COSPIN / HFT - User Notes

COSPIN/HFT Contact:

Dr. J. David Anglin
Herzberg Institute of Astrophysics
National Research Council of Canada
100 Sussex Drive
Ottawa, Ontario
Canada K1A 0R6

Phone: (1) 613 990-0752
Telefax: (1) 613 952-6605


E-mail: dave.anglin@nrc.ca

RECORD FORMAT:

      DIMENSION F1J(16),F2S(32)
C FREE FORMAT
      READ(1,*)IYEAR,IDOY,IHOUR,IMIN,ISEC,
     .         F1J,F2L,F2H,F3,F4,F5,F2S

PARAMETER LIST:

      IYEAR: year
      IDOY:  day of year
      IHOUR: hour
      IMIN:  minute
      ISEC:  second
      F1J(0):  Z>=1   (proton 0.28-7.0 MeV)
      F1J(1):   "     (proton 0.50-2.27 MeV)
      F1J(2):   "     (proton 0.76-1.37 MeV)
      F1J(3):  Z>=2   (helium 0.31-5.4 MeV/n)
      F1J(4):   "     (helium 0.38-3.9 MeV/n)
      F1J(5):   "     (helium 0.45-2.9 MeV/n)
      F1J(6):   "     (helium 0.51-2.26 MeV/n)
      F1J(7):   "     (helium 0.58-1.91 MeV/n)
      F1J(8):   "     (helium 0.64-1.66 MeV/n)
      F1J(9):   "     (helium 0.71-1.50 MeV/n)
      F1J(10):  "     (helium 0.78-1.35 MeV/n)
      F1J(11):  "     (helium 0.85-1.25 MeV/n)
      F1J(12):  "     (helium 0.91-1.17 MeV/n)
      F1J(13):  "     (helium 0.98-1.12 MeV/n)
      F1J(14):  "     (oxygen 0.34-29.6 MeV/n)
      F1J(15):  "     (oxygen 0.36-27.4 MeV/n)
      F2L:     Z>=1   (proton 0.29-6.7 MeV)
      F2H:      "     (proton 0.55-1.95 MeV)
      F3:      Z>=2   (helium 0.68-1.56 MeV/n)
      F4:      Z>=3   (carbon 0.8-4.9 MeV/n, oxygen 0.64-10.7 MeV/n)
      F5:      Z>=12  (sulphur 1.28-8.5 MeV/n, iron 0.8-34 MeV/n)
      F2S:     Z>=1   (see energy ranges for F2L and F2H)  sectors 1 to 32

FLUX UNITS:      (/cm2/s/sr)

TIME RESOLUTION: 10 minutes

NOTES:

1)      All data from the HFT are accumulated for an integral number of
        spacecraft rotations.  Counts in accumulation intervals which span
        either the start or end time of a 10 minute interval are apportioned
        based on the fraction of the accumulation interval in the 10 minute
        interval.

2)      At the lowest science bitrate (128 bps), the full F2S telemetry
        cycle is 1024 seconds and, because the F2S data are accumulated eight
        sectors at a time, approximately every other record will contain
        fill F2S data.  At low counting rates, the statistical accuracy of
        the multiplexed channels (F1J0 - F1J15 and F2S1 - F2S32) is poor.

3)      Although the data are averaged over several telemetry cycles, the
        software will ensure that either the F2L or F2H data are fill in any
        record depending on the operating mode of the HFT for the majority of
        the 10 minute interval.  The energy range for the F2S channel is the
        same as that for the non-fill value of F2L or F2H.

4)      The energy ranges shown are for the main ion species in a data
        channel.  The fraction of other ion species in a channel can vary
        substantially from one period to another.  When the energy spectra
        are steep, heavier ions may in fact dominant a channel.  Thus,
        caution is required in the interpretation of these data.  The energy
        limits are based on accelerator calibrations and estimations from
        range-energy loss tables for particles incident at right angles to
        the HFT detector.  For precise work, these intervals need to be
        adjusted because of the 60 degree opening angle of the HFT collimator
        (c.f., Anglin et al., JGR, 102, 1-36, 1997).