On Sun, May 26, 2013 at 10:20 PM, David Roberson <dlrober...@aol.com> wrote:
My model suggests that his device is unstable once a threshold drive level > is exceeded. Its temperature proceeds toward a dangerous level which might > lead to device failure if not halted. The drive heat source is abruptly > ended at a proper time which reverses the direction of the temperature > movement. > A relevant question is how fast the positive feedback takes over. If it proceeds quickly, then the reactor would just overheat and you'd get failure. If the feedback proceeds slowly enough to intervene, then presumably it can be pushed down before it gets too far. In the fission case of a fission reactor, I believe there is a short delay between when the reactor rods are moved and when the effect of the movement is fully realized in the new neutron flux that permits the use of a mechanical device for positioning the rods without the reactor becoming prompt critical. I'm thinking of the difference between the fast positive feedback of pointing a microphone at a speaker and a much slower version of it, where you could see that things are spinning out of control and then pull the microphone away before the sound gets really loud. Whatever that rate of change of the descent into positive feedback seems pertinent. Eric
