Modeling of Shell-mixing into Central Hotspot in Inertial Confinement Fusion Implosion

Abstract

Abstract: From mass conservation and energy conservation of hotspot, dynamics of hotspot combustion involving shell-mix are constructed by recalculating special internal energy and heat capacity, in which bremsstrahlung radiation loss and other energy transfer are considered. With power balance in hotspot, relations between fractions of shell-mixing in hotspot and ignition threshold and self-sustainable combustion are investigated. Theoretical analysis and numerical simulation show that enhancement of radiation loss induced by shell-mixing plays dominated role in failure of ignition. By adjusting materials and mixing fraction, effects to combustion paths are studied. Finally, two methods for degrading impact of shell-mixing are proposed.

Key words: inertial confinement fusion, implosion mixing, hotspot combustion, shell-mixing

CLC Number:

O532⁺.13

YU Chengxin, FAN Zhengfeng, LIU Jie, HE Xiantu. Modeling of Shell-mixing into Central Hotspot in Inertial Confinement Fusion Implosion[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2017, 34(4): 379-386.

References

[1] HE X T, LI J W, FAN Z F, et al. A hybrid-drive nonisobaric-ignition scheme for inertial confinement fusion[J]. Physics of Plasmas, 2016, 23,082706.
[2] TABAK M, HAMMER J, GLINSKY M E, et al. Ignition and high gain with ultrapowerful lasers[J]. Physics of Plasmas, 1994, 1:1626-1634.
[3] LINDL J D. Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain[J]. Physics of Plasmas, 1995, 2:3933-4024.
[4] LINDL J D, AMENDT P, BERGER R L, et al. The physics basis for ignition using indirect-drive targets on the National Ignition Facility[J]. Physics of Plasmas, 2004, 11:339-491.
[5] ATZENI S, MEYER-TER-VHEN J. The physics of inertial fusion[M]. Oxford:Clarendon Press, 2004.
[6] HAAN S W, LINDL J D, CALLAHAN D A, et al. Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility[J]. Physics of Plasmas, 2011, 18:051001.
[7] REGAN S P, EPSTEIN R, HAMMEK B A, et al. Hot-spot mix in ignition-scale implosions on the NIF[J]. Physics of Plasmas, 2012, 19:056307.
[8] HAMMEL B A, SCOTT H A, REGAN S P, et al. Diagnosing and controlling mix in National Ignition Facility implosion experiments[J]. Physics of Plasmas, 2011, 18:056310.
[9] REGAN S P, EPSTEIN R, HAMMEL B A, et al. Hot-spot mix in ignition-scale inertial confinement fusion targets[J]. Physics Review Letters, 2013, 111:045001.
[10] MACFARLANE J, GOLOVKIN I E, WANG P, et al. SPECT3D:A multi-dimensional collisional-radiative code for generating diagnostic signatures based on hydrodynamics and PIC simulation output[J]. High Energy Density Physics, 2006, 3:181.
[11] REGAN S P, DELETTREZ J A, MARSHALL F J, et al. Shell mix in the compressed core of spherical implosions[J]. Physics Review Letters, 2002, 89:085003.
[12] BAUMGAERTEL J A, BRADLEY P A, HSU S C, et al. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations[J]. Physics of Plasmas, 2014, 21:052706.
[13] MA T, PATEL P K, IZUMI N, et al. Onset of hydrodynamic mix in high-velocity, highly compressed inertial confinement fusion implosions[J]. Physics Review Letters, 2013, 111:085004.
[14] HURRICANE O A, CALLAHAN D A, CASEY D T, et al. Fuel gain exceeding unity in an inertially confined fusion implosion[J]. Nature, 2014, 506:343.
[15] PARK H S, HURRICANE O A, CALLAHAN D A, et al. High-adiabat high-foot inertial confinement fusion implosion experiments on the National Ignition Facility[J]. Physics Review Letters, 2014, 112:055001.
[16] EDWARDS M J, PATEL P K, LINDL J D, et al. Progress towards ignition on the National Ignition Facility[J]. Physics of Plasmas, 2013, 20:070501.
[17] KRAMERS H A. On the theory of X-ray absorption and of the continuous X-ray spectrum[J]. Philosophical Magazine Series 6, 2013, 46:836-831.
[18] SPITZER L. Physics of fully ionized gases[M]. New York:Interstellar Science, 1962.
[19] 王尚武, 张树发, 马燕云. 粒子输运问题的数值模拟[M]. 北京:国防工业出版社, 2013
[20] FAN Z F, LIU B, LIU J, et al. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model[J]. Physics of Plasmas, 2016, 23:010703.
[21] 范征锋, 刘彬,刘杰,等. 离子-电子非平衡机制降低中心热斑点火条件[J]. 强激光与粒子束, 2015, 27(8):082001.