on the AMD Xilinx Virtex Ultrascale+ device. It incorporates many developments from Serenity-A and Serenity-Z prototype cards and, where possible, adopts solutions being used across CERN. Due to shortage of components during recent semiconductor crisis, commonly in prototypes had be replaced by new ones after qualification. In this work, we discuss various...
An electron density map of ribulose 1,5-bisphosphate carboxylase-oxygenase (Rubisco) from tobacco ( Nicotiana tabacum ) has been obtained by X-ray crystallography at a nominal resolution 0.34 nm. Phases were determined multiple isomorphous replacement with three heavy atom derivatives and then refined solvent flattening. Rubisco is barrel-shaped, (422) symmetry. The fourfold axis runs down an open central channel, concentric the barrel. molecule measures 10.5 nm along axis, diameter 13...