Experimental verification of the theory of the cathode-ray oscillograph; and the influence of screen potential

The first section deals briefly with the experimental confirmation of the theory of the axial focusing coil. It is shown in the second section that the supposed difference between the actual and the calculated electrostatic sensitivities in the gas-focused oscillograph is non-existent when the necessary allowance is made for the fringing field a t the edge of the deflecting plates. The agreement between the magnetic sensitivities is also confirmed. The investigations described in the third section show that the screen materials are insulators and that the potential of the fluorescent spot is about 60 volts below that of the anode and independent of the beam current or energy over a wide range. The influence of this potential on the sensitivity of the beam is almost negligible.