Purpose of the flight and payload description

This balloon mission was aimed to observe neutrons emitted by the Sun using nuclear emulsion plates flown at an altitude of 10 mb by means of a stratospheric balloon over Hyderabad, India.

The neutrons were detected on the post-flight analysis of the nuclear emulsion by observing the protons recoiling from elastic collisions of neutrons with hydrogen nuclei in the nuclear emulsion.

In order to determine the flux of solar neutrons, if any, the scientists have used nuclear emulsion plates exposed at a height of 10 mb, together with emulsion plates which were dropped when the balloon reached ceiling altitude (ascent-descent stack) and ground control emulsion plates. All emulsions were freshly coated using Ilford emulsion gel at the Tata Institute of Fundamental Research a few days before the balloon flights. The 'ascent-descent stack' was used for correcting for accumulation of background events while the emulsion stack goes up in the balloon and down after the termination of the flight. The 'ground stack' was used to assess the background accumulation at ground level.

The balloon flight was made on a day when the sunspot number was at the peak of its 27-day variation. Furthermore, there was a visual solar flare of magnitude 3 a few hours before the balloon flight; it is possible that the neutron flux observed could be associated with a disturbed region of the Sun.

Details of the balloon flight

Balloon launched on: 3/23/1962 at ~ 7:00 IST
Launch site: Osmania University Campus, Hyderabad, India  
Balloon launched by: Tata Institute of Fundamental Research (TIFR)
Balloon manufacturer/size/composition: Zero Pressure Balloon  
End of flight (L for landing time, W for last contact, otherwise termination time): 3/23/1962 at ~ 15:00 IST
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): ~ 10 h

External references

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