Evaluation of reconstructed angular error of a continuous rotating HWP for LiteBIRD
Evaluation of reconstructed angular error of a continuous rotating HWP for LiteBIRD
复制标题
LiteBIRD 连续旋转 HWP 重建角度误差的评估
DOI：
10.1117/12.2576290
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Komatsu Kunimoto
中科院分区：
文献类型：
--
作者：
Sugiyama Shinya;Matsumura Tomotake;Sakurai Yuki;Katayama Nobuhiko;Takakura Satoru;Tashiro Makoto;Terada Yukikatsu;Sato Kosuke;Katsuda Satoru;Hoshino Yurika;Takaku Ryota;Komatsu Kunimoto
我们报告的光学编码器及其读出系统的低温冷却连续旋转半波片（HWP）偏振调制器单元（PMU）的LiteBIRD低频望远镜的发展。LiteBIRD是一个宇宙微波背景偏振卫星使命，目的是探测B模式偏振，B模式偏振源于原始引力波，从第二个拉格朗日点（L2）进行观测。LiteBIRD采用连续旋转的HWP来减轻系统性影响。HWP的位置角的知识与入射偏振角成一对一的关系。所需的重建精度约为1弧分，目标旋转频率稳定性为1 mHz。一个独特的发展约束来自地球和L2之间的遥测带宽限制，因此，我们实现了一个数字化的过程，以减少数据量，假设未来的实施板上处理的编码器数据之前的下行链路。演示实验使用的试验板模型的PMU：一个读出系统，使用FPGA（斯巴达-6）和一个旋转机构，使用超导磁轴承和交流电机。我们获得了编码器的数据，从旋转机构在两种条件下操作：液氮在室温下的压力和低于10 K的低温恒温器。我们证明了位置角精度< 0.5弧分的重建和0.12 GB/天的相应数据量，这至少比每天的总数据量小一个数量级。我们进一步讨论了位置角不确定性的来源及其对观测的影响。
We report the development of an optical encoder and its readout system for a cryogenically-cooled continuously rotating half-wave plate (HWP) polarization modulator unit (PMU) in the LiteBIRD low-frequency telescope. LiteBIRD is a cosmic microwave background polarization satellite mission to probe B-mode polarization, which originates from primordial gravitational waves, observing from the second Lagrange point (L2). LiteBIRD employs a continuously-rotating HWP to mitigate systematic effects. The knowledge of the position angle of the HWP is in a one-to-one relationship to the incident polarization angle. The required reconstruction accuracy is about 1 arcmin and the targeted rotational frequency stability is 1 mHz. A unique development constraint comes from a telemetry bandwidth limitation between the Earth and L2, and thus we implement a digital process to reduce the data volume assuming a future implementation of on-board processing of the encoder data before the downlink. The demonstrations were done experimentally using a breadboard model of the PMU: a readout system using FPGA (Spartan-6) and a rotational mechanism using a superconducting magnetic bearing and AC motor. We acquired the encoder data from the rotational mechanism operating under two conditions: liquid nitrogen at room pressure and below 10 K in a cryostat. We demonstrated the reconstruction of the position angle accuracy < 0.5 arcmin and the corresponding data volume of 0.12 GB/day, which is at least an order of magnitude smaller than the total data volume per day. We further discuss the sources of the position angle uncertainty and its implications to the observations.
登录
查看更多内容
影响因子：
8.7
作者：
Komatsu, E.;Smith, K. M.;Wright, E. L.
通讯作者：
Wright, E. L.
高温超导磁力轴承中的磁场不均匀性和扭矩
影响因子：
1.8
作者：
T. Matsumura;S. Hanany;J. Hull;B. Johnson;T. Jones
通讯作者：
T. Jones
LiteBIRD基于连续旋转半波片的偏振调制器单元的设计与开发
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
Z. Qin;Y. Wang;F. L. Fan;S. W. Cao;H. Haba;Y. Komori;S. Yano;D. Kaji;and K. Morimoto;Michinori Ishiwata;吉村浩明;Yuki Sakurai et. al.
通讯作者：
Yuki Sakurai et. al.
在阿塔卡马 B 模式搜索仪器上用温暖的快速旋转半波片调制宇宙微波背景偏振。
DOI：
10.1063/1.4862058
发表时间：
2013
期刊：
The Review of scientific instruments
影响因子：
--
作者：
A. Kusaka;T. Essinger;J. Appel;P. Gallardo;K. Irwin;N. Jarosik;M. Nolta;L. Page;L. Parker;S. Raghunathan;J. Sievers;S. Simon;S. Staggs;K. Visnjic
通讯作者：
K. Visnjic
影响因子：
2
作者：
Hu, W;White, M
通讯作者：
White, M