Estimates Of Upper Limit Of Neutron Yield In Experiments With Z-Pinch Dynamic Hohlraums At 8-Ma Pulsed Power Facility

In ongoing attempts to generate thermonuclear neutrons with the Z-pinch dynamic hohlraum concept at an 8-MA pulsed power facility, it has become possible to determine an upper limit for the neutron yield. The neutron time-of-flight diagnostic uses thick Pb shields and a specifically formulated fast liquid scintillator coupled to gated photomultiplier tubes to mitigate the hard bremsstrahlung x-ray (HXR) background that would otherwise overwhelm a potential neutron signal, and its suppression gives an upper-limit estimation for the neutron yield. A slow-neutron detector in the form of a BF3 counting system suggests a lower limit to the neutron yield although the early HXR pulse interference requires further confirmation as to whether the subsequent multiple pulses are induced by neutrons. Together, these measurements suggest a neutron-yield upper limit of 1.1 x 10(7). Published under an exclusive license by AIP Publishing.