MRI-R2: Development of POLAR-1, an expandable 5,000-detector CMB Polarimeter

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。宇宙微波背景（CMB）观测拥有关于早期宇宙的大量信息，它们最近将宇宙学转变为一门精确的科学。虽然膨胀宇宙的基本概念和成分已经很好地建立起来，但关于宇宙起源的基本问题仍然没有答案。测量CMB偏振提供了解决这些问题中最重要的问题的强大工具。CMB中的偏振模式可以分解为两个不同的分量，E模式和B模式，后者（尚未检测到）可以提供两个显着的见解。通过探测到的B模式偏振，人们可以研究宇宙的大尺度结构以及影响这种结构的参数，例如绝对中微子质量和暗能量演化。度标度的B模式偏振也应该带有来自宇宙引力波背景（CGB）的印记，让我们在宇宙诞生的第一秒的最小部分（10^-35）中瞥见宇宙。这个CGB信号是暴胀大爆炸发生时能量尺度的直接测量。该提案要求提供资金，用于开发一个增强型大幅面焦平面偏振计POLAR-1，该偏振计有4 608个偏振敏感超导测辐射热计，工作频率为150千兆赫，并与一个1.5米反射射电望远镜相结合。角分辨率和测辐射热计阵列尺寸的建议的组合，使其非常适合于研究透镜引起的和CGB产生的B-偏振。POLAR-1将以极高的显著性检测透镜诱导的B偏振，并搜索功率低至初始扰动的2%的CGB。该项目的更广泛的影响将是其路径探索性质的建设一个仪器~ 10倍更敏感的CMB极化。由于宇宙学抓住了公众的想象力，它是激发学生对科学兴趣的一个非常有效的工具。该项目将继续通过将研究生和本科生教育与技术和仪器开发、天文实地观测和科学分析相结合，为培养下一代科学家作出重大贡献。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The Cosmic Microwave Background (CMB) observations hold a remarkable wealth of information about the early Universe and they recently transformed cosmology into a precision science. While the basic notion and the ingredients of an expanding Universe are well established, fundamental questions on the Universe's origin still remain unanswered. Measuring the CMB polarization provides a powerful tool to address the most important of these questions. The polarization pattern in the CMB can be decomposed into two distinct components, E-mode and B-mode, and the latter (yet to be detected) can provide two remarkable insights. With the detected B-mode polarization, one can study the large-scale structure of the Universe and the parameters that affect this structure, such as absolute neutrino mass and Dark Energy evolution. The degree-scale B-mode polarization also should carry imprints from the Cosmic Gravitational-wave Background (CGB), giving us a glimpse of the Universe during its tiniest (10^-35) fraction of the very first second of life. This CGB signal is a direct measurement of the energy scale at which the inflationary Big Bang occurs. The proposal requests funds for development of an enhanced large-format focal plane polarimeter POLAR-1 with 4,608 polarization-sensitive superconducting bolometers operating at 150 GHz and integrated with a 1.5-m reflective radio telescope. The proposed combination of angular resolution and bolometer array size make it ideally suited to study both the lensing-induced and the CGB-generated B-polarization. POLAR-1 will detect lensing induced B-polarization with extremely high significance and search for CGB down to 2% of the initial perturbation in power. The project's broader impacts would be in its path-finding nature of building an instrument ~10x more sensitive to the CMB polarization. As cosmology captures the public imagination, it is a remarkably effective vehicle for stimulating students' interest in science. The project will continue contributing significantly to the training of next generation of scientists by integrating graduate and undergraduate education with technology and instrumentation development, astronomical field observations, and scientific analysis.