Development of a Polarimeter System for Solar Synoptic High-Sensitivity Observations

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。太阳日冕物质抛射（CME）是产生空间天气和太阳风暴的关键组成部分，可以影响我们的社会。它们可以破坏卫星，干扰无线电通信，甚至造成电网停电。该项目将开发一种仪器，提供有关日冕物质抛射的高灵敏度和高保真度信息。开发的系统将作为一个长期的平台，培训来自不同背景的学生在大熊太阳观测站。一个新的偏振测量系统将被开发来观察近红外（NIR）。该系统具有以下特点：（1）在近红外波段实现了太阳光的高速偏振。在NIR中的偏振测量可以提供比可见光更好的灵敏度。由于大气湍流干扰和偏振测量需要多幅图像，低速偏振仪不能可靠地测量真实偏振。这一系统将是第一个能够在近红外He I 10830埃谱线上实现高达100 Hz偏振测量速度的偏振仪，从而为太阳日冕物质抛射研究提供高灵敏度的真正偏振测量;（二）偏振测量系统将是第一个在近红外He I谱线上获得偏振测量的仪器，用于定期和天气学基础上的CME相关事件，即时二维视场（FOV）高达320“x 256”，而不需要目前在传统摄谱仪中使用的长狭缝扫描，这是搜索，监视和跟踪CME事件所必需的;（3）高速二维偏振图像将用于导出衍射-- 使用盲去卷积技术为每个斯托克斯矢量分量提供有限的图像，从而提供当前大型地面望远镜无法提供的衍射限制磁场图像，该奖项反映了NSF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 award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Solar coronal mass ejections (CMEs) are a key component in generation of space weather and solar storms that can impact our society. They can damage satellites, disrupt radio communications, and even create blackouts of the electricity power grids. This project will develop an instrument to provide high-sensitivity and high-fidelity information about CMEs. The developed system will serve as a long-term platform for training students from diverse backgrounds at the Big Bear Solar Observatory.A new polarimetry system will be developed to observe the near infrared (NIR). This system has unique features including: (1) High-speed solar polarization in the NIR. Polarization measurements in the NIR can provide better sensitivity than the visible. Due to the atmospheric turbulence disturbance and the fact that several images are required for the polarization measurements, a low-speed polarimeter cannot reliably measure the true polarization. This system will be the first polarimeter that can achieve a polarization measurement speed up to 100 Hz at the NIR He I 10830 Angstrom line, and thus provide a true polarization measurement with high sensitivity for solar CME investigations; (2) the polarimetry system will be the first instrument that acquires polarization measurements in the NIR He I line for CME associated events on a regular and synoptic basis over an instant 2-dimensional field of view (FOV) up to 320’’ x 256’’ without the need of the long slit scanning currently used in the tradition spectrograph, which is mandatory to search, monitor, and track CME events; (3) The high-speed 2-dimensional polarization images will be used to derive the diffraction-limited images for each of the Stokes vector components using the blind deconvolution technique, and thus to provide diffraction-limited magnetic field images that current large ground-based telescopes would not offer, and thus provide good image quality over a large FOV that is close to that provided by a space-based instrument.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.