DEVELOPMENT OF NEW FLOATING ZONE APPARATUS WITH DOUGHNUT STYLE ELLIPSOIDAL MIRROR

设计并制作了一种新型的带圆环形椭球镜的浮区装置，使温度沿水平方向均匀分布，以生长完美的超导氧化物晶体。通过计算机仿真，确定了环状椭球镜的最佳形状为长轴120 mm、短轴96 mm、焦距144 mm。该反射镜由一种特殊的铝合金试制而成，镜体内部表面镀金以有效地反射来自热源的红外层。并对可在反射镜中调节的半圆形卤素灯进行了实验设计和制作。与市售红外加热装置相比，新型红外加热装置的温度水平分布和垂直梯度明显均匀，速度较慢。

New floating zone apparatus with a doughnut style ellipsoidal mirror was designed and produced to uniform temperature distribution along the horizontal direction for growth of perfect superconducting oxide crystals. To design the doughnut style ellipsoidal mirror, the optimum shape of the mirror was determined to be 120 mm of the long axis, 96 mm of the short axis and 144 mm of the focus distance by computer-simulation. The mirror was produced experimentally from a specia aluminum alloy, and the surface inside the mirror was gold-coated to reflect the infrared lay effectively from the heat source. Also the semicircular halogen lamps to be adjusted in the mirror were designed and produced experimentally. The horizontal distribution and vertical gradient of temperature in the new apparatus were remarkable uniform and slow as compared with the commercial infrared heating apparatus.