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CURATOR
A pinboard by
Lydia Bingley

Graduate Student Researcher, University of California, Los Angeles

PINBOARD SUMMARY

This research seeks to understand fundamental physical questions regarding space weather dynamics. With the ever increasing launches of satellites, probes, and humans into space, the demand for improved models of space weather is higher than ever. Electronics and humans are left vulnerable to the harsh radiation environment when outside of Earth's atmosphere, increasing risk for spacecraft failure and negative health effects. This study investigates a processes believed to be responsible for emptying the Earth's radiation belts of harmful high energy particles. Quantifying the effect of this process has the potential to lead to significant improvements in space weather forecasting models.

6 ITEMS PINNED

The Engineering Radiation Monitor for the Radiation Belt Storm Probes Mission

Abstract: An Engineering Radiation Monitor (ERM) has been developed as a supplementary spacecraft subsystem for NASA’s Radiation Belt Storm Probes (RBSP) mission. The ERM will monitor total dose and deep dielectric charging at each RBSP spacecraft in real time. Configured to take the place of spacecraft balance mass, the ERM contains an array of eight dosimeters and two buried conductive plates. The dosimeters are mounted under covers of varying shielding thickness to obtain a dose-depth curve and characterize the electron and proton contributions to total dose. A 3-min readout cadence coupled with an initial sensitivity of ∼0.01 krad should enable dynamic measurements of dose rate throughout the 9-hr RBSP orbit. The dosimeters are Radiation-sensing Field Effect Transistors (RadFETs) and operate at zero bias to preserve their response even when powered off. The range of the RadFETs extends above 1000 krad to avoid saturation over the expected duration of the mission. Two large-area (∼10 cm2) charge monitor plates set behind different thickness covers will measure the dynamic currents of weakly-penetrating electrons that can be potentially hazardous to sensitive electronic components within the spacecraft. The charge monitors can handle large events without saturating (∼3000 fA/cm2) and provide sufficient sensitivity (∼0.1 fA/cm2) to gauge quiescent conditions. High time-resolution (5 s) monitoring allows detection of rapid changes in flux and enables correlation of spacecraft anomalies with local space weather conditions. Although primarily intended as an engineering subsystem to monitor spacecraft radiation levels, real-time data from the ERM may also prove useful or interesting to a larger community.

Pub.: 22 Sep '12, Pinned: 07 Aug '17

A RADIATION BELT DISTURBANCE STUDY FROM THE SPACE WEATHER POINT OF VIEW

Abstract: The radiation belts are a key region located close to the Earth, where the satellites travel. They are located in the centre of the magnetosphere and constitute a region sensitive to the variations of magnetosphere activity. The magnetosphere is in equilibrium in the solar wind. If the solar wind parameters change, then, the magnetospheric balance is upset. Using several processes, particles and energy from the solar wind can enter it, disturbing the magnetosphere and the radiation belts. In this paper, the am index has been used to define a new parameter named Cm, which is indicative of the energy level in the magnetosphere. The impact of CIRs (Corotating Interaction region) and of CMEs (Coronal Mass Ejection) on the magnetosphere has been studied from the Cm point of view, as well as the reaction of the radiation belts to a solar wind disturbance. The results show that the Cm parameter provides a new perspective in space weather studies as it clearly shows that the energy level can be higher for a CIR than for a CME. It also demonstrates that the events with several solar wind structures are much more effective to increase the energy level in the magnetosphere than single ones. Finally, Cm correlates better with the radiation belts fluxes, showing again that Cm is a good indicator of the inner magnetosphere activity. Nevertheless, the energy level in the radiation belts is maximised and the energy level in this population cannot go above a given value which depends on the altitude. The particles coming from the plasmasheet also push the particles from the highest altitudes to the lower ones, allowing the slot filling for Cm> <Cm>.

Pub.: 15 Jul '16, Pinned: 07 Aug '17