relativistic laser plasma research performed with...
TRANSCRIPT
Relativistic Laser Plasma Research performed with PW Lasers
2014.4.21. APLS
Chang Hee Nam1,2
1Center for Relativistic Laser Science (CoReLS), Institute for Basic Science (IBS), Korea; 2Dept of Physics and Photon Science,
Gwangju Institute of Science &Technology, Gwangju, Korea
Target
Relativistic Laser Science Laser-Matter Interactions and Related Phenomena
Explored at Relativistic Laser Intensities
Laser Pulse (>1018 W/cm2)
Plasma formation
Ultrahigh current density (> 108 A/cm2)
Relativistic electrons High-energy Protons
Neutrons
Positrons
Nuclear reaction
X-rays γ-rays THz
Electro-static field
Coherent X-rays
Ultrahigh magnetic field (> 1010 Gauss)
Research Plan Exploration of Relativistic Laser-Matter Interactions using
Super-intense Laser Pulses
Extreme Laser Field
Atto/Zeptosecond Science
Relativistic Laser-Matter Interaction
Applications: X-ray, electron, proton
Relativistic Laser-Plasma
Theory
Control of Relativistic Interaction Processes
Overview
1. Femtosecond PW laser system 2. Relativistic Laser Science A. Laser electron acceleration B. High energy proton generation C. Relativistic harmonic generation
• PW Ti:Sapphire Laser (1) Beam line I: 30 fs, 1.0 PW @ 0.1 Hz (2) Beam line II: 30 fs, 1.5 PW @ 0.1 Hz • 100-TW Laser: ∆t = 30 fs, E = 3 J @ 10 Hz
IBS Center for Relativistic Laser Science
Femtosecond oscillator
Pulse stretcher
Pulse compressor
Preamplifier Power amplifier
Ultrashort high power laser output
고출력 펨토초 레이저 기술
Chirped-Pulse Amplification (CPA) Technique
1. Femtosecond PW laser system 2. Relativistic Laser Science A. Laser electron acceleration B. High energy proton generation C. Relativistic harmonic generation
Atomic field strength: 92 5.1 10 V/cm;B
B
eEr
= ≈ ×2
16 23.5 10 W/cm8
BB
cEIπ
= ≈ ×
Relativistic Laser Intensities
Intensity for relativistic electron: (Relativistic regime) ( )
182 2
Re 02
1.4 10 W/cmm
I aµ
λ×
≈
Intensity for relativistic proton: (Ultra-relativistic regime) ( )
242
2
4.5 10 W/cmRp
m
Iµ
λ×
≈
0 00 2
0
speed of nonrelativistically oscillating electronspeed of light
NR
e e
eE eA vam c m c cω
= = = =
0When 1, 0.75 .a v c= = 0For 1, relativistic.a >
0For 1800, ultra-relativistic.p
e
Ma
m= =
Laser Wakefield Electron Acceleration
Electrons pushed by ponderomotive force (radiation pressure) of an intense laser pulse Restoring force to the original position Electron plasma wave created Injected electron bunch accelerated by
the plasma wave
Plasma wave by laser pulse ~ Waves by ship in sea
Acceleration by plasma wave ~ Surfing the wave in sea
Huge acceleration field > 100 GV/m
Electron current Gas Jet
Beam profiler
Wavefront sensor
ICT
Lanex Lanex
Dipole magnet
ICCD CCD
Focusing Mirror (f=4m)
Holed mirror
PW laser pusle (E=25~30 J, t=30 fs)
0.5 GeV 1 GeV 2 GeV 3 GeV
Electron energy Electron profile
0 5 -5 X (mrad)
0
5
-5
Y (
mra
d)
0.5 1.0 1.50
50
100
ICT
signa
l (m
V)
Time (µsec)
Double-stage Gas jet
4 mm
10 mm
Experimental Setup for Laser Electron Acceleration
Laser spot wavefront control
FWHM~25 μm
High-energy electron beam (>400 MeV) injected to the second gas jet
Investigation on multi-jet configuration with high energy electron injection
Charge of electron beam (4+10 mm): ~ 80 pC (> 0.5 GeV), ~10 pC (> 2 GeV)
Double-stage Gas jet
de = 2.1x1018 cm-3 (4 mm) ;de = 0.7x1018 cm-3 (10 mm) Electron energy spectrum
0
200
100
dN/d
E (p
C/G
eV)
Energy (GeV) 0.4 0.5 1.0 2 3 5
Multi-GeV e-Beam Generation with Dual Gas Jets
HT Kim et al., PRL (2013)
5.0
3.0
2.0
1.5
1.0
0.7
Electron energy spectrum (GeV)
LANEX 2
LANEX 3
Electron beam profile
LANEX 1
CCD
Al foil LANEX 1
LANEX 2 LANEX 3 Dipole magnet
ICCD ICCD
Gas cell
Concave mirror (f=6m)
PW laser pulse (E=26 J, τ0 =28 fs)
CCD
Electron acceleration using a single gas cell
Electrons over 2 GeV from a 10-mm gas cell Gas cell length = 10 mm Positively chirped 61 fs Intensity = 2x1019 W/cm2 (a0=3.1)
Top view (Thomson scattering)
Electron energy > 2 GeV
0
500
1000
1500
2000
dN/d
E (a
rb. u
nits
)
4.0 3.0 2.0 1.5 1.0 0.7
Electron energy (GeV)
Electron energy spectrum
Smooth propagation over the whole medium length of 10 mm
Laser Proton/Ion Acceleration Acceleration mechanism laser Target
thickness Characteristics Energy
scaling TNSA
(Target normal sheath acceleration)
I>1018 W/cm2
Linear pol. ~μm Broad spectrum, Thermal electrons
RPA (Radiation pressure
acceleration)
I>1020 W/cm2
Linear pol. Circular pol.
~nm
Quasi-monoenergetic,
collective electrons
Laser, not penetrating the target, heats electrons, which drag protons after penetrating the target.
μm-thick
Laser pulse pushes electrons as a whole, which drag protons.
nm-thick
2
PW Target chamber for proton experiment
OAP f = 80cm; 60cm
Target surface monitor
Target
Focal spot monitor
CR39
To Thomson Parabola
Target: polymer, DLC, Al Thickness: μm to 10 nm Intensity range w/ PM: 5x1019 W/cm2 – 7x1020 W/cm2 Pol.: s-pol or circular pol. on target Incident angle: 7 - 9 deg. to normal
PW Plasma mirror: contrast enhancement
Plasma formation on double plasma mirrors
Temporal profiles measured with a third-order cross correlator. Contrast 10-8 (w/o PM) -> 10-12 (w/ PM) Contrast enhancement: 104
Proton and C6+ measured with Thomson parabola
Target: 10-nm-thick polymer Laser intensity: 3.3 × 1020 W/cm2.
Proton energy: 45 MeV
IJ. Kim et al., PRL 111 (2013)
RPA with CP laser pulses: Experiment No oscillating term in radiation pressureNo heating J B×
Circular pol., 30fs, 6.1x1020 W/cm2, 15 nm polymer
Proton and C6+ spectra measured with Thomson parabola
Generation of 80 MeV protons!
Scaling of maximum proton energy to laser intensity
2 3 4 5 6 70
102030405060708090
Laser Intensity (x1020W/cm2)Max
imum
pro
ton
ener
gy (M
eV)
CP, 15 nm LP, 20 nm
CP: Quadratic scaling LP: Linear scaling
Outperformance of the CP case over the LP
Clear difference between LP and CP cases confirms the favorable role of CP laser pulses in RPA
Relativistic Electrons
High Energy Protons
X-rays, γ-rays
Coherent Atto/Zepto X-rays
Research Overview Journey into the deeper space-tim
e
Proteomics
Atto/Zepto science
Laser nuclear physics
Lab astrophysics
Synthesized Super-intense
Laser Pulse
Target
Fundamental LMI
Harnessing laser science at relativistic conditions “Matter under extreme environments”
“New horizon in time & space” “Discovery of novel physical processes”
Exploration of Relativistic Laser-Matter Interactions using Super-intense Laser Pulses
Contributors and Collaborators CoReLS/IBS; APRI/GIST Tae Moon Jeong, Jae Hee Sung, Seong Ku Lee, Hwang Woon Lee
S. Ter Avetisyan, I Jong Kim, Il Woo Choi, Himanshu Singhal K. Nakajima, Hyung Taek Kim Ki Hong Pae, Chul Min Kim Kyung Taec Kim, Hyuk Yun, Kyoung Hwan Lee, Dong Hyuk Ko Chang-Lyoul Lee
LOA (Laboratoire d’Optique Appliquée) V. Malka, F. Sylla, B. Vauzour, A. Flacco ELI-Beamlines; HiLASE; Czech Tech. Univ. T. Mocek, D. Margarone, O. Klimo, J. Limpouch, G. Korn
ILE/Osaka Univ. M. Murakami, N. Sarukura, K. Yamanoi, T. Shimizu
KAERI Y. Rhee