BAIKAL DUMAND[HIGH ENERGY NEUTRINO AND GAMMA-RAY ASTROPHYSICS]

我们计划的主要目标是发展实现贝加尔湖极高能中微子天体物理的基础技术。在我们看来，超高能中微子天体物理学的最终目的是理解只有中微子才能解释的宇宙。另一方面，能量低于极高能中微子天体物理的高能中微子天体物理学的目的是通过神经元来理解宇宙，参照高能伽马射线照亮的宇宙图像。如你所知，世界上有四个高能中微子天体物理项目。即杜曼德(夏威夷)、NT-200(贝加尔岛)、阿曼达(南极)和内斯特(陆地)。其中，只有[NT-200]成功地重建了对探测高能宇宙Muon-中微子绝对重要的高能Muon径迹。…存在严重的问题到目前为止，高能中微子天体物理学的实验和计算都取得了更多的进展。其中之一就是Muon-中微子的能量测定。在这个问题上，涨落起着重要的作用。在严格考虑涨落效应的情况下，我们计算了介子能量与切伦科夫光产生的关系，并研究了高能介子在水中的行为，正确地考虑了涨落，发现由韧致辐射引起的灾难性能量损失对介子能量的确定起着决定性的作用。在高能伽马射线天体物理方面，我们对俄罗斯制造的光电倍增管的性能进行了检验，该光电倍增管有望为与NT-200相连的高能伽马实验而改进。在这个项目中，我们为极高能中微子天体物理发展了一些技术。得到了极高能量的µ子产生韧致辐射和直接产生电子对的截面。这一截面有望用于极高能量下的介子能量测定。较少

The Main puropose of our project is to develope the fudamental techniques by which we could realize the extremely high energy neutrino astrophysics in the lake Baikal. In our opinion, the ultimate aim of the extremely high energy neutrino astrophysics is to understand the Universe which could be elucidated by neutrino only. On the other hand, the aim of the high energy neutrino astrophysics whose enery is lower than that of extremely high energy neutrino astrophysics is to understand the Universe by neurtino, reffering to the image of the Universe enlighted by high energy gamma-ray. As you know well, there are four projects on the high energy neutrino astrophysics in the world. Namely, DUMAND (Hawaii), NT-200 (the Baikal), AMANDA (south pole) and NESTOR(the Me diterranean). Among them, only [NT-200] has succeeded in the reconstructions of high energy muon tracks which are absolutely important for thedetection of the high energy cosmic muon-neutrino.There are serious problems to be over … More come in both experiments and the calculations in high energy neutrino astrophysics still now. One of them is the energy determination of muon-neutrino. In this problem, the fluctuation play an important role. We have calculated the relation between the muon energy and the Cherenkov light produced, taking into account the fluctuation effect rigorously.Also, we have examined the behavior of hig energy muon in water, taking into account the fluctuation correctly and have found that the catastrophic energy loss due to the bremsstrahlung play the decisively important role for the energy determination of the muon. As for the high energy gamma-ray astrophysics, we have examined the performances of Russian made photomultiplier which is expected to be improved for the high energy gamma-rsay experiment linked with NT-200.Some techniques have been developed in this project for the extremely high energy neutrino astrophysics. The cross sections for the extremely high energy muon to cause the bremsstrahlung and direct electron pair production have been obtained. The cross section is expected to be utilized the energy determination of the muon in extremaly high energies. Less