Peculiarities of Modeling LPP Source at 6.X nm

Transcription

1 V.Novikov, V.Ivanov, K.Koshelev, V.Krivtsun, A.Grushin, R.Kildiyarova, A.Solomyannaya Peculiarities of Modeling LPP Source at 6.X nm

2 Outline Theoretical base Optimal plasma parameters Band position Scaling CE by RZLINE modeling Laser types: Nd YAG vs CO 2 Conclusion 2

3 Fuel at ~ nm S S Churilov, R R Kildiyarova, A N Ryabtsev and S V Sadovsky Phys. Scr. 80 (2009) Tb 3

4 THERMOS_BELINE code COMPUTING OF LEVEL KINETICS & RADIATION TRANSPORT Main purpose: - to get CRE tables with arbitrary radiation field; - obtaining the realistic emission spectra; - in-line version for radiative hydro-dynamics; Method: - special averaging with given photon energy grid; - usage the stored data prepared beforehand. Sn The code makes possible self-consistent calculation of level kinetics and radiation transport for arbitrary plasma configurations. The code includes: radiation transport of overlapped spectral lines with arbitrary optical thickness and realistic line profiles; verified atomic database for low-z materials (H, He, C, N,O) and also for Xe, Sn, W, Tb,. 4

5 & Tb ions emission Mirror nm Tb XXIII - XXX (4p k 4d m 4f n ) XVII - XXII (4d m 4f n ) 5

6 Sn (13.5) vs (6.x) Material Sn Band 2% at 13.5 nm 0.6% at 6.x Ions VIII - XIV XVII - XXII Temperature ~ 35 ev ~ 100 ev Size ~ 200 um ~ 200 um Optical thickness Electron density CE 6

7 Sn ionization: T=32.5 ev Saha optically thick in the interval nm transparent plasma 7

8 ionization at T=90 ev D=200um 8

9 absorption in band D = 0.02 cm tau = 10 9

10 Sn (13.5) vs (6.x) Material Sn Band 2% at 13.5 nm 0.6% at 6.x Ions VIII - XIV XVII - XXII Temperature ~ 35 ev ~ 100 ev Size ~ 200 um ~ 200 um Optical thickness ~ 1 ~ 1 Electron density ~ /cm 3 ~ /cm 3 CE 10

11 Position of band Sn

12 Detailed spectrum 12

13 Influence of broadening Sn vs 13

14 Temperature dependence D = 200 um Ne= /cm 3 14

15 Temperature dependence D = 200 um Ne= /cm 3 15

16 Temperature dependence D = 200 um Ne= /cm 3 16

17 Temperature dependence D = 200 um Ne= /cm 3 17

18 Temperature dependence D = 200 um Ne= /cm 3 18

19 Temperature dependence D = 200 um Ne= /cm 3 19

20 Temperature dependence D = 200 um Ne= /cm 3 20

21 Temperature dependence D = 200 um Ne= /cm 3 21

22 Temperature dependence D = 200 um Ne= /cm 3 22

23 Dependence on plasma size Tb T = 110 ev Ne = /cm 3 T = 90 ev Ne = /cm 3 23

24 Dependence on plasma size Tb T = 110 ev Ne = /cm 3 T = 90 ev Ne = /cm 3 24

25 Dependence on plasma size Tb T = 110 ev Ne = /cm 3 T = 90 ev Ne = /cm 3 25

26 Sn (13.5) vs (6.x) Material Sn Band 2% at 13.5 nm 0.6% at 6.x Ions VIII - XIV XVII - XXII Temperature ~ 35 ev ~ 100 ev Size ~ 200 um ~ 200 um Optical thickness ~ 1 ~ 1 Electron density ~ /cm 3 ~ /cm 3 CE ~ 7% ~ 3% More realistic modeling is based on RHD calculations with the code RZLINE 26

27 2D Eulerian RMHD code RZLINE code Laser tracing, absorption and reflection of laser pulse, energy fluxes to and from target, electron and ion thermo-conductivity, radiative transfer in ~100 spectral groups, evaporation and condensation of target, ionization and recombination of plasma. RZLINE works with two types of tables: 1.Transparent case table 2.Optically thick case table (nontrasparent in band) Diffusion-like spectral radiation transport, calculation of EUV source size, detailed spectra, anisotropy of EUV radiation, fast ions. Nonhomogeneous grid ~ 10 5 r,z cells Calculation time ~ 2 hours on PC Temperature Electron density Photon energy range ev /cm ev

28 CE scaling flat target Nd YAG laser t = 2 ns D = 160 um 28

29 CE scaling Nd YAG laser E = 1 J D = 100 um 0.2 flat target 0 1e+013 1e+014

30 CE scaling flat target w/o including anisotropy including anisotropy CO 2 laser t = 60 ns D = 200 um 0.2 Experiment 0 1e+010 1e+011 1e+01 Power density, W/cm^2 30

31 Comparison with experiment flat target CO 2 laser E = 0.8 J t = 60 ns D = 200 um 31

32 Conclusion Comparison of & Sn plasma LPP source was fulfilled Optimal plasma for homogeneous ball with size D ~ 200 um,t ~ 90 ev, Ne ~ /cm 3 gives CE ~ 3 % in 0.6% band at nm Modeling by using the code RZLINE gives for plate target CE ~ 1 % for CO 2 laser 32