https://spdf.gsfc.nasa.gov/pub/data/ibex/release3/lo/mass_spectrometer_data/angular_histograms/band_4/aareadme.txt

For each 8-day orbit, this directory provides two 8-day, 
CSV-formatted files containing angular histograms 
for energy band 4.  Each pair of files is for hydrogen, and
for oxygen and carbon (labelled "Oxygen").

Energy band 4 has center energies of 110 and 132 eV for hydrogen 
and oxygen, respectively.

The angular histograms give the numbers of counts in each
1-deg bin in spacecraft spin phase, as accumulated over 
the full 8-day orbit.

The directory two levels up contains a documentation file 
created by the IBEX team, Maps_TOF_description.txt, that
should be read.