SAMPEX 6-second Particle Intensity Data

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This data set consists of 6-second particle intensities from the HILT, LICA, MAST and PET instruments. The data set covers the complete mission, from launch through 2004-182.

A subset of the attitude/orbit data is included - see below.

Notes on the time-stamps for these data

The data are 6-second averages. The time-stamp for each data record refers to the beginning of the 6-second period.

The time-stamps for these intensity data have been synced (in ground data processing) with the time-stamps of the attitude/orbit data, and with the time-stamps for the 6-second rates (RS Set) data, Thus, the timestamps in each of these data sets may be used to associate the intensities and rates data with the appropriate attitude/orbit data.

In addition, the intensity, attitude/orbit, and rates data have been filled so that they all contain the same number of records per day.

General Notes on the data

Intensities for differential intensities are in units of particles/sec cm2 sr MeV/n.
Intensities for integral intensities are in units of particles/sec cm2 sr.

Z>1 energy ranges listed below are for oxygen.

Flux 1-σ standard uncertainties due to statistics ( 1/sqrt(N) ) only.

The HILT, MAST, and PET instruments include instrument livetime counters that are used to correct the fluxes due to instrument deadtime. These corrections can have the effect of correcting the rate by more than a factor of 10 under high count rate conditions. When deadtime corrections are important, the saturation Data Quality Flag is raised to indicate that the fluxes are out of calibration.

The 4 HILT fluxes are affected by drift in the proportional counter and background effects. The HILT proportional counter gain decreased with time during the mission, as is typical for this type of device. The gain decrease modifies the energy range for the HILT fluxes, and this has been corrected for in the flux calculation. In addition, HILT fluxes are subject to background under very quiet conditions, and this background has been taken into account in the flux calculation.

More information on the SAMPEX spacecraft, instruments, operations, and the science data may be found in the SAMPEX Mission and Instrument Documentation.

Description of each data field

• Year:
  Four-digit year
• Day-of-year:
  Day of year, starting at 1
• Sec_of_day:
  Second of day, synced RS Set time-stamp when Flag_rstime is 1
• Sec_of_day_psset:
  Second of day contained in the original intensity data record - see time-stamp notes above.
• Flag_rstime:
  Flag indicating whether the time-stamp for the data record has been synced to its corresponding RS Set time-stamp - see time-stamp notes above. 1=synced, 0=not synced.
• Orbit_Number:
  SAMPEX Orbit Number. Launch into orbit 1. Orbit 2 starts at first ascending node through geographic equatorial plane.
• mdf_ver_i2:
  Software version number for MDF Generator.
• bl_igrf_ver_i2:
  Software Version number of the bl_igrf subroutine used to calculate the IGRF 1990 model magnetic field.
• mag_eph_ver_i2:
  Software version number for magnetic ephemeris library.

  LICA

• LICA1 (ssd_flux): Low energy ions and electrons >0.8 MeV >0.6 MeV.
  The overall correction triggering efficiencies depends on the mix of species triggering the SSDs, and so the calculation of calibrated flux of ions or electrons is not possible. Rather, the LICA SSD flux should be considered a qualitative measure of low energy ions and electrons only.
• LICA2 (lopri_flux): Z ≥ 1, 0.5-6.6 MeV/n
  The LICA 2 flux is primarily Helium, that had an average triggering efficiency of about 6% at launch. After that time, the efficiency for Helium varied as the microchannel plates aged due to repeated exposure to the radiation belts. To counteract that, the LICA MCP bias was adjusted periodically throughout the mission, but nevertheless the LICA 2 triggering efficiency varied with time. The overall efficiency at any given time was determined from the MCP gain settings, along with comparison with prelaunch data and spectral comparisons with the HILT sensor. For the flux calculation here, the efficiency was calculated as a function of time and used to correct the flux.
• LICA3 (hipri_flux): Z ≥ 6, 0.49-8.3 MeV/n
• ssd_sigma, lopri_sigma, hipri_sigma:
  Statistical uncertainties for LICA intensities
• lica_off, lica_ifc, lica_bhv, lica_sig, lica_ssd_sat, lica_mcp_sat
  LICA data quality flags.
  Executive summary:
  • If all flags are set to 0, the data are OK to use.
  • All data are set to FILL if either lica_off, lica_ifc, lica_bhv, lica_sig are set to 1.
  • LICA1 data are included but not in calibration if lica_ssd_sat is set to 1.
  • LICA2 and LICA3 data are included but not in calibration if lica_mcp_sat is set to 1.
  For more details, see the SAMPEX Data Quality Flags description.

  HILT

• HILT1 (he1_flux): Helium, 4-9 MeV/n
• HILT2 (he2_flux): Helium, 9-38 MeV/n
• HILT3 (hz1_flux): Z ≥ 6, 8.2-42 MeV/n
• HILT4 (hz2_flux): Z ≥ 6, 41-220 MeV/n
• he1_sigma, he2_sigma, hz1_sigma, hz2_sigma:
  Statistical uncertainties for HILT intensities
• hilt_off, hilt_ifc, hilt_sig, hilt_he1_sat, hilt_he2_sat, hilt_hz1_sat, hilt_hz2_sat:
  HILT data quality flags.
  Executive summary:
  • If all flags are set to 0, the data are OK to use.
  • All data are set to FILL if either hilt_off, hilt_ifc, hilt_sig are set to 1.
  • HILT1 are included but not in calibration if hilt_he1_sat is set to 1.
  • HILT2 are included but not in calibration if hilt_he2_sat is set to 1.
  • HILT3 are included but not in calibration if hilt_hz1_sat is set to 1.
  • HILT4 are included but not in calibration if hilt_hz2_sat is set to 1.
  For more details, see the SAMPEX Data Quality Flags description.

  MAST

• MAST1 (m12_flux): Z ≥ 1 (mainly protons), 5-12 MeV
• MAST2 (z2_flux): Helium, 8-15 MeV/n
• MAST3 (hizr1_flux): Z ≥ 6, 19.3-22.8 MeV/n
• MAST4 (hizr2_flux): Z ≥ 6, 22.8-31.0 MeV/n
• MAST5 (hizr3_flux): Z ≥ 6, 31.0-51.7 MeV/n
• MAST6 (hizr4_flux): Z ≥ 6, 51.7-76.2 MeV/n
• MAST7 (hizr5_flux): Z ≥ 6, 6.2-113 MeV/n
• MAST8 (hizr6_flux): Z ≥ 6, 113-156 MeV/n
  Note: The rate MAST 8 is affected by the failure of the D7detector around 21:51 UT on March 1, 2000 (day 61). After this time the rate increases since the anti-coincidence condition is removed, thus increasing theenergy window from 113-156 MeV/nucleon to >113 MeV/nucleon
• m12_sigma, z2_sigma, hizr1_sigma, hizr2_sigma, hizr3_sigma, hizr4_sigma, hizr5_sigma, hizr6_sigma:
  Statistical uncertainties for MAST intensities
• mast_off, mast_ifc, mast_sig, mast_adc_sat
  MAST data quality flags.
  Executive summary:
  • If all flags are set to 0, the data are OK to use.
  • All data are set to FILL if either mast_off, mast_ifc, mast_sig are set to 1.
  • All the data are included but not in calibration if mast_adc_sat is set to 1.
  For more details, see the SAMPEX Data Quality Flags description.

  PET

• PET1 (elo_flux): Electrons, 1.5-6.0 MeV
• PET2 (ehi_flux): Electrons, 2.5-14 MeV
• PET3 (plo_flux): Z ≥ 1 (mainly protons), 19-27 MeV/n
• elo_sigma, ehi_sigma, plo_sigma:
  Statistical uncertainties for PET intensities
• pet_off, pet_ifc, pet_sig, pet_p1hi_sat
  PET data quality flags.
  Executive summary:
  • If all flags are set to 0, the data are OK to use.
  • All data are set to FILL if either pet_off, pet_ifc, pet_sig are set to 1.
  • All the data are included but not in calibration if pet_p1hi_sat is set to 1.
  For more details, see the SAMPEX Data Quality Flags description.

  Attitude/Orbit

  A subset of the SAMPEX attitude/orbit data. For more, see the Complete attitude/orbit data set.
• GEO_Long
  Longitude in GEO coordinate system (0 to 360 degrees).
• GEO_Lat
  Longitude in GEO coordinate system (0 to 360 degrees).
• L_Shell
  L-shell parameter.
• Invariant_Lat
  Invariant latitude (degrees).
• Pitch
  Pitch angle of a particle heading down the instrument boresight (i.e., angle between S/C z-axis and (-1) times the local magnetic field vector), in degrees.
• Magnetic_Lat
  Algebraic magnetic latitude (degrees).
• Mag_Local_Tm
  Local time at magnetic equator along current field line (hr) ECD.
• Att_Flag
  Flag, data quality flag indicating source of attitude information (Applies only to pitch angle for the attitude/orbit data subset included here).
  Executive summary: flag =0,1,100, or 101 means attitude is OK. Other values indicate attitude is not OK.

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