Topic
Shields
About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.
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01 Apr 2016
TL;DR: In this paper, the authors compared four different shield designs and compared them to the most conventional radiation-protective material for spacecraft - aluminum, and concluded that a three-layer boron carbide shield provides the most effective protection from radiation.
Abstract: The paper deals with modeling of elemental composition and properties of heterogeneous layers in multilayered shields to protect spacecraft onboard equipment from radiation emitted by the natural Earth's radiation belt. This radiation causes malfunctioning of semiconductor elements in electronic equipment and may result in a failure of the spacecraft as a whole. We consider four different shield designs and compare them to the most conventional radiation-protective material for spacecraft - aluminum. Out of light and heavy chemical elements we chose the materials with high reaction cross sections and low density. The mass attenuation coefficient of boron- containing compounds is 20% higher than that of aluminum. Heterogeneous shields consist of three layers: a glass cloth, borated material, and nickel. With a protective shield containing heavy metal the output bremsstrahlung can be reduced. The amount of gamma rays that succeed to penetrate the shield is 4 times less compared to aluminum. The shields under study have the thicknesses of 5.95 and 6.2 mm. A comparative analysis of homogeneous and multilayered protective coatings of the same chemical composition has been performed. A heterogeneous protective shield has been found to be advantageous in weight and shielding properties over its homogeneous counterparts and aluminum. The dose characteristics and transmittance were calculated by the Monte Carlo method. The results of our study lead us to conclude that a three-layer boron carbide shield provides the most effective protection from radiation. This shield ensures twice as low absorbed dose and 4 times less the number of penetrated gamma-ray photons compared to its aluminum analogue. Moreover, a heterogeneous shield will have a weight 10% lighter than aluminum, with the same attenuation coefficient of the electron flux. Such heterogeneous shields can be used to protect spacecraft launched to geostationary orbit. Furthermore, a protective boron-containing and nickel coating can be deposited onto a finished housing frame of space equipment.
3 citations
TL;DR: In this paper, an experimental study on the influence of low-emissivity aluminium shields on the thermal properties of low density expanded polystyrene panels is presented, where every panel was cut horizontally, and aluminium foils were inserted between the slices as shields.
3 citations
Patent•
24 Sep 2015TL;DR: A data writer can have at least a write pole separated from first and second side shields by a continuous dielectric gap layer as mentioned in this paper, which increases relative to the sub-layer's distance from the write pole.
Abstract: A data writer can have at least a write pole separated from first and second side shields by a continuous dielectric gap layer. Each side shield may have first and second shield sub-layers configured with different magnetic moments that increase relative to the sub-layer's distance from the write pole. The side shields may wrap around a leading tip of the write pole to form a box shield.
3 citations