Vibrational characteristics of a superconducting magnetic bearing employed for a prototype polarization modulator
Vibrational characteristics of a superconducting magnetic bearing employed for a prototype polarization modulator
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用于原型偏振调制器的超导磁轴承的振动特性
DOI：
10.1088/1742-6596/871/1/012091
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and R. Yamamoto
中科院分区：
文献类型：
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作者：
Y. Sakurai;T. Matsumura;H. Sugai;N. Katayama;H. Ohsaki;Y. Terao;Y. Terachi;H. Kataza;S. Utsunomiya;and R. Yamamoto
研究了10K以下超导磁轴承(SMB)系统中悬浮转子的振动特性，研制了一种用于宇宙微波背景偏振实验的偏振调制器，它需要一个连续旋转的光学元件，称为半波片(HWP)。HWP必须在低于10K的温度下工作，因此SMB以最小的散热为HWP在约10K的低温下提供了平稳的旋转。为了了解HWP的振动对宇宙学观测的潜在干扰，有必要对SMB悬浮转子的振动特性进行表征。我们构建了一个原型模型，该模型由带有高温超导体阵列的SMB YBCO和永磁环NdFeB组成。转子位置由激光位移计和低温霍尔传感器通过磁场进行监测。在这个演示中，我们展示了使用我们的原型SMB系统对振动特性的测量结果。我们用弹簧常数和阻尼来表征振动特性，并讨论了这项技术在未来空间任务中的应用前景。
We present the vibrational characteristics of a levitating rotor in a superconducting magnetic bearing (SMB) system operating at below 10 K. We develop a polarization modulator that requires a continuously rotating optical element, called half-wave plate (HWP), for a cosmic microwave background polarization experiment. The HWP has to operate at the temperature below 10 K, and thus an SMB provides a smooth rotation of the HWP at the cryogenic temperature of about 10 K with minimal heat dissipation. In order to understand the potential interference to the cosmological observations due to the vibration of the HWP, it is essential to characterize the vibrational properties of the levitating rotor of the SMB. We constructed a prototype model that consists of an SMB with an array of high temperature superconductors, YBCO, and a permanent magnet ring, NdFeB. The rotor position is monitored by a laser displacement gauge, and a cryogenic Hall sensor via the magnetic field. In this presentation, we present the measurement results of the vibration characteristics using our prototype SMB system. We characterize the vibrational properties as the spring constant and the damping, and discuss the projected performance of this technology toward the use in future space missions.