With most fusion reaction involving deutrium, the evidence of neutrons suggests fusion reactions taking place. With aneutronic fusion (er, <2%), how will it be definitively determined that fusion reactions are taking place if it can't be based solely on neutrons formed? Temperature needed for the reaction to take place? Alpha particles? Extrapolations on the amount of neutrons formed? Which diagnostic tool carries the most weight, or is it going to be more of a series of tools that proves without doubt that these reaction are occurring?
LPP has instruments to detect neutrons, X-rays, and the current from the ion beam. I imagine the measurement of current from the ion beam (using a set of Rogowski coils) will be the all-important measurement. For more on LPP’s instruments (at least as of 2011), see here: https://focusfusion.org/index.php/site/category/C72