Observations and Results with isolated Maltese Cross

Maltese Cross Tube with isolated Cross


  • No electron shadow is visable independen from the acceleration voltage Va.
  • The screen looks similar to to previous experiment with VCVa.


  • The electrons impinging on the Maltese Cross charge the Cross so heavy that the interfering field blocks all electrons. So no electrons can reach the screen on a direct way.


The charge of the Maltese Cross can be measured with a static voltmeter. The voltage between cross and ground is as big as the acceleration voltage Va. Unfortunately the assembly of a measuring device seems to cause creeping currents. They interfere the experiment because charge can flow off the cross. So an electron shadow becomes visible. A video of this experiment is available here: Experiment with static Voltmeter