  An expression for the extrapolated fusion gain G = Pfusion /5 Pheat (Pfusion
being the total fusion power and Pheat the total heating power) of ITER in
terms of the confinement improvement factor (H) and the normalised beta (betaN)
is derived in this paper. It is shown that an increase in normalised beta can
be expected to have a negative or neutral influence on G depending on the
chosen confinement scaling law. Figures of merit like H betaN / q95^2 should be
used with care, since large values of this quantity do not guarantee high
values of G, and might not be attainable with the heating power installed on
ITER.
