Experimental results of X-ray generation via laser Compton … · 2010. 6. 24. · •Positron annihilation lifetime spectroscopy Ne w. 3 RRCAT, Indore, 11 March 2010 X-ray wave length

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RRCAT, Indore, 11 March 2010

Ryunosuke KurodaNational Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan

Experimental results of XExperimental results of X--ray generationray generationvia laser Compton scatteringvia laser Compton scattering

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FEL

Compact S-band linac

Laser Compton gamma-ray experiment(NRF, gamma-ray imaging)

Storage ring TERAS

Storage ring NIJI-IV

Positron Beam linePositron Beam line

Laser Compton X-ray source

Accelerator Facility at AISTAccelerator Facility at AIST(nearby KEK in Tsukuba)(nearby KEK in Tsukuba)

Introduction

Focus!Focus!

400 MeV linac(since 1978)

•Positron annihilation lifetime spectroscopy

New

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X-ray wave length

)cos1(2)2/1(

2

2220

φγθγλλ

−++

≅K

IcmeAK e 092

0 1085.0/ λ−×≈=

Laser Undulator Radiation

( )( ) 2

0

0

0

)cos(1cos1

cos1

cmE

EE

γφθθβ

φβ

+++−

+=

Scattered X-ray energy

φ

θ

Laser

Electron beam

γ m0c2

X-ray (λ (E))

(λ0 [µm] (E0[eV]), I [W/cm2] )High Power Laser

Scattered X-ray

High Energy Electron Beam

Interaction between high energy electron beam and high power laser

LCS XLCS X--ray sourceray source•Short pulse•Energy tunability•Quasi- monochromatic•Small source size•Good directivity •Good polarization•Compact system …etc

Principle of Laser Compton Scattering (LCS)

Many benefits!

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Application SpaceApplication SpaceLaser Compton Scattering (LCS) hard X-ray Source at AIST

Cs-Te

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YVO4ps-Osc

To modulator

1/4λPockels

cell

AOM

100pulse

CW mode-lock

RF amp. AWG

dump

OSC pulse picker

Pre Amp. & Pulse Modulator

FI

X 2 stage

Single pass G=10

Amplifiers & frequency converterFrom modulator

Flat pulse

AM pulse

SHG FHGYAG amp

1st order To amp.

25MHz,250MS/s14bit

YAG Pre. Amp.

79.3 MHz

KTP BBO

0.7W~0.8W

15mW

150mW 10mW

10Hz100 pulses

Diagram of compact UV laser system for rf gun(In order to generate single and multi-bunch electron beam)

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AOM1m

0.7m

AMP

Pre-AMP

PCConversion Crystal

Oscillator

UV laser statusAll solid-state and compactPulse energy: 10 µJ × 100 pulse/ macro pulsePulse width : 10ps(FWHM)Pulse number: 1 – 100 pulses

1m

We can arbitrary generate a single pulse and multi pulses (100 pulses).

Compact UV laser system for rf gun

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BNL-typeRF-gun

Evaporation Chamber at KEK

After evaporationMo plug

Compact Cs-Te cathode

load-lock system

Delivering unit

(in Collaborating with KEK and Waseda Univ.)

Energy：4 MeV (40MeV at linac out)Bunch charge：1 nCBunch length: 3 ps (rms) Bunch number: 1 – 100

(Bunch spacing: 12.6 ns )Repetition rate：10Hz (Max 50Hz)

Electron beam status at rf gun out

Cs-Te photocathode rf gun

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Q-switched Nd: YAG laser

10Hz

Q-switched Nd: YAG laser

50Hz

λ/2

PBS

Ti: SA

PC

PBS

AP

G

Stretcher

PBS

PBS

FR

G

G

OSC.Q-rayQ-ray10Hz

7W~9W Regen

Pre. AMP.

Main AMP.

Compressor

40mJ

300mJ

7W (700mJ)

200 ps

Pulse pick up @10 Hz

60 mJ

200 mJ

Laser StatusWavelength: 800 nmPulse energy: 100-140 mJPulse width: 100 fs(FWHM)

10Hz

4W

PD 79.3MHz → PLL circuit

SESAM(PZT)

OC 5W MillenniaOSC.

79.3 MHz

200 mW

50 fs

Vacuum pipe

1200gr/mm21200gr/mm2

12480gr/mm2

Collision Laser (CPA Ti:Sa laser) for single collision LCS

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fiber

Klystron

ps-laser

To rf gun laser

fs-laser

To CPA Ti:Sa laser system

Directional Coupler

Master Oscillator2856MHz

PD

2856MHz

To gun & Linacs

79.3 MHz

79.3 MHz

2856 MHzDrift compensator

Timingstabilizer

36th harmonics(2856MHz)

Timingstabilizer

Drift compensator

・Two lasers are synchronized to the master with 36th harmonics of their mode-lock frequencies.・Relative timing jitter between the master and the laser is < 10fs.

(F. Sakai, Proceedings of SPIE, 5194, 149-156 (2003)

(Drift <1ps)

This synchronization system has been accomplished in order to generate 150 fs LCS X-ray in FESTA project in collaborating with SHI.

Timing synchronization system (Low-jitter)

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0.2%Energy spread

40/30 µmBeam size (σx/σy)3 psBunch length (rms)1 nCBunch charge/bunch

20 ~ 42 MeVElectron EnergyTW TW Ti:SaTi:Sa Laser beam (CPA)Laser beam (CPA)

30 µmBeam size (σx/σy)100 fsPulse width (FWHM)

140 mJEnergy/pulse800 nmWave length

Electron beamElectron beam

3 ps

150 fs

Pulse width (rms)

~106 /s (max) @10Hz~20 keV90

~107 /s (max) @10Hz10 ~ 40 keV(tunable)165

Number of PhotonsMax photon energy

Collision angle (φ)

XX--ray beamray beamApplication to biological and medical research

in-line phase contrast imaging, K-edge imaging(because of quite small size of X-ray source about 30~40 µm)

Present beam status (single pulse collision – single pulse X-ray)

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1 Experimental results of in-line phase contrast imaging

2 Experimental results of K-edge imaging

I want to easily introduce applications to biological & medical uses

with our LCS X-ray source

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Sample 1 : lumbar vertebra of ratSample 2 : Hind limbs of Ovariectomized mouse (OVX*)

and Normal mouse *OVX mouse is female mouse whose ovary is extracted

and it forcibly make osteoporosis (bone disease).

X-ray energy : 30 keV

Detector : Blue Imaging Plate (IP)

Exposure Time: 30 min (18000pulse)

2m1m0~750mm

Be Window (30mmφ)SampleIPLaser Compton Scattering

X-ray Source

Experimental SetupIn Collaborating with Ibaraki Prefectural University of Health Sciences in Japan

H. Ikeura-Sekiguxhi, R. Kuroda et al., APL 92，131107 (2008)K. Yamada, R. Kuroda et al., NIMA (2009)(accepted)

InIn--line phase contrast imaging for biological applicationline phase contrast imaging for biological application

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Micro- focus X-ray tube(80kV)

Results of in-line phase contrast imaging①lumbar vertebra of rat ②Hind limbs of normal and OVX mouses

5mm

Normal

LCS X-ray source can realize more contrast enhancement than X-ray tube!

Comparison

Contrast enhancement

OVX

Absorption PhaseContrast

Distance between sample and detector40mm 750 mm

We can observe the bone erosion of OVX mousewhich is the initial symptom of osteoporosis !

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Samples: Sample1: Resolution chartSample2: Rabbit ears with iodinated contrast media (K-edge:33.17 keV)

Exposure time of 1 frame: 3ps (rms) @ single shot, 30 ps @10 shot

Detector: Real time camera (HARP) with X-ray II

2m

Be Window (30mmφ)

Specimen

Detector

Laser Compton X-ray Source

K. Yamada et al., ICFA Workshop "Compton Sources for X/γ Rays: Physics and Applications“, Italy, September 2008

In Collaborating with Prof. Mori Group at National Cardiovascular Center in Japanin order to research the new diagnosis for the initial symptom of the blood vessel disease

(such as diabetes)

K. Yamada, R. Kuroda et al., NIM A 608, pp. S7-S10 (2009)

K-edge imaging for angiography

using laser Compton X-ray source @AIST

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30 frame/sec

(X-ray is 10Hz)

1 frame: 3ps single shot X-ray

1 frame/sec

1 frame: 30 ps X-ray (10 shot)

1 frame/sec

1 frame: 30 ps X-ray (10 shot)

Real time imaging with picosecond (ps) X-ray pulse

Rabbit ear (iodine)Resolution chart Resolution chart

Single shot：250μm

10 shots ：125μmResolution Achieved spatial resolution of

single shot imaging is 480µm !(System optimization is not completed)

10mm

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Summary

・Present status of the hard X-ray source via LCS (single pulse X-ray)Max. X-ray energy : ~40keV (electron beam energy: 42MeV)Photon number : >107 photos/s @ 10HzQuasi-monochromatic, short pulse

・Biological and medical application have been started.Preliminary experiment of in-line phase contrast imaging and K-edge imaging was successfully performed using single-collisionLCS hard X-ray

Now, we are upgrading our system to increase X-ray yields up to 2 ×1010/s with Multi-collision LCS scheme. In near future, we will successfully upgrade our system for the biological and medical uses.

Laser Compton scattering hard X-ray source based on S-band linac

Thank you

for your attention !

Documents

Experimental results of X-ray generation via laser Compton … · 2010. 6. 24. · •Positron annihilation lifetime spectroscopy Ne w. 3 RRCAT, Indore, 11 March 2010 X-ray wave length