Compact monitor to control the isotope ratio of fusion plasma

The design of a compact monitor for controlling the isotope ratio of fusion plasma based on the use of electrostatic ion deflection and time-of-flight analysis systems is presented. It is shown that the chosen scheme of the monitor is quite effective in terms of suppressing the background radiation in the detector system due to the application of the coincidence method and pulse height distribution analysis of the recorded signals. The capabilities of the monitor are considered in the example of its use in the conditions of the ITER fusion reactor to measure the fluxes of deuterium and tritium atoms emitted by the plasma. It is shown that it can be successfully applied for monitoring the plasma isotope ratio in the presence of neutron shielding of the diagnostic vacuum channel, which provides neutron flux suppression at the detector locations to values less than or of the order of 108 cm-2 s-1.