Observations with a one square meter balloon-borne gamma-ray detector in the energy range above 10 MeV

A large area gamma-ray detector was flown on October 10, 1976 at an altitude of 1.55 millibars and at 320 North latitude. The instrument consists of an array of 16 multiwire proportional counters interspersed with sheets of tantalum which serve as converter. The detection of downward moving particles from the bottom of the array, in anticoincidence with counters on the top and sides, caused the proportional counter array to be read out. Prior to the flight, the instrument was calibrated using 20 MeV gamma-rays. The flight observed the region in right ascension from 22 hours to 11 hours and declination from 00 to 650 North. Preliminary results of an analysis of the flight data will be presented as well as results of the calibration