[show abstract][hide abstract] ABSTRACT: The Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) com- bines a suite of optical telescopes with numerical modeling to capitalize on the unique viewpoint of the NASA Solar Terrestrial Relations Observatory (STEREO) mission to advance our understanding of the three-dimensional nature of the solar corona and coronal mass ejections. The instrument suite consists of two white-light coronagraphs (COR1 and COR2), an extreme ultraviolet disk imager (EUVI), collectively referred to as the Sun Centered Imaging Package (SCIP), and a heliospheric imager (HI). SEC- CHI will observe CMEs from their birth at the Sun, through the corona to their impact at Earth, from two different viewpoints away from the Sun-Earth line. SECCHI will also obtain stereoscopic observations of coronal structures such as loops and stream- ers. A coordinated modeling and data visualization effort will be used to interpret the images, and to integrate the SECCHI observations with the in-situ and radio measure- ments that will also be obtained from STEREO.
Space Science Reviews 08/2013; · 5.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona and upper transition region emission lines in the wavelength
ranges 170 – 210Å and 250 – 290Å. The line centroid positions and profile widths will allow plasma velocities and turbulent
or non-thermal line broadenings to be measured. We will derive local plasma temperatures and densities from the line intensities.
The spectra will allow accurate determination of differential emission measure and element abundances within a variety of
corona and transition region structures. These powerful spectroscopic diagnostics will allow identification and characterization
of magnetic reconnection and wave propagation processes in the upper solar atmosphere. We will also directly study the detailed
evolution and heating of coronal loops. The EIS instrument incorporates a unique two element, normal incidence design. The
optics are coated with optimized multilayer coatings. We have selected highly efficient, backside-illuminated, thinned CCDs.
These design features result in an instrument that has significantly greater effective area than previous orbiting EUV spectrographs
with typical active region 2 – 5s exposure times in the brightest lines. EIS can scan a field of 6×8.5arc min with spatial
and velocity scales of 1arc sec and 25km s−1 per pixel. The instrument design, its absolute calibration, and performance are described in detail in this paper. EIS will
be used along with the Solar Optical Telescope (SOT) and the X-ray Telescope (XRT) for a wide range of studies of the solar
Solar Physics 04/2012; 243(1):19-61. · 3.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: We report the first absolute effective quantum efficiency (e-h pairs collected/predicted) measurements of a monolithic thinned back-illuminated CMOS active pixel sensor (APS) in the extreme ultraviolet and soft X-ray region (13-600 Å). The sensor was designed and fabricated under a joint Rutherford Appleton Laboratory/e2v research program and characterized in the Lockheed Martin Solar and Astrophysics calibration facility. We compare our QE results to the data and models developed for thinned CCDs with similar back surface passivation. Our results demonstrate that CMOS APS arrays show significant promise for use in space-based solar physics and astrophysics missions.
IEEE Electron Device Letters 04/2011; · 2.79 Impact Factor
[show abstract][hide abstract] ABSTRACT: We report first absolute effective quantum efficiency (e-h pairs collected/predicted) measurements of a monolithic, thinned, back-illuminated CMOS Active Pixel Sensor (APS) in the EUV and soft X-ray region (13-600 Å). The sensor was designed and fabricated under a joint RAL/e2v research program, and characterized in the Lockheed Martin Solar and Astrophysics (LMSAL) XUV calibration facility. We compare our QE results to data and models developed for thinned CCDs with similar back surface passivation. Our results demonstrate that CMOS APS arrays show significant promise for use in space-based solar physics missions.
[show abstract][hide abstract] ABSTRACT: We describe our programme to develop a large-format, science-grade, monolithic CMOS active pixel sensor for future space science missions, and in particular an extreme ultraviolet (EUV) spectrograph for solar physics studies on ESA's Solar Orbiter. Our route to EUV sensitivity relies on adapting the back-thinning and rear-illumination techniques first developed for CCD sensors. Our first large-format sensor consists of 4k×3k 5 μm pixels fabricated on a 0.25 μm CMOS imager process. Wafer samples of these sensors have been thinned by e2v technologies with the aim of obtaining good sensitivity at EUV wavelengths. We present results from both front- and back-illuminated versions of this sensor. We also present our plans to develop a new sensor of 2k×2k 10 μm pixels, which will be fabricated on a 0.35 μm CMOS process. In progress towards this goal, we have designed a test-structure consisting of six arrays of 512×512 10 μm pixels. Each of the arrays has been given a different pixel design to allow verification of our models, and our progress towards optimizing a design for minimal system readout noise and maximum dynamic range. These sensors will also be back-thinned for characterization at EUV wavelengths.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 04/2007; 573:250-252. · 1.14 Impact Factor
[show abstract][hide abstract] ABSTRACT: We describe our programme to develop a large-format science-grade CMOS active pixel sensor for future space science missions, and in particular an extreme ultra-violet spectrograph for solar physics studies on ESA's Solar Orbiter. Our route to EUV sensitivity relies on adapting the back-thinning and rear-illumination techniques first developed for CCD sensors. So far we have designed and tested a 4k x 3k 5-micrometer pixel sensor fabricated on a 0.25-micrometer CMOS imager process. Wafer samples of these sensors have been thinned by e2v technologies with the aim of obtaining good sensitivity at EUV wavelengths. We present our results to date, and plans for a new sensor of 2k x 2k 10-micrometer pixels to be fabricated on a 0.35-micrometer CMOS process.
[show abstract][hide abstract] ABSTRACT: The Extreme Ultraviolet Imaging Spectrometer (EIS) is a core instrument on the Japanese Solar-B mission and is due for launch in the summer of 2006. EIS is a 3.2 m long telescope employing grating optics and a pair of charge coupled device imaging cameras working in the extreme ultraviolet (EUV) region in two separate wavelength bands between 170-210 and 240-290 Å. To house all the telescope subsystems, a novel carbon fibre reinforced plastic structure was developed in collaboration with McLaren Composites Limited (UK) to meet a set of the demanding performance requirements in terms of dimensional stability, rigidity, and structural cleanliness as well as being able to survive the harsh launch environment of the Japanese M-V rocket. The final design was based on a honeycomb panel structure using stiff carbon fibre laminates. This case study describes some of the design challenges that were overcome for this project to produce the engineering, mechanical, and thermal models. Particular attention is given to the cleanliness control strategy to preserve the EUV optical throughput, the method of attachment to the spacecraft, and of optical subsystems as well as the instrument thermal design.
Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications 07/2005; 219(3):177-186. · 0.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: In the last few years, CMOS sensors have become widely used for consumer applications, but little has been done for scientific instruments. In this paper we present the design and experimental characterisation of a Monolithic Active Pixel Sensor (MAPS) intended for a space science application. The sensor incorporates a 525×525 array of pixels on a 25μm pitch. Each pixel contains a detector together with three transistors that are used for pixel reset, pixel selection and charge-to-voltage conversion. The detector consists of four n-well/p-substrate diodes combining optimum charge collection and low noise performance. The array readout is column-parallel with adjustable gain column amplifiers and a 10-bit single slope ADC. Data conversion takes place simultaneously for all the 525 pixels in one row. The ADC slope can be adjusted in order to give the best dynamic range for a given brightness of a scene. The digitised data are output on a 10-bit bus at 3MHz. An on-chip state machine generates all of the control signals needed for the readout. All of the bias currents and voltages are generated on chip by a DAC that is programmable through an I2C compatible interface. The sensor was designed and fabricated on a standard 0.5μm CMOS technology. The overall die size is 16.7mm×19.9mm including the associated readout electronics and bond pads. Preliminary test results show that the full-scale design works well, meeting the Star Tracker requirements with less than 1-bit noise, good linearity and good optical performance.
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment - NUCL INSTRUM METH PHYS RES A. 01/2003; 512(1):358-367.
[show abstract][hide abstract] ABSTRACT: An Active Pixel Sensor Test Structure, commissioned by the Rutherford Appleton Laboratory CCD Technology Group and designed by the Microelectronics Design Group, is being tested and evaluated by the University of Birmingham. The Test Structure includes four 16×16 pixel arrays, each array featuring a different 25mum pixel design: Photogate, QuadruDot, n-type diffusion [Diode(ndps)] and p-type diffusion [Diode(pdNw)] photodiodes. Measurements are currently underway to characterize the Active Pixel Sensor performance. Initial measurements indicate pixel array gains of 2.9, 3.4, 38 and 50 electrons per ADC unit, for the QuadruDot, Photogate, Diode(ndps) and Diode(pdNw) arrays. The test-structure architecture, experimental set-up, results and conclusions are discussed, with reference to the performance benefits of this technology for future space applications.
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment - NUCL INSTRUM METH PHYS RES A. 01/2003; 513:313-316.
[show abstract][hide abstract] ABSTRACT: The Heliospheric Imager (HI) is part of the SECCHI suite of instruments on-board the two STEREO spacecrafts. The two HI instruments will provide stereographic image pairs of solar coronal plasma and coronal mass ejections (CME) over a wide field of view (85 degrees), with an inner field limit of approximately 13 solar radii. These observations compliment the 15 solar radii field of view of the solar corona obtained by the other SECCHI instruments to provide unbroken coverage of the solar corona and heliosphere from the Sun to the Earth. The as-built characteristics of the HI will be presented along with the current data reduction and analysis approach. The constraints that HI observations place on models of CME propagation in the interplanetary medium will be discussed.