Development of optical micro-Pitot's Tube for Cryogenic Liquid

2015 Fiscal Year Final Research Report

• Project/Area Number: 26600135
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: General applied physics
• Research Institution: Osaka City University
• Principal Investigator: Obara Ken 大阪市立大学, 大学院理学研究科, 講師 (50347481)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ハイドロフォン / 光学式ハイドロフォン / 冷却アンプ / 高速密度測定 / 速度場測定 / 液体ヘリウムポンプ / レーザー

Outline of Final Research Achievements

The aim of this project is the fundamental study for developing a Fiber-Optic Probe Hydrophone (FOPH) that can be used in the wider range of temperatures to utilize the optical micro-Pitot's Tube system. The known problems of this system are their huge noise. We found that the origins of the noise are the fluctuation of the optical sensor and the power fluctuation of the coherent-light source. I have improved the latter problem by introducing a non-coherent light source whose output power is controlled by the feedback circuit located in the ice bath. I also developed the liquid-helium pump that produces a DC mass flow of liquid Helium in the low temepratures, whose flow will be measured by FOPH Pitot's tube. Although we could not succeeded in developing the micro-Pitot's Tube up to now, we made a prominent success in making the low temperature amplifier that can be operated in the liquid Helium temperature, which attracts the international interests.

Free Research Field

超低温実験物理学