urn:nasa:pds:context:instrument:ice.epas 1.0 1.11.0.0 Product_Context urn:nasa:pds:context:instrument:epas.ice 2021-02-24 1.0 Changed inst LIDs from u:n:p:c:i:instID.scID to u:n:p:c:i:scID.instID And per "Guide toPDS4 Context Products" v1.7, changed all lidvid_reference to lid_reference urn:nasa:pds:context:instrument_host:spacecraft.ice instrument_to_instrument_host Reinhard, R and B. Battrick (eds), 'Space Missions to Halley's Comet', European Space Agency ESA SP-1066, ESA Pub Div, Moordwijk, Netherlands, 1986. reference.ESA-SP1066 ENERGETIC PARTICLE ANISOTROPY SPECTROMETER Spectrometer not applicable not applicable Instrument Host Overview ======================== Energetic protons and heavy nucleons are detected by three identical charged- particle telescopes aligned at different angles (30deg, 60deg and 135deg) to the spin axis which is perpendicular to the ecliptic plane.. Each telescope consists of a 1 cm**2 solid-state detector of 30 micron thickness immediately followed by a 2 cm**2 detector of 150 micron thickness in anticoincidence. Pulse-height analysis resolves the particle total kinetic energies into eight channels between 35 keV and 1.6 MeV for protons. (These ranges are slightly mass-dependent for heavy ions because of detector dead-layer effects.) The count rate from each telescope and each channel is resolved into eight sectors in the equatorial plane to measure the anisotropy of the particles. A mechanical collimator defines a 16 degree half-width viewing cone and a geometrical factor of 0.05 cm2 sr for each telescope. A magnetic broom prevents < 400 keV electrons from entering the telescope while higher energy electrons trigger the second detector and so are not counted. To sample the three telescopes, eight energies and eight sectors requires 32 s at 1024 bit/s.