  RT-2 Experiment (RT - Roentgen Telescope) is a low energy gamma-ray
instrument which is designed and developed as a part of Indo-Russian
collaborative project of CORONAS-PHOTON Mission to study the Solar flares in
wide energy band of electromagnetic spectrum ranging from UV to high-energy
gamma-rays (~2000 MeV).
  RT-2 instruments will cover the energy range of 15 keV to 150 keV extendable
up to ~1 MeV. It consists of three detectors (two Phoswich detectors, namely,
RT-2/S, RT-2/G and one solid-state imaging detector RT-2/CZT) and one
processing electronic device (RT-2/E). Both Phoswich detectors will have time
resolved spectrum, whereas the solid-state imaging detector will have high
resolved image of the solar flares in hard X-rays. We have used Co-57 (122 keV)
radio-active source for onboard calibration of all three detectors. In this
paper, we briefly discuss the in-flight performance of RT-2 instruments and
present initial flight data from the instruments.
  This mission was launched into polar LEO (Low Earth Orbit) (~550 km) on 30th
January 2009 from Plesetsk Cosmodrome, Russia.
