Development and Characterization of SONNE - a Fast Neutron Spectrometer for the Solar Sentinels and/or Solar Orbiter Mission to the Inner Heliosphere
Abstract
An important goal in solar physics is the measurement of neutrons in the 1-20 MeV range -- the surest indication of low energy ion acceleration in the low corona. Detection of these particles from SEP and flaring events are needed to understand the full variability, intensity, and composition of the accelerated ion spectrum and, along with gamma-ray measurements, are key for understanding particle acceleration as a whole. Solar neutron measurements in this range could also have the great discovery potential of the postulated nanoflares. These nanoflares could be a significant agent for heating the solar corona. Since neutrons in this energy range suffer severe decay losses and flux divergence as they leave the Sun, measurements from the inner heliosphere on the Solar Sentinels and/or Solar Orbiter missions are needed. We report on the technical status of the ongoing characterization and simulation efforts of the SOlar NeutroN Experiment (SONNE) - a fast neutron imaging spectrometer developed with sensitivity to neutrons in the 1-20 MeV range. SONNE employs double scatter neutron detection techniques to perform imaging, thereby reducing the background and improving the instrument sensitivity. A laboratory prototype has been calibrated in the laboratory and performed measurements of monoenergetic neutron beams. Results show that the limited prototype instrument can perform imaging and spectroscopic measurements in the 1-20 MeV range with a energy resolution (σ) ~20% and an angular resolution (σ) ~5°. Monte Carlo calculations simulated the expected full instrument performance capabilities in the high background environment of the inner heliosphere during realistic flare scenarios. Results from the latest developments of the prototype instrument and simulation efforts will be presented.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2008
- Bibcode:
- 2008AGUSMSH41A..21W
- Keywords:
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- 7509 Corona;
- 7514 Energetic particles (2114);
- 7519 Flares;
- 7554 X-rays;
- gamma rays;
- and neutrinos;
- 7594 Instruments and techniques