Purpose of the flight and payload description
The GRAINE project has been developed for the observation of cosmic gamma-rays onboard long duration balloon missions. The instruments observes particles in the energy range between 10?MeV and 100?GeV, with emulsion plates that combines high precision, sensibility to the polarization and large-aperture-area.
The instrument is composed by a converter, timestamper, calorimeter and attitude monitor. Converter consists of an stack of emulsion films (with metal foils) where the beginning of electron pairs are detected. The timestamper is composed by a multi-stage shifter which gives a time resolution below a second to events at the converter. The calorimeter consists of a stack of emulsion films with metal plates that measures high energy particles either by measuring the energy of the electro-magnetic shower or the momentum of electron pair with multiple coulomb scattering. Particles of low energies are measured at the converter by measuring the momentum of electron pair with multiple coulomb scattering. The attitude monitor consists of a star camera.
By combining the attitude monitor information and the event timing, the gamma-ray direction relative to the celestial sphere is determined.
Details of the balloon flight