PROCEEDINGS ARTICLE | September 26, 2013
Proc. SPIE. 8862, Solar Physics and Space Weather Instrumentation V
KEYWORDS: Independent component analysis, Sun, Solar radiation models, Metals, Dielectrics, Ions, Sapphire, Thermal modeling, Solar processes, Temperature metrology
The upcoming Solar Probe Plus (SPP) mission requires novel approaches for in-situ plasma instrument design. SPP’s
Solar Probe Cup (SPC) instrument will, as part of the Solar Wind Electrons, Alphas, and Protons (SWEAP) instrument
suite, operate over an enormous range of temperatures, yet must still accurately measure currents below 1 pico-amp, and
with modest power requirements.
This paper discusses some of the key technology development aspects of the SPC, a Faraday Cup and one of the few
instruments on SPP that is directly exposed to the solar disk, where at closest approach to the Sun (less than 10 solar
radii (Rs) from the center of the Sun) the intensity is greater than 475 earth-suns. These challenges range from materials
characterization at temperatures in excess of 1400°C to thermal modeling of the behavior of the materials and their
interactions at these temperatures. We discuss the trades that have resulted in the material selection for the current
design of the Faraday Cup. Specific challenges include the material selection and mechanical design of insulators,
particularly for the high-voltage (up to 8 kV) grid and coaxial supply line, and thermo-optical techniques to minimize
temperatures in the SPC, with the specific intent of demonstrating Technology Readiness Level 6 by the end of 2013.
