Ion acceleration and neutron production in hybrid gas-puff z-pinches on the GIT-12 and HAWK generators

Z-pinch experiments with a hybrid configuration of a deuterium gas puff have been carried out on theHAWK(NRL,Washington,DC)and GIT-12(IHCE,Tomsk)pulsed power generators at 0.7 MA and 3MA currents,respectively.On GIT-12,neutron yields reached an average value of 231012 neutrons,and deuterons were accelerated up to an energy of 30 MeV.This was 50 times the ion energy provided by the generator driving voltage of 0.6 MV and the highest energy observed in z-pinches and dense plasma foci.To confirm these unique results independently on another device,we performed several experimental campaigns on theHAWKgenerator.Comparison of the experiments onGIT-12 andHAWKhelped us to understand which parameters are essential for optimized neutron production.Since theHAWKgenerator is of a similar pulsed power architecture as GIT-12,the experiments on GIT-12 and HAWK are important for the study of how charged-particle acceleration scales with the current.

Scenario of a magnetic dynamo and magnetic reconnection in a plasma focus discharge

The paper discusses a possible energy transformation that leads to the acceleration of fast ions and electrons.In plasma-focus discharges that occur during deuteriumfilling,which have amaximumcurrent of about 1MA,the accelerated deuterons produce fast fusion neutrons and fast electrons hard X-ray emissions.Their total energy,which is of the order of several kilojoules,can be delivered by the discharge through a magnetic dynamo and selforganization to the ordered plasma structures that are formed in a pinch during the several hundreds of nanoseconds of the pinch implosion,stagnation,and evolution of instabilities.This energy is finally released during the decay of the ordered plasma structures in the volume between the anode face and the umbrella front of the plasma and current sheath in the form of induced electric fields that accelerate fast electrons and ions.