Collaborative Research: The Simpson Neutron Monitor Network

这个为期三年的合作项目的重点是建立一个地面宇宙射线监测仪网络，称为中子监测仪（NMs），由三个美国学术机构组成的财团运营，即新罕布什尔大学、特拉华大学和威斯康辛河瀑布大学。1948年，约翰·辛普森教授根据他在曼哈顿计划中的经验，发明了NMs，用于探测和测量太空中的辐射，几乎比太空时代早了十年。它们驻扎在全球各地的地面上，在半个多世纪的时间里持续不断地测量宇宙辐射。NMs测量太空中辐射水平的趋势和变化，这是宇航员前往月球和火星旅行的关键信息。它们还可以探测到太阳到达地面的强烈的、短期的辐射爆发。所有这些活动完全是由太阳的活动驱动的。NMs坚固可靠，近年来与国际航天器舰队和其他国家的中子监测器一起使用时，具有新的重要性。现在，所有由美国赞助的NMs都被连接到辛普森中子监测网络中，这将使其更有效地协调操作和科学。在这个为期三年的合作项目中，该联盟将进行这项研究，从这些传统仪器中梳理出新的信息，并为世界各地的研究人员提供最新的辐射气候数据。进入地球大气层的宇宙射线是我们了解大尺度日球层结构、局部空间环境和太阳活动的信使。它们已经穿过行星际磁场并与之相互作用，它们携带着行星际磁场详细结构的信息。其中一些宇宙射线的能量足以到达地面。NM是一种地面粒子探测器，可以记录粒子簇中的核子成分。这与撞击地球大气层的高能宇宙射线的数量直接相关。对这些数据的分析用于了解太阳对太阳系的影响。由于地面观测站使用的探测器体积很大，中子监测器仍然是测量刚性1GV宇宙射线的最先进仪器。由新罕布什尔大学、特拉华大学和威斯康辛河瀑布大学运行的这些仪器的程序化连接将确保全球社会的高质量数据的连续性，正如国家空间天气计划和国会立法所呼吁的那样。来自这些仪器的数据被许多人使用，包括空间天气预报员、工业、空间科学家、国土安全和水文学家。气象站覆盖了从南极到北极的各个纬度。NM信号的来源包括来自银河系的宇宙射线，这些宇宙射线受到太阳活动的严重调制，以及来自太阳本身的高能质子爆发。这些物质的可变性揭示了行星际空间的条件、太阳的一般活动以及在整个宇宙中产生宇宙射线的基本过程。有了今天的计算资源，我们更好地了解这些仪器是如何检测辐射的，因此，该联盟将能够从这些主力设备中提取新的信息。这将揭示宇宙射线的分布如何随时间、地理和粒子能量的变化而变化。该联盟将研究如何永久保障监控网络的运行，以及如何以智能方式扩展网络，以补充现有站点的网络。该项目的教育和推广目标包括一个博士后的研究职位，为本科生提供各种各样的机会和经验，以及为高中生和小学生提供机会。该合作项目的研究和EPO议程支持AGS部门在发现、学习、多样性和跨学科研究方面的战略目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This three-year collaborative project is focused on building of a network of ground-based cosmic-ray monitors, called Neutron Monitors (NMs), operated by a consortium of three U.S. academic institutions, namely Universities of New Hampshire, Delaware and Wisconsin-River Falls. Invented by Prof. John Simpson in 1948, following his experience on the Manhattan Project, NMs have been used to detect and measure radiation in space, starting almost ten years before the space age. They are stationed on the ground all over the globe, providing continuous measurements of cosmic radiation for over a half century. NMs measure the trends and changes in the radiation levels in space, which is critical information for travel by astronauts to the Moon and Mars. They can also detect intense, short-term bursts of radiation from the Sun that reach the ground. All this activity is driven entirely by what the Sun is doing. NMs are robust and reliable and have assumed a new importance in recent years when used in conjunction with the international fleet of spacecraft and with neutron monitors in other countries. Now, all the NMs sponsored by the U.S. are being linked into what will be the Simpson Neutron Monitor Network, which will make it more efficient to coordinate operations and science.During this three-year collaborative project, the consortium will carry out this research, teasing new information out of these heritage instruments and providing researchers around the world with up-to-date radiation climate data. Cosmic rays entering the Earth’s atmosphere are messengers informing us about large-scale heliosphere structure, local space environment and solar activity. They have already passed through and interacted with the interplanetary magnetic field, and they carry information of its detailed structure. Some of these cosmic rays possess enough energy to reach the ground. A NM is a ground-based particle detector that records the nucleonic component in particle showers. This directly correlates with the number of high energy cosmic rays striking the Earth’s atmosphere. The analysis of these data is used to build an understanding of the Sun’s influence on the Solar System. Because of the large detector volume exploited by ground-based stations, neutron monitors remain the state-of-the-art instrumentation for measuring rigidity 1GV cosmic rays. The programmatic linking of these instruments run by the Universities of New Hampshire, Delaware and Wisconsin-River Falls will secure a continuity of quality data for the global community, as called out in the National Space Weather Plan and Congressional legislation. The data from these instruments are used by many, including, space weather predictors, industry, space scientists, homeland security and hydrologists. The NM stations span a wide range of latitudes, from the South Pole to the Arctic regions. The contributors to the NM signal include cosmic rays from the galaxy that are heavily modulated by solar activity and from the Sun itself in the form of high energy bursts of protons. The variability of these agents reveals conditions in interplanetary space, general solar activity and the fundamental processes that produce cosmic rays throughout the Universe. With today’s computing resources, we better understand how these instruments detect radiation, and the consortium will thus be able to extract new information from these workhorse devices. This will shed new light on how the distribution of cosmic rays varies with time, geography and particle energy. The consortium will study how to permanently secure the operations of the monitor network and intelligent ways of expanding the network to complement those at existing sites. The education and outreach goals of the project include a research position for a postdoc, a wide variety of opportunities and experiences for undergraduates, as well as opportunities for high school and elementary school students. The research and EPO agenda of this collaborative project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.