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T. Kawamura1, H. Nishimura2, F. Koike3, T. Johzaki2, Th. Schlegel4,5,D. H. H. Hoffmann4,5, K. Horioka1
1Tokyo Institute of Technology, Yokohama, Kanagawa, Japan2Institute of Laser Engineering, Osaka University, Osaka, Japan3Physics Laboratory, School of Medicine, Kitasato University, Kanagawa, Japan4Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany5Gesellschaft für Schwerionenforschung, Darmstadt, Germany
U.S.-Japan Workshop onHeavy Ion Fusion and High Energy Density Physics28(Wed.)-30(Fri.) September, 2005,Utsunomiya University.
Numerical study of Kaaaa radiation from high density plasma byenergetic charged particles
Motivation & Outline
In the fast ignition research,fast electrons play an essential role in the viewpoint of energy transport.
With the use of Kaaaa radiation,
1.) Distribution of Kaaaa spectra gives bulk-plasma temperature information. Fast electrons contribute to ionize the K-shell. Cold bulk electrons mainly ionize the outer-shell bound electrons.
2.) Potentiality of sub pico-second x-ray source.
Outline
Motivation
1.) Present status of development of the corresponding kinetics codefor fast ignition research with CHCl plastic targets.
2.) Consideration of Kaaaa radiation by energetic heavy ions.
Related papers:T. Kawamura, et al., PRE, Vol.66, 016402,(2002)H. Nishimura, et al., JQSRT, Vol.81, pp. 327,(2003), Erratum:Vol87,pp.211,(2004)T. Kawamura, et al., JQSRT, Vol.81, pp. 237,(2003)IFSA2003 proceedings, pp.1022,(2003)
Tokyo Institute of Technology
1s-vacant ionsGround & Singly excited ions
Cl8+ : 1s22s22p5, 1s22s22p4nllll
Population kinetics modeling on Kαααα emission.1s-vacant ions are created via inner-shell ionizationby fast electrons.
Radiative & Auger decays
Population : PGnd & PExc P1s-vacant>>
Cl9+ : 1s22s22p4, 1s22s22p3nllll
Cl10+ : 1s22s22p3, 1s22s22p2nllll
••
Recombination & Ionization
••
Cl9+ : 1s2s22p5, 1s2s22p4nllll
Cl10+ : 1s2s22p4, 1s2s22p3nllll
Cl11+ : 1s2s22p3, 1s2s22p2nllll
••
••
Recombination & Ionization
Recombination & Ionization Radiative & Auger decays
Radiative & Auger decaysRecombination & Ionization
Inner shellionization
DielectronicCapture
Tokyo Institute of Technology
1011
1012
1013
1014
1015
2600 2650 2700 2750 2800Emission Energy(eV)
Rad
iati
ve D
ecay
Rat
e(1/
sec)
HeααααCl14+
Cl12+
Cl13+Cl11+
Cl10+Cl9+Cl1+
Cl8+-
Transition energies and radiative decay rates for Kαααα lines ofpartially ionized chlorine atoms are calculatedwith GRASP-code.
Cl+ : 1s22s22p53s23p5-1s2s22p63s23p5
Cl2+ : 1s22s22p53s23p4-1s2s22p63s23p4
Cl8+ : 1s22s22p5-1s2s22p6
Cl9+ : 1s22s22p4-1s2s22p5
Cl10+ : 1s22s22p3-1s2s22p4
Cl11+ : 1s22s22p2-1s2s22p3
Cl12+ : 1s22s22p -1s2s22p2
Cl13+ : 1s22s2 -1s2s22pCl14+ : 1s22s -1s2s 2pCl15+ : 1s2 -1s 2p (Heαααα)
∆∆∆∆E from primary Kαααα (Cl+)is large!!
Information of Plasma Temperature can be obtained.
Tokyo Institute of Technology
Number of transitions of 1s2s22pNnllll(n=3-4,N=1-5)are 15100.
Kαααα transition rates are 1013-1014 1/sec.
Kαααα-lines of excited states completely overlap withthose of the ground state of the next charge state.
1014
2600 2650 2700 2750 2800
1013
1013
1013
1013
1013
1013
1014
1014
1014
1014
1014
Cl10+ : 1s2s22p4
Cl10+ : 1s2s22p33
Cl11+ : 1s2s22p3
Cl11+ : 1s2s22p23
llll
llll
Cl10+ : 1s2s22p34llll
Cl11+ : 1s2s22p24llll
Rad
iaiv
e D
ecay
Rat
e(1/
sec)
Emission Energy(eV)
Tokyo Institute of Technology
1013
1014
1015
1016
0
0.05
0.1
Ave
rag
e A
ug
er R
ate
(1/s
ec)
Flu
orescen
ce Yield
Charge State
KLL AugerKLM Auger
8 9 10 11 121012
1013
1014
1015
1016
0
0.2
0.4
0.6
0.8
0 5 10 15F
luo
rescence Y
ield
Charge State
Ave
rag
e A
ug
er R
ate
(1/s
ec) KLL Auger
KLM AugerKMM Auger
KLL-Auger is the most dominant process of all the Augertransitions for 1s-vacant ions.
Each Auger transition is calculated by "Auger code".S.Fritzsche, B.Fricke, Phys. Scr.T41,45(1992)
Average Auger rate of partially ionized Cl is about 1014-1015 1/sec.
Excited states of 1s-vacant ions:1s2s22pN3llll(N=1-5, llll=s,p,d)
Ground states of 1s-vacant Ions
Tokyo Institute of Technology
0
4
8
12
16
101 102 103
C:H:Cl=Fast Electron:
Ion Density:A
vera
ge
Ion
izai
ton
Sta
te
Bulk Electron Temperature(eV)
Fraction ofFast Electrons5%:1%:0%:
9X1022c m-3
1:1:1100keV
Average charge state is mostly governed by bulk electrontemperature.
Total Ion Density : 9X1022cm-3
Bulk e- : Fast e- = 99:1(C:H:Cl = 1:1:1)
6.0
6.1
6.2
6.3
103 104 105
8.1
8.2
8.3
8.4
103 104 105
7.0
7.1
7.2
7.3
103 104 105
Bulk Electron:
C:H:Cl=Bulk:Fast=
Ni=9X1022c m-3
Ni=9X1022c m-3
Fast Electron Temperature (eV)
Ave
rag
e Io
niz
atio
n S
tate
Ni=9X1022c m-3
75eV99:1
1:1:1
Bulk Electron:
C:H:Cl=Bulk:Fast=
100eV99:1
1:1:1
Bulk Electron:
C:H:Cl=Bulk:Fast=
50eV99:1
1:1:1
No Opacity effect
Tokyo Institute of Technology
Inte
nsity
( x10
7 erg/
sec/
cc/H
z )
0
1.0
1.5 Cl9+
(Ground)
Cl8+
(n=3)Cl
8+(n=4)
Cl10+
(Ground)
Cl9+
(n=3)Cl
9+(n=4)
Cl11+
(Ground)Cl
10+(n=4)
Cl10+
(n=3)
Cl12+
(Ground)
Cl11+
(n=3)Cl
11+(n=4)
Bulk Temperature : 100 eVPlasma thickness : 0.1 µµµµm
0.5
Cl13+
(Ground)
Cl12+
(n=3)Cl
12+(n=4)
2.0
TotalGround StateExcited States(n=3)Excited States(n=4)
Inte
nsi
ty(
x107 er
g/s
ec/c
c/H
z )
0
1.0
1.5 Cl9+
(Ground)
Cl8+
(n=3)Cl
8+(n=4)
Cl10+
(Ground)
Cl9+
(n=3)Cl
9+(n=4)
Cl11+
(Ground)Cl
10+(n=4)
Cl10+
(n=3)Cl
12+(Ground)
Cl11+
(n=3)Cl
11+(n=4)
Bulk Temperature : 75 eVPlasma thickness : 0.1 µµµµm
0.5
2.0
Satellites of excited states Cl(n-1)+ overlap withparent lines of ground states Cln+.
Fast Electron Temperature : 40 keV, Bulk e-: Fast e- = 99:1Ion Density Ni=9x1022cm-3 (C2H3Cl)
2640 2660 2680 2700 2720 2740 2760
Inte
nsi
ty(
x107 er
g/s
ec/c
c/H
z )
1.0
1.5
Emission Energy(eV)
Cl9+
(Ground)
Cl8+
(n=3)Cl
8+(n=4)
Cl10+
(Ground)
Cl9+
(n=3)Cl
9+(n=4)
Cl11+
(Ground)Cl
10+(n=4)
Cl10+
(n=3)
Cl12+
(Ground)
Cl11+
(n=3)Cl
11+(n=4)
Bulk Temperature : 125 eVPlasma thickness : 0.1 µµµµm
0.5
Cl13+
(Ground)
Cl12+
(n=3)Cl
12+(n=4)
2.0
Tokyo Institute of Technology
ILE OSAKA
Experimental setup on T6
T6 laser:@ 800 nm, ####100 mJ (on T)132 fs, P-pol.S= 15x21 µµµµm @ 70%contrast >10 -6
IL=2x1017 W/cm2 (Th=50 keV)
2D curved crystal spectrograph1:
Quartz [10.-1], 2d=6.6864 A
εεεε=2.44-2.85 keV, M= 1/8
1D curved crystal spectrograph2:PET[002], 2d=8.742 Aεεεε=1.48-1.73 keV, M=1
x-ray CCD
45 deg
d (µµµµm)
A B 200µµµµm
A d (µµµµm) B
target 1 CH 0~2 CHCltarget 2 Mg 0~2.2 Al
x-ray
9 µµµµm
(a)
(b)
spot-size
H.Nishimura, et al., JQSRT, Vol.81, pp.327, (2003)Erratum : Vol.87, pp.211, (2004)
photon energy (eV)
2600 2700 28002650 2750 2850
PVC-bare
PVC+ Pa 0.12 um
inte
nsity
(a.u
.)
ClK
αααα Cl
9+
Cl
(N-li
ke)
10+
Cl
(C-li
ke)
11+
Cl
(B-li
ke)
Cl
(Be-
like)
Cl
(Li-l
ike)
12+
13+
14+
Cl
(He
αααα )15
+
ClK
ββββ
experimental result 1
ILE OSAKA
The Kαααα lines from partially ionized plasma decease drastically withincrease in thickness of over-coatin g, inferrin g energy localization.
H.Nishimura, et al., JQSRT, Vol.81, pp.327, (2003)Erratum : Vol.87, pp.211, (2004)
Ion density(C2H3Cl) : Solid densityFast electron temperature : 50 keVIncident laser energy absorption : 15%
Assumptions:
Bulk electron temperature : 140 eVLife-time of fast electron : several ps
Result:
Neglecting advection term in the F-P equation.
Time evolution of bulk electron temperature and fractional number of fastelectrons are obtained from Fokker-Planck code.- Simulation was done in the region near target surface. -
Local deposition near target surface.Heat transport in the axial direction is inhibited.
10- 3
10- 2
10- 1
100
Bu
lk E
lect
ron
Tem
per
atu
re (
eV)
Time (ps)1.0 2.0
50
150
100
0 3.0 4.0 5.0 6.0 7.0
laser pulse
Tokyo Institute of Technology
Time dependent properties of Kαααα radiation combined with Fokker-Planckcode are obtained.- Simulation was done in the region near target surface. -
0 0.5 1 1.5 2 2.5 3
Inte
gra
ted
Kαααα
Inte
nsi
ty
Time (ps)
(x1
017 e
rg/s
ec/c
m2)
2.0
1.5
1.0
0.5
laser pulse
Cl9 +
Cl1 0 +
Cl1 1 +
Cl1 2 +
Cl1 3 +
Cl8 +
0 1 2 3 4 5Time (ps)
0.2
0.15
0.1
0.05
laser pulse
Cl1 3 +
Cl1 4 +
Cl1 5 +
(Heαααα)
X 10
Tokyo Institute of Technology
Comparison between simulation and experiment is madein the framework of intensity ratio for time-integrated data.
2.) Intensities of excited states Cln+ are grouped together with that of ground state Cl(n+1)+.
1.) Intensities of Cl+ - Cl8+ are grouped together as cold Kαααα emissions.
Cold Kαααα emission(Cl+ - Cl8+) Hot Kαααα emission
(Cl9+ - Cl15+)
Because of unresolved properties;
Hot Kαααα emissions show good agreement betweensimulation and experiment results.
Tokyo Institute of Technology
Consideration of Kα-radiation by ion beams for plasmadiagnosis. With spatial resolved observation of Kα-radiation,plasma heating process can be understood clearer than thetraditional way of “TOF”.
Tokyo Institute of Technology
~100µm
~1cmIon beam
hν hν hν hν hν
High Z plasma
Kα from low charge state Kα from high charge state
Spatial resolved diagnosis of heating process is possible.
For chlorine plasmas, ion energy of more than few tens MeVis necessary to occur the K-shell ionization.
Tokyo Institute of Technology
10-22
10-21
10-20
10-19
10-18
10-17
103
104
105
106
107
108
109
Cro
ss S
ecti
on
of
K-s
hell Io
niz
ati
on
(cm
2)
Energy(eV)
e- --> Cl
He2+
--> Cl
Ne10+
--> Cl
Ar18+
--> ClIon impact K-shell ionization:ADNDT, Vol.20, pp.503,(1977)
Electron impact ionization:J. Phys. B: Atom. Molec. Phys.,Vol.11, pp.541,(1978),and related papers.
In the calculation, ion energies are set so that the maximumcross sections can be obtained with the energy-spread of0.1 %, 1%, and 10%.
Tokyo Institute of Technology
10-21
10-20
10-19
10-18
10-17
106
107
108
109
K-s
hell Io
niz
ati
on
Cro
ss S
ecti
on
(cm
2)
Energy(eV)
25MeV 150MeV
400MeV
He2+
--> Cl
Ne10+
--> Cl
Ar18+
--> Cl
0 50 100 150 200
Electron Temperature(eV)
Cl6+
Cl5+
Cl4+
K!
em
iss
ion
(W
/cc
)
108
106
104
102
For chlorine plasmas, temperature diagnosis by Kα-radiationwith ion beams is suitable for electron temperature Te < 100 eV .
Tokyo Institute of Technology
Kα due to Dielectronic CaptureKα due to the K-shell Ionization by He2+ Impact
He2+ current : 1 kA/cm2
Enegry : 25 MeV (±0.1%)
0 50 100 150 200
K!
em
issio
n (
W/c
c)
Electron Temperature(eV)
Cl7+
Cl8+
Cl9+
Cl10+
1014
1012
1010
108
106
104
For chlorine plasmas, temperature diagnosis by Kα-radiationwith ion beams is suitable for electron temperature Te < 100 eV .
Tokyo Institute of Technology
Kα due to Dielectronic CaptureKα due to the K-shell Ionization by He2+ Impact
He2+ current : 1 kA/cm2
Enegry : 25 MeV (±0.1%)
40 50 60 70 80 90 100
Electron Temperature (eV)
K! dominated byInnershell Ionization
Cl9+
Cl10+
Cl11+
Cl9+
Cl10+
Cl11+
Laser-producedfree electrons
(50 keV,Fraction:1%)
1016
1014
1012
1010
108
106
(1kA/cm2
,1GeV:"E=10%)
Kr ions
(1kA/cm2
,1GeV:!E=10%)
40 50 60 70 80 90 100
Electron Temparture (eV)
K"
em
iss
ion
(W
/cc
)
K" dominated byInnershell Ionization
Cl3+
Cl2+
Cl+
Cl3+
Cl2+
Cl+
Laser-producedfree electrons
(50 keV,Fraction:1%)
Kr ions
1014
1012
1010
108
106
104
102
100
Emission density of Kα-radiations is very small in comparisonwith that by fast electrons generated by sub-ps laser pulses.
Tokyo Institute of Technology
Kα-radiation by ion beams is about 10-8 of that by LPP-scheme.
To get the same order of Kα-radiation by LPP-scheme,the difference of Kα yield must be covered by a large plasma.
Tokyo Institute of Technology
Kα-radiation by energetic heavy ions scheme:
1.) Ionization cross-section: 10~100 times larger than energetic electrons’.
2.) Ion beam density : ~1012 cm-3 at 1 kA/cm2 with He2+ beams. (cf.) Energetic electrons by laser-produced plasma scheme: ~ 1021 cm-3
Resultant plasma volume to get Kα-radiation by Ion beams:1.) Ion beam cross section : ~1cm2
2.) Ion Stopping range : ~100 µmon the assumption that plasma is heated up uniformly.
(cf.) With LPP-scheme :1.) e- beam cross section ~ laser spot size : ~ < 100 µm2
2.) heated depth ( in the T6-experiments ) : ~ < 0.1 µm
--> 10-2 cm3
--> 10-11 cm3
There may be potentiality to get Kα-radiation by ion beams.
Summary & Plans
Population kinetics and spectral synthesis codes of Kaaaa-emission ofpartially ionized Cl atoms has been developed.
Plans
Summary
1.) Code development for fast ignition:--> Code extension to cover polarized x-ray for the diagnosis of velocity distribution function ( in progress now ).
--> Comparing with experimental results, a plasma temperature of 100~150 eV on the target surface is deduced, and showing the potentiality for the generation of sub-ps x-ray.
Tokyo Institute of Technology
1.) Present status of development of the corresponding kinetics codefor fast ignition research with CHCl plastic targets.
2.) Consideration of Kaaaa radiation by energetic heavy ions.
Kaaaa radiation by high intense, energetic ( ~MeV, or GeV ) heavy ionbeams may be useful for the diagnosis of heated plasma.
2.) Consideration of Kaaaa radiation by intense heavy ion beams--> To proceed it further for purpose of plasma diagnostics.