A low-inductance 2-MV tube

A new multistage low-inductance tube for the OWL II coaxial water dielectric generator has been designed. The new tube uses stacked insulators and a dielectric lens to achieve high uniformity of field grading along with minimum inductance. With the new design the breakdown probability is reduced to less than 1% at 2 MV and less than 50% at 2.5 MV; the inductance is reduced below 25 nH compared to the 30 nH of the vacuum region in the old tube.