Tritium Minority Heating by Ion Bernstein Waves in Ignitor

A promising scenario of minority heating of Tritium ions by Ion Bernstein Waves (IBW) coupled by mode conversion of fast waves in D(H) plasmas has been recently proposed.\footnote{C. Castaldo and A. Cardinali, \textit{ Phys. of Plasmas}, in press (2010)} The tritium ions are accelerated at energies high enough to increase significantly the DT fusion reactivity at relatively low temperature. It has been shown that breakeven can be reached considering a specific heating scenario for the JET machine. A similar heating scheme is analyzed for the Ignitor machine at reduced parameters. It is shown that 10 MW of ICRF power at $f = 91.6 \textnormal{ MHz}, N_{||}=3.6$ that are coupled as fast waves to plasmas at $B_T=9 \textnormal{ T}, I_p=6 \textnormal{ MA}, n_{e0}= 2 \times 10^{20} \textnormal{ m}^{-3}, T_{e0}=T_{i0}=8 \textnormal{ keV}$, with 25\% T, 40\% D, 35\% H concentration, are mode converted to IBW near the D-H hybrid resonant layer and are efficiently absorbed by tritium ions via cyclotron damping at $\omega =2\Omega_T$. The tritium ions are accelerated at energies of the order of 100 keV, where the the DT fusion reactivity peaks. As a result about 50 MW/m$^3$ of peak fusion power are obtained, and the expected fusion power is about 30 MW, with $Q =2$. The detailed comparison between equivalent scenarios in 50-50 D-T plasma is underway by means of the JETTO transport code.