We have begun a program of repetitive operation of a high-current relativistic klystron on the CLIA facility at Physics International. Potential problems of beam formation have been investigated and found not to be a ...
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ISBN:
(纸本)0819407755
We have begun a program of repetitive operation of a high-current relativistic klystron on the CLIA facility at Physics International. Potential problems of beam formation have been investigated and found not to be a limitation at repetition rates as high as 200 Hz. We are presently beginning initial testing in repetitive mode of a 5 kA, 500 kv klystron, designed and tested in single shot mode at the Naval Research Laboratory. Initial results at 10 Hz do not indicate any problems that are inherently repetitive in nature.
An abridged text of a report on design and characteristics of a new three-lead temperature-current sensor with application of parametric bandgap-calibration is presented. The main distinction of the sensor consists of...
The current position of European Softcopy or Digital Photogrammetric Workstations (DPWS) in terms of operational systems as well as research and development activities is reviewed. European manufacturers (Leica, Matra...
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The current position of European Softcopy or Digital Photogrammetric Workstations (DPWS) in terms of operational systems as well as research and development activities is reviewed. European manufacturers (Leica, Matra, Galileo Siscam) have made significant strides in developing universal type DPWS for topographic applications. Operational close-range DPWS include the MAP vISION system and the Rolleimetric RS product line. European mapping organizations such as the Ordnance Survey (United Kingdom), the Institut Geographique National (France), the Institut Cartografic de Catalunya (Spain), the Landesvermessungsamt Nordrhein-Westfalen (Germany), and Eurosense (Belgium) have made first steps in using DPWS in the production environment, mainly for the automatic computation of digital terrain models and for orthoprojection. Within the universities there has been considerable research activity concerning design issues of DPWS, often focusing on specific applications. For example, work is in progress in Berlin, Glasgow, Hannover, and London on topographic applications, in Braunschweig and Zurich on close-range applications, and in Graz, London and Oberpfaffenhofen on radargrammetry. Similarly, a body of work on algorithmic aspects of DPWS has been carried out in Bonn, Darmstadt, Delft, Enschede, Karlsruhe, Lausanne, Munich, Stockholm, Stuttgart, and Zurich. These activities are reviewed and lead to a number of conclusions on the state-of-the-art and on future trends. The major ones are A DPWS is and will remain an interactive workstation, where the human operator handles less and less routine work, but stays responsible for verification and control. Digital orthoprojection is on the verge of becoming widely used in practice. Image matching techniques are applied in a number of DPWS for small-scale applications. The use of operational image understanding methods in DPWS has not yet been achieved. The incorporation of data from different sources, for example, optical and micr
Several photodetector applications require optimizing pulse response at moderate bandwidths. With current technology, such detector circuits can be op-amp based transimpedance amplifiers. Unfortunately, the usual tran...
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ISBN:
(纸本)0819409081
Several photodetector applications require optimizing pulse response at moderate bandwidths. With current technology, such detector circuits can be op-amp based transimpedance amplifiers. Unfortunately, the usual transimpedance topology, having a single feedback resistor, does not give enough control over pole placement for design optimization. If the single resistor is replaced by a tee-network, however, the transimpedance amplifier can be made to approximate any desired second-order network response. We present an analysis that shows how to choose resistor values to achieve desired second-order parameters: damped natural frequency and damping coefficient. Experimental results are presented that confirm the validity of our design method.
Software engineering principles suggest that complex software systems are best constructed from independent, self-contained modules, thereby maximizing the portability, maintainability and modifiability of the produce...
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ISBN:
(纸本)0819408069
Software engineering principles suggest that complex software systems are best constructed from independent, self-contained modules, thereby maximizing the portability, maintainability and modifiability of the produced code. This principal is important in the design of medical imaging workstations, where further developments in technology (CPU, memory, interface devices, displays, network connections) are required for clinically acceptable workstations, and it is desirable to provide different hardware platforms with the 'same look and feel' for the user. In addition, the set of desired functions is relatively well understood, but the optimal user interface for delivering these functions on a clinically acceptable workstation is still different depending on department, specialty, or individual preference. At the University of Washington, we are developing a viewing station based on the IBM RISC/6000 computer and on new technologies that are just becoming commercially available. These include advanced voice recognition systems and an ultra-high-speed network. We are developing a set of specifications and a conceptual design for the workstation, and will be producing a prototype. This paper presents our current concepts concerning the architecture and software system design of the future prototype. Our conceptual design specifies requirements for a Database Application Programming Interface (DBAPI) and for a User API (UAPI). The DBAPI consists of a set of subroutine calls that define the admissible transactions between the workstation and an image archive. The UAPI describes the requests a user interface program can make of the workstation. It incorporates basic display and image processing functions, yet is specifically designed to allow extensions to the basic set at the application level. We will discuss the fundamental elements of the two API's and illustrate their application to workstation design.
PACS research and development efforts at the University of Florida, Department of Radiology have been directed solely toward solving clinical problems with an objective of incorporating successful products or improvin...
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ISBN:
(纸本)0819408069
PACS research and development efforts at the University of Florida, Department of Radiology have been directed solely toward solving clinical problems with an objective of incorporating successful products or improving the functionality, performance, and reliability of the system. This paper describes the current network and system, experiences with system upgrades and changed, quality control measures used to verify that the system is operational, and current works in progress.
This paper presents a two-step liquid phase epitaxial growth procedure which is designed to yield the highest possible open circuit veltage InP solar cell. The design of the solar cell has been presented elsewhere [1]...
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Liquid-phase epitaxy (LPE) has emerged as the predominant materials growth technology for the fabrication of HgCdTe infrared (IR) detectors in the IR community over the past decade. This paper reviews one of the most ...
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ISBN:
(纸本)0819409081
Liquid-phase epitaxy (LPE) has emerged as the predominant materials growth technology for the fabrication of HgCdTe infrared (IR) detectors in the IR community over the past decade. This paper reviews one of the most successful LPE technologies developed for HgCdTe, specifically, 'infinite-melt' vertical LPE (vLPE) from Hg-rich solutions. A historical perspective and the current status of vLPE technology are reported. Extensive statistics of performance and producibility of the vLPE technology are elaborated to show its maturity and manufacturing readiness. Particular emphasis is placed on the key role of the double-layer heterojunction (DLHJ) detectors realized by the vLPE technology for high-performance second-generation focal plane arrays. Recent developments in the successful use of the vLPE technology for epitaxial growth on Si-based alternative substrates and for growth of triple-layer heterostructures for two-color applications, which further demonstrate the versatility of the technology, are also reported. The review concludes with a discussion of the prospects for use of the vLPE technology for fabricating advanced device structures of high performance as well as investigating fundamental material properties of HgCdTe.
Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signals to noise ratio ar...
Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signals to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.
Both thresholding and windowing are important tools in the reduction of false alarm rates in high sensitivity point source detection and correlation sensor signal processors. In a variable background environment, adap...
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