Editing Advanced Composition Explorer (section)

=== Electron, Proton, and Alpha-particle Monitor (EPAM) ===
[[File:ACE-epam sm.jpg|thumb|EPAM]]
The Electron, Proton, and Alpha Monitor (EPAM) instrument on the ACE spacecraft is designed to measure a broad range of energetic particles over nearly the full unit-sphere at high time resolution. Such measurements of ions and electrons in the range of a few tens of keV to several [[Electronvolt|MeV]] are essential to understand the dynamics of [[solar flares]], co-rotating interaction regions (CIRs), interplanetary shock acceleration, and upstream terrestrial events. The large dynamic range of EPAM extends from about 50 keV to 5 MeV for ions, and 40 keV to about 350 keV for electrons. To complement its electron and ion measurements, EPAM is also equipped with a Composition Aperture (CA) which unambiguously identifies ion species reported as species group rates and/or individual pulse-height events. The instrument achieves its large spatial coverage through five telescopes oriented at various angles to the spacecraft spin axis. The low-energy particle measurements, obtained as time resolutions between 1.5 and 24 seconds, and the ability of the instrument to observe particle anisotropies in three dimensions make EPAM an excellent resource to provide the interplanetary context for studies using other instruments on the ACE spacecraft.<ref name=gold98>{{cite journal |last=Gold |first=R. E. |title=Electron, Proton, and Alpha Monitor on the Advanced Composition Explorer Spacecraft |journal=Space Science Reviews |date=July 1998 |volume=86 |pages=541–562 |doi=10.1023/A:1005088115759 |bibcode=1998SSRv...86..541G |s2cid=115540562 |display-authors=et al.}}</ref>