We describe the operating principle, design and test results for the high-power semiconductor switch which based on the assembly of reverse switched dinistors (RSD). This switch has the following operating parameters:...
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ISBN:
(纸本)0819441317
We describe the operating principle, design and test results for the high-power semiconductor switch which based on the assembly of reverse switched dinistors (RSD). This switch has the following operating parameters: operating voltage - 25kV, peak operating current - up to 200kA, maximum transferred charge - up to 70C. The switch is intended for use by pulse power systems of Nd-glass lasers. The features of switch modes at such banks are discussed.
This paper describes the Rubicon(tm) actuator, discusses its test data and derives from the data the actuator's accuracy function based upon the observed accuracy of long and short stroke motion commands. The accu...
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ISBN:
(纸本)0819437387
This paper describes the Rubicon(tm) actuator, discusses its test data and derives from the data the actuator's accuracy function based upon the observed accuracy of long and short stroke motion commands. The accuracy is described in terms of the rms positioning error (in nanometers) for moves of a given size, regardless of position in the stroke.
In Free Gyroscopic Stabilized Seekers, the Primary Minor has the multiple functions of a magnetic rotor, the primary rotating mass and the primary reflector for the optical train. The introduction of rare-earth magnet...
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ISBN:
(纸本)0819437387
In Free Gyroscopic Stabilized Seekers, the Primary Minor has the multiple functions of a magnetic rotor, the primary rotating mass and the primary reflector for the optical train. The introduction of rare-earth magnetic alloys to this class of seeker has provided increased flexibility in materials selection, opto-mechanical design and cost of manufacture. Along with superior magnetic properties, the rare-earth alloy Neodymium-Iron-Boron (NdFeB) comes with the undesirable properties of anisotropic CTE, high susceptibility to corrosion and manufacturing challenges. This paper discusses the opto-mechanical design, structural and optical modeling and analysis of a primary mirror assembly utilizing an NdFeB insert with centrifugal, linear acceleration and thermal loading as well as the optical test results, qualification testing of long-term figure stability and validation of the mechanical/magnetic/opticaldesign model.
作者:
Robinson, DWNASA
Goddard Space Flight Ctr Greenbelt MD 20771 USA
A method of minimizing the optical distortion from gravity sag on a suspended large autocollimating flat mirror has been devised. This method consists of an inverted nine-point Hindle-Mount. A conventional Hindle-Moun...
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ISBN:
(纸本)0819437387
A method of minimizing the optical distortion from gravity sag on a suspended large autocollimating flat mirror has been devised. This method consists of an inverted nine-point Hindle-Mount. A conventional Hindle-Mount is located underneath a sky-viewing mirror and is primarily under compression loads from the weight of the mirror. It is not suitable for the situation where the mirror is viewing the ground, since a mirror would tend to fall out of the mount when in an inverted position. The inverted Hindle-Mount design consists of bonded joints on the backside of the mirror that allow the mirror to be held or suspended above an object to be viewed. This ability is useful in optical setups such as a calibration test where a flat mirror is located above a telescope so that the telescope may view a known optic.
Eyepieces are a part of visual optical systems. Because of their wide field of view and long eye-relief, it is difficult to further improve the existing eyepieces using all-refractive surfaces. Since diffractive eleme...
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ISBN:
(纸本)0819437387
Eyepieces are a part of visual optical systems. Because of their wide field of view and long eye-relief, it is difficult to further improve the existing eyepieces using all-refractive surfaces. Since diffractive elements demonstrate unique characteristics: negative dispersion and non-field curvature, the eyepiece design can be improved by using refractive-diffractive hybrid surfaces. In this paper, several design examples using refractive-diffractive hybrid surfaces to design moderate field of view (FOV) eyepieces were studied. Firstly, a design example using a diffractive surface to replace the negative piece in the cement doublet of a conventional Kellner type eyepiece is presented. Then a design example is given by employing two diffractive elements to replace the negative elements used in the conventional symmetrical eyepiece. For the above examples the eyepiece aberration correction techniques were also analyzed.
作者:
Huegele, VBNASA
George C Marshall Space Flight Ctr SOMTC Huntsville AL 35812 USA
A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator ...
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ISBN:
(纸本)0819437387
A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator when combined into the entire 17-foot diameter array. The mirror segments are aluminum hexagons that had the surface diamond turned and quartz coated. The array focuses sunlight reflected from a heliostat to a 4 inch diameter spot containing 8 kilowatts of power at the 15 foot focal point. The derivation of the surface figure for the respective mirror elements is shown. The alignment process of the array is discussed and test results of the system's performance are given.
The numerical calculation of diffraction integrals in systems with aberrations is addressed from the point of view of a new geometrical interpretation of the diffraction phenomena. This interpretation is based on the ...
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ISBN:
(纸本)0819437387
The numerical calculation of diffraction integrals in systems with aberrations is addressed from the point of view of a new geometrical interpretation of the diffraction phenomena. This interpretation is based on the division of the integration domain in semiperiodic zones that isolate the integrand oscillations. Moreover, the critical points of the aperture allow to identify the zones with a net contribution to the diffracted field. With the help of this interpretation it is possible to define methods for calculating the diffraction of a spherical wave incident on an aperture. We study the problems that arise when these methods have to be applied to waves in aberrated systems and we propose a solution based on the analysis of the behavior of the optical path of the wave incident on the exit pupil of the system.
In this paper, we present an opticaldesign of a near-infrared (at FeI 15648.5 Angstrom) birefringent filter system which is used to obtain the chromatic images of the sun and measure the solar magnetic field at the B...
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ISBN:
(纸本)0819437387
In this paper, we present an opticaldesign of a near-infrared (at FeI 15648.5 Angstrom) birefringent filter system which is used to obtain the chromatic images of the sun and measure the solar magnetic field at the Big Bear Solar Observatory (BBSO). This system consists of a prefilter, a liquid crystal analyzer, a wavelength-tunable birefringent filter and a Fabry-Perot Etalon. This system is expected to achieve a clean narrow pass band (1/8 Angstrom). It can also be tuned across the spectral line to obtain line profiles of two-dimensional fields of view. During the design of the tunable near-IR birefringent filter and the test of its components, we found the value of birefringence index mu (n(e) - n(o)) of calcite at spectral range near 15648.5 Angstrom is very different from the value in literature(1). Because the birefringence index is important for the design of birefringent optical components, the birefringence index of calcite and its thermal coefficient are measured. Some test results of the four pairs of calcite prate used in the birefringent filter are presented.
The Tropospheric Emission Spectrometer (TES) is one of the instruments slated to fly on the EOS Aura satellite in 2003. TES is a Fourier transform spectrometer designed to measure the concentration of various troposph...
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ISBN:
(纸本)0819437387
The Tropospheric Emission Spectrometer (TES) is one of the instruments slated to fly on the EOS Aura satellite in 2003. TES is a Fourier transform spectrometer designed to measure the concentration of various tropospheric chemical species. The Focal Plane Opto-Mechanical Assemblies (FPOMAs) are situated at the end of the TES optical train and are comprised of cryogenic telescopes, reimaging optics, and focal planes. We present the cryogenic opticaldesign of the FPOMA units and discuss optimization parameters and predicted performance. We present measured performance data and compare it with the predicted performance.
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