| 摘要 |
PURPOSE:To secure a stable focus adjustment free from dissipation due to superfluidity of a liquid helium, by making permanent magnets, respectively fixed on the upper and lower end sides of a support, repulse to each other vertically to hamper effect of thermal vibration or the like. CONSTITUTION:A container 10 is filled with a liquid helium on the bottom side thereof and the top thereof is closed with a top plate 10A having a drilled hole 10B for exchanging samples. The bottom 12A of a support 12 supports a sample S in such a manner as to make the sample S face an acoustic lens L in the liquid helium. Permanent magnet 12B are fastened separately inside the opening at the upper end of the support 12 while permanent magnets 14B, on the inner surface side at the lower end of respective driving bodies 14, facing the magnets 12B, not in contact therewith. The magnets 12B and 14B repulse to each other vertically thereby securing separation between the support 12 and the driving body 14. |
