Study of Undoped CsI or BaF_2 Calorimeter with wavelength shifter readout

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For the application of undoped CsI,we have tested 6 different kinds of wavelength-shifting materials to measure the readout efficiency and the attenuation length of lights. They are (a) Bicron BC408, (b) Bicron BC499-54, (c) Bicron BC499-55, (d) Bicron BC499-56, (e) Kurrary PMMA (acryl), and (f) Kurrary's SCSN81. We obtained an average 20% readout efficiency (for a short sample) and about 2-m attenuation length.In particular we are interested in 100% active calorimeter, in which we have to separate the lights from the shifter's light and (wavelength-shifted) CsI lights. We have tried pulse-shape analysis and/or shifters with less plastic-scintillating flour. As a result, we found that the shifter with less fours (such as the sample (c)) we might be able to separate them.For the application of undoped BaF_2, which attracts attention owing to its fast timing characteristic, the development of wavelength shifters is not easy because of its 220-nm UV lights. Finally we have obtained a sample of shifter from Bicron and we are going to test it.