R&D of High Resolution Calorimeter for Electron-Positron Collider in TeV Region

为下一代正负电子对撞机实验进行了量热计的研制研究。构建了由铅和闪烁光纤组成的原型模块。它具有电磁淋浴和强子淋浴的综合功能。为了获得较好的强子阵雨能量分辨率，将铅与闪烁纤维的组成安排为4:1。利用国家高能物理实验室（KEK）的质子同步加速器实验束流装置对其基本性能进行了测试。使用的光束是1 GeV到4 GeV的电子和负介子。测量了各种特性，如能量分辨率、位置分辨率和对入射位置的依赖。在1GeV入射能量下，电子（介子）的能量分辨率为14%（50%）。在强子能量解析中包含了12%的常数项，这主要是由于阵雨泄漏造成的。将梁试验结果与GEANT模拟程序的预测结果进行了比较，两者吻合较好。根据侧向阵雨发展的信息和阵雨前的输出，进行了电子和介子的分离。并尝试利用阵雨发展的时间信息进行分离。在研究量热计本身的同时，还研究了能在强磁场中工作的光子探测装置。根据光束测试结果，从物理分析的角度来看，原型量热仪可以满足各种要求。但需要指出的是，大批量生产的方法和降低成本的可能性尚未在这里进行研究，这将是未来的问题。

R&D study of a calorimeter has been performed for the next generation electron-positron collider experiment. A prototype module was constructed which consisted of lead and scintillating fibers. It had a combined function both for electromagnetic shower and for hadronic shower. In order to obtain a good energy resolution for hadronic shower, the composition of lead and scintillating fibers was arranged to be 4 : 1. Basic performances were tested using the test beam facility of Proton Synchrotron at National Laboratory for High Energy Physics (KEK). The beams used were electron and negative pions of 1 GeV to 4 GeV.Various properties such as energy resolution, position resolution, and dependence on the incident position were measured. The energy resolution of 14% (50%) at 1GeV incident energy was obtained for electrons (pions). The constant term of 12% was included in the hadronic energy resolution, which was mainly due to the shower leakage. The results obtained in the beam test were compared with the predictions of GEANT simulation program, and the good agreement was obtained.Based on information of lateral shower development and on pre-shower output, the separation between electrons and pions was performed. The separation was also tried by using the time information of the shower development.In parallel with the study of the calorimeter itself, the photon detection devices were also investigated which can be operated in the strong magnetic fields.Based on the beam test results, we found that the prototype calorimeter would satisfy the various requirements from the viewpoint of physics analyzes. It should be noted, however, that the method of mass-production and possibility of cost-down have not been investigated here and will be the future issues.