A5000315529- CCD and CMOS Imaging Sensors
- Particle Detector Development and Performance
- Infrared Target Detection Methodologies
- Radiation Detection and Scintillator Technologies
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Photocathodes and Microchannel Plates
- Atomic and Subatomic Physics Research
- Electron and X-Ray Spectroscopy Techniques
- Medical Imaging Techniques and Applications
- Advanced Optical Sensing Technologies
- Advanced Electron Microscopy Techniques and Applications
- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Dark Matter and Cosmic Phenomena
- Thermal Radiation and Cooling Technologies
- Photovoltaic System Optimization Techniques
- Laser Design and Applications
- Advanced X-ray and CT Imaging
- Radiation Effects in Electronics
- Nuclear reactor physics and engineering
- Advanced Fiber Laser Technologies
- Astro and Planetary Science
- Nuclear Physics and Applications
- Image and Signal Denoising Methods
University of Oxford
2017-2024
European Organization for Nuclear Research
2020
The Open University
2013-2016
We outline the experimental concept and key scientific capabilities of AION (Atom Interferometer Observatory Network), a proposed programme using cold strontium atoms to search for ultra-light dark matter, explore gravitational waves in mid-frequency range between peak sensitivities LISA LIGO/Virgo/ KAGRA/INDIGO/Einstein Telescope/Cosmic Explorer experiments, probe other frontiers fundamental physics. would complement planned searches as well mergers involving intermediate-mass black holes...
This paper outlines the centralized design and production of ultra-high-vacuum sidearm laser-stabilization systems for AION Ultra-Cold Strontium Laboratories. Commissioning data on residual gas steady-state pressures in chambers, magnetic field quality, laser stabilization, loading rate 3D magneto-optical trap are presented. Streamlining stabilization enabled Collaboration to build equip parallel five state-of-the-art Laboratories within 24 months by leveraging key expertise collaboration....
Abstract The Low Gain Avalanche Detectors (LGAD) has become the preferred technological choice for fast track timing detectors in High Energy Physics applications. Additional uses of such sensors are currently being investigated, ranging from Light Detection and Ranging (LIDAR) to Let particle dosimetry medical space This paper describes development test LGAD devices, fabricated using a commercial process Teledyne e2v silicon foundry. Motivation behind project, details TCAD simulations...
The Jovian system is the subject of study for Jupiter Icy Moon Explorer (JUICE), an ESA mission which planned to launch in 2022. scientific payload designed both characterisation magnetosphere and radiation environment local spacecraft, as well remote its satellites. A key instrument on JUICE high resolution wide angle camera, JANUS, whose main science goals include detailed phases three Galilean satellites, Ganymede, Callisto Europa, studies other moons, ring system, irregular
Current theories regarding the matter composition of universe suggest that half expected baryonic is missing. One region this could be residing in intergalactic filaments which absorb strongly X-ray regime. Present space based technology limited when it comes to imaging at these wavelengths and so new techniques are required. The Off-Plane Grating Rocket Experiment (OGRE) aims produce highest resolution spectrum binary star system Capella, a well-known source, soft range (0.2keV 2keV). This...
We describe the commissioning of a system which has been built to investigate optimal operation CCDs for LSST telescope. The test is designed low vibration, high stability and capable illuminating detector in flat-field, projected spot, pattern Fe-55 configurations. compare some considerations when choosing gain calibration method exhibit brighter-fatter effect. An optimisation study on prototype device full well with varying back substrate bias gate clock levels presented.
We have evaluated the imaging capabilities of Timepix4 hybrid silicon pixel detector for 100 keV and 200 electrons in a Transmission Electron Microscope (TEM). Using knife-edge method, we measured Modulation Transfer Function (MTF) at both energies. Our results show decrease MTF response Nyquist (spatial) frequency, dropping from approximately 0.16 to 0.0046 keV. However, by using temporal structure detected events, including arrival time amplitude provided Timepix4, enhanced spatial...
Correlated double sampling (CDS) is a process used in many charge-coupled device readout systems to cancel the reset noise component that would otherwise dominate. CDS processing typically consists of subtracting integrated video signal during “signal” period from “reset” period. The response this depends, therefore, on shape with respect integration bounds. In particular, amount appearing final image and linearity pixel value charge are affected by choice timing intervals. We use digital...
Correlated charge collection phenomena in CCD sensors are presently of interest due to their potentially major implications space and ground based astronomy missions. These effects may manifest as a signal dependent Point Spread Function (PSF), or nonlinearity the Photon Transfer Curve (PTC). We present theoretical background simple analytical model on previously published solutions Poisson's equation which aims aid conceptual understanding how various device parameters relate magnitude...
Charge-coupled devices (CCDs) currently constitute the standard detector for precision astronomical telescopes such as Large Synoptic Survey Telescope (LSST) due to their high linearity, sensitivity and dynamic range. Charge transfer properties can however be degraded by presence of defect levels in silicon band-gap, which act trapping centers signal charge. The technique single trap-pumping used a tool probe underlying relevant potentially mitigate against effects. In this paper we present...
Pixellated monolithic silicon detectors operated in a photon-counting regime are useful spectroscopic imaging applications. Since high energy incident photon may produce many excess free carriers upon absorption, both and spatial information can be recovered by resolving each interaction event. The performance of these devices terms the resolution is large part determined amount diffusion which occurs during collection charge cloud pixels. Past efforts to predict X-ray sensors have used...
The e2v CCD236 is a swept charge device (SCD) designed as soft X-ray detector for spectroscopy in the range 0.8 keV to 10 [1]. It benefits from improvements design over previous generation of SCD (the CCD54) [2] allow increased area, reduction split events and radiation hardness [3]. To enable suppression surface dark current clocked continuously, therefore there no positional information making responsivity variations difficult measure. This paper describes investigated techniques achieve...
This paper presents a brief review of charge-redistrbution effects in charge-couple devices observed both flat-field and spot data. Experiments are described that allow such phenomenon to be measured simply the parallel transfer direction using only equipment capable providing illuminations. A more detailed investigation into signal-dependant PSF shape distortions descibed for p- n-channel CCDs identical design. number methods minimise effect presented include different image electrode...
The Off-plane Grating Rocket Experiment (OGRE) is a high resolution soft X-ray spectrometer sub-orbital rocket payload designed as technology development platform for three low Technology Readiness Level (TRL) components. incident photons will be focused using light-weight, resolution, single-crystal silicon optic. They are then dispersed conically according to wavelength by an array of off-plane gratings before being detected in focal plane camera comprised four Electron Multiplying...
Dynamic charge collection effects in thick CCDs have received interest recent years, due to the performance implications for both ground and space based precision optical astronomy. The phenomena manifest as "brighter - fatter" effect Point Spread Function (PSF) measurements, nonlinearity signal dependence spatial autocorrelation photon transfer measurements. In this paper we present validation results from simple, analytically predictive models effect, using an e2v CCD250. model is intended...
This paper outlines the centralised design and production of Ultra-High-Vacuum sidearm Laser-Stabilisation systems for AION Ultra-Cold Strontium Laboratories. Commissioning data on residual gas steady-state pressures in chambers, magnetic field quality, laser stabilisation, loading rate 3D Magneto-Optical Trap are presented. Streamlining stabilisation enabled Collaboration to build equip parallel five state-of-the-art Laboratories within 24 months by leveraging key expertise collaboration....
The shape and size of the stored charge packet within a CCD pixel after exposure has implications for optimal device operation, susceptibility to radiation damage modelling dynamic collection effects such as "Brighter-Fatter Effect". Above full well capacity, phenomena bleed trails surface loss occur. In this paper we discuss why accurately reproducing saturation in simulations based on electrostatics is difficult, present an approach storage pixels using commercial semiconductor simulation...
Dynamic charge collection effects (e.g. the "Brighter-Fatter" effect) are present in thick, deeply depleted CCDs. These can cause distortion of point spread function, and correlations between nearby pixel values. Much has been written already about how to characterise mitigate this effect. This presentation will focus on more standard performance parameters a CCD gain, noise, linearity, uniformity, apparent QE, full well) be influenced by brighter-fatter effect, describe some methods...
CDS is a process used in many CCD readout systems to cancel the reset noise component that would otherwise dominate. processing typically consists of subtracting integrated video signal during "signal" period from "reset" period. The response this depends therefore on shape with respect integration bounds. In particular, amount appearing final image and linearity pixel value charge are affected by choice timing intervals. paper, we use digital system which highly oversamples (as compared...
This contribution outlines the results of investigations into effects radiation damage in mini-MALTA depleted monolithic pixel sensor prototype using a micro-focus X-ray beam at Diamond Light Source. The in-pixel photon response was measured for three different design variations: one with standard continuous $\mathrm{n^-}$ layer layout and front-end, extra deep p-well gap designs modified front-end. showed decrease 12\% after irradiation to 1e15 $\mathrm{n_{eq}/cm^2}$. two new did not show...