ALPS II: Commissioning and Data Taking

天文观测已经确定，宇宙大部分是黑暗的，大约85%的物质是由未知的粒子组成的。确定这种暗物质的性质将影响我们对宇宙学、天体物理学和粒子物理学的基本知识，并且是对超越标准模型的新物理学进行最广泛搜索的基础，标准模型迄今为止在描述我们的理解方面非常有效。标准模型的扩展预测了弱相互作用的光（亚电子伏特）粒子，包括轴子，它们已被引入作为暗物质的主要候选者。任意光粒子搜索（ALPS） II实验旨在为这些低质量粒子提供迄今为止使用光穿墙（LSW）技术的任何测量的最高搜索灵敏度。位于德国汉堡DESY的ALPS II探测器目前正在建设中，该合同支持佛罗里达大学的ALPS II小组使用该团队开发的外差探测方案进行即将到来的调试和科学运行。该实验为博士后和学生研究人员提供了一个独特而多样化的培训基地，以发展电子和反馈控制系统，真空和低温，计算方法和数据分析算法，大型探测器的调试和操作以及暗物质物理和宇宙学方面的技能。ALPS实验旨在寻找将光子转化为低质量粒子的相互作用，反之亦然，从而使光子重新出现在原本不透光的墙后面。这些低质量粒子包括类轴子粒子，它们的标量对应物，以及隐藏的扇区光子，它们将贡献甚至完全构成无所不在的暗物质。ALPS II实验由两根120米长的5.3 T HERA偶极子串组成，这些偶极子串在墙的两侧。光学腔用于在墙的一侧建立高达1兆瓦的功率，而另一侧的第二个腔用于放大再现过程。与用于寻找类轴子粒子的太阳镜和光镜不同，ALPS没有对恒星演化做出任何假设；它也没有假设任何特定的暗物质模型。这个实验只依赖于光子和假定的非标准模型粒子之间的基本相互作用。在再生光子方面，ALPS II的实验将超越以往LSW的12个数量级，并探索最近受到天文学和其他观测青睐的参数空间。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。

Astronomical observations have established that the Universe is largely dark, with approximately 85% of the matter made of yet unknown particles. Determining the nature of this dark matter will impact our fundamental knowledge of cosmology, astrophysics and particle physics and is the basis for one of the most extensive searches for new physics beyond the Standard Model that has been so effective in describing our understanding to date. Extensions of the Standard Model predict weakly interacting light (sub-electronvolt) particles, including axions, which have been introduced as a primary candidate for the dark matter. The Any Light Particle Search (ALPS) II experiment is designed to provide the highest search sensitivity for these low-mass particles of any measurements to date that use the Light Shining Through a Wall (LSW) technique. Located at DESY in Hamburg, Germany, the ALPS II detector is now under construction and this award supports the ALPS II group at the University of Florida to perform the upcoming commissioning and science runs using the heterodyne detection scheme developed by the team. The experiment provides a unique and diverse training ground for postdoctoral and student researchers to develop skills in electronics and feedback control systems, vacuum and cryogenics, computational methods and data analysis algorithms, large-scale detector commission and operation, and dark matter physics and cosmology. The ALPS experiment is designed to search for interactions that turn photons into low-mass particles and vice versa, allowing photons to reemerge behind an otherwise light tight wall. These low-mass particles include axion-like particles, their scalar counterparts, as well as hidden sector photons, and would contribute or even exclusively form the omnipresent dark matter. The ALPS II experiment consists of two 120 m long strings of straightened 5.3 T HERA dipoles on each side of the wall. An optical cavity is used to build up the power to up to 1 MW on one side of the wall while a second cavity amplifies the recreation process on the other side of the wall. In contrast to helioscopes and also haloscopes used also in the search for axion-like particles, ALPS makes no assumptions about stellar evolution; nor does it assume any specific dark matter model. The experiment only depends on proposed fundamental interactions between photons and postulated non-standard-model particles. The ALPS II experiment will surpass past LSW searches by 12 orders of magnitude in regenerated photons and explores a parameter space which has lately been favored by astronomical and other observations.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.