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

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 14 Oct 2003 13:46:41 +0200
From: Finn Hammer <f-h@xxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Re-entrant portion of the sphere (VDG) (fwd)



High Voltage list wrote:


> From: Antonio Carlos M. de Queiroz <acmq@xxxxxxxxxxxxxxxx>


> Note that professional machines today always continue the terminal down
> to ground using equipotential rings, biased through a string of
> resistors
> or corona points. The terminal can then be just a cylinder with one end
> rounded, and there is no problem in using a sphere with a hole, or just
> slits for the belt.
>
> Antonio Carlos M. de Queiroz

This is interesting news to me.
Should the distance between these rings be the same, and should the
resistors equalizing them have the same value?

I would like to build a nice VDG myself, and have been wondering how to
design a ball terminal without creating too much leakage corona aat the
entry point of the belt.

As for the belt, itself. I hear that this rubber belt from fysiotherapy
(thera-something) is good. How do you glue it together.

I would like to use something a bit more substantial, any other ideas?

Cheers, Finn Hammer