Generation and Focussing of Intense Pulsed Light-Ion Beam at Nagaoka–ETIGO Project–

An intense pulsed light-ion beam generator, “ETIGO-1”, has been constructed at the Technological University of Nagaoka. In a preliminary stage of experiments done at less than half full power, we produced V d (diode voltage)∼760 kV, I d (diode current)∼65 kA, I i (ion current)∼14 kA by use of a spherically-shaped, magnetically-insulated diode. Using a geometric focussing technique, we have obtained maximum current density J i ∼4 kA/cm 2 (at the focussing point), yielding a focussing gain of ∼50. The focussing spot is observed to be less than 10 mm in diameter. The extracted ion current exceeds by more than a factor of 3 the spacecharge-limiting current of ions.