The energy spectrum of the deuteron beam along the electrode axis (0-d
egrees) in a plasma focus discharge has been determined with a time of
flight (TOF) method and with a differential filter method in the ion
energy interval E = 0.3-9 MeV. The ion TOF method is applied to single
-ion pulse events with an ion emission time t(E) that is only weakly d
ependent on the ion energy E for E > 0.3 MeV. The correlation of the i
on beam intensity with the filling pressure, the neutron yield and the
hard X-ray intensity is also reported.