eprintid: 14264
rev_number: 21
eprint_status: archive
userid: 2716
dir: disk0/00/01/42/64
datestamp: 2013-01-11 10:06:59
lastmod: 2022-05-09 10:03:59
status_changed: 2013-01-11 10:06:59
type: thesis
metadata_visibility: show
item_issues_count: 0
creators_name: Yáñez Vico, Carlos
contributors_name: Sanz Recio, Francisco Javier
contributors_name: Tikhonchuk, Vladimir
title: Hydrodynamic stability theory of double ablation front structures in inertial confinement fusion.
ispublished: unpub
subjects: nuclear
subjects: aeronautica
keywords: Linear stability theory, inertial confinement fusion, mid-Z ablators, double ablation front, Rayleigh-Taylor instability.
abstract: The aim of inertial confinement fusion is the production of energy by the fusion of thermonuclear fuel (deuterium-tritium) enclosed in a spherical target due to its implosion. In the direct-drive approach, the energy needed to spark fusion reactions is delivered by the irradiation of laser beams that leads to the ablation of the outer shell of the target (the so-called ablator). As a reaction to this ablation process, the target is accelerated inwards, and, provided that this implosion is sufficiently strong a symmetric, the requirements of temperature and pressure in the center of the target are achieved leading to the ignition of the target (fusion). One of the obstacles capable to prevent appropriate target implosions takes place in the ablation region where any perturbation can grow even causing the ablator shell break, due to the ablative Rayleigh-Taylor instability. The ablative Rayleigh-Taylor instability has been extensively studied throughout the last 40 years in the case where the density/temperature profiles in the ablation region present a single front (the ablation front). Single ablation fronts appear when the ablator material has a low atomic number (deuterium/tritium ice, plastic). In this case, the main mechanism of energy transport from the laser energy absorption region (low density plasma) to the ablation region is the electron thermal conduction. However, recently, the use of materials with a moderate atomic number (silica, doped plastic) as ablators, with the aim of reducing the target pre-heating caused by suprathermal electrons generated by the laser-plasma interaction, has demonstrated an ablation region composed of two ablation fronts. This fact appears due to increasing importance of radiative effects in the energy transport. The linear theory describing the Rayleigh-Taylor instability for single ablation fronts cannot be applied for the stability analysis of double ablation front structures. Therefore, the aim of this thesis is to develop, for the first time, a linear stability theory for this type of hydrodynamic structures.
date: 2012-11-19
date_type: completed
id_number: 10.20868/UPM.thesis.14264
full_text_status: public
pages: 224
institution: Aeronauticos
department: Fisica
thesis_type: phd
refereed: TRUE
rights: by-nc
citation:   Yáñez Vico, Carlos  (2012).  Hydrodynamic stability theory of double ablation front structures in inertial confinement fusion..  Thesis (Doctoral), E.T.S.I. Aeronáuticos (UPM) <https://oa.upm.es/view/institution/Aeronauticos/>.   https://doi.org/10.20868/UPM.thesis.14264 <https://doi.org/10.20868/UPM.thesis.14264>. 
document_url: https://oa.upm.es/14264/2/CARLOS_YA%C3%91EZ_VICO.pdf