Improvement of calibration assessment for gold fast-neutron activation analysis using plasma focus devices

Abstract

By exploiting the gamma detector-shielding configuration in a plasma focus (PF) device dedicated to fast-neutron activation analysis of gold, a reliable neutron counter may be established. The decay of 207Pbm induced by neutrons in the lead shielding surrounding the photon detector produces gamma photons of 569.7 and 1063.6 keV, which peaks are registered in the same spectrum containing the 279 keV peak of the photons following the 197Aum decay from fast-neutron activation. These decay peaks are found to be linearly correlated to the neutron flux and represent a stable and robust internal standard for monitoring the intrinsic variability in neutron flux production by PF devices. A comparison with the usual external neutron counter techniques shows a great improvement both for the calibration assessment and for the in-field measurements when this internal counter is considered.

Enhanced and reproducible neutron emission from a plasma focus with pre-ionization induced by depleted uranium (U238)

“…Plasma focus pulsars are among the cheapest available neutron generators, with unique features of extremely short pulses (hundreds of nanoseconds) that suit a number of interesting applications. The emitted neutrons can be applied to perform radiography and substance analysis like the detection of gold in sand and presence of water, taking the advantage of the penetration and activation properties of the neutral radiation [13][14][15][16][17].…”

Small plasma focus as neutron pulsed source for nuclides identification

“…Although activation with thermal neutrons would yield a better sensitivity, because of its large activation cross section, a comparatively long half-life of 198 time. An antecedent of this part of the present work is that of Tartari et al 14 which employed fast neutrons from a plasma focus device for Au detection.…”

Neon soft x-ray yield optimization in spherical plasma focus device

“…The optimization of plasma focus devices for these applications are necessary in terms of neutron yield or x-ray productions. Therefore, neutron optimization studies [25][26][27] and x-ray optimization studies [28][29][30][31] are conducted experimentally and theoretically with different gases.…”