Mark S. Robbins

Bio: Mark S. Robbins is an academic researcher. The author has contributed to research in topics: Dark current & Optics. The author has an hindex of 4, co-authored 4 publications receiving 38 citations.

Proton-induced leakage current in CCDs

Abstract: The effect of different proton fluences on the performance of two E2V Technologies CCD47-20 devices was investigated with particular emphasis given to the analysis of 'random telegraph signal' (RTS) generation, bright pixel generation and induced changes in base dark current level. The results show that bright pixel frequency increases as the mean energy of the proton beam is increased, and that the base dark current level after irradiation scales with the level of ionization damage. For the RTS study, 500 pixels on one device were monitored over a twelve hour period. This data set revealed a number of distinct types of pixel change level fluctuation and a system of classification has been devised. Previously published RTS data is discussed and reviewed in light of the new data.

A study of electron-multiplying CCDs for use on the International X-ray Observatory off-plane x-ray grating spectrometer

Abstract: CCDs are regularly used as imaging and spectroscopic devices on space telescopes at X-ray energies due to their high quantum efficiency and linearity across the energy range. The International X-ray Observatory's X-ray Grating Spectrometer will also look to make use of these devices across the energy band of 0.3 keV to 1 keV. At these energies, when photon counting, the charge generated in the silicon is close to the noise of the system. In order to be able to detect these low energy X-ray events, the system noise of the detector has to be minimised to have a sufficient signal-to-noise-ratio. By using an EM-CCD instead of a conventional CCD, any charge that is collected in the device can be multiplied before it is read out and as long as the EM-CCD is cool enough to adequately suppress the dark current, the signal-to-noise ratio of the device can be significantly increased, allowing soft X-ray events to be more easily detected. This paper will look into the use of EM-CCDs for the detection of low energy X-rays, in particular the effect that using these devices will have on the signal to noise ratio as well as any degradation in resolution and FWHM that may occur due to the additional shot noise on the signal caused by the charge packet amplification process.

The effect of protons on E2V Technologies L3Vision CCDs

Abstract: The effect of different 10 MeV equivalent proton fluences on the performance of E2V Technologies (formerly Marconi applied technologies, formerly EEV) L3Vision Charge Coupled Devices (CCDs) was investigated. The first experimental radiation damage results of the L3Vision device are presented, with emphasis given to the analysis of damage to the gain register of the device. Changes in dark current and generation of bright pixels in the CCD image, store, readout register and gain register as a result of proton irradiation are reported and viewed in light of the potential use of the device in space-based applications. r 2003 Published by Elsevier B.V.

Compact CMOS Camera Demonstrator (C3D) for Ukube-1

Abstract: The Open University, in collaboration with e2v technologies and XCAM Ltd, have been selected to fly an EO (Earth Observation) technology demonstrator and in-orbit radiation damage characterisation instrument on board the UK Space Agency's UKube-1 pilot Cubesat programme. Cubesat payloads offer a unique opportunity to rapidly build and fly space hardware for minimal cost, providing easy access to the space environment. Based around the e2v 1.3 MPixel 0.18 micron process eye-on-Si CMOS devices, the instrument consists of a radiation characterisation imager as well as a narrow field imager (NFI) and a wide field imager (WFI). The narrow and wide field imagers are expected to achieve resolutions of 25 m and 350 m respectively from a 650 km orbit, providing sufficient swathe width to view the southern UK with the WFI and London with the NFI. The radiation characterisation experiment has been designed to verify and reinforce ground based testing that has been conducted on the e2v eye-on-Si family of devices and includes TEC temperature control circuitry as well as RADFET in-orbit dosimetry. Of particular interest are SEU and SEL effects. The novel instrument design allows for a wide range of capabilities within highly constrained mass, power and space budgets providing a model for future use on similarly constrained missions, such as planetary rovers. Scheduled for launch in December 2011, this 1 year low cost programme should not only provide valuable data and outreach opportunities but also help to prove flight heritage for future missions.

Commissioning, on sky performance and first operations of JPCam, a 1.2 Gpixel camera for the wide-field 2.6m Javalambre Survey Telescope

Abstract: Commissioning results, on-sky performance and first operations of the Javalambre Panoramic Camera (JPCam) are presented in this paper. JPCam is a 1.2 Gpixel camera deployed on the 2.6m, large field-of-vie Javalambre Survey Telescope (JST250) at the Observatorio Astrof´ısico de Javalambre. JPCam has been conceived to perform J-PAS, a photometric survey of several thousand square degrees of the northern sky in 56 optical bands, 54 of them narrow-band filters (145 ˚A FWHM), contiguous and equi-spaced between 370 and 920nm, producing a low resolution photo-spectrum of every pixel of the observed sky, hence promising crucial breakthroughs in Cosmology and galaxy formation and evolution. JPCam has been designed to maximize field-of-view and wavelength coverage while guaranteeing a high image quality over the entire focal plane. To this aim, JPCam is equipped with a mosaic of 14 9.2k x 9.2k, 10µm pixel, low noise detectors from Teledyne-E2V, providing a FoV of 4.1 square degrees with a plate scale of 0.2267′′/pix. In full frame mode, camera electronics allows read times of 10.9s at 633kHz read frequency (16.4s at 400kHz) with a readout noise of 5.5e− (4.3e−). Its filter unit admits 5 filter trays, each mounting 14 filters corresponding to the 14 CCDs of the mosaic and allowing all the J-PAS filters to be permanently installed. To fully optimize image quality, position of JST250 secondary mirror and JPCam focal plane are maintained optically aligned by means of two hexapod systems. To perform this task, JPCam includes 12 auxiliary detectors, 4 for autoguiding and 8 for image quality control through wavefront sensing.

Displacement Damage Effects in Irradiated Semiconductor Devices

Abstract: A review of radiation-induced displacement damage effects in semiconductor devices is presented, with emphasis placed on silicon technology. The history of displacement damage studies is summarized, and damage production mechanisms are discussed. Properties of defect clusters and isolated defects are addressed. Displacement damage effects in materials and devices are considered, including effects produced in silicon particle detectors, visible imaging arrays, and solar cells. Additional topics examined include NIEL scaling, carrier concentration changes, random telegraph signals, radiation hardness assurance, and simulation methods for displacement damage. Areas needing further study are noted.

Sensors and camera systems for scientific, industrial, and digital photography applications : 24-26 January 2000, San Jose, USA

Abstract: In this age of modern era, the use of internet must be maximized. Yeah, internet will help us very much not only for important thing but also for daily activities. Many people now, from any level can use internet. The sources of internet connection can also be enjoyed in many places. As one of the benefits is to get the on-line sensors and camera systems for scientific industrial and digital photography applications ii book, as the world window, as many people suggest.

Random telegraph signals in charge coupled devices

Abstract: An investigation of fluctuating pixels resulting from proton irradiation of an E2V Technologies CCD47-20 device is presented. The device structure, experimental set up and irradiation methodology are described, followed by a detailed analysis of radiation induced random telegraph signals, RTS. The characteristics of the observed flickering pixels are discussed in detail and the proposed models explaining the mechanism behind the phenomena are viewed in light of the collected data.

The Noise Performance of Electron-Multiplying Charge-Coupled Devices at X-ray Energies

Abstract: Electron-multiplying charge-coupled devices (EM-CCDs) are used in low-light-level (L3) applications for detecting optical, ultraviolet, and near-infrared photons (10-1100 nm). The on-chip gain process is able to increase the detectability of any signal collected by the device through the multiplication of the signal before the output node. Thus, the effective readout noise can be reduced to subelectron levels, allowing the detection of single photons. However, this gain process introduces an additional noise component due to the stochastic nature of the multiplication. In optical applications, this additional noise has been characterized. The broadening of the detected peak is described by the excess noise factor. This factor tends to a value of √{2} at high gain (>; 100x). In X-ray applications, the situation is improved by the effect that Fano factor f has on the shot noise associated with X-ray photon detection (f ≈ 0.12 at X-ray energies). In this paper, the effect of the detection of X-ray photons in silicon is assessed both analytically and through a Monte Carlo model of the gain amplification process. The excess noise on the signal is predicted (termed the modified Fano factor) for photon detection in an EM-CCD at X-ray energies. A hypothesis is made that the modified Fano factor should tend to 1.115 at high levels of gain (>; 10x). In order to validate the predictions made, measurements were taken using an 55Fe source with Mn k-alpha X-ray energy of 5898 eV. These measurements allowed the hypothesis to be verified.

Proton irradiation of EMCCDs

Abstract: This paper describes the irradiation of 95 electron multiplication charge coupled devices (EMCCDs) at the Paul Scherrer Institut (PSI) in Switzerland, to investigate the effects of proton irradiation on the operational characteristics of CCDs featuring electron multiplication technology for space use. This work was carried out in support of the CCD development for the radial velocity spectrometer (RVS) instrument of the European Space Agency's cornerstone Gaia mission. Previous proton irradiations of EMCCDs, have shown the technology to be radiation hard to /spl sim/10/spl times/ the required six-year Gaia lifetime proton fluence, with no device failures or unexpected operational changes. The purpose of the study described in this paper was to further investigate the statistical probability of device failure as a result of radiation damage, the large number of devices and high proton fluence used, making the study equivalent to testing /spl sim/50 complete RVS CCD focal planes to the expected end of life proton dose. An outline of the earlier EMCCD proton irradiations is given, followed by a detailed description of the proton irradiation and characterization of the 95 devices used in this latest study.