A hybrid-drive nonisobaric-ignition scheme for inertial confinement fusion

Abstract

A new hybrid-drive (HD) nonisobaric ignition scheme of inertial confinement fusion (ICF) is proposed, in which a HD pressure to drive implosion dynamics increases via increasing density rather than temperature in the conventional indirect drive (ID) and direct drive (DD) approaches. In this HD (combination of ID and DD) scheme, an assembled target of a spherical hohlraum and a layered deuterium-tritium capsule inside is used. The ID lasers first drive the shock to perform a spherical symmetry implosion and produce a large-scale corona plasma. Then, the DD lasers, whose critical surface in ID corona plasma is far from the radiation ablation front, drive a supersonic electron thermal wave, which slows down to a high-pressure electron compression wave, like a snowplow, piling up the corona plasma into high density and forming a HD pressurized plateau with a large width. The HD pressure is several times the conventional ID and DD ablation pressure and launches an enhanced precursor shock and a continuous compression wave, which give rise to the HD capsule implosion dynamics in a large implosion velocity. The hydrodynamic instabilities at imploding capsule interfaces are suppressed, and the continuous HD compression wave provides main pdV work large enough to hotspot, resulting in the HD nonisobaric ignition. The ignition condition and target design based on this scheme are given theoretically and by numerical simulations. It shows that the novel scheme can significantly suppress implosion asymmetry and hydrodynamic instabilities of current isobaric hotspot ignition design, and a high-gain ICF is promising.

Harmonic effects on ion-bulk waves and simulation of stimulated ion-bulk-wave scattering in CH plasmas

“…However, the energy was stored in the nonlinear IBk waves only when the wave number k was larger than a special value [2], which has not been explained and calls for a clear interpretation. This Letter will give a clear and detailed interpretation of these phenomena from the view of harmonics effects.On the other hand, the research of IBk waves will give a guidance to a new scattering mechanism in the field of laser plasmas interaction (LPI) [8,9] related to inertial confinement fusion (ICF) [10,11]. As we know, laser scattering mainly includes stimulated Brillouin scattering (SBS) [12] from IAWs, stimulated Raman scattering (SRS) [13] from Langmuir waves (LWs).…”

“…On the other hand, the research of IBk waves will give a guidance to a new scattering mechanism in the field of laser plasmas interaction (LPI) [8,9] related to inertial confinement fusion (ICF) [10,11]. As we know, laser scattering mainly includes stimulated Brillouin scattering (SBS) [12] from IAWs, stimulated Raman scattering (SRS) [13] from Langmuir waves (LWs).…”

Growth rate and gain of stimulated Brillouin scattering considering nonlinear Landau damping due to particle trapping

“…The electron density is taken to be higher than 0.25n c , thus the stimulated Raman scattering [25] and two-plasmon decay instability [26,27] are excluded. The CH 4 , C 5 H 12 , C 2 H 4 , C 2 H 2 plasmas are taken as typical examples since they are common in ICF [1,3]. The ion temperature is T i = 0.5T e and the slow mode will be excited and dominate in SBS.…”

“…PACS numbers: 52.38.Bv, 52.35.Fp, 52.35.Mw, 52.35.Sb Backward stimulated Brillouin scattering (SBS) is a three-wave interaction process where an incident electromagnetic wave (EMW) decays into a backscattered EMW and a forward propagating ion-acoustic wave (IAW), which will lead to a great energy loss of the incident laser and is detrimental in inertial confinement fusion (ICF) [1][2][3]. In the indirect-drive ICF [2,3] or the hybrid-drive ignition [1,[4][5][6], CH was chosen as the standard ablator material for ICF ignition capsules due to its low atomic number, high density, and a host of manufacturing considerations. Thus, the inside of hohlraum will be filled with low-Z plasmas, such as H or CH plasmas from the initial filled material or from the ablated material off the capsule.It is one of the key issues for the success of laser fusion to control backward SBS.…”

Burst behavior due to the quasimode excited by stimulated Brillouin scattering in high-intensity laser–plasma interactions

“…Multiple ion species are contained in the laser fusion program [4]. In the indirectdrive ICF [2,3] or the hybrid-drive ignition [1], the inside of hohlraum will be filled with low-Z plasmas, such as H or CH plasmas from the initial filled material or from the ablated material off the capsule. Typically, in hybrid-drive ICF, the laser intensity can reach as high as I 0 ∼ 10 16 W/cm 2 , the strong-coupling modes will be excited by SBS.…”