Diagnosing fuel rho R and rho R asymmetries in cryogenic deuterium-tritium implosions using charged-particle spectrometry at OMEGA

摘要

Determining fuel areal density (rho R) in moderate-rho R (100-200 mg/cm(2)) cryogenic deuterium-tritium (DT) implosions is challenging as it requires new spectrometry techniques and analysis methods to be developed. In this paper, we describe a new method for analyzing the spectrum of knock-on deuterons (KO-Ds), elastically scattered by primary DT neutrons, from which a fuel rho R can be inferred for values up to similar to 200 mg/cm(2). This new analysis method, which uses Monte Carlo modeling of a cryogenic DT implosion, improves significantly the previous analysis method in two fundamental ways. First, it is not affected by significant spatial-yield variations, which degrade the diagnosis of the fuel rho R (spatial yield variations of about +/- 20% are typically observed), and second, it does not break down when the fuel rho R exceeds similar to 70 mg/cm(2).