In this paper, we show that low energy gamma rays down to few keV can be de
tected with CsI(Tl) crystal detector. A clear peak at 6 keV from a radioact
ive source is observed. In addition, we also show that alpha particles and
gamma rays can be separated greater than 3 sigma level down to 50 keV regio
n using the different time characteristics of the crystal for both signals.
With further background study, we should be able to determine CsI(Tl) be a
good candidate detector in search for weakly interacting massive particles