https://doi.org/10.1140/epjd/e2017-80126-6
Regular Article
Effects of alpha stopping power modelling on the ignition threshold in a directly-driven inertial confinement fusion capsule
1 CMLA, Centre de Mathématiques et de Leurs Applications, ENS Cachan and CNRS, 61 Av. du President Wilson, 94235 Cachan Cedex, France
2 CEA, DIF, 91297 Arpajon Cedex, France
3 ETSI Aeronáutica y del Espacio, Universidad Politécnica de Madrid, 28040 Madrid, Spain
4 Los Alamos National Laboratory, Los Alamos, 87545 New Mexico, USA
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e-mail: mauro.temporal@hotmail.com
Received: 24 February 2017
Received in final form: 30 March 2017
Published online: 25 May 2017
The alpha-particle energy deposition mechanism modifies the ignition conditions of the thermonuclear Deuterium-Tritium fusion reactions, and constitutes a key issue in achieving high gain in Inertial Confinement Fusion implosions. One-dimensional hydrodynamic calculations have been performed with the code Multi-IFE [R. Ramis, J. Meyer-ter-Vehn, Comput. Phys. Commun. 203, 226 (2016)] to simulate the implosion of a capsule directly irradiated by a laser beam. The diffusion approximation for the alpha energy deposition has been used to optimize three laser profiles corresponding to different implosion velocities. A Monte-Carlo package has been included in Multi-IFE to calculate the alpha energy transport, and in this case the energy deposition uses both the LP [C.K. Li, R.D. Petrasso, Phys. Rev. Lett. 70, 3059 (1993)] and the BPS [L.S. Brown, D.L. Preston, R.L. Singleton Jr., Phys. Rep. 410, 237 (2005)] stopping power models. Homothetic transformations that maintain a constant implosion velocity have been used to map out the transition region between marginally-igniting and high-gain configurations. The results provided by the two models have been compared and it is found that – close to the ignition threshold – in order to produce the same fusion energy, the calculations performed with the BPS model require about 10% more invested energy with respect to the LP model.
Key words: Plasma Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017
