A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using DHe-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase DHe-proton signal-to-background by a factor of 1000, allowing for the first time simultaneous measurements of shock and compression-bang times in DHe-filled surrogate implosions at the NIF.
We have carried out several experiments on the Los Alamos proton radiography (pRad) facility to explore the growth of perturbations subjected to shockless acceleration. These experiments have involved both Tantalum and depleted Uranium plates with various initial amplitudes. The experimental platform is based on the one first developed by Barnes et al. [1] and further advanced by Raevsky [2]. This paper presents both the data for these experiments and an initial attempt to model the experiments using the simulation code FLAG [3].