These hourly fluxes of protons, alpha particles, and electrons
are based on hourly count rates pulled from the IMP8/CRNC
(Cosmic Ray Nuclear Composition) web site at the University
of New Hampshire.


We at GSFC/SPDF have converted these count rates (CR) to
fluxes (F), for each energy bin spanning E1 to E2 MeV/n,
using F = CR / [2.05 * (E2-E1)].

The data labelled "Heavies" have not been converted from
rates to fluxes.  They include fluxes of both particles of all
masses that penetrate the anticoincidence shield and
non-penetrating heavy particles (CNO, Z>8).

Extensive documentation of the CRNC instrument and of
a 15-min pulse height analysis and coincidence mode
count rate data set from which the hourly rates were
determined by the CRNC team is available at
ftp://spdf.gsfc.nasa.gov/pub/data/imp/imp8/particles_uchi/15min_asci/voldesc.sfd.  
The 15-min data set is itself accessible from
ftp://spdf.gsfc.nasa.gov/pub/data/imp/imp8/particles_uchi/15min_asci/

Note that as a default, our interface plots log-scaled fluxes
vs. time.  Because some fluxes may be zero, we have
plotted such points at 10**-5, which is significantly lower
than meaningful fluxes in most channels, but not so low as to
compress meaningful flux variations to near-invisibility.

Note also that while the labelling shows flux units for all
parameters, the units for any options in the "Heavies"
column are counts per sec.