Balloon-borne x-ray spectrometer for detection of x rays produced by thunderstorms

A new balloon-borne instrument designed by the author detects x rays produced in thunderstorms. The instrument uses a sodium iodide (NaI) scintillation detector, and flies on a small meteorological balloon. A three bin (30 to 60, 60 to 90, and 90 to 120 keV) x-ray spectrum is acquired every 0.25 s. The deployment of these detectors with electric-field meters has resulted in several vertical profiles of x-ray intensity and electric-field strength. These data support the hypothesis that the electric field generated by the thunderstorm can produce energetic electrons, which in turn emit bremsstrahlung x rays.