J³ - A CubeSat for Radiation Testing : Science Requirements Derivation, Analysis of Radiation Environment and Simulation of Instrument Response

• Main Author: Wolff, Friederike
• Format: Bachelor Thesis
• Language: English
• Published: 2015
• Subjects: Technology; GRAS; Monte-Carlo; Penetrating Radiation; JUICE; Simulation; CubeSat; J3; Anti-Coincidence Shield; RATEX-J; Teknik; Jupiter; Kiruna
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-42873

Plasma analyzers have been of exceptional importance to any interplanetary exploration mission since the beginning of the space age. They allow the investigation of various processes in the magetospheres or the solar wind. However, their operation also poses significant challenges, one of which is the presence of false counts due to penetrating radiation. Although (penetrating) radiation is known to pose problems to almost all spacecraft systems, plasma instruments that use time-of-flight chambers are particularly susceptible. This is of particular importance for missions to the Jovian system because Jupiter’s magnetosphere contains relativistic electrons in large quantities due to its exceptionally strong magnetic field. To mitigate such effects, several approaches are being investigated by IRF (Institutet f ̈or Rymdfysik) in Kiruna. Among these are the implementation of an anti-coincidence shield in one of the plasma analyzers for its contributions to ESA’s JUICE (Jupiter and Icy Moon Explorer) mission. Also, the response of MCPs (Micro-Channel-Plates) and CEMs (Channel Electron Multipliers), two particle detectors that will be used, to penetrating electrons shall be characterized. Verifying systems designed for the Jovian environment is difficult because it is not possible to replicate this environment on Earth. The electron accelerators that will be used during ground-based test produce fluxes of electrons that are significantly higher than those found in the Jovian environment. Therefore, such tests will be complemented by deploying an instrument containing the anti-coincidence system on the J3 CubeSat in an Earth-bound orbit to test its response to relativistic electrons within the Earth’s magnetosphere. This approach has limited applicability as well since the energy cut-off in Earth’s magnetosphere is much lower than in the Jovian environment, but presents a complementary solution to ground-based testing. The thesis will show that a radiation testing for the JUICE mission can be conducted in Low Earth ...