Re: van de graaff tube (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 29 Nov 2004 10:46:10 -0700
From: Gomez Addams <gomez@xxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: van de graaff tube (fwd)


On Nov 29, 2004, at 8:42 AM, High Voltage list wrote:

> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Sun, 28 Nov 2004 23:18:21 -0600
> From: Dr. Resonance <resonance@xxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: van de graaff tube (fwd)
>
>
>
> Assuming you are spraying the lower pulley at 5-7 kV DC, the 2.5 inch 
> wide
> belt will deliver charge to the upper terminal at an approximate rate 
> of
> 12-15 uA DC.  If you are using a self-excited design, the max charge 
> rate
> will be approx 3-4 uA DC.
>
> A gray PVC tube will leak at approx 1 uA downward.  A black PVC tube 
> will
> leak at 2.5 uA DC downward, so the black will not work.  Your HV 
> terminal
> will not acquire a charge.

Question: isn't that leakage rate dependent on the length and diameter?