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Energy selective imaging systems based on monolithic CdZnTe arrays operated in a high speed counting mode

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 1996年第1-2期380卷 323-330页

作者： Polichar, R Schirato, R Shreve, D Reed, J Polichar, A Science Applications International Corporation 4161 Campus Point Court San Diego CA 92121 USA

The excellent inherent energy resolution of CdZnTe and the evolution of techniques to fabricate this material into large, multi-pixel monolithic arrays, have encouraged the development of practical, multi-function, x-ray imaging systems. These systems are capable of simultaneously recording the x-ray image of an object while identifying the average atomic number of each of its internal components. The primary improvement of this new sensor technology is the ability to break down the detected radiation into energy bins after passing through the sample. The reduced fraction of scattered radiation recorded in a collimated, linear scanner image makes it possible to separate differing energy regions of the beam with a single bremsstrahlung source and a single, multiple discriminators. Such imaging systems have immediate applications in security and contraband detection, as well as a number of specialized uses in medical imaging. This review covers recent work carried out at SAIC in the development of these systems including the characterization of the detector devices, the requirements for the electronic readout system and a number of examples of images taken with prototype systems. Studies have been conducted with examples of both linear and area arrays using relatively simple processing electronics. Problems of incomplete charge collection and energy separation are discussed along with potential solutions to these issues. Imaging measurements made with these systems exhibit noise limits set by the available statistics and excellent point spread functions. Practical limitations in the useful pixel resolution approach 0.1 mm with stopping thickness of several millimeters. This suggests that high resolution scanners with x-ray tube potentials of several hundred kilovolts are feasible with this technology.

关键词： x-ray imaging dual energy position sensitive solid state detector array room temperature cadmium zinc telluride

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Design and characterization of CMOS APS imagers on two different technologies

Design and characterization of CMOS APS imagers on two diffe...

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Conference on solid state sensor arrays - development and applications II

作者： Cavadore, C Solhusvik, J Magnan, P Gautrand, A Degerli, Y Lavernhe, F Farre, J Saint-Pe, O Davancens, R Tulet, M SUPAERO Dept Elect F-31055 Toulouse 4 France

ISBN: (纸本)0819427411

In this paper, we present experimental results from measurements on CMOS APS imager designed by CIMI-SUPAERO on two different technologies. In both cases, pixels with photoMos and photodiode structures have been designed. The first circuit has been developed using a standard CMOS DLP/DLM 1.2 mu m process from Austria Micro Systems. The detector array consists of 32x32 square pixels with 50 mu m pixel pitch;fill factor is 75 % for photodiode (PD) and 50 % for photoMos (PM). The circuit is also including row and column address decoders and the readout circuitry so as to perform on-chip correlated double-delta sampling to reduce column to column fixed pattern noise. Two other chips have been developed with a standard CMOS SLP/DLM process from MIETEC with 0.7 mu m design rules, which includes a 128x128 pixels array, with 21 mu m pixel pitch and analogue readout circuitry. Among 10 different arrays, no faulty one was observed for both circuits. In this paper, we compare both performances of 32x32 pixels and 128x128 pixels in terms of dark current, quantum efficiency, conversion gain, dynamic range, linearity and spatial uniformity.

关键词： Active Pixel sensor APS CMOS image sensors characterisation

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A comparative analysis of one-port Colpitt and two-port Pierce SAW oscillators for DMMP vapor sensing

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sensorS AND ACTUATORS B-CHEMICAL 2006年第1期114卷 316-325页

作者： Nimal, AT Singh, M Mittal, U Yadava, RDS Solid State Phys Lab Delhi 110054 India

This paper reports an experimental study on chemical sensitivity and noise behavior of Colpitt and Pierce SAW oscillators based on 433.92 MHz one-port and two-port SAW resonator devices, respectively. The oscillators are characterized for phase noise as well as Allan variance. The sensitivity for DMMP (di-methyl methyl phosphonate) vapor is imparted by providing a diallyl-bisphenol polymer precursor as a selective interface coated on to both the SAW devices in an identical manner. Comparative vapor sensing experiments are carried out under simultaneous exposure to the same DMMP vapor stream in different ranges of vapor concentration and duration. A new data acquisition method is employed which is wireless and automated. It uses an antenna pickup at the input of a spectrum analyzer with PC control interface. The results show that the two-port Pierce oscillator is more stable but less sensitive than the one-port Colpitt oscillator. It is found that under the conditions of analyte exposure durations longer than 30 s the one-port Colpitt oscillator yields higher signal to noise ratios. The results are interpreted in terms of phase response characteristics and different sensitivities of the one-port and two-port SAW devices towards mass loading and viscoelastic effects. (c) 2005 Elsevier B.V. All rights reserved.

关键词： SAW oscillator DMMP sensor phase noise Allan variance mass and viscoelastic loading

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Optical refractometry using a, monolithically integrated Mach-Zehnder interferometer

Optical refractometry using a, monolithically integrated Mac...

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1997 International Conference on solid-state sensors and Actuators

作者： Maisenholder, B Zappe, HP Kunz, RE Moser, M Riel, P Paul Scherrer Inst Zurich Switzerland

ISBN: (纸本)0780338294

Integrated optical sensors, based on evanescent wave sensing, are useful for numerous applications, including medical, environmental and food analysis. System miniaturization is a key issue in their further development. We present the design and fabrication of a novel refractometric transducer, where all optoelectronic components (lasers, waveguides, modulators, detectors and sensor pads) are monolithically integrated on a 5 x 0.15 mm(2) chip and report on its performance as a refractometer in a flow-through system.

关键词： optical sensor evanescent wave interferometer integrated optics

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Impedance extraction microsystem for nanostructured electrochemical sensor arrays

Impedance extraction microsystem for nanostructured electroc...

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作者： Yang, Chao Michigan State University

学位级别：Ph.D.

Electrochemical biosensors transform biochemical reactions into electrical information through various electrode transducers. With their high sensitivity and specificity, electrochemical biosensors are ideal agents to detect many inorganic and organic substances. Recently, the microfabrication of biosensors has matured to the point where high density arrays can be generated. A microsystem comprised of such arrays and an integrated circuit (IC) suitable for sensor interrogation and information extraction enables the capabilities of electrochemical sensors to be employed in applications that require miniaturization, including point of care medical diagnostics and distributed safety and security monitoring. In such a microsystem, the interrogation IC must provide extremely high sensitivity, to read the weak response from the miniaturized sensors, and be capable of multi-channel simultaneous readout, to support high density (∼100 elements) arrays. This dissertation focuses on overcoming the challenges and limitations in electronics that impede the development of electrochemical microsystems. Specifically, this research targets electrochemical impedance spectroscopy, an essential assay technique for many sensor interfaces. Several possible architectures for multichannel impedance spectroscopy were explored in this dissertation. The key functional blocks, identified as an impedance extractor and digitizer and a wide frequency range quadrature signal generator, were designed, tested, and implemented within a prototype biosensor array system to validate the design. The results of this research pave the way for further development of ICs for electrochemical sensors and lay a solid foundation for future implementations of fully integrated electrochemical impedance microsystems.

关键词： Electrochemical sensorsImpedance Bioelectric

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solid-state aspect sensor

Solid-state aspect sensor

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Shuttle Pointing of Electro-Optical Experiments 1980

作者： Cassidy, L. Kaplan, L. Perkin-Elmer Corporation Optical Technology Division DanburyCT06810 United States

Programs in development for the near future will require pointing sensors with accuracies in the region of 1 arc-sec and sub-arc-sec stability. The Advanced X-Ray Astronomical Facility, Annular Suspension Pointing System, Shuttle Infra-Red Telescope Facility and Stereosat are representatives of these programs. This paper describes a solid state Aspect sensor which could support this pointing capability and the testing technology necessary to verify its performance. The sensor uses a Charge Coupled Device (CCD) array integrated with a high-performance optical assembly. Perkin-Elmer has developed in-house a solid state sensor which could be used for precision pointing and attitude estimation applications. A test facility has been established which can be used to evaluate CCD arrays and optical assemblies for their suitability and use in a star sensor. The detail design of a stellar sensor to meet 1 arc-sec pointing requirements is presented. Optical performance characteristics are discussed, as is the verification testing of a prototype optical assembly. Test data are provided. The optical assembly is a 253-mm focal length, F/l.5 catadioptric lens system. Discussion of the solid state focal plane includes focal plane requirements and centroiding algorithms, focal plane and CCD test facilities, representative test data from linear CCD arrays, and a candidate CCD array for this application. An integrated sensor test station is described. Important considerations in the development of this precision pointing sensor are also presented, along with the predicted sensor performance based upon computer simulations. © 1981 SPIE. All rights reserved.

关键词： Focusing

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solid state IMAGE SENSING: A NEW AND VERSATILE TOOL FOR SCIENCE AND INDUSTRY.

SOLID STATE IMAGE SENSING: A NEW AND VERSATILE TOOL FOR SCIE...

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Asilomar Conf on Circuits, Syst, and Comput, 7th, Annu, Conf Rec, Pap

作者： Weckler, Gene P.

Recent developments pertaining to solid state image sensors are reviewed. Advances in signal processing are discussed and characteristics and performance of typical sensor arrays are presented. New and novel applications ranging from scientific instruments to non-contact measurements for industrial process control. The basic device consists of a silicon chip containing a row of photodiodes and a parallel shift register. Connected to each stage of the shift register is the gate of an MOS switch which couples the adjacent photodiode to a common video line. Both linear and area arrays have emerged from the development stage. New and novel applications ranging from scientific instruments to non-contact measurements for industrial process control are described and illustrated.

关键词： Semiconductor diodes, Photodiode

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Charge-transfer-efficiency (CTE) measurement techniques applied to proton-irradiated, linear charge-coupled devices

Charge-transfer-efficiency (CTE) measurement techniques appl...

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Conference on solid state sensor arrays - development and applications II

作者： Dutton, TE Woodward, WF Lomheim, TS Aerospace Corp Sensor Syst Subdiv Los Angeles CA 90009 USA

ISBN: (纸本)0819427411

Charge-Transfer-Efficiency (CTE) is a parameter that is associated with the optical performance and radiometric accuracy of a Charge-Coupled Device (CCD). While modern CCD's are typically quoted as having CTE>0.99999, we show that a) this efficiency can be degraded by exposure to energetic protons and b) the measured efficiency, at least in the case of irradiated devices, is dependent on the size of the signal being transferred. A comparison of two techniques of CTE measurement is presented, with emphasis on an Fe-55 X-ray charge-generation and collection technique tailored especially for use with linear CCD's. While our technique follows the same general X-ray method widely used to characterize area CCD's, its implementation, including the processing of the resulting experimental data, is somewhat novel. The X-ray technique requires no special device circuitry or equipment and, in our configuration, may be used on virtually any linear or bilinear CCD;the same general technique is used on area arrays. It is shown that the technique is appropriate for characterizing small-signal CTE with or without a high background. It is also shown that the electrical injection CTE, while requiring the injection circuitry to be designed and built-in to the CCD structure, is more appropriate for large-signal CTE measurement. Data are presented showing experimental pre-and post-irradiation CTE measured as a function of signal level and background level for a two-phase linear CCD. Additionally, it is shown that in our tests, the CTE degraded even at very small accelerated doses (<10 kRad(Si) of ionizing proton dose), but further degradation was at least partly compensated by an enhanced background due to increasing dark currents.

关键词： charge transfer efficiency CTE X-ray charge coupled device CCD electrical injection proton irradiation

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Conducting polymers in chemical sensors and arrays

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ANALYTICA CHIMICA ACTA 2008年第1期614卷 1-26页

作者： Lange, Ulrich Roznyatouskaya, Nataliya V. Mirsky, Vladimir M. Univ Regensburg Inst Analyt Chem Chemo & Biosensors D-93040 Regensburg Germany Moscow MV Lomonosov State Univ Dept Chem Moscow 119992 Russia

The review covers main applications of conducting polymers in chemical sensors and biosensors. The first part is focused on intrinsic and induced receptor properties of conducting polymers, such as pH sensitivity, sensitivity to inorganic ions and organic molecules as well as sensitivity to gases. Induced receptor properties can be also formed by molecularly imprinted polymerization or by immobilization of biological receptors. Immobilization strategies are reviewed in the second part. The third part is focused on applications of conducting polymers as transducers and includes usual optical (fluorescence, SPR, etc.) and electrical (conductometric, amperometric, potentiometric, etc.) transducing techniques as well as organic chemosensitive semiconductor devices. An assembly of stable sensing structures requires strong binding of conducting polymers to solid supports. These aspects are discussed in the next part. Finally, an application of combinatorial synthesis and high-throughput analysis to the development and optimization of sensing materials is described. (C) 2008 Elsevier B.V. All rights reserved.

关键词： conducting polymers chemical sensors electroactive polymers gas sensors combinatorial techniques electropolymerization sensor array

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Large format CID x-ray image sensor

Large format CID x-ray image sensor

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Conference on solid state sensor arrays - development and applications II

作者： Carbone, J Alam, Z Borman, C Czebiniak, S Ziegler, H CIDTEC Liverpool NY 13088 USA

ISBN: (纸本)0819427411

A large format (31 x 23 mm(2) display) CID imager module capitalizes on CID large well capacity and radiation resistance to image dental x-rays. The module, which consists of the imager, conversion phosphor and ancillary electronics, is encapsulated in a 40 x 28 x 5 mm(3) robust package that is lightproof, moisture-proof and meets FDA and RFL/EMI standards. Data exposure and readout is simple. The imager normally exists in an active reset mode until X-ray application automatically places the imager into a charge integration mode. Readout begins immediately upon completion of the x-ray exposure or manual application of an external trigger source. The imager returns to the reset mode once the data read out is complete. Pixels are arranged in an SVGA compatible 800(H) x 600(V) format. Each pixel is square and 38.5 microns/side. The imager is coated using a proprietary phosphor deposition process that results in a limiting resolution of 9 LP/mm from an X-ray illumination source. Better than 2,000:1 dynamic range and shot-noise limited operation is achieved. Direct X-ray detection and attendant noise is minimized via the phosphor and epitaxial layer that lies beneath the pixel array. The imager/module architecture and electro-optical performance are described in detail here in.

关键词： CIDs dental X-ray electronic imaging radiation-hardened charge transfer device

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