STM Gallery | TARO HITOSUGI (一杉 太郎)

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Our STM SETUP STM-PLD system

We have designed an Low-temperature High-magnetic field STM-PLD system, which is installed in the Integration Laboratory (Katahira Campus). This system enables us to perform STM measurements without exposing samples to air after preparing thin films using PLD. In addition, our STM can apply a magnetic field of up to 7 T vertically and 1 T along any direction, using a superconducting vector magnet, which is ideal to control the spin direction and to investigate the anisotropy of the spin interaction directly.

In order to achieve these measurements with the-best-in-the-world stability, vibrational noise must be removed as much as possible.

-We constructed a massive base slab (Concrete in the above figure) on the bed rock, and put a thick fiber concrete block with a pit on it. Total of 80 Tons of concrete were used to form those concrete bases.

-Active vibration isolation dampers are used to mount a honeycomb table on the fiber concrete block. A passive vibration isolation table is installed on the honeycomb table and finally supports vacuum chambers, cryostat and STM head.

 

 

-In addition, all of them are located inside a soundproofed room. Operators and all electronic components, which may produce acoustic noise, are located outside the room during measurement.

We also plan to replace a commercial STM head by an ultra-stable home-made STM in the near future. This unique system will be absolutely the only one STM in the world with PLD, and opens the door to explore science in nano-scale oxide materials. See more details in Rev. Sci. Instrum.

我々の研究室では、床振動と音響の影響を最大限排除するため、様々な工夫を凝らしています。とくに実験環境という観点で、そのいくつかをここで紹介します。

1) 建物から切り離した独立基礎とすること
岩盤まで穴を掘り、そこに80トンのコンクリートを流し込んで独立基礎としている。

2) アクティブ除振装置を導入して、STMが載るパッシブ除振とあわせて2段除振とした。
アクティブ除振装置は20 Hz程度までの振動を効果的に減衰する機能を有する。
パッシブ除振に比べ、除振装置の共振周波数付近の振動の増幅を抑制できる点が大きなメリットである。

3) 防音壁を2重に巡らし、音響ノイズを低減する。
TLD-75(厚み44 cm)の防音壁で2重に囲んでいる。上面は1重である。

以上の設計の詳細に関しては、Rev. Sci. Instrum. をご覧下さい。