Oil-immersed RFCs?

From: 	Felix[SMTP:73374.1547-at-CompuServe.COM]
Sent: 	Friday, August 29, 1997 6:25 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Oil-immersed RFCs?

Suppose you want a pair of 5 millihenry chokes to protect neon transformers,
The consensus seems to be that you wind them single-layer to prevent
layer-to-layer arcing. But the solenoid equations translate this into
things the size of a 10-gallon bucket, or alternatively a baseball bat,
roughly speaking. Do chokes have to be that cumbersome? Why not wind
them multi-layer and immerse in oil? I have seen corona occur within
oil so I assume that you'd have to have enough windings to keep 
layer-to-layer voltage below some value, based on the 50 to 60 kv 
spikes that you're presumably trying to choke, and the corona-ing
propensity of the high frequency components of those spikes.
Can anyone tell me of criteria for spacing layers of windings to
make the multi-layer, oil-immersed choke work?