利用云室观察某些基本粒子的径迹,是一个十分巧妙的办法。在高三的原子物理教学中,应用威尔逊云室演示a粒子的径迹,能有效地激发学生的学习兴趣,消除对原子物理知识学习的神秘感。但目前中学使用的云室体积大,价格高,农村中学难配备。由于观察不方便,有些学校干脆放弃不做。这里介绍的自制威尔逊云室,具有制作简单,现象明显的特点。在1987年全国中学物理实验教学经验交流会上获三等奖。结构如图1,由云室、照明及高压、抽气膨胀三部分组成。制作方法如下:取一集气瓶洗净, 在底部铺垫一层脱脂棉花,吸收适量的酒精,构成云室。高压电极用直径0.8毫米的漆包线,刮去漆皮,负极做成圆环在下,正极连接一层锡箔贴在橡皮塞的下部,位于负极之上。注意不要与负极短路。两电极分别穿过橡皮塞引出,与高压源相连接。高压源与照明电路见图2,其中R_1、R_2为限流保护电阻,防止人体触电。 Using the cloud room to observe the track of some elementary particles is a very clever way. In the third-year atomic physics teaching, using the Wilson Cloud Room to demonstrate the track of a particle can effectively stimulate students’ interest in learning and eliminate the mystery of learning about atomic physics knowledge. However, cloud rooms currently used by middle schools are bulky and expensive, and rural middle schools are difficult to equip. Due to the inconvenience of observation, some schools simply gave up. The homemade Wilson Cloud Room introduced here has the features of simple production and obvious phenomena. In 1987 the national secondary school physics experiment teaching experience exchange meeting won the third prize. The structure is shown in Fig. 1. It consists of three parts: cloud room, lighting, high pressure, and pumping expansion. The preparation method is as follows: Take a set of cylinders and wash it. Lay a layer of skimmed cotton at the bottom and absorb an appropriate amount of alcohol to form a cloud chamber. High-voltage electrode with 0.8 mm diameter enameled wire, scrape off the patent leather, negative electrode made of a ring in the next, the positive electrode is connected to a layer of tin foil attached to the lower part of the rubber plug, located above the negative electrode. Be careful not to short circuit to the negative electrode. The two electrodes are respectively led through the rubber plug and connected with the high voltage source. High-voltage source and lighting circuit shown in Figure 2, where R_1, R_2 is a current limiting protection resistor to prevent human body from electric shock.