New Experimental Techniques for Neutrino Experiments

中微子是宇宙中最丰富的粒子之一，它们是许多天体物理过程的关键，它们可能是解释宇宙物质-反物质不对称性的关键。已知它们在自然界中有三种类型或“风味”。“人们还观察到，中微子可以通过一个被称为中微子振荡的过程来切换口味。从这样的振荡实验中，我们发现中微子必须有质量。这是第一个已知的迹象表明，有物理超越了非常成功的粒子物理标准模型。中微子质量仍然是物理学中最重要的未决问题之一，因此实验正在寻找确定它的方法，因为它们的丰度可能在我们宇宙的演化中发挥重要作用。在过去的80年里，由于电子光谱技术的日益强大，基于β谱的精确测量的直接实验室测定一直在扩大。2009年，PI提出了一种新技术，通过该技术可以提取低能电子的能谱。这种技术被称为回旋辐射发射光谱学（克雷斯），它依赖于探测和测量电子在磁场中回旋运动产生的相干辐射。中微子质量的知识对科学界有着广泛的影响，特别是在核物理、粒子物理和宇宙学领域。克雷斯技术是低能电子的通用光谱技术，具有广泛的适用性。可能的应用实例包括用于核不扩散的稀有放射性同位素的检测、菲尔茨干涉项测量、低能电子原子散射和高压计量学。PI希望针对本科生参与这种研究对代表性不足的少数民族，特别是对美洲原住民社区的成员。经过三年的研发，Project 8实验已成功演示首次探测到来自单电子的回旋辐射。随着原理证明的牢固确立，该奖项为研发计划的下一阶段提供了持续的支持，朝着从氚β衰变测量中微子质量的方向发展。具体而言，下一阶段是对氚β谱进行第一次测量，以确定该技术的可扩展性。这种在亚电子伏特中微子质量范围内的直接测量对于宇宙学、新标准模型的结构非常重要，它将阐明寻找无中微子双β衰变的关键未知因素。

Neutrinos are amongst the most abundant particles in the Universe, they are keys to many astrophysical processes, and they may hold the key to explaining the matter-antimatter asymmetry of the Universe. They are known to occur in nature in three types, or "flavors." It has also been observed that neutrinos could switch flavors through a process known as neutrino oscillation. From such oscillation experiments, it is found that neutrinos must have a mass. This is the first known indication that there is physics beyond the very successful Standard Model of Particle Physics. Neutrino mass remains one of the most important open questions in physics and so experiments are searching for ways to determine it since with their abundance they could play an important role in the evolution of our Universe. Direct laboratory determinations based on the precise measurement of the beta spectrum have been expanding over the past 80 years due to increasingly powerful electron spectrometry techniques. In 2009, the PI proposed a new technique by which the energy spectrum of low energy electrons can be extracted. The technique, known as Cyclotron Radiation Emission Spectroscopy (CRES), relies on the detection and measurement of coherent radiation created from the cyclotron motion of electrons in a magnetic field.Knowledge of neutrino masses has broad implications for the scientific community, particularly in the fields of nuclear physics, particle physics, and cosmology. The CRES technique, being a general spectroscopic technique for low energy electrons, has broad applicability. Examples of possible application include detection of rare radioactive isotopes for nuclear non-proliferation, Fiertz interference term measurements, low energy electron-atom scattering, and high voltage metrology. The PI wishes to target undergraduate student participation in such research toward underrepresented minorities, particularly toward members of the Native American community.After three years of research and development, the Project 8 experiment has successfully demonstrated the first detection of cyclotron radiation from single electrons. With the proof of principle firmly established, this award provides continued support for the next stage of the R&D program, moving toward a neutrino mass measurement from tritium beta decay. In particular, the next phase is to make a first measurement of a tritium beta spectrum in order to determine the scalability of the technique. Such a direct measurement in the sub-eV neutrino mass range is important for cosmology, the structure of the new Standard Model, and it will illuminate a key unknown in the search for neutrino-less double beta decay.