A study on the capabilities and accuracy of Kapton based TOF space dust and debris detectors

The growing population of space debris in the near-Earth environment means there is an increased need for space-based detectors, capable of measuring and distinguishing natural space dust and anthropogenic orbital debris populations, to monitor and quantify the relative threat they pose. This has led to much research into the development of new detectors, including those based on time of flight (TOF) designs which can give impact speed and direction. Kapton’s favourable properties (e.g. its low mass and ability to be manufactured as thin films) and tried and tested space applications, suggest it may be suitable for use in TOF detectors where impactor speed is measured by passage through several films with known separation. To test the measurement accuracy of such a detector, a prototype Kapton based TOF space dust and debris detector was constructed, and impacted at 2 and 4 km s^-1. For a Kapton film thickness of 12.5 lm and projectiles of 1 mm in size, within experimental uncertainties of 1%, there was no difference between incident projectile speed (as measured independently) and that measured by the TOF detector. This, confirms that Kapton based TOF detectors are capable of measuring particle speed to a high degree of accuracy, making them suitable for measuring the near-Earth particle environment

Hypervelocity impact induced light flash experiments on single and dual layer Kapton targets to develop a time of flight space dust and debris detector

The impact flash from hypervelocity impact on thin (12.5 µm) Kapton film was observed. The projectile sizes ranged from 0.1 to 1 mm, with speeds from 2 to 5 km s−1 and penetrated the Kapton intact, leaving holes the same size as the projectile (to within measurement errors). The flash intensity (normalised to impactor mass) scaled with impact speed to the power 5.5. However, the data also suggest that at constant speed the intensity scales with the area of the hole in the Kapton and not the projectile mass (i.e. with some property of the target and not as a function of the projectile energy or momentum). Using two layers of Kapton, it was possible to construct a Time of Flight (TOF) system, which used the time of the onset of the flash in each layer to produce flight speeds accurate to within typically 1%. When compared to the projectile speed pre-impact, there was no indication of projectile deceleration during passage through the Kapton film. In addition, when PVDF acoustic sensors were placed on the Kapton film, they exhibited an electromagnetic “pick-up” signal from the impact of projectile on the Kapton, confirming suspicions of signal interference from past work with acoustic sensors. The ability of the light flash to provide accurate impact timing signals suggests the TOF system would be suitable for use as a cosmic dust or debris impact detector in space (e.g. Low Earth Orbit)

Physical analytical model for LT-GaAs and LT-Al0.3Ga0.7 As MISFET Devices

Proceedings of the IEEE Hong Kong Electron Devices Meeting134-13

Effects of mechanical milling on preparation and properties of CuAl1-xFexO2 thermoelectric ceramics

CuAl1-xFexO2 (x = 0, 0.1, and 0.2) thermoelectric ceramics produced by a reaction-sintering process were investigated. Pure CuAlO2 and CuAl0.9Fe0.1O2 were obtained. Minor CuAl2O4 phase formed in CuAl0.8Fe0.2O2. Addition of 10 mol% Fe lowered the sintering temperature obviously and enhanced the grain growth. At x = 0.1, electrical conductivity = 3.143 Omega(-1) cm(-1), Seebeck coefficient = 418 mu V K-1, and power factor = 5.49 x 10(-5) W m(-1) K-2 at 600 degrees C were obtained. The reaction-sintering process is simple and effective in preparing CuAlO2 and CuAl0.9Fe0.1O2 thermoelectric ceramics for applications at high temperatures. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Modeling of LT-GaAs and LT-Al0.3Ga0.7As MISFET devices

A theoretical model is developed for LT-GaAs and LT-Al0.3Ga0.7As MISFETs and is compared with experimental data. This model is based upon the analytical solution of Poisson's equation, the current continuity equation and the Chang-Fetterman velocity-field equation. When the device is operating in the linear region and knee region the one-dimensional Poisson equation has been considered. When the device is in the saturation regime, the two-dimensional Poisson equation has been solved analytically. The resulting output current-voltage characteristics are in excellent agreement with experimental data

Low-temperature grown GaAs and Al0.3Ga0.7As MISFETs - characterization and model development

Workshop on High Performance Electron Devices for Microwave and Optoelectronic Applications, EDMO43-5223

Prolyl isomerization of the CENP-A N-Terminus regulates centromeric integrity in fission yeast

10.1093/nar/gkx1180Nucleic Acids Research4631167-117