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3731.3D像素传感器辐照不均匀的ATLAS正向物理探测器光束试验研究
[计算机、通信和其他电子设备制造业] [2014-05-13]
Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) o er advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper.
关键词:传感器;光电跟踪;探测器;辐照
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3732.交通运输构造中分布式光纤防腐监测系统的初步研究和论证
[计算机、通信和其他电子设备制造业] [2014-05-13]
For this study, a novel optical fiber sensing system was developed and tested for the monitoring of corrosion in transportation systems. The optical fiber sensing system consists of a reference long period fiber gratings (LPFG) sensor for corrosive environmental monitoring and a LPFG sensor coated with a thin film of nano iron and silica particles for steel corrosion monitoring. The environmental effects (such as pH and temperature) are compensated by the use of the reference LPFG sensor. The sensor design, simulation, and experimental validation were performed in this study to investigate the feasibility of the proposed sensing system for corrosion and environment monitoring. The detailed investigations of the proposed sensing system showed that within the detection limitation of the thin coated layer, the proposed sensor could monitor both the initial and stable corrosion rate consistently. Compared to the traditional electrochemical method, the proposed optical fiber sensing system has a converter coefficient of 1 nm/day=3.746(10-3 A/cm2). Therefore, the proposed nano iron/silica particles dispersed polyurethane coated optical fiber sensor can monitor the critical corrosion information of the host members in real time and remotely. With multiple LPFGs in a single fiber, it is possible to provide a cost-effective, distributed monitoring solution for corrosion monitoring of large scale transportation structures.
关键词:传感器;光纤;防腐;交通系统
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3733.用于膜隔离超导转变边缘传感器过剩热容的声子机制
[计算机、通信和其他电子设备制造业] [2014-05-13]
The mechanics of phonon transport in membrane-isolated superconducting transition edge sensors is discussed. Surveys of the literature on this type of sensor reveal a number of designs with excess heat capacity and a smaller subset that exhibit decoupling of the superconducting film from the underlying dielectric. A simple model is addressed in which the membrane, despite its thermal isolation, fails to fully thermalize to the temperature of the metal film heating it. A population of phonons exists which is emitted by the metal film, partially thermalizes the dielectric and is then reabsorbed in the metal film without escaping from the device structure to the thermal bath. The size of this population and its contribution to the heat capacity are estimated for several device scenarios.
关键词:传感器;超导薄膜;德拜-休克尔理论;声子
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3734.500C碳化硅电子和传感器的封装技术
[计算机、通信和其他电子设备制造业] [2014-05-13]
Various SiC electronics and sensors are currently under development for applications in 500C high temperature environments such as hot sections of aerospace engines and the surface of Venus. In order to conduct long-term test and eventually commercialize these SiC devices, compatible packaging technologies for the SiC electronics and sensors are required. This presentation reviews packaging technologies developed for 500C SiC electronics and sensors to address both component and subsystem level packaging needs for high temperature environments. The packaging system for high temperature SiC electronics includes ceramic chip-level packages, ceramic printed circuit boards (PCBs), and edge-connectors. High temperature durable die-attach and precious metal wire-bonding are used in the chip-level packaging process. A high temperature sensor package is specifically designed to address high temperature micro-fabricated capacitive pressure sensors for high differential pressure environments. This presentation describes development of these electronics and sensor packaging technologies, including some testing results of SiC electronics and capacitive pressure sensors using these packaging technologies.
关键词:传感器;微机电系统;碳化硅;芯片
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3735.智能多级传感器用于航空航天结构应用机织复合材料的受损识别和缓解
[计算机、通信和其他电子设备制造业] [2014-05-13]
Combining global and local measurements at multiple physical scales was demonstrated to provide a physically based framework to estimate the location, severity and type of damage in composite airframe structures. Unique spectral signatures of fiber Bragg grating sensors were correlated to individual failure modes of representative composite laminates. A combined experimental/numerical formulation for the optimization of sensor placement for an embedded sensor network was then developed based on a cost function of component lifetime. The cost incorporated both the increase in lifetime through the identification of damage modes through the sensor responses and the decrease in lifetime through the host-sensor interactions. The optimization methodology was based on a combined theoretical/experimental approach incorporating both the experimentally driven characterization of the role of embedded sensors on the component lifetime and computational modeling of damage mechanisms and sensor-host interactions within the composite material. The optimization procedure, as a function of embedded sensor density, revealed regions where the component lifetime was increased and decreased. A specialized finite element formulation was then derived and implemented to predict how the electrical-mechanical-thermal behavior of carbon nanotube (CNT) reinforced polymer composites is affected by electron tunneling distances, volume fraction, and physically realistic tube aspect ratios.
关键词:传感器;光纤布拉格光栅传感器;复合材料结构;损伤识别
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3736.爱达荷国家实验室超声测温法最新发展。NPIC和HMIT2012。
[计算机、通信和其他电子设备制造业] [2014-05-13]
The Idaho National Laboratory (INL) has initiated an effort to evaluate the viability of using ultrasonic thermometry technology as an improved sensor for detecting temperature during irradiation testing of advanced fuels proposed within the Fuel Cycle Research and Development (FCR&D) program sponsored by the U.S. Department of Energy (US DOE). Ultrasonic thermometers (UTs) work on the principle that the speed at which sound travels through a material (acoustic velocity) is dependent on the temperature of the material. UTs have several advantages over other types of temperature sensors . UTs can be made very small, as the sensor consists only of a small diameter rod which may or may not require a sheath. Measurements may be made up to very high temperature (near the melting point of the sensor material) and, as no electrical insulation is required, shunting effects observed in traditional high temperature thermocouple applications are avoided. Most attractive, however, is the ability to introduce multiple acoustic discontinuities into the sensor, as this enables temperature profiling with a single sensor. The current paper presents initial results from FCR&D UT development efforts. These developments include improved methods for fabricating magnetostrictive transducers and joining them to waveguides, characterization of candidate sensor materials appropriate for use in FCR&D fuels irradiations (both ceramic fuels in inert gas and sodium bonded metallic fuels), enhanced signal processing techniques, and tests to determine potential accuracy and resolution.
关键词:传感器;燃料循环研究与发展;超声检测;温度测量
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3737.基于改进的楔形和锥形探头的流量变量的超音速测量的风洞和飞行试验结果
[计算机、通信和其他电子设备制造业] [2014-05-13]
The results of supersonic wind-tunnel tests on three probes at nominal Mach numbers of 1.6, 1.8 and 2.0 and flight tests on two of these probes up to a Mach number of 1.9 are described. One probe is an 8 deg. half-angle wedge with two total-pressure measurements and one static. The second, a conical probe, is a cylinder that has a 15 deg., semi-angle cone tip with one total-pressure orifice at the apex and four static-pressure orifices on the surface of the cone, 90 deg. apart, and about two-thirds of the distance from the cone apex to the base of the cone. The third is a 2 deg. semi-angle cone that has two static ports located 180 deg. apart about 1.5 inches behind the apex of the cone. The latter probe was included since it has been the "probe of choice" for wind-tunnel flow-field pressure measurements (or one similar to it) for the past half-century. The wedge and 15 deg. conical probes used in these tests were designed for flight diagnostic measurements for flight Mach numbers down to 1.35 and 1.15 respectively, and have improved capabilities over earlier probes of similar shape. The 15. conical probe also has a temperature sensor that is located inside the cylindrical part of the probe that is exposed to free-stream flow through an annulus at the apex of the cone. It enables the determination of free-stream temperature, density, speed of sound, and velocity, in addition to free-stream pressure, Mach number, angle of attack and angle of sideslip. With the time-varying velocity, acceleration can be calculated. Wind-tunnel tests of the two probes were made in NASA Langley Research Center fs Unitary Plan Wind Tunnel (UPWT) at Mach numbers of 1.6, 1.8, and 2.0. Flight tests were carried out at the NASA Dryden Flight Research Center (DFRC) on its F-15B aircraft up to Mach numbers of 1.9. The probes were attached to a fixture, referred to as the Centerline Instrumented Pylon (CLIP), under the fuselage of the aircraft. Problems controlling the velocity of the flow through the conical probe required for accurate temperature measurements are noted, as well as some calibration problems of the miniature pressure sensors that required a re-calculation of the flow variables. Data are presented for angle of attack, pressure and Mach number obtained in the wind tunnel and in flight. In the wind tunnel some transient data were obtained by translating the probes through the shock flow field created by a bump on the wind-tunnel wall.
关键词:传感器;超音速流动;风洞试验;流量分布
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3738.陆地卫星和热红外成像
[计算机、通信和其他电子设备制造业] [2014-05-13]
The purpose of this chapter is to describe the collection of thermal images by Landsat sensors already on orbit and to introduce the new thermal sensor to be launched in 2013. The chapter describes the thematic mapper (TM) and enhanced thematic mapper plus (ETM+) sensors, the calibration of their thermal bands, and the design and prelaunch calibration of the new thermal infrared sensor (TIRS).
关键词:传感器;光谱灵敏度;热映射;红外成像
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3739.传感器调度的信息几何方法
[计算机、通信和其他电子设备制造业] [2014-05-13]
An information-geometric approach to sensor management is introduced that is based on following geodesic curves in a manifold of possible sensor configurations. This perspective arises by observing that, given a parameter estimation problem to be addressed through management of sensor assets, any particular sensor configuration corresponds to a Riemannian metric on the parameter manifold. With this perspective, managing sensors involves navigation on the space of all Riemannian metrics on the parameter manifold, which is itself a Riemannian manifold. Existing work assumes the metric on the parameter manifold is one that, in statistical terms, corresponds to a Jeffreys prior on the parameter to be estimated. It is observed that informative priors, as arise in sensor management, can also be accommodated. Given an initial sensor configuration, the trajectory along which to move in sensor configuration space to gather most information is seen to be locally defined by the geodesic structure of this manifold. Further, divergences based on Fisher and Shannon information lead to the same Riemannian metric and geodesics.
关键词:传感器;探测器;大地测量;信息几何形状
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3740.使用MGL-S9AB超点传感器进行高频磁场定向查找
[计算机、通信和其他电子设备制造业] [2014-05-13]
Aircraft based direction finding (DF) in the high frequency (HF) band is difficult due to the aircraft's size with respect to wavelength and limited azimuthal resolution. A B-dot sensor is useful for detection of the time varying magnetic field and offers improved integration into an aircraft. What the B-dot sensor gains in integration it gives up in sensitivity because it is designed for frequencies above 5 GHz. Design of an airborne HFDF array using Bdot sensors is based in maximizing the physical extent of the array and eliminating multiple main beams. The goals of this research are to complete a computational analysis of a B-dot sensor, evaluate a cluster of closely spaced B-dot sensors, and design an array of B-dot sensor clusters on a simulated airborne HFDF platform. The B-dot sensors are simulated to determine the sensitivity of the sensor and sensor cluster. Eight and ten-sensor elements are placed on a simulated airframe to characterize the direction finding capability in the HF band. Additionally, a field test is accomplished to compare the simulated B-dot sensor cluster to an actual cluster of Bdot sensors. The B-dot sensor is inadequate for use in an HFDF array due to a lack of sensitivity, but based on initial simulations a larger B-dot sensor, designed for 700 MHz, offers equivalent sensitivity to previous research. Utilizing a cluster of sensors improves the radiation efficiency by 6 dB. The eight and ten-element arrays offer a limited direction finding capability due limited sidelobe reduction. The addition of two sensors does present sidelobe reduction; therefore, additional sensors will improve the direction finding capability of the airborne HFDF array.
关键词:传感器;探测器;测向;高频率