Radiation-Driven Hydrodynamics of High-ZHohlraums on the National Ignition Facility

An initial design of hohlraum driven by a shaped laser pulse

“…For the models concerned in this paper, we use n e ¼ 0.1 as a criterion for giving initial size of a hohlraum in which a low plasma filling with maximum achievable radiation is required. Note that this is different from that used in Dewald et al (2005), in which l IB ¼ 0.7R LEH is taken as a criterion for a hot hohlraum. Here, R LEH is the LEH radius and l IB is the inverse bremsstrahlung absorption length.…”

“…In this section, we first relate the radiation temperature T r to input laser power P and time t by power balance (Sigel et al, 1988), and then extend the plasma-filling model (Dewald et al, 2005;McDonald et al, 2006;Schneider et al, 2006) to the case of a hohlraum driven by a shaped laser pulse.…”

“…In the plasma-filling model (Dewald et al, 2005;McDonald et al, 2006;Schneider et al, 2006), the laser beam channel is characterized by laser power, electron density n e , electron temperature T e , and ionization state Z h of the hot plasma inside laser channel. The radiation ablated volume surrounding the laser channel is characterized by the radiation temperature T r and electron density Zn i , in which Z is the ionization state and n i is the ion density of the radiation volume.…”

Hard X-ray and hot electron environment in vacuum hohlraums at NIF

“…Also annotated in Figure 2a are features ascribed to Au-Kα and Kedge absorption. Figure 2b also shows a correlation between the hot electron fraction and the time to reach 10% critical density normalized to the laser pulse length based on an analytic plasma filling model [6.] described in more detail elsewhere [7,8] …”

Quasi-Self-Similarity for Laser-Plasma Interactions Modelled with Fuzzy Scaling and Genetic Algorithms

“…It has been shown analitically that plasma filling by hohlraum wall ablation imposes an upper bound to hohlraum X-ray production. Current simulations indicate that hohlraums used in inertial confinement fusion ( ICF) are optimized to drive a fusion capsule to ignition before reaching the x-ray production limits ( Dewald et al, 2005 ). In the future NIF ignition experiments, the deuterium-tritium fuel capsule will be placed inside a larger hohlraum.…”