2007 Volume 2 Pages 021
A new and simple control method of the unstable operating point in the Force Free Helical Reactor (FFHR) is proposed for the ignited operation with high-density plasma. Proportional-integration-derivative (PID) control of the fueling has been used to obtain the desired fusion power with the fusion power error of e(Pf) = (Pfo − Pf) in the stable operating point. We have discovered that in the unstable regime the error of the fusion power with an opposite sign of e(Pf) = −(Pfo − Pf) can stabilize the unstable operating point. Around the unstable operating point, excess fusion power supplies fueling and then increases the density and decreases the temperature. Less fusion power in the sub-ignited regime reduces the fueling, decreases the density, and increases the temperature. The operating point approaches the final unstable operating point as oscillation is damped away.
