Precise Test for the Casimir Effect using Roberval's Balance

为了检验卡西米尔效应，应使用电罗伯瓦尔天平直接测量两个金属板之间的力。该探测器的研制过程如下：（1）在石英片上真空蒸镀金制备金属片。尽管板的表面应足够清洁以将两个板放置在小于1微米的位置，但在板的表面上发现了一些大于几微米的团簇。研究了石英片的清理方法，并改变真空蒸发条件以避免金团簇的产生。(2)用干涉仪测量两块金属板之间的绝对距离。绝对距离精度达到50 nm。利用激光干涉仪和电动执行器，可以控制两个金属板之间的距离，精度小于10 nm。(3)为了避免金属板的振动，电动罗伯瓦尔的平衡放在气垫上。探测器内部的空气对流也被控制，以减少金属板的振动。金属板的制造仍然存在一些技术困难，所以探测器的发展是继续的。

In order to test the Casimir effect, the force between two metal plates should be directly measured using the electric Roberval's balance. The detector was developed as follows ;(1) Metal plates were fabricated by gold vacuum evaporation onto quartz plates. Though the surface of the plates should be clean enough to place two plates closer than one micron, some clusters larger than several microns were found on the surface of the plates. The clean-up method of the quartz plates were investigated, and the conditions of the vacuum evaporation were changed to avoid the gold clusters.(2) Interferometer was used to measure absolute distance between two metal plates. The accuracy of the absolute distance of 50 nm was achieved. Using the laser interferometers and the electric actuator, the distance between two metal plates can be controlled in the accuracy less than 10 nm.(3) To avoid the vibration of the metal plates, the electric Roberval's balance was put on the air cushion. Convection of the air inside the detector was also controlled to reduce the vibration of the metal plates.Some technical difficulties still exists in the fabrication of the metal plates, so the development of the detector is continued.