Neutron diagnostics for pulsed high-density thermonuclear plasmas

Abstract

Time-resolved measurements of the neutron flux from the Scylla IV-P linear theta-pinch experiment have been made with scintillator-photomultiplier combinations. Calibration of the detectors is accomplished by a comparison of their time-integrated output with the total neutron yield measured using a foil-activation technique for which an accurate calibration has been established. The temperature of the Maxwellian ion velocity distribution that would produce the observed flux is obtained from the Maxwellian reactivity < sigmav >(DD) for D (d,n)He3 and measurements of the temporal evolution of the plasma column density and dimensions. This determination of the time history of the ion temperature is in good agreement with the plasma energy measured using other techniques.

Nevada Test Site-Directed Research, Development, and Demonstration. FY2005 report

“…These detectors are used with other activation detectors and methods to measure the neutron yield of these pulsed neutron generators. Other activation detectors and methods have utilized copper (Cooper, 2001), indium (Ruiz, 1992), arsenic ( Jacobs, 1979( Jacobs, , 1983, lead ( Jacobs, 1965;Lanter, 1966Lanter, , 1968, and rhodium (Ekdahl, 1979). For the activation methods, each material has properties that are preferred for different yield determinations.…”