The Medium Energy Particle Spectrometer for the European Space Agency Lagrange (L5) Mission
Abstract
The M edium E nergy P article S pectrometer (MEPS) instrument is a particle instrument for the European Space Agency Lagrange(L5) mission which serves as a space weather monitor. Measuring medium-to-low energy ions, and electrons is important for monitoring space weather. This is required to provide warnings on shock arrival and estimates of expected geomagnetic storm strength. Monitoring particles can also provide an immediate indicator of possible CME occurrences. Therefore to address all these, MEPS is designed to measure the energy spectra and angular distributions of energetic electrons (30-600 keV) and ions (30-6000 keV/nuc). The MEPS consists of two double-ended telescope pairs with four view cones per pair, two dedicated for electrons and two for ions. The telescope relies on the magnet/foil-technique and dE/dx vs. E technique to cleanly separate and measure electrons, protons and ions. Each telescope consists of a stack of three solid-state detectors, with thicknesses 300-300-20 μm. The outer 300 μm detector is covered with a thin polyimide foil about 5 μm thick which stops ions below ~600 keV/nuc but allows electrons to pass almost unaffected. This detector is operated in anti-coincidence with the second 300 μm detector and thus observes the energy spectrum of stopping electrons. The other end of the telescope has a magnet that deflects electrons with energies less than ~600 keV and a 20 μm Si detector in front of the middle 300 μm Si detector. This thin and thick detector pair form an ion telescope which observes particles with energies from 30-6000 keV/nuc again using the dE/dx vs. E technique. To verify the low energy detection ability of the designed telescope, we built a demonstration model of MEPS with one 20 μm and two 300 μm thick detectors and calibrated it with protons and alpha particles at an accelerator facility. Here we present a brief overview of MEPS and first calibration results of the demo model of MEPS.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH33C3370K
- Keywords:
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- 4323 Human impact;
- NATURAL HAZARDS;
- 7594 Instruments and techniques;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7924 Forecasting;
- SPACE WEATHER;
- 7934 Impacts on technological systems;
- SPACE WEATHER