HR: 17:45h
AN: AE14A-08 INVITED     [Abstracts]
TI: CORONAS-F/AVS-F Observations of Terrestrial Gamma-ray Flashes
AU: * Arkhangelskaja, I
EM: irene.belousova@usa.net
AF: Moscow Engineering Physics Institute, Kashirskoe Shosse 31, Moscow, 115409 Russian Federation
AB: Terrestrial gamma ray flashes (TGFs) were first detected by BATSE experiment onboard CGRO satellite. Whole BATSE database contains 78 TGF but it is possible to define duration only for 65 ones. We have analyze all BATSE TGF temporal profile and obtain that these duration is in region from 0.01 to 20 ms. TGFs are produced in a process of bremsstrahlung of the runaway electrons in the middle atmosphere which are accelerated upward by the thundercloud electric field and collide with the material constituting the atmosphere. These electrons are very energetic (E near 1 MeV) and the gamma radiation pattern is directed along the beam. The AVS-F (amplitude-time Sun spectrometry) apparatus is intended to study characteristics of fluxes of hard X-rays, gamma-rays and neutrons from the Sun and solar flares and to detect and record events like gamma-ray bursts. The experiment is carry out at the CORONAS-F special-purpose automatic station (NORAD catalog number 26873, International Designator 2001-032A) that had been launched from Russian kosmodrom Plesetsk at 11:00 UT of 31 July 2001 into a circular orbit oriented towards the Sun with inclination 82.5 degrees and altitude near 500 km. The AVS-F apparatus uses signals produced by the SONG-D detector (based on the CsI(Tl) crystal of 20 cm and height of 10 cm, energy deposition ranges of 0.1 to 17.0 MeV and and 4.0 to 94.0 MeV by up to date calibration data), XSS-1 detector (the semiconductor detector with 3-30 keV energy deposition range) and the anticoincidence signal generated by the plastic scintillation counter of SONG-D. The basic time resolution of AVS-F apparatus is 16 sec in the bands of X-ray and low-energy gamma-emission registration and 128 sec for high- energy gamma-band. But AVS-F apparatus also allow to obtain event temporal profile with 1 ms time resolution in the low energy gamma-band. Using data of this type we have separated several short events with duration 1 to 16 ms in AVS-F database. These short events are similar to TGF on temporal profiles shape and duration and one of them were registered during strong tropical cyclone Beni. Two events started at 21:00 were found on July 19 2004 very close to RHESSI event at 21:24:01.530. The characteristics of these events are discussed in presented work.
DE: 3304 Atmospheric electricity
SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005