Non-cryogenic ICF-target

Transcription

1 Non-cryogenic ICF-target 1, V.E. Sherman, 3 N.V. Zmitrenko 1 P.N.Lebedev Physical Institute of Russian Academy of Sciences, Moscow, RF St.-Petersburg Polytechnic State Iniversity, RF M.V. Keldish Instititute of Applied Mathematics of Russian Academy of Sciences, RF 10 th Direct Drive and Fast Ignition Workshop. Prague. May 7-30, 01 General problem: effect of the light impurities such as H, Li, Be, N, C on ignition and combustion of ICF-targets. (Origin of the impurities: 1. non-cryogenic solid thermonuclear fuel, namely, DT-hydrides of light metals such as Be and Li;.mixing DT-fuel with target s ablator (H, Be, C.) Non-cryogenic ICF-targets Non-cryogenic fast-ignited ICF-target gain

2 Effect of the light impurities on ignition and combustion of ICF-targets. Impurities in DT-fuel 1. Mixing the DT-fuel with target s ablator H-, Be-, C-impurities. Non-cryogenic solid thermonuclear fuel. DT-hydrides of light metals as the solid chemical compounds of hydrogen s isotopes containing minimal atomic fraction of inert atoms: BeDT,Li BeD T, Li Be D 3 T 3, Li DT, Amine-boraneNT 3 BD 3. Two applications 1. Studying the influence of DT-fuel mixing with target s ablator on ignition and gain. Searching the possibilities to use the solid chemical compounds of hydrogen s isotopes as a non-cryogenic thermonuclear fuel, despite decreasing the caloric content of such a fuel in comparison with DT-ice.

3 Effect of the light impurities on ICF-targets ignition., D.V. Il in, V.E. Sherman. Plasma Physics Reports 011, v.37, p. 1096: The dependences of ignition criterion, ignition energy and gain of DT-fuel on the arbitrary concentration of light impurities for homogeneous, isobaric and isochoric plasmas. Ignition criterion: < > + 4 > ( ρr) σ v ( η η ) F α n β ( ρ u ) r ( ρ ) c T 3 / R T 1/ R T 7 / β =0 - isobaric, β = isochoric, β = - homogeneous plasmas 1 x χ =, χ = F χ χ χ χ 1 + ( Z 1) x 1 + ( Z 1) x a a x a r 1 + ( µ /.5 1) x a 1 + ( µ /.5 1) ; x-impurity's concentr. BeDT is most promising material as a solid non-cryogenic fuel with a maximal ratio χ F /χ : r BeDT χ F /χ r =0.038 (χ F =0.13, χ r =3.44) Li Be D 3 T 3 χ F /χ r =0.031 (χ F =0.1, χ r =3.17); Li BeD T χ F /χ r =0.09 (χ F =0.09, χ r =3.06)

4 ( ρr) 1/ 3/ 1/ µ * 1 + Z β *.5 min 0.3, g ( 1 x) 0.06 Z Z cm * * Impurities effect on ignition Isochoric (fast-ignited) plasma T ig =15-0 kev C-10% C-0% Be-0% ρr, г/см C-5% Be-10% Be-5% 1 1 Pure DT T, кэв Carbon -5%. (ρr) ig : g/cm T ig : 10 1 kev E ig growth: 3.8 times

5 Ignition of BeDT-plasmas (x 0.33, µ* = 4.67, Z * =, (Z ) * = 6) homogeneous 10 BeDT isochoric ρr, г/см DT isobaric T, кэв 33% impurity of beryllium increases: (ρr) min in about5 times and T ig in about times in comparison with pure DT-fuel. Burning out BeDT : g = ρr ρr ~ 5 6 g / cm DT : g = ρr ρr ~ 3 4 g / cm ρr ρr+ 6.5

6 Spark ignition. Analytical consideration Ignition requirements for isobaric BeDT-plasma : (ρr) ig(min) =0.9 g/cm and T ig =15 kev BeDT-plasma energyof the burning target ρr> ( ρr) and ρ > > ρ ig cold ( ) ρ E J ( ρr 0.9) ig plasma ρ ρ ig c ig G F 86 Gain: G E / E F fusion plasma ρr ( ρr 0. 9) ρr ( ρr 0.9) ρig ρc G F E ig, MJ E c, MJ E, MJ ρ ig, g/cm 3 ρr = 6 г/см, g 0.36 ρ c =500 g/cm ρ c =1000 g/cm These gains could be enough for heavy ion fusion at the driver energy of 15-0 MJ. Spark-ignited BeDT-target can be used as a source of neutrons in the hybrid fusion-fission reactor at the laser energy 5-7 MJ.

7 Fast ignition. Analytical consideration. Ignition requirements for isochoric BeDT plasma: (ρr) ig(min) = 1.5 g/cm and T ig = 0 kev BeDT-plasma energy of the burning target ρr> > ( ρr) and ρ = ρ E plasma ig ( J) ( ρr) 3ρ/3 + ρ ig G F Gain: G E / E F fusion plasma 64 ρr 1 0.3( ρr) 3 + ρr ( ρr) 3ρ/3 G F E ig, kj E c, kj E, kj ρr = 6 g/cm, g 0.36 ρ=300 g/cm ρ=500 g/cm ρ=700 g/cm ρ=1000 g/cm The target with BeDT-fuel can be fast ignited by laser-produced beams of electrons or ions with energy kj at the fuel density of g/cm 3 or fast ignited by heavy ion beam with energy of kj at the fuel density of g/cm 3.

8 Fast-ignited BeDT-target. Numerical simulations BeDT E L (MJ) Mass (mg) Radius (cm) Hydro efficien. (%) τ LAS (nс) Impl. time (ns) ρr (g/cm )

9 Fast-ignited BeDT-target. Laser & target. M ρr τ L R

10 Fast-ignited BeDT-target. Compression. R=0.5 cm, M=8.0 mg E L =1.7 MJ. τ L = 36 ρr=6.65 g/cm

11 Fast-ignited BeDT-target. Gain vs ignition energy. 40 G= E E laser fusion + E ignition E L =1.7 MJ. τ L = 36 ns R=0.5 cm, M=8.0 mg 30 Gain 0 ρr 6.65 g/cm ρ max 960 g/cm Ignition Energy, kj

12 Fast-ignited BeDT-target. Gain vs total energy. E L (MJ) Mass (mg) ρr (g/cm ) E G= fusion E laser + Eignition BeDT ICF-target BeDT target for hybrid E laser +E ig, J Fast-ignited BeDT ICF target: Laser Energy MJ, Ignition Energy kj Fast-ignited BeDT target for hybrid: Laser Energy < 0.5 MJ

13 Fast-ignited BeDT-target for hybrid. E L =0.57 MJ. τ L = 7.5 ns R=0.19 cm, M=3.5 mg G= E 15,00 E laser fusion + E ignition 10,00 ρr 5.5 g/cm ρ max 90 g/cm 3 5,00 0, E ig, kj 00 Fast-ignited BeDT target for hybrid. Laser Energy: MJ. Ignition Energy: kj

14 Conclusions It is suggested to apply the targets with solid non-cryogenic BeDT-fuel as: (1) Fast-ignited ICF-target at the ignition energy of kj and compressing driver energy of 4-5 MJ ; () Fast-ignited target for hybrid at the ignition energy of kj and compressing driver energy of MJ; (3) Spark-ignited target for heavy ion fusion at the driver energy of 15-0 MJ; (4) Spark-ignited target for hybrid at the laser energy 5-7 MJ.