《寻找暗物质的太阳望远镜》

  • 来源专题:重大科技基础设施领域知识集成服务平台
  • 编译者: 魏韧
  • 发布时间:2020-09-14
  • 物理学界最想寻找的物质当属暗物质。全世界的科学家用不同的途径、实验和方法来追踪暗物质。德国电子同步加速器研究所(DESY)将很快开展几个寻找暗物质粒子的实验。其中一个正在赫拉加速器的地下大厅里开展,第一批部件刚刚运到。
    这个实验被称为BabyIAXO,具有两个装置:一是寻找太阳发出的暗物质粒子的望远镜;二是一个更大、更强的实验原型IAXO(国际轴子天文台),计划在2024年上线。DESY目前正在开展两个实验寻找暗物质,即ALPS II和BabyIAXO,用来特别是被称为轴子的暗物质粒子。
    理论上已经预测到了轴子,但是还没有在任何实验中观察到。它们属于被称为微束(“弱相互作用亚电子束粒子”)的粒子家族,所有这些粒子的特点都是质量小,不与其他粒子和力相互作用。理论预测,它们有时会转变成普通的轻粒子,可以用复杂的测量方法检测到,但只能在极强的磁场中进行。
    因此,如果一个轻粒子突然出现在一个本来不应该出现的强磁场中,这可能是一个轴子的迹象。ALPS II和BabyIAXO都依赖于此特殊性质。但是,当ALPS II自己产生轴子并把它们送过非透明围护时,BabyIAXO将关注太阳的中心,根据理论轴子应该一直从太阳中心落在我们身上。
    这需要足够的技术。首先,需要坚固且长的大孔径磁铁。目前正在欧洲核子研究中心开发磁体,首批部件已经在测试中。BabyIAXO将比之前在欧洲核子研究中心打造的实验“CAST”增强大约四倍。拟议的大型IAXO的敏感度将再次提高五倍。
    捕捉光粒子的探测器必须极其灵敏且无噪声。西班牙、法国和德国的几个研究团队正在为这项任务准备探测器。磁铁产生的光需要聚焦在尽可能小的区域。美国、意大利和丹麦参与BabyIAXO项目的协作伙伴也在与欧洲空间局(ESA)和美国宇航局(NASA)协作开发这种望远镜。
    第三个大部件是旋转塔。它承载着整体90吨的重量,必须足够稳定,使太阳望远镜能够360度旋转并跟踪太阳的中心。BabyIAXO必须始终非常精确地正对太阳中心,但这并非易事,因为它位于地下大厅。在天文学中,具有满足这些条件的旋转装置经常被用于望远镜,BabyIAXO的塔的原型载体前身来自柏林Adlershof,是切伦科夫望远镜阵列项目保存的原型,这个原型研究已经完成,塔被回收用于BabyIAXO。
    还有其他几个关于BabyIAXO设施复用的例子,包括HERA对撞机的大厅和由欧空局提供的磁铁内部聚焦系统。磁体开发人员还利用了欧洲核子研究中心的ATLAS实验磁体组的现有工具。

  • 原文来源:https://www.desy.de/news/news_search/index_eng.html?openDirectAnchor=1816&two_columns=0
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