Study of Undoped CsI or BaF_2 Calorimeter with wavelength shifter readout

对于非掺杂CSI的应用，我们测试了6种不同的波长移位材料，测量了读出效率和光的衰减长度。它们是(A)Bicron BC408、(B)Bicron BC499-54、(C)Bicron BC499-55、(D)Bicron BC499-56、(E)Kurrary PMMA(Acryl)和(F)Kurrary的SCSN81。我们获得了平均20%的读出效率(对于短样本)和大约2米的衰减长度。特别是我们对100%有源量热计感兴趣，在其中我们必须将光与移位器的光和(波长移位的)CSI光分开。我们已经尝试了使用塑料闪烁较少的面粉的脉冲形状分析和/或移位器。因此，我们发现用较少的四个移位器(如样品(C))就可以分离它们。对于非掺杂BaF_2的应用，由于其快速的定时特性而引起人们的注意，由于其220 nm的紫外光，波长移位器的开发并不容易。最后，我们已经从Bicron获得了Shift的样品，并将对其进行测试。

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.