SUNRISE-3 Balloon-borne Solar Observatory: Development of Scan Mirror Mechanism for Spectropolarimeter

スキャンミラー機構(SMM: Scan Mirror Mechanism)は, スリット分光観測によって2 次元空間上に広がる天体の物理量を診断するために必要な技術である．国際共同大気球太陽観測実験「SUNRISE-3」に搭載する近赤外線偏光分光観測装置SCIP(Sunrise Chromospheric Infrared spectroPolarimeter)は, 近赤外線の広い波長範囲をスリット分光することで, 太陽彩層大気の高精度な物理量診断を目指している．彩層大気は, 一つ一つの微細な磁場が広く空間構造を形成しており, かつダイナミックに変化するため, 広視野を高精度・高速で走査するSMMが必須である．そこで, 電磁吸引式アクチュエータおよび静電容量センサを内蔵し, クローズドループ制御によって高精度なミラー傾動制御を実現するSMM を開発した．光学試験によってSMM の性能を検証した結果, 「広いスキャン範囲(±1005秒以上)」・「十分な安定度(3σ
The scan mirror mechanism (SMM) enables a slit-spectroscopic observation system to diagnose physical quantities of an astronomical object in the two spatial dimensions. The SCIP (Sunrise Chromospheric Infrared spectroPolarimeter), onboard the international joint balloon project SUNRISE-3, adopts the slit-scan observation system to diagnose the physical quantities in the solar chromosphere precisely. Since magnetic elements in the chromosphere has broad spatial scales and they behave highly dynamic, the SMM needs to scan rapidly and widely with high accuracy. To meet such requirements, we have developed the SMM in which the mirror tilt is controlled by electro-magnetic actuators with sensing tilt by gap-based capacitance sensors. The optical measurements verified the performances required to the SMM; a wide scan range (larger than +/- 1005 arcsec in mechanical angle), high stability (3σ less than 1 arcsec), and rapid response (shorter than 32msec). Thermal cycling tests and thermal vacuum tests have verified that the SMM achieves such performances in the thermal-vacuum environments expected in the balloon flight.
形態: カラー図版あり
Physical characteristics: Original contains color illustrations
資料番号: AA2030024005
レポート番号: JAXA-RR-20-009