Illumination Uniformity Study for the Direct Drive J.-L. Feugeas Centre Lasers Intenses et Applications, Université Bordeaux 1 – CNRS – CEA France 6th Direct Drive and Fast Ignition Workshop Lisbon, 11th–14th May

Collaborators J. Breil, Ph. Nicolaï, G. Schurtz L. Hallo, M. Olazabal-Loumé, X. Ribeyre Centre Lasers Intenses et Applications, Université Bordeaux 1 - CNRS- CEA, 33405 Talence cedex, France J.-L. Feugeas CELIA 2

Summary A new tool has been developed to provide a nominal configuration of illumination for any direct drive project The code CECLAD has been developed in CELIA to study the direct-drive illumination of any target Several parameters have been studied to optimize the uniformity of illumination - Beam size variation - Beam balance - Beam pointing - Beam centering - Target position A solution of illumination has been proposed to answer to the baseline specification of HIPER J.-L. Feugeas CELIA 3

Summary/Conclusions Speckle pattern for each beam 4 J.-L. Feugeas CELIA 4

CECLAD

A tool to study the illumination : various 3D configurations

A tool to study the illumination : control parameters of each beams

A tool to study the illumination : absorption

A tool to study the illumination : robustness analysis Normal variation of target or beam imperfections : Target position Beams size variation Beams balance Beams pointing Beams centering

A tool to study illumination : diagnostic of optimisation 1/e a m=1 m=2 m=3 m=4

x100 x100 A tool to study the illumination : Legendre analysis 12 10 8 rms = 0.15 % a = 0.61 m = 1.02 48 (-4) 12 x100 x100 10 8 11

A tool to study the illumination : validation Validation with studies of the literature : Ref. POP B. Canaud et al 2002 49° 59°5 33°2 78° 59°5 33°2 rms = 16.23 % rms = 0.2474 % Validation with analytical solutions (Ref. J. Opt J. Xiao and B. Lu) : - perfect uniform irradiation Validation with known configuration : Omega

HIPER

300 kJ on target – 15 kJ per beams – 50 beams @ 3 The specification for HiPER : number of compression (ns) beams Modelling with a shaped adiabat (Atzeni, Bellei, Schiavi) based on theoretical and experimental work by Betti et al (LLE) Energy : 300 kJ 15 kJ per beam at the output of the main amplifier section Wavelength : 2 baseline : conversion 70 % 3 option : conversion (70 %)2 = 50 % Transmission : 80 % A 3 : 50 beams x 15 kJ x 50 % (conversion 3) x 80 % (transmission) = 300 kJ Pulse shape : Adiabatic shock plus ramp plus final < 200 ps resolution 300 kJ 50 beams 5 ns, 2-3 70 kJ 10 ps PW

a m The 48 beams configuration is a good candidate : 0.12 % RMS Nb m a (%) rms (%) 6 (-1) 1.63 1.02 78 1.73 8 (-1) 1.66 1.01 79 0.96 32 (-1) 1.33 0.83 87 0.31 42 (-5) 1.9 0.79 97 0.18 46 (-8) 1.12 0.63 96 0.12 48 (-4) 1.02 0.61 94 0.15 60 (-5) 1.067 0.567 97 0.06 60 () 1.08 0.63 94 0.09 a m J.-L. Feugeas CELIA 15

The 48 beams configuration seems the best candidate with the cone rms (%) (%) 0.12 94 % 0.61 1.02 48 (-4) a m Nb 47° 74°95 21°24 30° The 48 beams configuration gives : rms 0.15 % ratio of power 94 % disconnection of 1 (or 2) ring of 4 beams is enough to put the cone or beams dedicated for the fast ignition. Robustness of the configuration : zooming in time stability analysis Calotte : r2 = (R sin(30°))2 r2/ 4R2 = 1/16 = 6.25 % Beams off 4/48 = 1/12 = 8.33 % 5/42 = 11.9 % 8/46 = 17.4 % 5/60 = 1/12 = 8.33 % J.-L. Feugeas CELIA 16

The 48 beams configuration is a good candidate J.-L. Feugeas CELIA 17

The 48 beams configuration is a good candidate The 48 beams configuration gives : energy on the cone energy in the cone reduced (0.08/4.18) Other configurations lead to higher energy on/in the cone J.-L. Feugeas CELIA 18

x100 x100 The 48 beams configuration : Legendre analysis 12 10 8 rms = 0.15 % a = 0.61 m = 1.02 48 (-4) x100 x100 19

rms = 0.15 % a = 0.61 m = 1.02 44 20

At the end of the 1-50 modes End of free flight time Weakly non linear Mode 12 dominates 11 ns 10.4 ns 11 ns 10.8 ns J.-L. Feugeas CELIA 10.6 ns 21

J.-L. Feugeas CELIA 22

Robustness of the 48 beams configuration Normal variation of Beam imperfections : Balance : 10 % Beam pointing : 5 % Beam centering : 2 % Several low l-mode sources of direct-drive illumination non-uniformity can come from imperfections or can be significantly reduced by those same parameters. Normal repartition of the beam to beam imbalance A Gaussian repartition around 10 % of balance imperfections between beams after 100 000 configurations 1.05 % 0.26 % 0.59 % rms (0.15 %) max min mean after 100.000 configurations Marshall APS 03

Robustness of the 48 beams configuration

Robustness of the 48 beams configuration Normal repartition of the beam to beam imbalance A Gaussian repartition around 10 % of balance imperfections between beams after 100 000 configurations 1.05 % 0.26 % 0.59 % rms (0.15 %) max min mean after 100.000 configurations Normal repartition of the beam pointing A Gaussian repartition around 5 % of beam defaults of pointing after 100 000 configurations 3.2 % 0.82 % 1.2 % rms (0.15 %) max min mean after 100.000 configurations Normal repartition of the beam centering A Gaussian repartition around 2 % of beam centering after 100 000 configurations % rms (0.15 %) max min mean after 100.000 configurations J.-L. Feugeas CELIA 25

Robustness of the 48 beams configuration Normal variation of Beam imperfections : Beam size variation : (a +/- a ,m +/- m ) Balance : 10 % Beam pointing : 5 % Beam centering : 2 % Target position Several low l-mode sources of direct-drive illumination non-uniformity can come from imperfections or can be significantly reduced by those same parameters. For example, on OMEGA Marshall APS 03

Algorithm of definition of nominal configuration IRRADIATION Illumination non uniformity 48 beams, (a=0.61, m=1.02.) rms = 0.15 %, l-modes : 12, 8 and 10 Energy : 130 kJ TARGET Baseline target definition Small - Large - Reference LOW MODES ASYMETRY Hydrodynamics instabilities analysis FACILITY 27 J.-L. Feugeas CELIA X Ribeyre, Ph Nicolaï, G Schurtz, M Olazabal-Loumé, J Breil, P.-H. Maire, J.-L. Feugeas, L Hallo and V. T Tikhonchuk

LMJ

Optimisation de configuration d’éclairement Attaque Directe en configuration LMJ attaque indirecte (33°2, 49°, 59°5) DECENTRAGE décentrage Θ Avantages : simplicité de mise en place et de réglages Interrogation : absorption évolution en temps au cours de l’implosion perte d’énergie (à coté) robustesse Sens trigonométrique Θ1 Θ2 Θ3 a : tache m : puissance

Retrouver les résultats existant

of UV light for each beam. Goal : choc ignition Configuration : LMJ able to produce 1.8 MJ of UV light (3) and 550 TW of peak power. 240 beams delivering 8.2 kJ of UV light for each beam. Goal : choc ignition 49° 59°5 33°2 49° 59°5 33°2 59°5 78° 33°2 49° 59°5 33°2 49° 59°5 49° 59°5 49° 59°5 33°2 J.-L. Feugeas CELIA 31

49° 59°5 33°2 J.-L. Feugeas CELIA 32

59°5 78° 33°2 x100 J.-L. Feugeas CELIA 33

49° 59°5 33°2 J.-L. Feugeas CELIA 34

49° 59°5 33°2 x100 J.-L. Feugeas CELIA 35

49° 59°5 x10 J.-L. Feugeas CELIA 36

49° 59°5 x100 J.-L. Feugeas CELIA 37

of UV light for each beam. Goal : choc ignition Configuration : LMJ able to produce 1.8 MJ of UV light (3) and 550 TW of peak power. 240 beams delivering 8.2 kJ of UV light for each beam. Goal : choc ignition 59°5 49° 59°5 49° 49° 59°5 33°2 49° 59°5 33°2 J.-L. Feugeas CELIA 38

Optimisation de configuration Solution optimale calculé par le code d’éclairement Attaque Directe en configuration LMJ attaque indirecte (33°2, 49°, 59°5) Θ1 = 11.88 ° Θ2 = 5.33 ° Θ3 = 19,22 ° a = 1 m = 1.91 srms = 16.23 % Pi / Pa = 137/160 = 85,7% srms = 0.16 % Pi / Pa = 133/167 = 79,44% Optimisation de configuration

The 48 beams configuration is a good candidate