Probe Measurements of the Discharge in an Operating Electron Bombardment Engine

plot of electron density and energy variations (accelerating potential applied) ............... 13 17.Radial plot of electron energy and density variations near grids (no accelerating potential applied) .............. 14 18.Radial plot of electron energy and density variations near grids (accelerating potential applied) ............... 15 19.Axial plot of electron energy and density variations (no accelerating potential applied) .............. 16 20.Axial plot of electron energy and density variations (accelerating potential applied) ............... 17 21.Approximation of the mercury ionization cross section ....... 18 22.Ionization coefficient for Maxwell electrons .......... 19 23.Ionization rate curve (no accelerating potential applied) ......