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

束流监测器由μ子探测器、铅玻璃量能器系统、否决/触发计数器系统和水/蒸发光纤系统组成。1）铅玻璃量热计：对铅玻璃量热计的研究大致分两步进行。第一步是使用电子束的束流测试。通过束流实验，对部分样品计数器进行了相对于束流电子能量的绝对标定。此外，还获得了许多关于聚类等方面的知识。然后，作为第二步，再次使用宇宙射线粒子校准所有计数器。由于在上述两个步骤中已知电子和宇宙射线粒子的脉冲高度之间的关系，所有的铅玻璃计数器都得到了很好的校准。2）水/闪烁光纤系统：这部分研究的第一步是选择用于该探测器的光纤。结果表明，0.7mmphi多包层光纤。通过大量的工作，确定了纤维板的生产方案。目前正在进行最后的大规模生产。制作了一个小型光纤探测器样机，并进行了宇宙线测试。结果表明，该探测器具有较好的位置分辨率和探测效率，为研制满足中微子振荡实验要求的探测器奠定了基础。为了进行最后的检查，在KEK PS建造了一个包括所有组件的中微子束监测器原型，并进行了测试。

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.