Thin Silicon Detector Technology for Use in Imaging Solar ENAs Project

<p> <strong>Top Level Objective: </strong>To enable capabilities for imaging and spectral measurements of energetic neutral hydrogen atoms (ENAs) produced with energies <em>∼</em>1MeV/nuc in explosive solar events.</p> <p> <strong>Overarching Science Question: </strong>How and why does the Sun vary and affect the Earth and the rest of the solar system? [NASA 2010 Science Plan]</p> <p> <strong>Primary Scientific Application: </strong>Investigation of energetic particle acceleration by shocks and/or magnetic reconnection in the solar corona. <strong>Technology: </strong>Ultra-thin (<em><</em><em>∼ </em>10 <em>μ</em>m) silicon strip detectors with spatial resolution an order of magnitude better than previously achieved. <strong>Approach: </strong>Detectors fabricated on thin membranes supported by a thick frame made using micro-electro-mechanical systems (MEMS) techniques starting from commercially-available silicon-on-insulator (SOI) wafers. <strong>Technical Advantages: </strong>Ease of manufacture, mechanical robustness, excellent membrane uniformity, flexible approach that can be customized for numerous applications.</p> <p> <strong>Most Immediate Application: </strong>ENA imaging in SEP events using a combination of coded aperture imaging and <em>dE/dx </em>versus total energy particle identification with energy threshold below 1MeV.</p> <p> <strong>Benefits for Heliophysics: </strong>ENA imaging capability provides a fundamentally new probe of acceleration processes occurring in the corona.</p> <p> <strong>Status of Development: </strong>Simpler position-sensitive thin <em>dE/dx </em>detectors produced from SOI wafers has been demonstrated and are planned for use on the Solar Probe Plus mission.</p> <p> <strong>Proposed New Effort: </strong>1) Produce and test thin detectors with position resolution <em>∼</em>0.1–0.2mm. 2) Produce thin dead layers suitable for detectors with overall thickness <em><</em>10 <em>μ</em>m. 3) Determine how thin <em>dE/dx </em>detectors can be made using the SOI technique. 4) Demonstrate how large a detector active area can be achieved using SOI. 5) Simulate application of this type of detector in a solar ENA imager.</p> <p> <strong>Technological Goal: </strong>Take the thin-silicon strip detector technology from TRL2 (technology concept and/or application formulated) to TRL3-4 (analytical and experimental critical function and/or characteristic proof-of-concept [TRL3]; component and/or breadboard validation in laboratory environment [TRL4]) to enable future prototyping of an optimized solar ENA imager.  </p> <p> N/A</p>