同軸型パルスチューブ冷凍機を用いた低磁気ノイズＳＱＵＩＤ非破壊検査システムの開発

• 廿日出 好

  豊橋技術科学大学

• 葛西 直子

  産業技術総合研究所

• 高島 浩

  産業技術総合研究所

• 丸野 善生

  岩谷瓦斯株式会社

• 石山 敦士

  早稲田大学理工学部

書誌事項

タイトル別名

• Development of a Low-Magnetic-Noise Nondestructive Inspection System Using a Superconducting Quantum Interference Device Cooled by a Coaxial Pulse Tube Cryocooler
• ドウジクガタ パルスチューブ レイトウキ オ モチイタ テイジキ ノイズ SQUID ヒハカイ ケンサ システム ノ カイハツ

抄録

A small, low-magnetic-noise nondestructive inspection (NDI) system that uses a high-T_c superconducting quantum interference device (SQUID) cooled by a coaxial pulse tube cryocooler (PTC) has been developed. The key components for realizing the compact, low-noise system developed in this study, include the following: a high-T_c SQUID gradiometer, the coaxial PTC, and a SQUID-mount stage separated from the cold head of the cryocooler. The high-T_c SQUID gradiometer contributes not only to stable system operation when subjected to the environmental noise without magnetic shielding, but also a decrease in magnetic noise caused by the mechanical vibration of the SQUID, which is transmitted from the cryocooler. By using the coaxial PTC, which was constructed of non-magnetic materials, both magnetic noise and the mechanical vibration are well suppressed compared to conventional two-axial PTCs. In addition, the coaxial PTC is designed to be compact (50 mm diameter, 400 mm height, and 4 kg weight) for practical use. The SQUID-mount stage separation contributes to stable operation by reducing the transmitted vibration to the SQUID, and thermal stability at the SQUID-mount stage. The magnetic flux noise spectrum of the cryo-cooled system was measured and compared with that of a liquid-nitrogen-cooled system using the same SQUID. From the comparison, no increase in magnetic noise due to the cryocooler was observed, although the magnetic flux noise level of the cryo-cooled system was dominated by SQUID operation noise, which was rather high, (i.e., around 100 μΦ₀/Hz^1/2 at 100 Hz). The relation between the mechanical vibration at the SQUID and magnetic noise is discussed.

収録刊行物

• 低温工学

  低温工学 38 (12), 686-692, 2003

  公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)

キーワード

• SQUID-NDI system
• high-<i>T</i>_c SQUID gradiometer
• coaxial pulse tube cryocooler
• low magnetic noise

詳細情報

• CRID: 1390282679591985024
• NII論文ID: 10012477682
• NII論文ID: 30017305369
• NII書誌ID: AN00333419
• DOI: 10.2221/jcsj.38.686
• COI: 1:CAS:528:DC%2BD2cXhtVSjsbY%3D
• ISSN: 18800408
• ISSN: 03892441
• NDL書誌ID: 6814623
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6814623
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可