Development of a Precise Sample Position Control Device for Beam ExPeriments

利用超高压步进电机、滑动轴承和滚珠丝杠构成了一种用于分子或离子束散射实验的精密可控机械手。机械手的机械部分和超高压铝真空容器的机械部分是在我所机械车间建造的，电子部分是由我们实验室准备的。在本实验室还进行了工作台等的运动试验和真空试验，该机械手可以实现X、Y、Z、Rheta、Phi、倾斜六个自由度的样品相对于光束轴的位置控制。样品的移动范围为：XY轴-lt；正负22 mm，Z轴&lt；正负&gt；12 mm，倾角&lt；正负&gt；7^ﾟ，树叶和Phi均为360^ﾟ，样品交换垂直移动830 mm。完成了(X，Y，Z，Rheta)轴的运动测试，没有任何问题。其他运动现在正在接受测试。真空测试是由分子泵、离子泵和旋转泵组成的抽气系统进行的。在抽气初期，气体大量释放，但经过多次烘烤后，真空度达到10^&lt；-9；Torr。为了检查真空的质量，我们用四重质谱仪对残余气体进行了分析。除了常见的残气成分(H_2、H_2O、CO、CO_2)外，还检测到了一些碳氢化合物和氯化氢分子。起因不明。其他问题包括运动过程中轴承排出的气体和运行中电机温度的升高。这些问题应该在不久的将来得到解决。

A precisely controlable manipulator for use in molecular or ion beam scattering experiments was constructed by using uhv stepping motors, slide bearings and ball screws. The mechanical parts of the manipulator and the uhv aluminum vacuum container were constructed in the mechanical workshop of our institute, and the electronic parts were prepared by our laboratory. The movement test of the stages etc. By a personal computer and the vacuum test were also done in our laboratory.The manipulator can control the sample position against the beam axis with six freedoms of ( X, Y, Z, rheta, phi, inclinatin ). The moving ranges of the sample were <plus-minus>22mm for the XY axis, <plus-minus>12mm for the Z axis, <plus-minus>7^ﾟ for the inclination, 360^ﾟ for both rheta and phi, and 830mm for vertical movement for sample exchange. The movement test for ( X, Y, Z, rheta) axis was finished without any problems. The other movements were now under testing. The vacuum test was carried out by a pumping system with a combination of a tarbo-molecular pump, an ion pump and a rotary pump. In the initial stage of pumping a large amount of gas was released, but the vacuum pressure reached into 10^<-9> Torr after several cycles of baking. In order to check the quality of the vacuum we analyzed the residual gas with a quadruple mass spectrometer. Some hydrocarbons and hydrogen chloride molecules in addition to the usual residual gas components (H_2, H_2O, CO, CO_2 ) were detected. The origin is unclear. Other problems are the outgas from the bearings during the motion and the increasing of temperature of the motor in operation. These problems should be solved in near future.