  The WIMPs search project PICO-LON has been started with multilayer thin
NaI(Tl) crystals. The thin (0.05cm) and wide area (5cmx5cm) NaI(Tl) crystals
was successfully developed. The performances of thin NaI(Tl) scintillator was
measured and they showed good energy resolution (20% at 60keV) and good
position resolution (20% in 5cmx5cm wider area).
