Study of a neutrino beam monitor for the Long Baseline Neutrino Oscillation Expcriment

光束监测器由一个介子探测器、一个铅玻璃量热计系统、一个否决/触发计数器系统和一个水/闪烁光纤系统组成。这个大容器用于以下两个部分。1)铅玻璃量热计：铅玻璃量热计的研究大致分为两步。第一步是电子束测试。通过束流测试，对一些样品计数器进行了相对于束流电子能量的绝对校准。此外，还获得了有关聚类等方面的知识。然后，作为第二步，再次使用宇宙射线粒子校准所有计数器。由于在上述两步中已知了电子脉冲高度与宇宙射线粒子之间的关系，因此所有铅玻璃计数器都经过了很好的校准。2)水/闪烁光纤系统：该部分研究的第一步是选择用于该探测器的光纤。因此，0.7mmphi光纤具有多层包层。经过多方努力，确定了纤维片材的生产方案。目前正在进行最终量产。制作了一个小型光纤探测器原型，并通过宇宙射线进行了测试。结果表明，该方法可以获得较好的位置分辨率和效率。通过本文的研究，我们建立了一种能够满足中微子振荡实验要求的探测器的制造方法。为了进行最后的检查，一个包括所有组件的中微子束监测器的原型被建造并在KEK ps进行了测试，数据正在分析中。

The beam monitor consists of a muon detector, a lead glass calorimeter system, a veto/trigger counter system and a water/scintillating fiber system. This grand-inaide was used for the following two parts.1) Lead glass calorimeter : The study of the lead glass calorimeter was done roughly in two steps. The first step was a beam test using an electron beam. By the beam test, some sample counters were absolutely calibrated relatively to the beam electron energy. In addition, much knowledge about clustering etc. was obtained. Then, as the second step, all counters were calibrated by using cosmic ray particles again. As the relation between pules height by electrons and cosmic ray particles is known in the above described two steps, all lead glass counters were well calibrated.2) Water/Scintillating fiber system : The first step of the study of this part was the selection of fibers to be used in this detector. As the result, 0.7mmphi fiber with multi-cladding. By a lot of efforts, the production scheme of fiber sheet was established. Final mass production is now underway. A small size prototype fiber detector was made and tested by a cosmic ray. It showed that a reasonably good position resolution and efficiency can be obtained.By the present study, we established the way to make a detector which can meet the requirement from the neutrino oscillation experiment. For the final check, a prototype of the neutrino beam monitor including all components was constructed and test at KEK PS.The data are now being analyzed.