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 produced 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.