The Calibration and Simulation of the GRB trigger detector of the Ultra Fast Flash Observatory

¹ Department of Energy Engineering, National United University, Miao-Li, Taiwan ;
e-mail: mahuang@nuu.edu.tw
² Laboratoire de l’Accélérateur Linéaire, University of Paris-Sud 11, Orsay, France
³ Technical University of Denmark, Copenhagen, Denmark
⁴ Instituto de Astrofisica de Andalucía, CSIC, Granada, Spain
⁵ National Space Organization, Taiwan
⁶ LeCosPA, National Taiwan University, Taipei, Taiwan
⁷ Korea Institute of Industrial Technology, Cheonan, Korea
⁸ Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Korea
⁹ University of Valencia, Valencia, Spain
¹⁰ Institute for the Early Universe, Ewha Womans University, Seoul, Korea
¹¹ Department of Physics, Ewha Womans University, Seoul, Korea
¹² Sungkyunkwan University, Suwon, South Korea
¹³ Department of Astronomy, Yonsei University, Seoul, Korea
¹⁴ SINP, Moscow State University, Moscow, Russia

Abstract

The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector, called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB and then triggers to determine the direction of the GRB and then alerts the Slewing Mirror Telescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes. This report details the calibration of the two components: the MAPMTs and the YSO crystals and simulations of the UBAT. The results shows that this design can observe a GRB within a field of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 s after the appearance of a GRB X-ray spike.