Results of the comparision between grounded and ungrunded Maltese cross
Observations:
The „electron-shadow” of the Maltese cross has now no sharp edge. The screen shows a blurred outline of the „electron-shadow”. This outline is slightly brighter than the inner shadow.
The outer „shadow” of the Maltese cross has no corners - they are now rounded.
Rising the acceleration voltage Va makes the „electron-shadow” bigger.
Rising the acceleration voltage Va extend the impinge area of the electrons on the fluorescent screen.
Evaluation:
The electrons impinging on the Maltese cross charge the cross negative. This charge generates an interfering electric field arround the cross. This field deflects the electrons. The impinge area increases and the outlines get blurred.
All corners of the Maltese cross are rounded because the electric field is stronger near the corners.
Propagating
