A High Throughput CMB Polarization Receiver with Dual-Frequency-Band Bolometric Pixels

最成功的宇宙模型是在宇宙大爆炸后的一小部分秒内经历一段巨大的膨胀时期。早期宇宙中的这种“相变”解释了一些关键的观测结果，包括宇宙的极端平坦性、可观测宇宙中因果无关区域的非常相似的性质，以及磁单极子的缺乏。对膨胀的一个重要预测是，被认为在最后一次光子散射时存在的引力波所印记的偏振的“惯用手”。寻找这种“B模”偏振信号是对膨胀的基本测试，是对相变运行的能量尺度的诊断，也是ASTRO2010年调查天文学和天体物理学中的新世界、新地平线确定的未来十年的关键科学主题之一。加州大学伯克利分校的禤浩焯·李博士和美国其他地方以及加拿大、英国和日本的合作者计划进行一项实验，首次使用智利阿塔卡马高原上的专用无线电天线和最先进的7588像素测辐射热计阵列来探测和探索B模偏振，以绘制150和220 GHz双频的天空图，比目前的实验具有更高的灵敏度和数量级。POLARBEAR-2项目在科学上有很好的动机，在技术和管理方面也有同样充分的理由，因为试点项目POLARBEAR-1现已完成，并在智利现场获得了初步数据。通过该项目取得的技术发展将对天文探测的其他波长区域，包括亚毫米波段具有重要意义。博士后和学生的参与被包括在开发和测试的重要元素中，延续了加州大学伯克利分校射电天文学硬件和技术培训的强大传统。极地2项目的开发资金由NSF的天文科学部通过其先进技术和仪器计划提供。

The most successful model of the universe involves a period of immense expansion during the first small fraction of a second following the Big Bang. This "phase-change" in the early universe explains a number of key observations, including the extreme flatness of the universe, the very similar properties of causally unrelated regions of the observable universe, and the lack of magnetic monopoles. An important prediction of inflation is the "handedness" of polarization imprinted by gravitational waves that are thought to have existed at the time of the last photon scattering. Searching for this "B-mode" polarization signal is a fundamental test of inflation, diagnostic of the energy scale over which the phase change operated, and one of the key science themes identified for the next decade by the ASTRO2010 survey New Worlds, New Horizons in Astronomy and Astrophysics. Dr. Adrian Lee of the University of California Berkeley and collaborators elsewhere within the U.S. as well as in Canada, United Kingdom, and Japan plan an experiment to detect and explore for the first time the B-mode polarization using a dedicated radio antenna high on the Atacama Plateau in Chile and a state-of-the-art 7,588 pixel bolometer array to map the sky at the dual frequencies of 150 and 220 GHz with higher sensitivity and an order of magnitude faster than current experiments. The project, POLARBEAR-2, is very well motivated scientifically and equally well justified on a technical and management footing by the pilot project POLARBEAR-1, now complete and obtaining initial data at the Chilean site. Technical developments made through the project will be important at other wavelength regions of astronomical detection, including the sub-mm. Postdoctoral and student involvement is included in important elements of the development and testing, continuing the strong tradition of training in the hardware and techniques of radio astronomy at U.C. Berkeley.Funding for the development of the POLARBEAR-2 project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.