  An experimental technique for the light lambda-hypernuclei structure studies
by using (negative kaon, neutral pion) reaction and Neutral Meson Spectrometer
(NMS) developed at the BNL has been described. Position dependence calibration
of the BGO conversion planes of the NMS was invented as the solution to the
crucial constraint of the high resolution in single-lambda spectroscopy.
Position parameters of the BGO crystal rods were fitted out from the
out-of-kaon beam measured data as obtained by the original small highly
collimated Co-60 source method, based on the coincidences between top and
bottom signals of each BGO rod.
