DocumentCode :
158142
Title :
Design of a space-borne antenna for controlled removal of energetic Van Allen belt protons
Author :
de Soria-Santacruz, Maria ; Bautista, Godofredo ; Gettliffe, Gwendolyn V. ; Martinez-Sanchez, Manuel ; Miller, David W.
Author_Institution :
Massachusetts Inst. of Technol., Cambridge, MA, USA
fYear :
2014
fDate :
1-8 March 2014
Firstpage :
1
Lastpage :
20
Abstract :
The energetic protons trapped in the inner Van Allen belt pose a risk to humans and spacecraft operating in Low Earth Orbit (LEO). These particles come from cosmic rays, solar storms and other processes, and they are a hindrance to development of space technologies. The Radiation Belt Remediation (RBR) idea has been proposed as a way to solve this problem through Ultra/Very Low Frequency (VLF/ULF) transmissions in the magnetosphere capable of inducing pitch angle scattering of the hazardous particles and precipitating them into the atmosphere. Whistler-type emissions (VLF band, tens of kHz) have been extensively studied for precipitation of energetic trapped electrons, but much less work has been devoted to the controlled removal of inner belt protons. The latter would require the man-made radiation of Electromagnetic Ion Cyclotron (EMIC) waves into the magnetosphere (ULF band, less than 10 Hz), the frequency of which is close to the cyclotron frequency of the trapped protons. In this paper we first identify the space-borne transmitter capable of radiating EMIC waves, and we estimate its radiation impedance and radiation pattern. The selected antenna configuration consists of a DC rotating coil, which is equivalent to two AC phased-orthogonal coils but with negligible self-inductance. However, the radiation resistance of magnetic dipoles is very small. For this reason, we propose a design based on superconductors and multiple turn arrangements. One of the most challenging aspects of using superconductors in space is their cooling system. This paper presents a preliminary thermal and mechanical design of a superconducting coil antenna capable of radiating EMIC waves into the magnetosphere. The coil is composed of high temperature superconducting tapes (HTS), which have to be kept below 77 K. Active thermal control and the use of cryogenics are therefore required to reject the heat coming from environmental sources. This preliminary design is used to calculate the po- er radiated from the antenna, its radiation pattern and its effect on the energetic proton population of the inner Van Allen belt. The feasibility of the remediation concept, as well as a scientific mission scaled down to detectability of the proton precipitating fluxes are finally addressed at the end of the paper.
Keywords :
antenna radiation patterns; atmospheric electron precipitation; atmospheric techniques; cooling; cosmic ray protons; cryogenics; magnetic moments; magnetospheric electromagnetic wave propagation; radiation belts; space vehicles; superconducting coils; transmitters; whistlers; AC phased-orthogonal coils; DC rotating coil; EMIC waves; HTS; LEO; RBR; VLF-ULF transmission; active thermal control; antenna radiation impedance estimation; antenna radiation pattern estimation; cooling system; cosmic rays; cryogenics; electromagnetic ion cyclotron frequency; energetic Van Allen belt protons; energetic trapped electrons; environmental sources; hazardous particles; high temperature superconducting tapes; inner belt protons removal; low earth orbit; magnetic dipoles; magnetosphere; man-made radiation; mechanical design; multiple turn arrangements; pitch angle scattering; proton precipitating fluxes; radiation belt remediation; radiation resistance; self-inductance; solar storms; space-borne antenna; space-borne transmitter; spacecraft; superconducting coil antenna; superconductors; thermal design; ultra low frequency transmission; very low frequency transmission; whistler-type emissions; Coils; Dipole antennas; High-temperature superconductors; Plasmas; Protons; Transmitters;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Aerospace Conference, 2014 IEEE
Conference_Location :
Big Sky, MT
Print_ISBN :
978-1-4799-5582-4
Type :
conf
DOI :
10.1109/AERO.2014.6836244
Filename :
6836244
Link To Document :
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