SAMPEX MAST 6-Second Rate Data Documentation

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This data set consists of 6-second particle rates from the MAST instrument. The data set covers the complete mission, from launch through 2004-182. The rates are not calibrated or converted into physical units. Calibrated particle intensities are also available.

The data are derived from the SAMPEX RS Set data, documented in the SAMPEX NGDF Data File Description.

The time-stamps for the attitude/orbit (PS Set) data have been synced (in ground data processing) with the time-stamps for these 6-second rate data, and with the time-stamps for the particle intensity data.

Thus, the timestamps in each of these data sets may be used to associate the appropriate attitude/orbit data with each 6-second intensity or rates data record.

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

The Basic Rates are counts accumulated over 6-second intervals. The multiplexed rates are sampled during 1, 2, or 4 6-second periods every 96 seconds. Thus, their units are also counts/6 seconds, but the data are valid only once (or twice, or 4 times) per 16 data records.

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

  1. year:
    Four-digit year
  2. day:
    Day of year (starting at 1)
  3. hr:
    Hour of day
  4. min:
    Minute of hour
  5. sec:
    Second of minute
  6. fp_year:
    Year, floating-point
  7. fp_doy:
    Day of year, floating-point
  8. sec_of_day:
    Second of day
  9. Subcom:
    The subcom defines the multiplexed rates for HILT, MAST, and PET. Valid values are 6 thru 21. Thus, each subcom cycle lasts 16×9 = 96 seconds.

    Basic Rates

  10. Z1_Sec:
    OR of Z1R0, R1, R2 (almost all proton chance coincidences)
  11. ADC_OR:
    Trigger of any ADC; protons >~3 MeV, detector noise
  12. Live_Time:
    Instrument Livetime, 732 counts/6 seconds = 99.7%
  13. PEN:
    Mostly CNO > ~150 MeV/nuc
  14. Z1:
    Almost all proton chance coincidences
  15. Z2:
    He 8-15 MeV/nuc (5-15 in some periods)
  16. HIZR0:
    Z >= 6, 17-19.5 MeV/nuc for O (14.5-19.5 for some periods)
  17. HIZR1:
    Z >= 6, 19.5 - 23 MeV/n Oxygen
  18. HIZR2:
    Z >= 6, 23 - 31.1 MeV/n Oxygen
  19. HIZR3:
    Z >= 6, 31.1 - 51.9 MeV/n Oxygen
  20. HIZR4:
    Z >= 6, 51.9 - 76.5 MeV/n Oxygen
  21. HIZR5:
    Z >= 6, 76.5 - 113 MeV/n Oxygen
  22. HIZR6:
    Z >= 6, 113 - 156 MeV/n Oxygen

    Multiplexed Rates

  23. M1XSA:
    M1 Z2-level discriminator
  24. M1XSB:
    M1 HIZ level discriminator
  25. M2YSA:
    M2 Z2-level discriminator
  26. M2YSB:
    M2 HIZ level discriminator
  27. M3XSA:
    M3 Z2-level discriminator
  28. M3XSB:
    M3 HIZ level discriminator
  29. M4YSA:
    M4 Z2-level discriminator
  30. M4YSB:
    M4 HIZ level discriminator
  31. D1A:
    D1 Z2-level discriminator
  32. D1B:
    D1 HIZ-level discriminator
  33. D2A:
    D2 Z2-level discriminator
  34. D2B:
    D2 HIZ-level discriminator
  35. D3A:
    D3 Z2-level discriminator
  36. D3B:
    D3 HIZ-level discriminator
  37. D4A:
    D4 Z2-level discriminator
  38. D4B:
    D4 HIZ-level discriminator
  39. M1X1:
    M1 position ADC trigger
  40. M1XS:
    M1 ADC trigger
  41. M2Y1:
    M2 position ADC trigger
  42. M2YS:
    M2 ADC trigger
  43. M3X1:
    M3 position ADC trigger
  44. M3XS:
    M3 ADC trigger
  45. M4Y1:
    M4 position ADC trigger
  46. M4YS:
    M4 ADC trigger
  47. D1:
    D1 ADC trigger
  48. D2:
    D2 ADC trigger
  49. D3:
    D3 ADC trigger
  50. D4:
    D4 ADC trigger
  51. D5:
    D5 ADC trigger
  52. D6:
    D6 ADC trigger
  53. G1:
    Low-level anticoincidence guard
  54. G2:
    HIgh-level anticoincidence guard
  55. D7:
    D7 discriminator
  56. G35L:
    LL anticoincidence guard D3 or D5
  57. G35H:
    HL anticoincidence guard D3 or D5
  58. G47L:
    LL anticoincidence guard D4 or D7
  59. G47H:
    HL anticoincidence guard D4 or D7
  60. G6L:
    LL anticoincidence guard D6
  61. G6H:
    HL anticoincidence guard D6
  62. MAST_HAZ:
    ADC trigger close to previous ADC trigger
  63. D5A:
    D5 Z2-level discriminator
  64. D5B:
    D5 HIZ-level discriminator
  65. D6A:
    D6 Z2-level discriminator
  66. D6B:
    D6 HIZ-level discriminator
  67. M12:
    Logical AND of M1 & M2
  68. M34:
    AND of M3 & M4 (=M3 in certain periods)
  69. L:
    OR of Z2-level discriminators
  70. H:
    OR of HIZ-level discriminators
  71. Z1R0:
    Nominal stop in M4 (or M3 in certain periods)
    Subcom=6 or 13 or 14 or 21
  72. Z1R1:
    Nominal proton stop in D1 (mostly chance coinc.)
    Subcom=7 or 15
  73. Z1R2:
    Nominal proton stop in D2 (mostly chance coinc.)
    Subcom=8 or 16
  74. Z1R3:
    Nominal proton stop in D3 (mostly chance coinc.
    Subcom=9 or 17
  75. Z1R4:
    Nominal proton stop in D4 (mostly chance coinc.)
    Subcom=10 or 18
  76. Z1R5:
    Nominal proton stop in D5 (mostly chance coinc.)
    Subcom=11 or 19
  77. Z1R6:
    Nominal proton stop in D6 (mostly chance coinc.)
    Subcom=12 or 20
  78. Z2R0:
    Probable He stop in M4 (or M3 in certain periods)
    Subcom=6 or 13 or 14 or 21
  79. Z2R1:
    Probable He stop in D1
    Subcom=7 or 15
  80. Z2R2:
    Probable He stop in D2
    Subcom=8 or 16
  81. Z2R3:
    Probable He stop in D3
    Subcom=9 or 17
  82. Z2R4:
    Nominal He stop in D4 (mostly chance coinc.)
    Subcom=10 or 18
  83. Z2R5:
    Nominal He stop in D5 (mostly chance coinc.)
    Subcom=11 or 19
  84. Z2R6:
    Nominal He stop in D6 (mostly chance coinc.)
    Subcom=12 or 20


    A subset of the SAMPEX attitude/orbit data. For more, see the
    Complete attitude/orbit data set.
  85. GEO_Long
    Longitude in GEO coordinate system (0 to 360 degrees).
  86. GEO_Lat
    Longitude in GEO coordinate system (0 to 360 degrees).
  87. L_Shell
    L-shell parameter.
  88. Invariant_Lat
    Invariant latitude (degrees).
  89. 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.
  90. Magnetic_Lat
    Algebraic magnetic latitude (degrees).
  91. Mag_Local_Tm
    Local time at magnetic equator along current field line (hr) ECD.
  92. 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.