39th international conference on plasma physics and CF, February 6 – 10, 2012, Zvenigorod.

NON-Cryogenic thermonuclear target for inertial fusion WITH a SOLID FUEL as deuterium-tritium HYDRIDES of light Metals

*S.Yu. Gus’kov, D.V. Il’in, V.E. Sherman

St.-Petersburg State Institute of Engineering (LMZ-VTUZ), St.-Petersburg, Russia,
e-mail:
*P.N. Lebedev Physical Institute RAS, Moscow, Russia, e-mail:

Theoretical and numerical studies [1,2] on ignition and burning of deuterium-tritium (DT) plasma of inertial confinement fusion (ICF) target in the presence of inert impurities of the light elements identified the prospects of solid chemical compounds of hydrogen isotopes with light elements as a thermonuclear fuel of non-cryogenic ICF targets, despite the reduction in caloric content of such a fuel in comparison with pure DT-plasma. The use of such a fuel would eliminate the application of cryogenic technology for creating and delivering a thermonuclear target in the reactor chamber, which will significantly simplify and reduce the cost of nuclear power plant based on inertial confinement. In [1,2] have shown that the most promising fuel of non-cryogenic ICF targets are the deuterium-tritium hydrides of light metals as beryllium and lithium: first of all - beryllium hydride BeDT, as well as mixed hydrides Li2BeD2T2 and Li2Be2D3T3.

This paper presents the results of numerical simulations of burning the targets with BeDT-fuel for the case of homogeneous and two cases of heterogeneous plasmas, namely, the isobaric and isochoric plasmas corresponding, respectively, to spark ignition and fast ignition of ICF-target. The simulations were performed by use the TERA program complex [3], which includes the unit of calculating the kinetics of fusion reactions by Monte Carlo method. It is proposed and justified to use non-cryogenic targets with BeDT-fuel as: (1) laser fusion target fast ignited at an ignition energy of 25-50 kJ and compressing laser energy of 2-3 MJ; (2) spark ignited targets for heavy ion fusion at an ion beam energy of 15-20 MJ; (3) spark ignited target at laser energy of 5-7 MJ as a source of neutrons for a hybrid (fusion-fission) nuclear power.

Particular attention was paid to investigation the influence of plasma thermal radiation on the non-cryogenic ICF-targets combustion. Burning the pure DT-plasma occurs at a small ratio of plasma emissivity J to the rate of fusion energy yield WTN, J/WTN <1. The presence of inert impurities reduces the rate of fusion reaction and increases the plasma emissivity and, therefore, leads to increasing the ratio J/WTN. Under these conditions the question about the target's transparency for its own radiation acquires the important value. It is shown that the fraction of radiation energy leaving in the plasma is a function of the parameter ρ2R<Z2<Z<μ>-2T-7/2, where ρ, R, T are, respectively, the density, radius and temperature of the plasma; <Z>, < Z2>, <μ> are, respectively, an average values of charge, square of the charge and atomic weight of the plasma. This leads to disruption of the conventional scaling of ignition's and combustion's characteristics on the ρR-parameter in the target with a high content of inert impurities. In particular, the increase in density (at the conservation of ρR-parameter) leads to more lenient requirements for ignition and increases the efficiency of thermonuclear burning. The universal dependence of the radiative energy loss for a spherical target with an arbitrary concentration of light impurities for any temperature and density have been obtained.

This work was supported by the Ministry of Education and Science RF under the program “Development of the Scientific Potential of Higher Education for 2009-2011” (Project no. 2.1.1/12138) and by the Russian Foundation for Basic Research (Project no. 11-02-00587-а).

References

[1].S.Yu.Gus'kov et al. Book of abstr. of 38-th Zvenigorod conf. on Plasma Physics 2011, p. 121.

[2].S.Yu. Gus'kov, D.V. Il'in, V.E. Sherman. Plasma Physics Reports 2011, V. 37, p.1020

[3].S.Yu. Gus'kov, D.V. Il'in, A.A. Levkovsky et al. Laser and Particle Beams 1998, V. 16, P.129.

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