Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Inexpensive neutron source
Date: Oct 26, 4:56 pm
Poster: Jim Lux

On Oct 26, 4:56 pm, Jim Lux wrote:

>>These are intended to be used at several amps of current and modest voltage (~150 watts total power), but will tolerate high voltage and low current (at least it has remained intact so far).
>Deuterium requires a fixed and well known threshold to fuse based on cross section or temperature. None of these are even remotely reached in the deuterium lamp. The current has no meaning in this as the voltages involved with the arc anode to cathode are tens of thousands of volts to low. The gas temperature in the hot arc is on the order of several thousands of degrees at most. Again, way outside of the thermal criteria as well.

I think he's running it "cold cathode" with a fairly high voltage across the tube (essentially in a glow discharge?)

The point about arcing making RF noise and fooling the counter is valid, but potentially eliminated if you were to put the counter in a shielded box with thin metal walls. The fast neutrons would go right through, the RF power wouldn't. Aluminmum foil wrapped over everything (and battery powered, of course) would probably do the trick.