绝缘体二次电子发射系数测量装置的研制

 成功研制了测量绝缘体二次电子发射系数的测量装置，该装置主要由栅控电子枪系统、真空系统和电子采集系统组成，测量装置产生的原电子流的能量范围为0.8~60 keV。采用单脉冲电子枪法，测量了原电子能量范围为0.8~45 keV的多晶MgO的二次电子发射系数。测量中，收集极(偏置盒)离材料表面设置为约35 mm，偏置电压设置为 45 V。测量得到：用磁控溅射法制备的MgO的二次电子发射系数最大值约为2.83，处于 2~26范围内，其对应的原电子能量约为980 eV。这表明该装置测量的绝缘体二次电子发射系数是可信的，但用磁控溅射法制备的MgO的二次电子发射系数较低，这可能是制备MgO时引入了过多的杂质在MgO二次电子发射体里面所引起的。

Device for measuring secondary electron emission yield of insulator

A device for measuring secondary electron emission yield of insulator was set up successfully, which was made up of electron gun system, vacuum system and electrical system, the energy band of primary current produced by the device was 0. 8 -60 keV. By the single-pulse electron gun method, the secondary electron emission yield of polycrystal MgO yield was measured when the primary electron energy band was 0.8-45 keV. In the experimental measurement, the distance from material surface to secondary electron collector was 35 mm, the bias voltage was 45 V. The maximum measured yield of MgO produced by the method of magnetron sputtering was 2. 83, which was in the range of 2 to 26, and the corresponding primary electron energy was 980 eV. These results proved that the secondary electron emission yield of insulator measured with the device is credible, but the yield of MgO is smaller than the normal yield of MgO. The reason might be that when the MgO is produeed by the method of magnetron sputtering, too much impurity is set in the MgO, this condition results in the decrease of the yield of MgO.