https://spdf.gsfc.nasa.gov/pub/data/ibex/hi/time_series/direct_events/band_1/aareadme.txt

This directory provides 8-day (full IBEX orbit) 
"direct event" files produced by the IBEX-Hi instrument
in energy band 1.  Energy band 1 covers 0.38-0.59 keV.

See the readme files in parent directories, and the 
IBEX team-generated documentation files contained in those
directories.