Neutron spectrometry concepts for diagnosing DT plasmas of Q∼1

For burning DT plasmas (Q→∞), we have devised the use of special HFC (high flux and count rate) neutron spectrometers (NS). These can accept very high rates (capability limit CnCAP>10-100 MHz) as limited only by the available collimated neutron flux (Fn) from the plasma; i.e., the attained count rate is Cn=εFn with ε being the (flux) detection efficiency. Cn can be seen as the product of the statistical accuracy (1/σN, σN=1/√Nn) and the time resolving power (1/Δt, where Δt is the time resolution), i.e., Cn=(1/σN)2/Δt; Cn is thus a figure of merit for the measurement and should be maximized. (author) 8 refs., 3 figs