Ion mass spectrometer

An ion mass spectrometer is described which detects and indicates the characteristics of ions received over a wide angle, and which indicates the mass to charge ratio, the energy, and the direction of each detected ion. The spectrometer includes a magnetic analyzer having a sector magnet that passes ions received over a wide angle, and an electrostatic analyzer positioned to receive ions passing through the magnetic analyzer. The electrostatic analyzer includes a two dimensional ion sensor at one wall of the analyzer chamber, that senses not only the lengthwise position of the detected ion to indicate its mass to charge ratio, but also detects the ion position along the width of the chamber to indicate the direction in which the ion was traveling

Perceived orientation, spatial layout and the geometry of pictures

The purpose is to discuss the role of geometry in determining the perception of spatial layout and perceived orientation in pictures viewed at an angle. This discussion derives from Cutting's (1988) suggestion, based on his analysis of some of the author's data (Goldstein, 1987), that the changes in perceived orientation that occur when pictures are viewed at an angle can be explained in terms of geometrically produced changes in the picture's virtual space

Thermal protection systems for space transportation vehicles

The topics addressed are history of reusable external insulation (RSI), and examples of shuttle RSI development challenges, which includes: (1) manufacturing of raw materials, such as fibers, coating components; (2) design of tile planform size, strain isolation, and gap heating; (3) insulation, such as bonding, bond verification, tolerances, and quality control; and (4) operation, such as durability, and water proofing

Aeroacoustics of subsonic turbulent shear flows

Sound generation in turbulent shear flows is examined. The emphasis is on simultaneous calculation of the turbulent flow along with the resulting sound generation rather than the alternative acoustic analogy approach. The first part of the paper is concerned with solid surface interaction. The second part concentrates on the sound generated by turbulence interacting with itself

Generation of instability waves at a leading edge

Two cases are considered. The first is concerned with mean flows of the Blasius type wherein the instabilities are represented by Tollmien-Schlichting waves. It is shown that the latter are generated fairly far downstream of the edge and are the result of a wave length reduction process that tunes the free stream disturbances to the Tollmien-Schlichting wave length. The other case is concerned with inflectional, uni-directional, transversely sheared mean flows. Such idealized flows provide a fairly good local representation to the nearly parallel flows in jets. They can support inviscid instabilities of the Kelvin-Helmholtz type. The various mathematically permissible mechanisms that can couple these instabilities to the upstream disturbances are discussed