Validity of the Objectives and Solutions of the Ignitor Program*

The validity of the objectives of the Ignitor Program\footnote{B. Coppi, A. Airoldi, et al. \textit{Nucl. Fusion} \textbf{41} (9), 1253 (2001)} and its design solutions have been reaffirmed recently\footnote{P.H. Rebut, \textit{EPS Conference on Plasma Physics, Rome, 19 June 2006}}: i) in order to prove the scientific feasibility of relevant fusion reactors, burning plasmas with $Q \ge 50$ should be produced and studied, ii) copper magnets are the most convenient solution for machines capable of reaching this objective, iii) experiments that do not include a divertor are the most efficient, at producing the highest plasma currents with the best confinement parameters. Ignitor is in fact designed to operate with either an ``extended-limiter'' configuration or with a double X-point configuration (X-points on the first wall). The experiment can reach the conditions where the thermonuclear instability is excited $(Q\rightarrow\infty)$ or where the plasma can be kept under quasi-stationary conditions with large values of $Q$ and the input of modest amounts of ICRH power. The maximum plasma currents with reasonable safety factors are up to 11 MA, corresponding to average poloidal fields $B_p\approx 3.4$ T. The latest physics and technology developments are presented.\\ $^*$Sponsored in part by ENEA of Italy and by the U.S. DOE.