59th Annual Meeting of the APS Division of Plasma Physics
Volume 62, Number 12
Monday–Friday, October 23–27, 2017;
Milwaukee, Wisconsin
Session TI2: Direct Drive, Fast Ignition, and Kinetic Modeling
9:30 AM–12:30 PM,
Thursday, October 26, 2017
Room: 102ABC
Chair: John Kline, Los Alamos National Laboratory
Abstract ID: BAPS.2017.DPP.TI2.4
Abstract: TI2.00004 : Exploring the dynamics of kinetic/multi-ion effects and ion-electron equilibration rates in ICF plasmas at OMEGA
11:00 AM–11:30 AM
Preview Abstract
Abstract
Author:
H. Sio
(MIT)
During the last few years, an increasing number of experiments have shown
that kinetic and multi-ion-fluid effects do impact the performance of an ICF
implosion. Observations include: increasing yield degradation as the
implosion becomes more kinetic; thermal decoupling between ion species;
anomalous yield scaling for different fuel mixtures; ion diffusion; and fuel
stratification. The common theme in these experiments is that the results
are based on time-integrated nuclear observables that are affected by an
accumulation of effects throughout the implosion, which complicate
interpretation of the data. A natural extension of these studies is
therefore to conduct time-resolved measurements of multiple nuclear-burn
histories to explore the dynamics of kinetic/multi-ion effects in the fuel
and their impact on the implosion performance. This was accomplished through
simultaneous, high-precision measurements of the relative timing of the
onset, bang time and duration of DD, D$^{\mathrm{3}}$He, DT and
T$^{\mathrm{3}}$He burn from T$^{\mathrm{3}}$He (with trace D) or
D$^{\mathrm{3}}$He gas-filled implosions using the new Particle X-ray
Temporal Diagnostic (PXTD) on OMEGA. As the different reactions have
different temperature sensitivities, $T_{i}(t)$ was determined from the data.
Uniquely to the PXTD, several x-ray emission histories (in different energy
bands) were also measured, from which a spatially averaged $T_{e}(t)$ was also
determined. The inferred $T_{i}(t)$ and $T_{e}(t)$ data have been used to
experimentally explore ion-electron equilibration rates and the Coulomb
Logarithm for various plasma conditions. Finally, the implementation and use
of PXTD, which represents a significant advance at OMEGA, have laid the
foundation for implementing a $T_{e}(t)$ measurement in support of the main
cryogenic DT programs at OMEGA and the NIF. This work was supported in part
by the US DOE, LLE, LLNL, and DOE NNSA SSGF.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.DPP.TI2.4