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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Charge-coupled device image sensor study

The design specifications and predicted performance characteristics of a Charge-Coupled Device Area Imager and a Charge-Coupled Device Linear Imager are presented. The Imagers recommended are intended for use in space-borne imaging systems and therefore would meet the requirements for the intended application. A unique overlapping metal electrode structure and a buried channel structure are described. Reasons for the particular imager designs are discussed.

Source record↗
NASA NTRS1976

A backside illuminated 400 x 400 charge-coupled device imager

Large-area backside illuminated charge-coupled device imagers have been fabricated using double level aluminum transfer electrode technology. Devices with 100 x 160 and 400 x 400 resolution elements have been fabricated using buried channel technology for high charge transfer efficiency. Detailed optical characterization has been performed on these imagers over the temperature range -40 to +24 C and at several operating frequencies between 10 kHz and 1 MHz.

Antcliffe, G. A.↗
NASA NTRS1982

The development and applications of charge-coupled devices for space astronomy

The developments in charge-coupled device technology over the past decade are reviewed, with emphasis on the relevance of these developments to astronomical applications. The characteristics and limitations of current commercial devices are described, and the future requirements on CCDs for space astronomy are summarized for the X-ray and near UV, optical, and infrared wavelength ranges. Emphasis is placed on the commonality of technological development which is called for, including the issues of quantum detection efficiency (photon entrance and depletion depth), charge transfer efficiency, modulation transfer function, output noise level, and array size. The system requirements on focal plane instrumentation for space astronomy are summarized, and shown to have much in common for the different wavelength bands. These requirements are discussed in terms of CCD mosaicing, cryogenic cooling, and electronics. The overlap in CCD developments in the defense, astronomical and commercial arenas is summarized.

Griffiths, R. E.↗
NASA NTRS1985

Isolation Mounting for Charge-Coupled Devices

CCD's suspended by wires under tension. Remote thermoelectric cooling of charge coupled device allows vibration isolating mounting of CCD assembly alone, without having to suspend entire mass and bulk of thermoelectric module. Mounting hardware simple and light. Developed for charge-coupled devices (CCD's) in infrared telescope support adaptable to sensors in variety of environments, e.g., sensors in nuclear reactors, engine exhausts and plasma chambers.

Goss, W. C.↗
NASA NTRS1989

Radiation damage in scientific charge-coupled devices

Radiation damage is reported on CCDs (charge-coupled devices) that have been primarily exposed to 1.25-MeV gamma rays (Co-60 source). Two important classes of radiation damage are discussed, namely, bulk and ionization effects. Bulk damage or displacement damage is a process in which silicon atoms are displaced from their normal lattice positions by high-energy photons or particles. Single atomic displacements or cluster defect damage is produced, depending on the energy and type of radiation experienced by the detector. Bulk damage creates trapping sites within the CCD's signal channel which in turn degrades charge-transfer efficiency.

Janesick, James↗
NASA NTRS1976

A photon counting array photometer using an intensified charge coupled device

An array photometer which uses an intensified charge coupled device was developed. This system, the University of Maryland Array Photometer (UMAP), has the ability to discriminate single photoelectron events in real time at a 4 Megahertz rate. The photosensor uses an S-20 photocathode and a Fairchild CCD202 with a 100 by 100 array of separate individual channels. The overall system has demonstrated a noise level which permits single photoelectron discrimination, a scan rate of 400 frames per second, a very linear response, and very low lag. The UMAP system has a very large dynamic range exceeding 10,000 in the photon counting mode. A special technique to extend the dynamic range to 1,000,000 was described. The performance parameters of this system, both in the laboratory and on the telescope were cited. Data from these observations were discussed to illustrate the system sensitivity, which is basically limited by the pixel size in the array, rather than the electrooptics.

Currie, D. G.↗
NASA NTRS1973

Two-phase charge-coupled device

A charge-transfer efficiency of 99.99% per stage was achieved in the fat-zero mode of operation of 64- and 128-stage two-phase charge-coupled shift registers at 1.0-MHz clock frequency. The experimental two-phase charge-coupled shift registers were constructed in the form of polysilicon gates overlapped by aluminum gates. The unidirectional signal flow was accomplished by using n-type substrates with 0.5 to 1.0 ohm-cm resistivity in conjunction with a channel oxide thickness of 1000 A for the polysilicon gates and 3000 A for the aluminum gates. The operation of the tested shift registers with fat zero is in good agreement with the free-charge transfer characteristics expected for the tested structures. The charge-transfer losses observed when operating the experimental shift registers without the fat zero are attributed to fast interface state trapping. The analytical part of the report contains a review backed up by an extensive appendix of the free-charge transfer characteristics of CCD's in terms of thermal diffusion, self-induced drift, and fringing field drift. Also, a model was developed for the charge-transfer losses resulting from charge trapping by fast interface states. The proposed model was verified by the operation of the experimental two-phase charge-coupled shift registers.

Kosonocky, W. F.↗
NASA NTRS1990

Multi-Pinned-Phase Charge-Coupled Device

Multi-pinned-phase (MPP) technology allows charge-coupled device (CCD) to operate totally inverted during both integration and readout while maintaining other performance characteristics. MPP-CCD made with positive doping implants defining barrier phases. When all phases biased together into inversion, dark current reduced, and potential of charge-collecting wells is difference between potentials of barrier and collection phases. Advantages include complete elimination of residual image effects during integration and readout, low pixel nonuniformity, and increase in quantum efficiency in near infrared because higher operating temperatures used. More tolerant to ionizing radiation environments.

Janesick, James R.↗
NASA NTRS1974

Charge coupled device image sensor study

An evaluation of a charge-coupled device (CCD) image sensors for use in spacecraft-borne imaging systems was conducted. The study resulted in design recommendations for two sensors, an approximately 500 times 500 element imaging device and a 1 times 190 element linear imaging device with a 190 times 121 buffer store. Emphasis was placed on the higher resolution, area-imaging sensor. The objectives of the proposed sensors are listed, results of the experiments are analyzed, and estimates of the device performance are presented. A summary of the major technical recommendations is included.

Source record↗
NASA NTRS1982

Study of Two Digital Charge-Coupled Devices

Recent report describes reliability study of two charge-coupled-device (CCD) shift registers. Major objective of study was to establish methodology for selecting, testing, screening, derating and applying CCD's. Includes a discussion of CCD structures and operating principles. Characteristics of SCCD and BCCD types are compared.

Wilson, D. D.↗
NASA NTRS1972

Fast-interface-state losses in charge-coupled devices.

A simple model is presented that makes it possible to predict signal losses in charge-coupled devices due to fast-interface-state trapping. Presented experimental losses in a twelve-bit two-phase charge-coupled device with overlapping Si and Al gates are shown to agree well with the prediction of the model.

Carnes, J. E.↗
NASA NTRS1973

Electrode materials for charge coupled devices

The use of polycrystalline silicon in charged coupled semiconductor devices is discussed. In particular, the electrical and optical properties of the material are characterized.

Gajda, W. T. J.↗
NASA NTRS1979

Programmable charge-coupled device /CCD/ correlator for pattern classification

The potential use of charge coupled device (CCD) programmable digital/analog correlators for multispectral data classification is discussed. CCD digital/analog correlator technology and the experimental evaluation of a 32-stage 4-bit test device are presented. The design of an IC for use in a multispectral classification system for 16 sensors and 8 bit accuracy is reviewed.

Mayer, D. J.↗
NASA NTRS1982

Galileo Institute for Astronomy (IFA) charge-coupled device (CCD) system

A fully portable self-contained charge-coupled device system has been constructed for shared use with the Galileo Project Imaging Team. The detector currently incorporated in the system is a Texas Instruments 500 x 500 three-phase CCD that has been thinned to operate in the backside illuminated mode. The detector and camera mainframe electronics were provided by the Jet Propulsion Laboratory. The support electronics and control interfaces necessary to operate the mainframe were constructed. The data system, which is built around a DeAnza Visacom VC-5000 Image Processor with an imbedded LSI-11 minicomputer, was also integrated. The capability to do image processing in real-time at the telescope has proved to be extremely valuable. The overall system read noise has been measured at 25 electrons. Full-well capacity is 40,000 electrons. Some results from laboratory tests and initial observing runs at the Mauna Kea 2.2-m telescope are presented.

Hlivak, R. J.↗
NASA NTRS1984

Calculation of resolution for a windowless charge coupled device (CCD)-Digicon

A new version of an intensified charge-coupled device (ICCD) system, which is based on the incorporation of a CsI mesh photocathode and a thinned backside-illuminated CCD into a Space Telescope design Digicon tube, is being developed for future use in space-based observations in the Extreme Ultraviolet waveband. In this paper, a report is presented of the results of computer simulations involving the effects of the non-uniform electrostatic field near the mesh photocathode on imaging properties (especially, the spread function and modulation transfer function) of the detector system. The results are of importance in the design of the front end of the tube and the selection of optimum tube operating conditions. The overall resolution characteristics of the tube, including the effects of the mesh, the electron optics of the region between the mesh photocathode and the CCD target, and the structure of the CCD itself, are estimated.

Jia, X. Z.↗
NASA NTRS1990

Nitric Oxide Enhances Charge-Coupled Device

Simple treatment increases and stabilizes quantum efficiency of charge-coupled-device photodetector illuminated on back surface at wavelengths less than 4,500 Angstrom. Must be biased in strong accumulation mode. Physical principle of enhancement explained more fully in "Metal Film Increases CCD Output" (NPO-16815). Useful for imaging at wavelengths from ultraviolet to blue; for example, in astronomical observations.

Hecht, Michael H.↗
NASA NTRS1986

Statistical performance of the intensified charged coupled device

The first analysis of the statistical performance of the intensified charge coupled device (CCD) is presented. The Poisson statistics of the arriving photons, the exponential pulse height distribution of the microchannel plate in the image intensifier, and the effects of discrete digitization of the charge in reading the CCD are included. A range of intensifier gains from the high levels that permit pulse counting to the low levels that can be used with the accumulation of charge on the CCD is considered. As a tool for this analysis, an analytical model of the performance of the detector system that is generally useful for predicting many aspects of system performance under a wide range of conditions is developed. The statistical penalty for operating the intensified CCD in the charge accumulation mode is not severe, and in some applications it may be desirable to accept this penalty to gain the advantages of increased dynamic range through charge accumulation. This investigation has revealed no pathological aspects of the operation of the detector system.

Sandel, B. R.↗