CCSD3ZF0000100000001NJPL3IF0PDSX00000001
PDS_VERSION_ID                     = PDS3

RECORD_TYPE                        = STREAM
OBJECT                             = INSTRUMENT
  INSTRUMENT_HOST_ID               = "ULY"
  INSTRUMENT_ID                    = "GRB"
  OBJECT                           = INSTRUMENT_INFORMATION
    INSTRUMENT_NAME                = "SOLAR X-RAY/COSMIC GAMMA-RAY BURST
INSTRUMENT"
    INSTRUMENT_TYPE                = "GAMMA-RAY BURST DETECTOR"
    INSTRUMENT_DESC                = "

      Instrument Overview
      ===================

      (excerpted from [HURLEYETAL1992])

      The GRB experiment was proposed in 1977 with a twin experiment
      aboard the NASA spacecraft. This approach had numerous
      advantages: a carefully intercalibrated pair of experiments at
      opposite ecliptic latitudes would survey the solar equatorial
      regions extensively, and stereoscopic observations would be
      relatively easy to compare with matched detectors.
      Triangulation baselines for cosmic gamma-ray bursts would be
      long, and the fact that two detectors in the network would be
      out of the ecliptic plane would provide a particularly
      favorable geometry for localization (non-coplanar detectors
      are required for arrival time analysis).

      With the unique mission opportunities, however, came unique
      design constraints. A radiation-hardened microprocessor was
      required to survive the passage through the Jovian radiation
      belts; few were available during the design phase of the GRB
      experiment. The limited performance of the unit chosen dictated
      simplified operating modes for the experiment. Electrical power
      aboard Ulysses is provided by a radioisotope thermoelectric
      generator (RTG) containing 10 kg of 238Pu (about 10^5 Ci). The
      GRB instrument would be the first cosmic gamma-ray burst
      detector to have to operate in this unfavorable background
      environment. To minimize the interference from the RTG, the
      sensors had to be mounted on the magnetometer boom, and were
      required to be essentially amagnetic. (More precisely, the
      remnant field could not exceed 2 x 10^-5 G at 25 cm.) Finally,
      the mass and power allocations for the GRB experiment were
      small compared to inner planet missions-2 kg and 2.6 W,
      respectively.

      Scientific Objectives
      ----------------------
      The Ulysses solar X-ray/cosmic gamma-ray burst instrument
      (acronym: GRB) has three main scientific objectives. The first
      is the study and monitoring of solar flare X-ray emission. The
      second is the detection and localization of cosmic gamma-ray
      bursts. The third is the in-situ detection of Jovian auroral
      X-radiation. . . . For a review of experimental data on solar
      flare X-rays, see [DENNIS1985], [DENNIS1988]. Reviews of
      cosmic gamma-ray burst observations have appeared in
      [HURLEY1988], [HURLEY1989].

      Jovian X-radiation was first detected by [METZGERETAL1983]
      using the Einstein satellite. X-rays in the 0.2-3 keV band
      were imaged with 4'' resolution, and provided evidence that
      the sources of X-radiation were the Jovian north and south
      auroral zones. The origin of the X-rays could have been either
      electron bremsstrahlung in the Jovian upper atmosphere, or
      characteristic line emission from atmospheric atoms excited by
      heavy ions precipitating from the Io torus. These two models
      make very different predictions about the hard X-ray flux in
      the Ulysses GRB energy range."
  END_OBJECT                       = INSTRUMENT_INFORMATION

  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "DENNIS1985"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "DENNIS1988"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "HURLEY1988"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "HURLEY1989"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "HURLEY1992"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "HURLEYETAL1992"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO
  OBJECT                           = INSTRUMENT_REFERENCE_INFO
    REFERENCE_KEY_ID               = "METZGERETAL1983"
  END_OBJECT                       = INSTRUMENT_REFERENCE_INFO

END_OBJECT                         = INSTRUMENT
END