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

This directory provides subdirectories containing 8-day (full IBEX orbit)
 "direct event" and histograms data files
produced by the IBEX-Hi instrument.  These two data types
are defined in the readme files of their respective 
subdirectories, and in this directory's  "TS_description.txt"
file created by the IBEX team.

All data files in the subdirectories of this directory have
the name oBBBB.hi_DD-E.txt, where
BBBB is the orbit number, including leading zeroes
DD is DE or HB for direct events or histograms, respectively
E gives the energy band number (1-6).