Thickness effect on secondary electron emission of MgO layers

Robust and High Current Cold Electron Source Based on Carbon Nanotube Field Emitters and Electron Multiplier Microchannel Plate

“…CNT/MgO system was chosen as it was noticed from available literature data that it had the highest secondary emission yield [13][14][15][90][91][92]. The data required for simulating MCP channel with MgO/CuO, MgO/CNT and lead silicate/glass was assumed from literature [13][14][15][89][90][91][92]. Lead silicate/glass which is the most commonly used in conventional MCP was also simulated.…”

“…the crystal size, porosity of the MgO. Due to porosity, most of the primary electrons can penetrate some distance into the volume of dielectric releasing more secondary electrons as compared to MgO deposition obtained from sol-gel which seems to be less porous [90,93]. SEY of MgO depends on various parameters such as crystal size, surface properties, porosity [90,93].…”

“…Due to porosity, most of the primary electrons can penetrate some distance into the volume of dielectric releasing more secondary electrons as compared to MgO deposition obtained from sol-gel which seems to be less porous [90,93]. SEY of MgO depends on various parameters such as crystal size, surface properties, porosity [90,93]. High SEY values were observed from single crystal MgO as the secondary electron loss mechanism are relatively less in them [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73].…”

“…So a new material system i.e. MgO-coated CNTs was chosen which had shown enormously high secondary electron emission yield [13][14][15][90][91][92] as shown in figure 4.…”

“…Its SEY depends on the coating thickness which is in the range of few nm to few microns. The minimum and maximum reported values of SEY for MgO/CNT are 400 and 22000, respectively [13][14][15][90][91][92], which is the highest of all the materials. Even though the exact mechanism of high SEY from MgO/CNT system is not clearly understood, it is assumed as Townsend avalanche [93] that can be explained as follows.…”