Resultats récents sur l’accélération d’ions : optimisation de faisceau et applications

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Resultats récents sur l’accélération d’ions : optimisation de faisceau et applications J. Fuchs

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Resultats récents sur l’accélération d’ions : optimisation de faisceau et applications. J. Fuchs. Collaboration. M. Nakatsutsumi , S. Buffechoux , A. Mancic , P. Antici, P. Audebert M. Tampo, Y. Fukuda, H. Daido O. Willi, T. Toncian , M. Amin M. Borghesi, L. Romagnani, G. Sarri - PowerPoint PPT Presentation

Transcript of Resultats récents sur l’accélération d’ions : optimisation de faisceau et applications

Resultats récents sur l’accélération d’ions : optimisation de faisceau et applications

J. Fuchs

Collaboration

FZD

Vavilov U.

CPhT

M. Nakatsutsumi, S. Buffechoux, A. Mancic, P. Antici, P. Audebert

M. Tampo, Y. Fukuda, H. Daido

O. Willi, T. Toncian, M. Amin

M. Borghesi, L. Romagnani, G. Sarri

R. Kodama, A. Kon

H. Pépin, S. Fourmaux

T. Cowan, U. Schramm, K. Zeil, S. Kraft, T. Burris

A.Andreev

V. Tikhonchuk, J. Psikal, E. d’Humières

P. Mora

L. Gremillet, E. Lefebvre

Y. Sentoku, S. Gaillard

S. Atzeni, A.Schiavi

PMRC/KPSI

- - - - - - - - - - - - - - --

+ -+ -+ -+ -

Surface contaminant (H2O)

H+ ion

Bulk Target (Al)

e-

Laser:400 fs

5e1019 W cm-2

Proton beam characteristics:

• high number (~1013)• high energy (>10 MeV)• produced in a short time (~ few ps)• collimated (<20° divergence half angle)

Source d’ions par laser CPA

E (MeV)0 10

109

1010

1011

1012

1013

ddEdN

)srMeV1(

5 15 20

1014

E (MeV)0 10

109

1010

1011

1012

1013

ddEdN

)srMeV1(

5 15 20

1014

Energy increase: beyond present-day record of 60 MeV?

Obvious route: « brute force » (laser energy increase)

10-10

10-8

10-6

10-4

10-2

100Perf. Gaussian

Typical Real Pulse

Lo

g (

I)

Time

• 2: Use of low-density plasmas

• 3: Geometrical e- confinement

• 4: Tighest laser focusing

More clever strategies?

• 1: Decrease the target thickness (less e- spread + volumetric target heating)

P. Antici, J. Fuchs, et al., Phys. Plasmas 14, 030701 (2007).D. Neely et al., Appl. Phys. Lett. 89, 021502 (2006)T. Ceccotti et al., PRL 99, 185002 (2007)

L. Willingale et al., Phys. Rev. Lett. 96 245002 (2006)A. Yogo et al., PRE 77, 016401 (2008)

0.1

1

10

100

1016 1017 1018 1019 1020 1021

300fs – 1 ps40-60 fs100-150 fs

I2 (W.cm

-2.µm

2)

LOA

JanuspLULI

Nova PW

RAL PW

RAL VulcanRAL Vulcan

OsakaCUOS

MPQ

Tokyo ASTRATokyo

RAL Vulcan

TokyoYokohama

1022 10231024

1000

10000

simulations

experiments

Prospects for energy increase by laser intensity increase

J. Fuchs et al., Nature Physics 2, 48 (2006)

Fro

nt-

end

1st

apm

li

2nd

am

pli

3rd

am

pli

ELI laser facility

Route 3: geometrical confinement of hot electrons use of targets smaller than the « normal » sheath size

0

1

2

3

4

0 40 80 120

Nh 9 µm

R (µm)

n e (

cc)

Denser, more uniform sheath ?

S. Buffechoux, submitted (2009)

Au 2 μm thick target

4

6

8

10

12

14

16

1000 104

105

106

107

max_E (feb08)max_E (feb09)

Surface (microns²)

Max. proton energy increases when reducing the target surface

Size ofstandardtargets

Comparable increase of conversion efficiency

(a) (b)

40

40

00

z (µ

m)

y (µm)-1.456

0.068

1.593

40

40

00

z (µ

m)

y (µm)-1.657

-0.144

1.369

Spreading of electrons over a large area

2D PIC simulations, A. Andreev, J. Psikal, V. Tikhonchuk

Electron energy spectra of hot electrons behind the interaction region

Effective confinement = hot electrons are reflected quickly from edges

foil of transverse width 80 foil of transverse width 20

2D PIC simulations, J. Psikal, V. Tikhonchuk, A. Andreev

Applications tirant partie des paramètres uniques de ces sources

Sondage de champs E & B :•Particules chargées•Faible taille de source résolution spatiale ~µm•Faible durée à la source résolution temporelle ~ps

Production de « matière dense et chaude »

classical plasma

denseplasma

= 1

= 10

Density ( g/cm3)

103

104

101

102

102 104100

10-4 10-2 1

= 100

highdensity matter

Al

white dwarf

ii ~ 1 5,

ii ~ 1 30,

ii ~ 1 200,

(Ze)2

a kB T =

CP

A

ns laser

CP

Ans laser

B

RAL VulcanB

2 mm 1 mm

TLaser = 0 ps TLaser = 0 ps

Force de Lorentz magnétique déflexion dépend de la direction de sondage

50 J, 1 ns at 1 µmfocal spot of 50 µmI=3-6 x1014 W/cm2

6 µm thick Al

100

200

300

400

0 100 200 300 400

100

200

300

400

0 100 200 300 400

100

200

300

400

0 100 200 300 400

50

-10

-40

-30

-20

100

200

300

400

0 100 200 300 400

100

200

300

400

0 100 200 300 400Tra

nsv

. Dir

ecti

on [

μm

]

Laser Direction [μm]

Tra

nsv

. Dir

ecti

on [

μm

]

TLaser = -250 ps

8

7

6

Laser Direction [μm]

CHIC 2D hydrodynamic code (G. Schurtz, CELIA-Bordeaux): I=5x1014 W/cm2, 50 µm spot radius, =13

B in T log10(E) with E in V/m

E fieldTex ne magnetic field

Low-density plasma

High-density plasma

2D Hydrodynamic simulations exhibit 2 zones of B field with reversed amplitude

Recent application: ultrafast generation & probing of transient WDM state of matter

SolidIonization +

Electron heating

Ene

rgy

tran

sfer

to

ions

ExpansionWDM

~ 10 ps

Probe

pu

mp

Probing the local atomic structure of the matter and the

its temperature

This allows to probe local atomic structure changes using ultrafast X-ray Absorption Near-Edge Spectroscopy

1,54 1,55 1,56 1,57 1,58 1,59 1,6 1,61

Te = 0.025 eVTe = 0.077 eVTe = 0.095 eVTe = 0.13 eVTe = 0.17 eVTe = 0.43 eVTe = 0.86 eVTe = 2.6 eV

0

0,5

1

1,5

2

2,5

Photon Energy (keV)

0

0,5

1

1,5

2

2,5

1,54 1,55 1,56 1,57 1,58 1,59 1,6 1,61

Te = 0.025 eVTe = 0.1 eVTe = 0.5 eVTe = 1 eV

Photon Energy (keV)

QMDHNC-NPA

0

0,5

1

1,5

2

1,54 1,55 1,56 1,57 1,58 1,59 1,6 1,61

"Cold" shot

Te = 0.27 ± 0.15 eV

Te = 1.4 ± 0.23 eV

Te = 2.74 ± 0.25 eV

X-ra

y Ab

sorp

tion

(nor

mal

ized

to

the

"pla

teau

" w

ithou

t XA

NES

str

uctu

res)

Photon energy (keV)

Experiment

200 m

10 m

400 fs, 30 J E

Summary

Several routes for beam optimization of laser-accelerated protons:

Use of small targets high-energy ions, high-efficiency and collimation BUT requires high contrast

Use of tight focushigh-energy ions, high-efficiency AND provides high contrast

Present developed applications : generation & probing of WDM (astrophysics, ICF) and radiography of fields