Re-entrant portion of the sphere (VDG) (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 13 Oct 2003 06:55:12 EDT
From: Lyonelb@xxxxxxx
To: hvlist@xxxxxxxxxx
Subject: Re-entrant portion of the sphere (VDG)

  A large diameter sphere with a small re-entrant radius is a must.The point
of column entry is the electrically weakest region on the terminal. This can
be offset to a considerable extent by arranging the electrode with a
re-entrant portion into which the column fits. This results in a diminution of the
field intensity at this point and thus in a shielding of this electrically weak
region.
  However  to make this re-entrant  portion is not easy.   Any idea ?

Lyonel Baum