Re: 130kW Coil Update [helium gap]

From: 	Jim Lux[SMTP:jimlux-at-earthlink-dot-net]
Sent: 	Friday, December 12, 1997 10:42 AM
To: 	Tesla List
Subject: 	Re: 130kW Coil Update [helium gap]

To Ed, Greg:

Ed wrote:
> 	According to the Handbook of Chemistry and Physics,
> at -180 degrees C the specific heat of He is 1.25, and that of
> H2 is 2.64.  They don't give a value for He at room temperature,
> but H2 at 15 deg C has a specific heat of 3.389. N2 at
> 15 deg C the value is 0.2477.  Units for all are cal/g.  On
> the basis of those numbers, would thin He would be a much
> better coolant.  (I have read that divers using He-O2 atmosphere
> at high pressures have problems withstaying warm.)

Oddly enough, the difference in specific heat (in cal/g) between H2 and N2
is about 14:1, which is the difference in density. Diatomic gases, at
normal pressures and temperatures (not 10's of atmospheres, etc.) have a
pretty much fixed heat capacity per volume...