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: Deceleration uses energy too!
Date: Mar 31, 4:28 pm

On Mar 31, 4:28 pm, wrote:

A lot of folks might not consider all aspects of fusor power consumption. Ideally, we want a lot of recirculation. That is, the same ions not involved in first pass collisions being thriftily recycled to a second, third or more passes through the reaction zone. (generally considered an advantage of the IECF devices and keeping the plasma in the reaction zone from going purely maxwellian.)

This condition is usually found more in the higher vacuum systems where the mean free path is about 1 meter or more. (~10e-4 torr).

In glow discharge systems (10e-3 torr) two passes might be about the max expected. This would be rare but the number of ions is up due to density so, once again, it is a tradeoff.

Each pass reqires that work be done to not only accelerate the ion into the reaction zone but to fully decelerate it and reaccelerate it for each successive pass.

While we are not having to re-ionize the ions over and over again, we are having to use the gas and the brakes electrostatically rather constantly. The deceleration is intrinsically wasted energy. So in a high recirculation machine 50% of the motional kenetic energy used in overcoming ionic inertia is lost!

Just thought some might like to cogitate on this a bit.

Richard Hull