The NEMO Collaboration installed an underwater detector including most of the critical elements of a possible km$^3$ neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box, including the data transmission, the power distribution, the timing calibration and the acoustic positioning systems. These technical solutions will be evaluated, among others proposed for the construction of the km$^3$ detector, within the KM3NeT Consortium. The main test of this test experiment was the validation of the proposed design solutions mentioned above. We present results of the analysis of data collected with the NEMO Mini-Tower. The position of PMTs is determined through the acoustic position system; signals detected with PMTs are used to reconstruct the tracks of atmospheric muons. The angular distribution of atmospheric muons was measured and results were compared with Monte Carlo simulations.
Studies of the muon-induced neutron background in LSM: detector concept and status of the installation
冷暗物质(CDM)的一个很好的候选粒子是超对称中性伴子,或者更一般的弱相互作用大质量粒子(WIMP)。在直接检测实验中,WIMP与检测介质的预期相互作用率低于0.01事件/kg/天。这使得背景条件的良好知识非常重要,特别是随着检测器灵敏度的不断提高。背景成分之一与宇宙μ子有关,特别是μ子诱导的中子。详细的研究进行了雪绒花合作在这方面的介绍。这项活动包括GEANT 4模拟与完整的事件拓扑结构,以及一个专门的测量与一个新的中子计数器安装在2008年秋季在LSM(Alternatoire Souterrain de Modane,法国)。这个计数器被纳入现有的μ子否决系统,从而允许监测与入射μ子一致的中子。
EUSO-TA是一个地基望远镜,位于美国犹他州望远镜阵列(TA)的Black Rock Mesa站点。该仪器的主要目的是通过探测宇宙射线簇射产生的紫外线来观测超高能宇宙射线。EUSO-TA由两个1 m2的菲涅尔透镜组成,视场约为11 x11度。光聚焦在由36个滨松多阳极光电倍增管组成的光电探测器模块上,总共有2304个通道。在操作过程中,望远镜被放置在TA荧光检测器前面的一个棚子里。我们介绍了2015年和2016年EUSO-TA观测活动的结果,包括探测到的宇宙射线、流星和激光发射。还显示了当前仪器设置和探测器升级到第二阶段的详细情况。