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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： C. Fiorini A. Longoni W. Buttler Dipartimento di Ingegneria Nucleare CESNEF Politecnico di Milano Milan Italy Dipartimento di Elettronica e Informazione Politecnico di Milano Milan Italy Ingenieur-Büro Entwicklung mikroelektronischer Schooltungen Essen Germany

In this paper we present a multi-channel VLSI implementation of ROTOR, a time-variant-parameters shaping amplifier designed for the readout of high-rate asynchronous signals from multi-element solid-state X-ray detection systems. In particular, ROTOR was optimised for high-rate X-ray spectroscopy with multi-element Semiconductor Drift Detectors in applications using synchrotron light sources, such as X-ray holography or EXAFS experiments. A 30 channels circuit has been implemented in the 1 /spl mu/m/5 V JFET/CMOS technology of the Fraunhofer-Institut, Duisburg (Germany). Each analog channel features a trapezoidal weighting function, 1.6 /spl mu/m wide, obtained by means of a switched-current technique. A digital section, directly integrated on the ROTOR chip, allows the timing and control of all the analog switches of the amplifiers as required for the circuit functionality, without the need of external signals. The results obtained in the experimental characterization of the circuit and in spectroscopy measurements by using Silicon Drift Detectors are presented.

关键词： Silicon sensor arrays X-ray detection Spectroscopy CMOS technology Very large scale integration Signal design solid state circuits X-ray detectors Synchrotrons

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Real time /spl beta/-imaging with silicon hybrid pixel detectors: investigations into amino acids uptake and genetics

Real time /spl beta/-imaging with silicon hybrid pixel detec...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： E. Bertolucci M. Conti A. Di Cosmo M. Maiorino G. Mettivier M.C. Montesi G. Paolella T. Pecorella P. Russo R. Scognamiglio Dipartimento di Scienze Fisiche UniversitaE28099di Napoli Federico II and INFN Napoli Italy Department of Computer Science UniversitaE28099 di Napoli Federico II Napoli Italy

We present some additional results obtained with the BETAview system, a digital system for real time /spl beta/-imaging based on semiconductor pixel detectors and on a single photon counting read-out chip. In this paper, we describe the system assembled with a Si detector, 300 /spl mu/m thick, segmented into 64/spl times/64 square pixels with 170 /spl mu/m pitch. The solid state pixel array detector is bump-bonded pixel by pixel to a low threshold, single particle counting electronics, the photon counting chip (PCC) developed by the Medipix1Collaboration for biomedical applications. Each cell (corresponding to a detector pixel) of the front-end chip has a maximum count rate of 2 MHz, a minimum nominal threshold of 1400 e~ (corresponding to about 5 keV in Si) and contains a 15-bit counter. The detector sensitive area is about 1 cm/sup 2/, but several detectors could be assembled in arrays. The measured background counts were about 3.5/spl middot/10/sup -2/ cps/cm/sup 2/, which implies a very high sensitivity of the device. The detection threshold used in this experiment was 15 keV. In this paper we show the results obtained in the real time monitoring of two biological dynamic processes: an amino acid uptake and the thermal denaturation process of oligonucleotides. Specifically, we have followed over time the accumulation of a marked amino acid ([/sup 14/C]L-Leucine) into Octopus vulgaris eggs cells. After about 20 min from the beginning of the uptake process, the radioactively marked eggs become clearly visible over the background culture radioactive medium. We also describe the successful performance of the /spl beta/-imaging system in genetic studies involving the real time reconstruction of denaturation and kinetics curves for two different /sup 32/P-radiolabeled nucleotides.

关键词： Silicon Detectors Real time systems sensor arrays Amino acids Digital systems Assembly systems solid state circuits Counting circuits Biomedical measurements

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Sub-nanosecond avalanche transistor drivers for low impedance pulsed power applications

Sub-nanosecond avalanche transistor drivers for low impedanc...

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Pulsed Power Plasma Science

作者： L.L. Molina F.J. Zutavern A. Mar G.M. Loubriel Sandia National Laboratories USA Sandia National Laboratories

Summary form only given. Ultra compact, short pulse, high voltage and current pulsers are needed for a variety of non-linear electrical and optical applications. With a fast rise time and short pulse width, these drivers are capable of producing sub-nanosecond electrical and optical pulses by gain switching semiconductor laser diodes. Gain-switching of laser diodes requires a sub-nanosecond pulser with low output impedance (5 W or less) to generate a fast (<100 ps) optical pulse. The designed pulsers also could be used for triggering photo-conductive semiconductor switches, gating high speed optical imaging systems, and providing electrical and optical sources for fast transient sensor applications. Building on concepts from Lawrence Livermore National Laboratory, the development of pulsers based on solid state avalanche transistors was adapted to low impedances. As each successive stage is avalanched in the circuit, the amount of overvoltage increases, increasing the switching speed and improving the turn on time of the output pulse at the last stage. The output of the pulser is coupled into the load using a parallel plate charge line. The impedance and associated discharge time of this transmission line is tailored to the impedance and pulse duration requirements of the load. With the adapted circuit modifications, we have designed and evaluated a driver pulser capable of delivering 200 V DC into a 5 W load with a 250 ps risetime and a 500 ps pulsewidth. Results from transmission line, resistive, and semiconductor laser diode test loads will be presented.

关键词： Driver circuits Impedance Optical pulses Optical sensors Diode lasers Pulse circuits High speed optical techniques Nonlinear optics Space vector pulse width modulation Optical pulse generation

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Trends in the development of solid state amperometric and potentiometric high temperature sensors

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solid state IONICS 2000年第137期136卷 519-531页

作者： Göpel, W Reinhardt, G Rösch, M Univ Tubingen Inst Phys & Theoret Chem D-72076 Tubingen Germany Univ Tubingen Steinbeis Transfer Ctr Interface Anal & Sensors D-72076 Tubingen Germany

High temperature sensors based on solid electrolytes are well established in many applications. In this context. stabilized zirconia as an oxygen ion conductor plays the key role to monitor oxygen. Recent trends in the use of stabilized zirconia aim at the detection of other exhaust or environmental gases like NOx, CO or hydrocarbons. This is possible by, e.g. monitoring currents of specific electrode reactions at a given voltage ('amperometric devices') or monitoring voltages between different electrodes which result from specific electrode reactions including the kinetically determined formation of surface oxygen during different catalytic reactions ['mixed-potential (non-Nernstian) devices']. In all applications, the catalytic and electrochemical properties of the electrode materials play a key role for achieving reproducible sensor signals. This requires controlled microstructures down to the atomic scale. Therefore, extensive work now focuses on the structural as well as functional optimization of known, and on the development of new electrode materials. In this promising trend particular emphasis is put on the in-situ spectroscopic and microscopic characterization of the various interfaces under sensor operation conditions. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： stabilized zirconia amperometric sensors potentiometric sensors mixed potentials sensor arrays multi-component analysis interface analysis in-situ spectroscopy

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Fiber optic sensor technology: an overview

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sensorS AND ACTUATORS A-PHYSICAL 2000年第1-3期82卷 40-61页

作者： Grattan, KTV Sun, T City Univ London Sch Engn Dept Elect Elect & Informat Engn London EC1V 0HB England

This work presents an overview of progress and developments in the field of fiber optic sensor technology, highlighting the major issues underpinning recent research and illustrating a number of important applications... 详细信息

关键词： fiber optics sensors measurement

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Application of Schottky barrier bolometer arrays to cooled sensors

Application of Schottky barrier bolometer arrays to cooled s...

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conference on Infrared Technology and applications XXVI

作者： Shepherd, FD Murguia, JE Solid State Sci Corp Hollis NH 03049 USA

ISBN: (纸本)0819437751

We describe a model for cooled thermal imaging sensors, based on silicon Schottky diode bolometer arrays. The sensing mechanism is the modulation of Schottky diode dark current with temperature. The proposed array is identical to Schottky diode arrays, which would be used for uncooled thermal imaging, except for a change of the sensing electrode metal. We separate the thermal and electrical response of the detector elements and discuss sensor limitations related to detector thermal isolation. At a 180 K operating temperature, we project NEDT's in the 3 to 20 mK range, depending upon system f/number. A 20 cm aperture sensor based on this technology should have a noise equivalent power below 10(-11) watts.

关键词： cooled sensors infrared imaging bolometer arrays thermionic emission

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Uniform III-V semiconductor quantum wire and quantum dot arrays by natural self-faceting on patterned substrates

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THIN solid FILMS 2000年第1-2期367卷 32-39页

作者： Ploog, KH Nötzel, R Paul Drude Inst Solid State Elect Berlin Germany

We review the unique self-organizing growth mechanisms on planar and patterned high-index semiconductor substrates in atomic hydrogen assisted molecular beam epitaxy (MBE) allowing the reproducible fabrication of dense arrays of quantum wires and quantum dots with large confinement energy and uniform size distribution needed for realistic device applications. On not intentionally patterned substrates, hydrogen induced nanometer-scale self-faceting is directly applied for the formation of conductive quantum wires on GaAs(331)A exhibiting pronounced anisotrapy of the electron conductivity. In conventional MBE on intentionally patterned GaAs(311)A substrates the self-limiting formation of a fast growing mesa sidewall is highlighted. The systematic engineering of growth selectivity by appropriate pattern design reveals high flexibility for the fabrication of dense arrays of quantum wires, dot-like nanostructures, and coupled wire-dot arrays with superior control of nanostructure size and position. A new dimension in nanostructure formation is introduced by combining the natural self-faceting on GaAs(311)A substrates with patterned growth in atomic hydrogen assisted MBE producing linear arrays of quantum dots with minimized size fluctuations. (C) 2000 Elsevier Science S.A. All rights reserved.

关键词： III-V semiconductors molecular beam epitaxy patterned growth quantum wires quantum dots

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Ferroelectric and antiferroelectric films for microelectromechanical systems applications

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THIN solid FILMS 2000年 377卷 712-718页

作者： Xu, BM Cross, LE Bernstein, JJ Penn State Univ Mat Res Lab University Pk PA 16802 USA Charles Stark Draper Lab Inc Cambridge MA 02139 USA

In this paper we have introduced several types of ferroelectric and antiferroelectric thin (thickness m) and thick (thickness >1 mum) films developed in our group for sensor, actuator and transducer applications in... 详细信息

In this paper we have introduced several types of ferroelectric and antiferroelectric thin (thickness <1 m) and thick (thickness >1 mum) films developed in our group for sensor, actuator and transducer applications in microelectromechanical systems (MEMS). Ferroelectric lead zirconate titanate (PZT) films of up to 12 mum in thickness have been prepared on Pt-buffered silicon substrates, which allows for the conventional, through-thickness polarization, and of up to 5 mum in thickness on insulating layer (ZrO2) passivated silicon substrates, which allows for the novel, in-plane polarization. The in-plane poled films make it possible to develop d(33)-mode rather than d(31)-mode bending devices, which immediately leads to two-times improvement in device performance because d(33) approximate to 2 d(31). It also can greatly increase the voltage sensitivity of bending devices because the film thickness and electrode spacing are separated as independent variables, and thus, smaller film capacitance can be obtained by using wider electrode spacing even for fixed film thickness. In addition to PZT ferroelectric films, we have also developed antiferroelectric films as an alternative for high-strain microactuators. The strain level of the antiferroelectric films can reach more than 0.4%, and both digital and analog actuation can be realized by modifying the compositions of the films. As an example for MEMS applications, micromachined, unimorph-type two-dimensional transducer arrays have been fabricated based on both the through-thickness and in-plane polarized PZT films, which can be used for miniaturized, high-resolution acoustic imaging such as hand-held diver's sonar system, medical ultrasound imaging, and non-destructive testing. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： ferroelectric films antiferroelectric films microelectromechanical systems micromachined transducer arrays

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development of individually addressable micro-mirror-arrays for space applications

Development of individually addressable micro-mirror-arrays ...

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conference on MOEMS and Miniaturized Systems

作者： Dutta, SB Ewin, AJ Jhabvala, M Kotecki, CA Kuhn, JL Mott, DB NASA Goddard Space Flight Ctr Greenbelt MD 20771 USA

ISBN: (纸本)0819438340

A two dimensional array of individually addressable micro-mirrors with 100 mu mx100 mum pixel size, capable of tilting +/- 10 degrees by electrostatic actuation is being developed and fabricated at the Detector development Laboratory of NASA, GSFC. The development requires integration of CMOS and MEMS fabrication processes. We have completed extensive analytical studies and performed laboratory tests to compare model predictions with actual performance of a 3x3 array. We are testing the address and driver circuit for a 32x32 array and also developing the process integration of the CMOS and MEMS fabrication of the larger arrays. The mirrors are capable of operating at cryogenic temperature for astronomical applications. Our goal is to extend the development to a 256x256 array for a wide variety of space applications including the Multi-Object-Spectrometer in the Next Generation Space Telescope (NGST).

关键词： MEMS micro-mirror-array cryogenic MEMS cryogenic CMOS NGST

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Design and fabrication of optical-MEMS pressure sensor arrays

Design and fabrication of optical-MEMS pressure sensor array...

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conference on MOEMS and Miniaturized Systems

作者： Dasgupta, S Zhou, J Wolff, JM Jackson, HE Boyd, JT Univ Cincinnati Dept Elect & Comp Engn & Comp Sci Cincinnati OH 45221 USA

ISBN: (纸本)0819438340

arrays of pressure sensors utilizing microelectromechanical systems (MEMS) technology for fabrication of the sensing element and interrogation by fiber optics are described. Optically interrogated MEMS devices are potentially more suitable for many propulsion applications involving harsh environments than electrically interrogated MEMS devices. Pressure sensor elements form a Fabry-Perot interferometer so that reflected light measures pressure. Rationale for the design of the geometry of sensor elements and array configurations will be presented. These devices are designed to provide sensitivity over a given pressure range, ease of fabrication, and array configurations useful for propulsion characterization. sensor element and array fabrication will be discussed. These sensor elements are fabricated by etching shallow cavities in glass substrates followed by electrostatic bonding of silicon onto the glass over the cavity. The silicon is then etched to form the pressure sensitive diaphragm. Linear arrays having 6 elements will be described. Experimental results for static pressure tests and dynamic pressure tests carried out in a shock tube demonstrate reasonable linearity, sensitivity and time response.

关键词： fiber-optic micromachined sensor arrays dynamic response Fabry-Perot pressure sensors

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