放射光セミナー 070425 s - Photon Factorypf · 2010-01-05 · Linear / circular polarization – For linear / circular dichroism Pulse light (sub-nsec - µsec) – For time

テラヘルツ放射光利用の現状とテラヘルツ放射光利用の現状と大強度大強度CSRCSRテラヘルツ光への期待テラヘルツ光への期待

木木村村真真一一分子分子科学研究所科学研究所UVSORUVSOR施設施設

OutlineOutlineIntroduction of UVSORIntroduction of UVSOR--IIIIIR + THz beamline BL6B at UVSORIR + THz beamline BL6B at UVSOR--IIII–– OpticsOptics–– PerformancePerformanceApplicationApplication–– THz spectroscopy of large samplesTHz spectroscopy of large samples–– THz spectroscopy under high pressuresTHz spectroscopy under high pressuresDevelopment of Coherent SR at UVSORDevelopment of Coherent SR at UVSOR--IIIICSRCSR--ERL?ERL?Conclusion and prospectsConclusion and prospects

UVSOR Facility, Institute for Molecular Science

Collaborators and acknowledgmentsCollaborators and acknowledgmentsExperimentsExperiments–– Spectroscopy at high pressuresSpectroscopy at high pressures

T. Mizuno @ SOKENDAI+UVSORT. Mizuno @ SOKENDAI+UVSOR–– CSRCSR

M. Katoh, A. Mochihashi, M. Shimada @ UVSORM. Katoh, A. Mochihashi, M. Shimada @ UVSORM. Hosaka, Y. Takashima @ Nagoya Univ.M. Hosaka, Y. Takashima @ Nagoya Univ.T. Takahashi @ Kyoto Univ.T. Takahashi @ Kyoto Univ.

SamplesSamples–– SmSSmS

N.K. Sato, K. Matsubayashi @ Nagoya Univ.N.K. Sato, K. Matsubayashi @ Nagoya Univ.–– SmBSmB66

S. Kunii @ Tohoku Univ.S. Kunii @ Tohoku Univ.

This work was performed at UVSOR and was partially supported by MEXT of Japan.


THz / Wavenumber / Photon energy?THz / Wavenumber / Photon energy?

1 THz = 33 cm1 THz = 33 cm--11 = 4 meV= 4 meV


10-3 10-2 10-1 100 101 102 103 104 105108

109

1010

1011

1012

1013

1014

"Infrared"UVSOR

SPring-8

Bril

lianc

e (p

h/s/

mra

d2 /mm

2 in 0

.1%

b.w

.) a

t 100

mA

b.c

.

Phoron energy (eV)Photon energy (eV)

WhatWhat’’s s IR&THzIR&THz synchrotron radiation?synchrotron radiation?

IR+THz is a tail of SRUVSOR Facility, Institute for Molecular Science

“THz”

Properties of IRProperties of IR--SRSR(compared to other light sources)(compared to other light sources)

High brilliance High brilliance –– For microspectroscopyFor microspectroscopyVery bVery broadbandroadband–– For probing electromagnetic dynamicsFor probing electromagnetic dynamicsLinear / circular polarizationLinear / circular polarization–– For linear / circular dichroismFor linear / circular dichroismPulse light (subPulse light (sub--nsecnsec -- µµsecsec))–– For time structure experimentsFor time structure experiments



Black body

Small SR-ring（UVSOR, 1985～）

Large SR-ring（SPring-8, 2000～）

Electron beam

Electron beam

High brilliance property of IRHigh brilliance property of IR--SRSR

-500

50 -500

50 -500

50 -500

50

25 : 1

Inte

nsi

ty

X (µm)

GlobarIR-SR

Y (µm)

Peak intensity of SR is about 102 times higher than that of globar source.

Focusing at the sample position of IR microspectroscopy station of BL43IR at SPring-8

IR-SR is sharper than BB light source.

IR-SR facilities in the worldJapan UVSOR 6B FIR, multipurpose, high pressure (solid state physics)

MIR, multipurpose, IRMCD (solid state physics)SPring-8 43IR MIR&FIR, microscopy under extreme conditions

surface science, multipurpose, pump-probeUSA NSLS U2A MIR, microscopy under high pressure (geology)

U2B MIR, microscopy for biologyU4IR FIR&MIR, surface scienceU10A MIR, multipurpose (solid state physics)U10B MIR, multipurpose, wide energy rangeU12IR FIR, pump-probe (solid state physics)

ALS 1.4.2 MIR, multipurpose, surface science1.4.3 MIR, microscopy (biology)

SRC 031 MIR, microscopyFrance super-ACO SIRLOIN, MIR, multipurposeUK SRS 13.3 FIR&MIR, microscopy, surface scienceSweden MAX I 073 FIR&MIR, high resolution (gas)Germany ANKA Edge radiation

BESSY II MIR, microscopy, CSRItaly DAΦNE SINBAD MIR, FIR

Elletra MIRTaiwan SRRC MIR, microscopySwitzerland SLS MIR&FIR microscopy

ESRF MIR, microscopyKorea PLS, China NSRL,,, under consideration

Red characters mean FIR is available.

Blue characters mean MIR is only available.




Reconstructed Reconstructed IR+IR+THTHzz beam linebeam line（（BL6BBL6B））at USORat USOR--II (since 2004)II (since 2004)

Acceptance angle of SRFrom 80(H) x 60(V) mrad2

To 215(H) x 80(V) mrad215(H) x 80(V) mrad2 2

UVSORUVSOR--II storage ringII storage ring

Bending duct

6-axes pulse motor stage for MM

1.44m

ee-- beam size: beam size: σσxx=0.2mm, =0.2mm, σσyy=0.03mm, =0.03mm, σσzz=15psec=15psec

-8 -6 -4 -2 0-4

-2

0

2

4

Ver

tical

bea

m s

ize

(mm

)

-8 -6 -4 -2 0 Horizontal beam size (mm)

-4

-2

0

2

4

σD =0.02049

Beam size at emission point

-2

-1

0

1

2

-2 -1 0 1 2

-2 -1 0 1 2

σD =0.3684

Horozontal beam size (mm)

-2

-1

0

1

2

σD=0.6307

Ver

tical

bea

m s

ize

(mm

)

Beam size at focal point (hν~0.5eV)

S. Kimura et al., NIMA 467-468, 437 (2001).cf. R. Lopez-Delgado and H. Szwarc, Opt. Commun. 19, 286 (1976). ← in an orbital plane

ρ ≈ 40m

-2600 -2500 -2400 -2300

10000

10500

11000

-1000

-500

0

500

1000

10000

10500

11000

Magic mirror with vertical focusing

Beam size at the first Beam size at the first focal pointfocal point of BL6Bof BL6B

hν = 0.1eV

-4 -2 0 2 4

Horizontal axis (mm)

1mm

-4

-2

0

2

4

Ver

tical

axi

s (m

m)

Beam size at the first focusing point @ BL6B

2mm

Calculation(hν=0.1eV)

Experiment(hν=0.1~1eV)

-4 -2 0 2 4

-4

-2

0

2

4

0.5000

2.125

3.750

5.375

7.000

Intensity (arb.units)

1.21mm

X axis (mm)

1.17mm

Y axis (m

m)

Here !


Photon flux and brilliancePhoton flux and brilliance

10-3 10-2 10-1 100 101108

109

1010

1011

1012

old-BL6A1I=300mA

Black body(T=1400K)

SPring-8 BL43IRI=100mA

Bril

lianc

e @

firs

t foc

usin

g po

int

(ph/

s/m

m2 /m

rad2 /0

.1%

b.w

.)

hν (eV)

BL6BI=500mA


10-3 10-2 10-1 100

1012

1013

1014

1015

SPring-8 BL43IR(I=100mA)

Black body source(for large sample)(1400K, φ5mm, 0.015sr)

BL6B(IR)(I=500mA)

old-BL6A1(I=300mA)

Pho

ton

flux

(ph/

s/0.

1% b

.w.)

hν (eV)

Black body source(for microscope)(1400K, φ1mm, 0.015sr)

Photon flux Brilliance(due to large acceptance angle) (performance of the magic mirror)

Si bolometer saturates in a multi-bunch operation !


End stations of End stations of BL6BBL6B at USORat USOR--IIII

Bending #6

BrukerIFS66v/S

JASCOFARIS-1

To BL6U

Magic mirror

THz microscope

Refection-absorption spectroscopy station

0 500 1000

Diamond /z-cut Quartz window

This chamber can be removed for the other experiments (IR-MCD, FIR-RAS and so on).



Physical properties Physical properties ofof SmBSmB66Electrical resistivity

[ J. W. Allen, B. Batlogg, and P. Wachter, Phys. Rev. B 20, 4807 (1979). ]

[ J.-N. Chazalviel et al.,

Phys. Rev. B 14, 4586 (1976). ]

XPS (I(Sm2+):I(Sm3+)=3:7)

Semiconductor with two gaps (EG ~ 5, 17meV)

Mixed valence


1 10

0.85

0.90

0.95

1.00

T=80K

Ref

lect

ivity

Photon energy (meV)

SmB6

T=5K

Hot carriers in SmB6

Impurity state Main gap

BL6B (UVSOR-II) In Lab.

(mercury lamp)

EF

DOS 17meV

Large spectral change is due to the thermally excited carriers across the small energy gap.

T=20K

[ S. K. et al., Phys. Rev. B 50, 1406 (1994). ]

Old data

Not clear?

Clear

THz spectroscopy under pressures

Microscope

Diamond anvil pressure cell

•Horizontal optical pass•Energy range

•Laboratory: 50 meV ～ 1.2 eV•UVSOR-II BL6B: 5 meV ～ 50 meV

• Pressure media：Apiezon grease N• Pressure is measured by a ruby

fluorecence method.

1.0 mm

0.5 mm

Pressure MediaRuby

Sample

Gasket

reflection

DAC

Microsope @ BL6B

Diamond anvil cellDiamond anvil cell

Spatial resolution of microscope in the THz region at BL6B

100µm


Spatial resolution of THz microscope at BL6B of UVSOR-II

200µm

Visible image 200µmUVSOR-II+ Ge/KBr+MCT(500-8000cm-1)

UVSOR-II+ Mylar6µ+Si bolo.(50-600cm-1)

∆r ~ 12 µm ∆r ~ 60 µmUVSOR Facility, Institute for Molecular Science

MIR FIR (THz)

USAF test target200µm

Physical properties of SmSNaCl-type crystal structure

• P < 0.6 ~ 0.8 GPa:•Black phase•Semiconductor

•EG~103 K ~ 86 meV•Ionic crystal with Sm2+

• P < 1.9 GPa•Golden phase•Strongly correlated semiconductor

•EG~100 K ~ 9 meV•Mixed valence of Sm2+ and Sm3+

• P > 1.9 GPa•Magnetic metal with Sm3+



Pressure dependence of Pressure dependence of RR((ωω)) in SmSin SmS[T. Mizuno et al., in preparation.]

EF

DO

S

E

FD

EG

0.0 0.5 1.010-4

10-3

10-2

10-1

100

Nef

f (/S

mS

)

Pressure (GPa)

run0 run1 run2

GoldenGoldenphasephase

Black phaseBlack phase

EG~1000K

EG~850K

Two phase coexistence?

50 1000.0

0.5

1.0

Photon energy (meV)

Ref

lect

ivity

1.45 GPa

0.85 GPa

0.65 GPa

0.45 GPa

0.20 GPa

1 atm

1

1

1

1

1

Exp. Calc.

Scientific program at UVSORScientific program at UVSOR--II BL6BII BL6B

Electrodynamics of solids @ Electrodynamics of solids @ multimulti--extreme conditionsextreme conditions–– Very low temperature (~0.4K)Very low temperature (~0.4K)–– High pressures (~20GPa)High pressures (~20GPa)–– High fields (~6T)High fields (~6T)

THzTHz microspectroscopymicrospectroscopyFIRFIR--RAS of adsorbed moleculesRAS of adsorbed moleculesTHz spectroscopy of THz spectroscopy of protainsprotainsTHz excitation with coherent SR.THz excitation with coherent SR.–– 101033~10~1044 higher intensity than the higher intensity than the

present IRSR.present IRSR.




CSRCSR from relativistic electron beamfrom relativistic electron beamWavelength (λ)

Electromagnetic wave

Bunch length » λ

Bunch length ≤ λ

→ incoherence

→ full coherence

++

＝＝

→ partial coherence


How can we make fine structures in How can we make fine structures in electron bunches?electron bunches?

Spontaneous electron bunch instability.Spontaneous electron bunch instability.–– Bursting mode.Bursting mode.

Modulation induced by extra electric fields.Modulation induced by extra electric fields.–– Bunch slicing Bunch slicing by shortby short--pulse laser.pulse laser.


UVSOR-BL6B IR Beamline(S. Kimura et al., AIP Conf. Proc. 705 (2003),

0.1 0.5 1 5 100.1

10

1000

100000.

1. ｴ 107

10-1

101

103

105

107

0.1 0.5 1 5 10Wave number (cm-1)

N・f(1

/λ)

Coherent Terahertz Pulses by Bunch Slicing

Incoherent SR

CSR from whole bunch

CSR from slicing

LaserLaserUndulatorUndulator

IRIR--BLBL


25cm-1

Coherent Terahertz Pulses by Bunch SlicingCoherent Terahertz Pulses by Bunch Slicing

Stable and periodic.


[ M. Katoh et al., Proc. EPAC06, 3377 (2006). ]

The width originates from the InSbhot electron detector response.


Laser width dependence of CSR spectrumLaser width dependence of CSR spectrum

The dip is made by laser.

Onset shifts to the lower wavenumber side with increasing pulse width.

This is the evidence of the CSR originates from the dip induced by laser.

10 200

Laser width = 160 fsec 320 fsec 530 fsec 710 fsec

CS

R In

tens

ity (a

rb. u

nits

)

Wavenumbers (cm-1)

OnsetOnset

0.1 0.5 1 5 100.1

10

1000

100000.

1. ｴ 107

10-1101103

105

107

0.1 0.5 1 5 10Wave number (cm-1)

Short Short pulsepulse

Long Long pulsepulse

[ M. Katoh et al., Proc. EPAC06, 3377 (2006). ]

Average power of CSRAverage power of CSR


Commercial THz source

UVSOR-II BL6B

SPring-8 BL43IR


CSRCSRの利用研究の利用研究 @ BESSY@ BESSY--IIIIサブテラヘルツの大強度を利用

[E. J. Singley et al., Phys. Rev. B 69, 092512 (2004).]



High power CW THz sources

[M. Tonouchi, nature photonics 1, 97 (2007).]

THz gap

High power CW THz sources

[M. Tonouchi, nature photonics 1, 97 (2007).]

0.1psP

ower

(W/c

m-1) i

n 10

0x10

0mra

d2

1ps

Application of intense THz CSR• Probe

– Imaging in a wide spatial region• Ex.) Full human body.

– Near-field microscopy• Phase separation of superconducting phase.

• Excitation– Nonlinear optics

• Photo-induced phase transition.– Chemical reaction

• Site-specific excitation.• Microwave effect.

An example of THz imaging(QCL, narrow band imaging)

An example of THz imaging(broad band, multicolor imaging)


This proposal was selected in BESAC 20 year BES Facilities Roadmap.

Project[ http://circe.lbl.gov/ ]

Conclusion and prConclusion and proospectspectssPresent use of THzPresent use of THz--SRSR–– Spectroscopy of solids under low temperature, Spectroscopy of solids under low temperature,

pressures and magnetic fields.pressures and magnetic fields.–– Broadband spectroscopy of solids.Broadband spectroscopy of solids.–– Microspectroscopy of solids, bioMicrospectroscopy of solids, bio--materials etc.materials etc.Future Future ---- Breaking the present concept.Breaking the present concept.–– Use of intense THzUse of intense THz--CSR.CSR.

Excitation light.Excitation light.–– Ex.) THz pump Ex.) THz pump -- probe experiment of impurities, etc.probe experiment of impurities, etc.

Advanced Probing.Advanced Probing.–– Multicolor wide spatial region imaging.Multicolor wide spatial region imaging.–– Investigation of the local electronic structure of solids by Investigation of the local electronic structure of solids by

THzTHz--SNOM.SNOM.UVSOR Facility, Institute for Molecular Science

Documents

放射光セミナー 070425 s - Photon Factorypf · 2010-01-05 · Linear / circular polarization – For linear / circular dichroism Pulse light (sub-nsec - µsec) – For time