Instrument Information
IDENTIFIER urn:nasa:pds:context:instrument:epps-eps.mess::1.2
NAME Energetic Particle and Plasma Spectrometer Energetic Particle Spectrometer for MESSENGER
TYPE Charged Particle Detector
DESCRIPTION The Energetic Particle Spectrometer (EPS) is a critical component of the MESSENGER Energetic Particle and Plasma Spectrometer (EPPS) suite, designed to investigate the high-energy electrons and ions within Mercury's magnetosphere. Constructed by the Johns Hopkins University/Applied Physics Laboratory, the EPS operates over a broad energy spectrum, detecting electrons from 25 keV to over 500 keV and ions from 10 keV/nucleon to approximately 3 MeV. The instrument aims for a throughput of 5 kHz, ensuring robust event processing. Utilizing a time-of-flight (TOF) measurement strategy within its cylindrical sensor geometry, the EPS effectively distinguishes particle species?including protons, alpha particles, carbon, nitrogen, oxygen, and iron?by analyzing the energy and velocity of incoming particles against a look-up table to ascertain their mass. The detection mechanism involves solid-state detectors positioned to capture scattering events induced by particles colliding with start and stop foils, thereby enabling high-resolution measurements of incident particles across varied angles. The integration of multiple detector modules allows for comprehensive spectral analysis, which is periodically compiled, compressed, and transmitted via telemetry. Additionally, the EPS monitors operational metrics, including voltage and temperature parameters, to ensure system integrity. This detailed exposition of EPS underscores its pivotal role in advancing our understanding of Mercury's planetary field and the characteristics of its magnetospheric environment.
MODEL IDENTIFIER
NAIF INSTRUMENT IDENTIFIER
SERIAL NUMBER
REFERENCES Andrews, G.B., T.H. Zurbuchen, B.H. Mauk, H. Malcom, L.A. Fisk, G. Gloeckler, G.C. Ho, J.S. Kelley, P.L. Koehn, T.W. LeFevere, S.S. Livi, R.A. Lundgren, and J.M. Raines, The Energetic Particle and Plasma Spectrometer instrument on the MESSENGER spacecraft, Space Science Reviews, 131, 523-556, 2007.