放射光X線による100ピコ秒時間分解研究の現状とフェムト秒時間分解実験への期待
KEK-PF
足立伸一• はじめに• 100ピコ秒X線研究の現状• サブピコ秒X線への期待光源のエネルギーとパルス幅
Pulse duration (sec)

10-6
micro
放射光

10-9
nano

赤外・可視・紫外
レーザー

10-12
pico

レーザー・プラズマ
X線
未開拓地レーザー
高次高調波

10-15
femto
10-18
atto

1

10102

Energy (eV)

103

104

Bond softening in Bismuth (SPPS)
Phonon-polariton wave
in LiTaO3 (ALS)Fritz et al. (2007) Science 315, 633.

Cavalleri at al. (2006) Nature 442 664.

Magnetic excitations inpermalloy squares (SLS)
Raabe et al. (2005) Phys. Rev. Lett. 94,217204Time Domain Science with SR
最近の報告例Ni(II) porphyrin (APS)
Chen et al. (2001) Science 292, 262.

C2H4I2 in methanol (ESRF)
Ihee, et al., (2005) Science 309, 1223.

Mutant myoglobin (ESRF)
Schotte et al.(2003) Science 300, 1944.

Femtosecond X-ray Pulses at 0.4 ÅGenerated by 90º Thomson Scattering: A Tool
for Probing the Structural Dynamics of Materials
Schoenlein et al. (1996) Science 274, 236.

Electron: 50 MeV, 1.3nC, 20 ps (FWHM)
Laser: 60mJ, 100fs, 10Hz, 800 nm
X-ray: 30 keV, ~300fs, 2 x 105 photons/pulse/15%

“Rapid advances in diode-pumped, solid state lasers andsuperconducting linac structures may provide
substantially higher x-ray brightness in future Thomson
sources by operating at very high repetition rates.”

1996
Electron: 50 MeV, 1.3nC, 20 ps (FWHM)
Laser: 60mJ, 100fs, 10Hz, 800 nm
X-ray: 30 keV, ~300fs,

2 x 105 photons/sec/15%b.w.

2007Electron: 60 MeV, 0.1nC, 0.1 ps
Laser: 10 mJ, 0.1 ps, 1 kHz, 800 nm
X-ray: 42 keV,1 X 109 photons/sec/10%b.w. !!

Laser-Compton X-ray source at ERL testfacility (60-150MeV)
EXray = 2γ2ELaser(1-cosθL)/(1+γ2θ2)
Flux = (NLNe/wh)(Leff/Lb)σcELaser = 1.55eV, Eelectron = 60 MeV (γ=117), θL = 90 degree のとき、軸上(θ=0)でEXray = 42.4 keVelectronlaserθL

レーザーパルス（1.55eV, 10mJ)のフォトン数： NL = 4 x 1016 photons
電子バンチ中の電子数（60MeV, 0.1nC)： Ne = 6 x 108 electrons
電子バンチの水平幅： w = 50 x 10-6 m
電子バンチの高さ：
h = 50 x 10-6 m
コンプトン散乱断面積： 1 x 10-28

1パルスあたり、
Flux = 1 x 106 phs/pulse/10%b.w.
1 kHzのとき、
Flux = 1 x 109 phs/sec/10%b.w.

既存放射光との比較• 同じエネルギーバンド幅、繰り返し周波数で比較すると（１０Wレーザー使用）、– AR-NW14A: 1012 phs/s/10%b.w. @ 1kHz
– Compact ERL: 109 phs/s/10%b.w. @ 1kHz

• エンハンスメント共振器が使用できると、（小林先生（産総研）の昨日の講演、1GHz、10µJ）
レーザー出力は10Wから10kWへ。単位時間当たりのX線フォトン数は1000倍。既存放射光と同等以上。
– 109 → 1012 phs/s/10%b.w.

Source

Pulse length(fs)Repetition
rate (Hz)Photon flux

Energy range

Compact ERL/LaserCompton Source(1nC, 10kHz)

~150

1000

1 x 109 phs/sec/10%b.w.
1 x 106 phs/sec/0.1%b.w.
1 x 106 phs/pulse/10%b.w.

10-100 keV

PF-AR NW14(80nC, 794kHz, 60mA)

100 x 103794 x 103

1 x 1015 phs/sec/10%b.w.
1 x 1012 phs/sec/0.1%b.w.
1 x 109 phs/pulse/10%b.w.
1 x 106 phs/pulse/0.1%b.w.

5-30 keVKEK-ERL
Low-rep. mode
(1nC, 10kHz, 0.01mA)

100 – 1000

10000

1 x 1011 phs/sec/10%b.w.
1 x 107 phs/sec/0.1%b.w.
1 x 107 phs/pulse/10%b.w.

5-30 keV

Laser Bunch Slicing(ALS upgrade)

200

40000

5 x 107 phs/sec/0.1%b.w.

0.2-10 keV

Laser-produced plasma
X-ray

~100

10

6 x 1010 phs/pulse/4πsr

8 keV (Cu-Kα)

Laser / high harmonicgeneration

100 - 0.1

10 - 10000~ 108 phs/sec/0.1%b.w.

10 eV-1 keV

Sub-Picosecond Pulse
Source (SLAC)80

102 x 107 phs/pulse/1.5%b.w.

8-10 keV

KEK PF-BT line

500

20

~ 107 phs/pulse/10%b.w.

0.2-10 keV

X-FEL （LCLS, SCSS,
European XFEL)

230

120

2 x 1012 phs/pulse/0.2%b.w.

1-10 keVX-ray beam characteristics fromsuperconducting-linac-based LaserCompton X-ray sources• High repetition frequency (< 1GHz)• Hard X-ray available (~ 10-100 keV)
• Short pulse duration (~ 100 fs)• Large beam divergence (~ 10 mrad)• Relatively high average photon flux (~ 1010
photons/sec/~10%b.w. @ 10 kHz)100ピコ秒X線研究の現状とサブピコ秒X線への期待
pulse laser

Nozawa et al.
J. Synchrotron Rad. (2007). 14, 313-319.

PF-AR NW14A
通年大強度単バンチ 時間分解実験に最適
ERATO腰原非平衡ダイナミクスプロジェクト

Bond softening in Bismuth (SPPS)
Fritz et al. (2007) Science 315, 633.

Photo-induced Phase Transition
Chollet et al. (2005) Science, 307, 86.

Motivations forfemtosecond X-ray

C2H4I2 in methanol (ESRF)
Ihee, et al., (2005) Science 309, 1223.

Mutant myoglobin (ESRF)
Schotte et al.(2003) Science 300, 1944.

Motivations for femtosecond X-rayex.1) coherent phonon

Ultrafast Bond Softening in Bismuth:
Mapping a Solid’s Interatomic
Potential with X-rays
Fritz et al. (2007) Science, 315, 633.

Laser Power: 0.7 (green), 1.2 (red), 1.7 (blue), and 2.3(gray) mJ/cm2

Shockwave-induced lattice
deformation at NW14A

レーザー誘起衝撃圧縮下のCdSのナノ秒分解白色X線回折KouheiIchiyanagi・CdS単結晶は約3万気圧でウルツ鉱型から岩塩型構造になることが知られている。
・時間分解分光衝撃実験によってナノ秒オーダーで変化し、寿命の短い中間相が存在することが示唆されている。

M. D. Kundson and Y. M. Gupta, et al. Phys. Rev. B. 59.
11704 (1999).

ナノ秒分解白色X線回折実験のセットアップ

レーザー入射前のラウエ回折パターン

X-ray
pulse
入射X線スペクトル

Laserpulse
実験条件

レーザー YAG 1064 nm, 850 mJ, 8 ns, 10 Hz
Spot size φ400 μm
X-ray 100 ps, white X-ray, 1 kHz
Spot size 250x250 μm

Motivations for femtosecond X-rayex.2) photo-induced phase transition

Gigantic Photoresponse in ¼-FilledBand Organic Salt (EDO-TTF)2PF6
Chollet et al. (2005) Science, 307, 86.

Toward time-resolved
electron density analysis @ NW14A

Matthieu
Chollet

MEM analysis
300K
700 me-/A3
沖本洋一先生「強相関電子材料における光誘起相転移の超高速ダイナミクス」

Motivations for femtosecond X-rayex.3) reaction dynamics in solution

Ultrafast X-ray Diffraction ofTransient MolecularStructures in Solution
Ihee et al. Science (2005) 309, 1223.

Reaction dynamics in solution@ NW14
Liquid jet nozzle

Multilayer chamber

Collaboration with
Hyotcherl Ihee Group(KAIST, Korea)

Solution scattering profiles

λ= 0.827 Ådetx = 51.8 mmq < 7 Å-1

UV spectroscopy revealed dumped oscillations
in femtosecond time domain
Caging and Geminate Recombination Following
Photolysis of Triiodide in Solution
Gershgoren et al., J. Phys. Chem. A 1998, 102, 9-16

田原太平先生「超高速反応する分子の核波束運動実時間観測と励起状態ポテンシャル曲線のトポロジー」

Motivations for femtosecond X-rayex.4) proteins

Watching a Protein as it Functions
with 150-ps Time-Resolved X-ray
Crystallography
Schotte et al. Science (2003) 300, 1944.

Myoglobin (Mb)
• Stores molecularoxygen in muscle• M.W. ~ 16,000• 1290 atoms• 153 amino acids• Contains 1 heme
• Reversibly binds O2,CO, NO etc

Fe(II) porphyrin (heme) in myoglobin
MbL + hν ⇄ Mb + L (L=O2, CO, NO, etc)
Photo-switchable
Structural distortion causeschanges in electronic structure
Fe(II) d6 LS

Fe(II) d6 HS

Experimental setup
X-ray: 0.827 Å (15 keV)
Laser: YAG SHG (532 nm)
15 kHz, 10 mW/mm2
Sample temperature: 40 K
Detector: marccd165
Data statistics:
Resolution: 50 – 1.1 Å
No. of observations: 138,198
No. of unique refs: 37,292
Rmerge: 3.3 %Completeness: 94.7 %Redundancy: 3.7
CCDsampleX-ray (0.827 Å)

Ayana Tomita
Laser (532 nm, 10 kHz, 10 mW/mm2)

Visible absorption spectra of Mb and MbCO
MbCO + hν ⇄ Mb + CO532 nm

Electron density of the heme
before and after photo-excitation
Cyan: MbCO
Magenta: Photo-excited

MbCO andMb
Mbw.o.
withligand
CO
Photo-excited
Photo-excited!
Fe(II) HSLS
overlappedSwitching protein structureby photo-excitation
Cyan: MbCO
Magenta: Photo-excitedSummary• X線を用いた時間分解測定法は、非平衡状態（短寿命種）の構造情報、電子密度分布を直接観測できることが最大の利点。
• 現在の100ピコ秒分解能では不十分であり、サブピコ秒分解能が必要な実験系が多く存在する。
• そのためには、コンパクトERLによるサブピコ秒X線光源が極めて有望。

Project members @ KEK NW14
Shunsuke Nozawa(ERATO)

Tokushi Sato
(TITECH DC)

Ryoko Tazaki(ERATO)

Ayana Tomita(TITECH DC)

Hirohiko Ichikawa(ERATO)

Sachiko Maki
(TITECH MC)

Laurent Guérin(ERATO)Jiro Itatani(Group Leader,LBNL)

Kouhei Ichiyanagi(KEK PD)

Masahiro Daimon(Research Manager)

Matthieu Chollet(JPSJ PD)

Shin-ya Koshihara(Project Director)

Collaborators
Beam line NW14

Time-resolved solution scattering••

KEK– Hiroshi Sawa
– Hiroshi Kawata– Takeharu Mori– Shigeru Yamamoto– Kimichika Tsuchiya– Tatsuro Shioya– and all Photon Factory
StaffsMyoglobin•

Yokohama City University– Sam-Yong Park(EDO-TTF)2PF6•

Kyoto University– Hideki Yamochi– Gunji Saito

Korea Advanced Institute ofScience and Technology– Hyotcherl Ihee
– Kyung Huan Kim– Jae Hyuk Lee

Other collaborations
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•
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Tokyo Institute of Technology
The University of Chicago
Univ. Rennes 1
State Univ. of New York at Buffalo
Univ. of Copenhagen
Laurence Berkley National Lab.
Oxford Univ.
Tohoku Univ.
Osaka City Univ.