UVSOR Users Meeting                 Place: Okazaki Conference Center
November 15, 2007
13:00 - 14:10
Opening Remarks

S. Hino (Ehime Univ.)

Preface

N. Kosugi (UVSOR)

Present Status of UVSOR-II Accelerators

M. Katoh (UVSOR)

High-Resolution VUV ARPES Beamline BL7U

S. Kimura (UVSOR)

14:20 - 15:20
A Project for Constructing a New Undulator Beamline BL6U

E. Shigemasa (UVSOR)

Evaluation of Higher Diffracted Light Contaminations in BL5B

F. Suzuki (Univ. Fukui)

Present Status of Application Experiments of the UVSOR-II FEL

M. Hosaka (Nagoya Univ.)

15:30 - 16:30
Intense THz Coherent Synchrotron Radiation at UVSOR-II
Measurement of Photoabsorption Cross Sections of Fullerenes and Study on
Their Photodissociation Dynamics at BL2B
How the Encapsulated Atoms Affect the Electronic Structure of theFullerene Cages?

M. Shimada (UVSOR)
H. Katayanagi (IMS)
S. Hino (Ehime Univ.)

16:30 - 18:20 Poster Session
18:30 Banquet
November 16, 2007
9:00 - 10:00
Optical Reflectance, Photoluminescence, and Photoluminescence Excitation
Spectra of AlN

K. Fukui (Univ. Fukui)

Exciton Decay Processes in AlGaN Alloys

T. Sakai (Univ. Fukui)

Impurity Band Structure of Boron Doped Diamond

T. Inushima (Tokai Univ.)

10:10 - 11:30
Development of Radiation Watching by Nuclear Emulsion

Y. Taira (Nagoya Univ.)

Optical Response of Heavy Electron Meterials by Infrared Spectroscopy

T. Nanba (Kobe Univ.)

Chemical Evolution Study Using Synchrotron Radiation - Chirality
Emergence in Amino-Acid-Films by Circularly Polarized FEL VUVSX Spectroscopy of Amino Acid Films

J. Takahashi (NTT
Microsystem Integration
Laboratories)
K. Nakagawa (Kobe Univ.)

11:40 - 12:40
Photoemission Study of Surface-Chemical-Controlled Surface-Passivated Si
Nanoparticle

A. Tanaka (Kobe Univ.)

Electronic Structure of Crown Ether Ultrathin Films

K. Okudaira (Chiba Univ.)

Present Status of Angle-Resolved Photoemission End Stations at UVSOR-II

T. Ito (UVSOR)

165

Poster Session
P1

Characterization of Catalytically Active Mo Species for Methane Dehydroaromatization by Means of

H. Aritani (Saitama Inst. Tech., Osaka

Mo L-Edge XANES

Prefectute Univ.) et al.
Y. Danhara (Osaka Electro-Communication

P2

Luminescence and Excitation Spectra of Tl+ Centers-Doped Phosphors P3

Carrier concentration dependence of thermoelectric properties in layered cobalt oxides NaCoO2

S. Kuno(Nagoya University) et al.

P4Electronic structure and phase stability of Pd-based bulk metallic glasses

D. Fukamakia (Nagoya Univ.) et al.

P5

Univ.) et al.

Investigation into the origin of unusual behaviors in thermoelectric power of La 2-xSrxCuO4 by meansof angle-resolved photoemission spectroscopy

H. Komoto (Nagoya University) et al.

P6

Photolysis of Isovaline by UV ray and various irradiation

T.Ogawa (Yokohama National Univ.) et al.

P7

Local structure analysis of trace elements in bioceramic materials

Y. Kawashima (Waseda Univ.) et al.

P8

XANES analysis of local environment of Ga ions in SrTiO3:(Pr,Ga)

S. Matsuda (Waseda Univ.) et al.

P9Theoretical analysis of impurity-induced phonon by first-principles lattice dynamics calculations

H. Murata (Waseda Univ.) et al.

P10

Optical Properties of Transparent Conductive Oxides -Ga2O3

T. Ishikawa (Gifu Univ.) et al.

P11

Optical Properties in VUV to Visible Regions for Fluoride Crystals Doped with Rare Earth Ions

T. Nakamura (Gifu Univ.) et al.

P12

Phosphorescence Property of Rare Earth Ion-doped Hydroxyapatite excited by UVSOR

M. Ohta (Niigata Univ.) et al.

P13Absolute Photoionization cross section of C70 at 25-120 eV

B. P. Kafle (Grad. Univ. Adv. Studies) et al.

P14

Temperature dependence of the optical reflectance spectra of InN

T. Yanagawa (Univ. Fukui) et al.

P15

Crystal anisotropy effect on excitonic luminescence in AlGaN

M. Kishida (Univ. Fukui) et al.

P16

Correlation between Coloration and Optical Properties in Yttrium Oxysulfide Single Crystals

S. Tokunaga (Univ Fukui) et al.

P17

P18

Comparative study of photoluminescence properties between YPO4:Zr4+,Mn2+ and ScPO4:Zr4+,Mn2+
phosphors
Dependence of photoluminescence properties on Brion concentrations- ion concentrations in
PbCl2:Brcrystals

Y. Inada (Univ Fukui) et al.

S. Izuhara (Univ Fukui) et al.

P19

Measurements of time resolved decay spectra by using ICCD detector at the single bunch operation

F.Suzuki (Univ. Fukui) et al.

P20

The concentration dependency of Eu ions for excitation spectra of BaMgAl10O17:Eu

H. Yoshida (Kwansei Gakuin Univ.) et al.

P21

Nd3+:(La1-x,Bax)F3-x Grown via Micro-Pulling Down as Vacuum Ultraviolet Scintillator and Potential
Laser Material

S. Ono (Nagoya Inst. Tech.) et al.

P22

Ultraviolet Photoemission Spectra of Layered Metal Oxide Thin Film

T. Miyazaki (Ehime Univ.) et al.

P23Electron structure of halogen bonding studied by UPS

R. Sumii (KEK-PF) et al.

P24

Nano-clusters in Pd-Ni-P Bulk Metallic Glasses Studied by Synchrotron Spectroscopy

T. Mochizuki (Nagoya Univ.) et al.

P25

Electronic Structure of Fe-based Heusler-type Thermoelectric Alloys

T. Mochizuki (Nagoya Univ.) et al.

P26

Photoinduced Phenomena in Amorphous Semiconductor Materials by UVSOR

K. Hayashi (Gifu University)

P27

XANES Spectra of Sulfur amino acids at S K-edge

Y. Izumi (Kobe Univ.) et al.

P28

A study of a molecular orientation of crown ether in thin films by ARUPS

Y. Suzuki (Chiba Univ.) et al.

P29

A study of molecular orientation of Bis-(o-diiminobenzosemiquinonate)Nickel(II) Complex in thefilms by AR-UPSin the films by AR-UPS

N. Mitsuo (Chiba Univ.) et al.

P30

Photoluminescence Analysis of Lanthanum Aluminate Single Crystals

K. Kanai (Waseda University) et al.

P31

Characterization of Mg-modified titanias synthesized by the glycothermal method

Y. Sazanami (Kyoto Univ.) et al.

P32

P33

Change in the Metal 3d derived molecular electronic state due to Metal-phthalocyanine/Ag(111)interaction
Change of electronic structure of para – ferro magnetic phase transition on EuO : Three-dimensional
angle-resolved photoemission spectroscopy

T.Aoki (Chiba Univ.) et al.

H. Miyazaki (Nagoya Univ., UVSOR) et al.

P34

Infrared-Terahertz Spectroscopy of CeIn3 under a pressure

P35

Terahertz Spectroscopy of SmS under Pressure

P36

Soft x-ray magnetic circular dichroism at high magnetic field and low temperature

T. Nakagawa (IMS) et al.

P37

Electronic states of a single crystal of Rubrene studied by Photoelectron Yield Spectroscopy

Y. Nakayama (Chiba Univ.) et al.

P38

T. Iizuka (Kobe Univ., UVSOR) et al.
T. Mizuno (Grad. Univ. Adv. Studies, UVSOR)
et al.

Systematic Study of Quantum Criticality in Ce1-xGdxCoSi3:Ce and Gd 4d-4f resonant photoemission
spectroscopy

166

H.J. Im (Sungkyunkwan Univ., UVSOR) et al.

UVSOR Lunch Seminar
FY2007
July 23

Prof. Yunsang LEE, Department of Physics, Soongsil University, Korea
Charge-orbital ordered state in half-doped layered manganites

Feb. 8Mr. Masahiro ITO, Graduate School of Science and Technology, Niigata University and UVSOR
Metastability of carbonyl sulfide (OCS) dications

Feb. 8

Mr. Takuya IIZUKA, Graduate School of Science and Technology, Kobe University and UVSORInfrared-to-Terahertz Spectroscopy of CeIn3 under pressureMar. 13

Dr. Miho SHIMADA, UVSOR Facility, Institute for Molecular Science
Generation of Coherent Synchrotron Radiation (CSR) produced by an interaction between electron
beam and external laser

Mar. 13

Dr. Tatsuo KANEYASU, UVSOR Facility, Institute for Molecular Science
Development of an electron-ion coincidence spectrometer and its application to decay dynamics inmolecules following core hole creation

167

UVSOR Workshop on Terahertz Coherent Synchrotron Radiation
Place: Okazaki Conference Center and UVSOR Facility
September 23th, 2007
15:00-㻌 Registration and UVSOR site tour.
18:00-㻌 Get together party
September 24th, 2007
8:30-㻌 Breakfast
9:15-㻌 Opening Remark
1. Light Source (1); Linac
9:30-㻌 Status of Coherent Radiation Beamline at KURRI-LINAC
9:55-㻌 Bunch compression at the SPring-8 linac for successive
generation of THz pulse train in the isochronous ring
10:20-㻌 Coffee break
2. Light Source (2-1); Storage Ring
10:50-㻌 The BESSY (and MLS) Low Alpha Optics and the Generationof Coherent Synchrotron Radiation
11:15-㻌 Coherent THz radiation at NewSUBARU
11:40-㻌 Observation of THz CSR burst in UVSOR-II
12:05- Lunch
3. Light Source (2-2); Storage Ring
13:20- Status of the ANKA Short Bunch Operation
13:45- CSR studies at the ALS and optimizing a storage ring for THz
14:10- Generation of THz CSR with laser-bunch slicing in UVSOR-II
electron storage ring
4. Light Source (3); ERL
14:35- Applications of Intense CSR from a cw Linac at Jefferson Lab
15:00- An Intense Terahertz Radiation Source at the Compact ERL
15:25-㻌 Coffee break
5. Applications
15:55- Scientific Experiments at BESSY using Coherent Synchrotron
Radiation
16:20- Coherent Synchrotron Edge Radiation and Applications at ANKA
16:45- Coherent THz radiation from photo-injected linac and applications
to studies of materials
17:10- Closing remark

M. Katoh (UVSOR)
T. Takahashi (Kyoto U.)
Y. Shoji (New SUBARU)

G. Wuestefeld (BESSY)Y. Shoji (New SUBARU)
M. Shimada (UVSOR)

A.-S. Mueller (ANKA)
M.C. Martin (ALS)
A. Mochihashi (UVSOR)
G. P. Williams (J-lab)
K. Harada (KEK)U. Schade (BESSY)
Y-L. Mathis (ANKA)
L. Carr (NSLS)
S. Kimura (UVSOR)

18:30- Banquet at an Izakaya restaurant (Japanese pub)
September 25th, 2007
9:00-㻌 Move to Awaji Island by public transportations.

168

Status of Coherent Radiation Beamline at KURRI-LINAC
T. Takahashi
Research Reactor Institute, Kyoto University, Japan
In the electron linear accelerator at Research
Reactor Institute in Kyoto University (KURRILINAC), properties of several types of coherent
radiation (synchrotron radiation [1], transition
radiation [2], Cherenkov radiation [3], diffraction
radiation, and Smith-Purcell radiation [4], prebunched FEL [5]) in the THz-wave and millimeterwave regions have been experimentally investigatedsince 1991. The beamline for the millimeter-wave
spectroscopy has been constructed [6], in which
coherent transition radiation (CTR) has been used asa light source and the spectroscopic research of N2O
gas [6] and electron spin resonance using a pulsed
magnet [7] have been demonstrated.
The KURRI-LINAC consists of an injector,
pre-buncher, two accelerator tubes. The specifications
are represented in Table. 1.

The forward coherent transition radiation emitted
from a Ti window and the backward one from an
Al-foil are used as a light source. The beamline isequipped with a grating-type monochromator and a
Martin-Puplett type interferometer in series. Whenthe interferometer is used as a spectrometer thegrating in the monochromator is replaced with a flat
mirror. Three types of detectors are prepared, i.e. aliquid-helium-cooled Si bolometer (Infrared Lab.), a
hot-electron InSb bolometer (Infrared Lab.), and amillimeter-wave diode-type detector (DXP-10,
Millitec) according to the sensitivity and the response
time. The degree of instability of the observed
intensity is within 2%.
Coherent radiation is especially useful as a picosecond pulsed light source for the time-resolved
spectroscopy and the pulseradiolysis study. Since theaccelerating frequency of this linac is 1.3 GHz(L-band), the interval between pulses in the CTR
pulse train is 770 ps (23 cm). The spectrum from thesuccessive bunches is constituted of the higher
harmonics of 1.3 GHz [6]. As a result, the CTR canbe treated as a light source with a continuous
spectrum only when the spectral resolution is lower
than 1/23 = 0.0434 cm-1 and the delay in thetime-resolved measurement is restricted within 770 ps.
In order to lift these restrictions, the single-bunch
beam has been generated by installing a high-speed
avalanche-type pulser in the electron injector. The
degree of impurity of single bunch was estimated tobe 1.5% by means of the cross-correlationinterferogram.
The following researches in the millimeter-wave
region are in progress at this beamline:a) Optical conductivity of superionic conductors(collaboration research),b) Optical properties of water (collaboration
research),c) Optical properties of polymeric materials underirradiation (collaboration research),d) Development of pulseradiolysis system.

Table 1. Specifications of KURRI-LINAC
Operation Mode
Short Pulse
Long Pulse
RF frequency
1300 MHz
Energy46 MeV
30 MeV
Pulse Width2㨪100 ns
0.1㨪4 Ps
Repetition Rate
1㨪300 Hz1㨪200 Hz
Peak Current
8A
500 mA
Beam Power
Max. 10 kW
This linac has been operated for collaboration
research programs with other universities since 1964
and research activities have covered the nuclear datawith pulsed neutron source, electron irradiation, andcoherent radiation. The time of operation in 2006 wasabout 2,700 hr. The distributed user-time to theresearch of coherent radiation is about ten weeks per
year. The schematic diagram of the beamline isshown in Fig. 1.
6KYKPFQY#NHQKN

GNGEVTQP
DGCO

HTQO.DCPF.KPCE#EEGNGTCVQT4QQO
5JKGNF9CNN[1] Y. Shibata, et al., Phys. Rev. A 44 (1991) R3449.
[2] Y. Shibata, et al., Phys. Rev. A 45 (1992) R8340.
[3] T. Takahashi, et al., Phys. Rev. E 50 (1994) 4041.
[4] Y. Shibata, et al., Phys. Rev. E 57 (1998) 1061.
[5] Y. Shibata, et al., NIM 528 (2004) 162.
[6] T. Takahshi, et al., Rev. Sci. Instrum. 69 (1998)
3770.
[7] Y. H . Matsuda, et al., Physica B 346-347(2004) 519-523.

'ZRGTKOGPVCN4QQO/QPQEJTQOCVQT+PVGTHGTQOGVGT

Fig. 1. The schematic diagram of the coherent
radiation beamline.

169Bunch compression at the SPring-8 linac for successive generation of THz
pulse train in the isochronous ring
T. Asaka, H. Dewa, H. Hanaki, Y. Hisaoka*, T. Kobayashi, T. Matsubara*, T. Mitsui*, A.
Mizuno, Y. Shoji*, S. Suzuki, T. Taniuchi, H. Tomizawa, and K. Yanagida
SPring-8, JASRI, Sayo-cho, Sayo-gun, 679-5198, Japan*NewSUBARU, LASTI, University of Hyogo, Kamigori-cho, Ako-gun, 678-1205, Japan
Performance of the electron gun is essential. The
quasi-isochronous ring as a circulator can be a modelof a bending arc of ERL. Many circulations in thering would enhance problems, which would occur in
ERL arc.
We hope that this new beam handling would bringus new understandings on beam physics. What wewould see is a transient process starts from a shortpulsed intense beam. We can observe energy
spreading by instabilities or CSR in time domain. The
turn-by-turn time structure of a bunch will bemeasured using a streak camera and a beam profile bya fast gated ICCD camera. The diode detector in THz
region is a diagnostic on fine time structure in abunch.
Turn number 50
025

Abstract
We have already demonstrated our idea ofcirculating a short and intense bunch in a synchrotron
radiation ring. The idea is based on the understandingthat it is almost impossible to store short andhigh-charged electron bunch in a storage ring but it is
not difficult to produce that kind of bunch at a linac.
When the short bunch is produced at a linac andinjected into an ideal isochronous ring, the time
structure of the bunch is frozen and it emits
short-pulsed radiation for every turn. It would supply
a strong coherent radiation pulse train in THz region
for beam lines in the storage ring.
In our previous work [1] we compressed thebunch of the SPring-8 linac to a few picoseconds(r.m.s.) by means of an energy compression system
and a beam transport line from the linac to
NewSUBARU. The bunch charge was about 0.02 nC.
The NewSUBARU storage ring was set at
quasi-isochronous condition and the bunch circulated
for about 50 turns after injection while maintaining
the short bunch length. A strong coherent radiation
was observed using a Shottkey diode detector, which
was sensitive to 0.1 - 0.14 THz radiation. Fig. 1
shows the turn-by-turn radiation power after injectionin the storage ring. The radiation power at the initial
turn was raised by the bunch compression. This highpower radiation lasted longer by setting the ring
quasi-isochronous. At the present, the imperfection of
the isochronous condition produces the increase ofbunch length and the reduction of coherent radiation
power.
Our plan for the next few years, which is not yet
approved, is to install the photo-cathode electron gun
developed at SPring-8. According to the expectedbeam parameters listed in Table 1, the beam would beshorter and stronger with the smaller energy spread.
Consequently it would supply more lasting shorter
pulses in the ring. The smaller energy spread isimportant not only because this parameter is atrade-off of the bunch compression, but also that thesmall energy spread reduces the bunch elongation due
to the higher order momentum compaction factor.
Many improvements of the linac since 1998 forstability and reliability were also essential for thisresearch.
Our method is partly very similar to ERL (Energy
Recovery Linac). There is no stationary state in thering or bending arc, therefore its performance as alight source strongly depends on the initial beam.

Power (mW)

0.3

0.25
0.2

Compressed
Single bunch
Quasi-isochronous
ring

0.15
0.1
NormalOperation

0.05
0

0

5

10

15

Time from injection (s)20

Fig. 1. The turn-by-turn coherent radiation power
after injection. The line with open circles shows thepower obtained with the parameters of normal
operation, where there were three bunches in a pulse.
The line with filled circles shows the power obtained
from one compressed bunch in the quasi-isochronous
ring. The bunch charge was about 0.02 nC/bunch inboth cases.
Table 1. Beam parameters at 1.0 GeV with thepresent thermionic electron gun and the expectedparameters with the new photo-cathode electron gun.
Present
Next
Electron Gun
ThermionicPhoto-Cathode
Energy Spread (+/-) 0.5%(+/-) 0.1%
Bunch Length
2.2 ps< 1 psBunch Charge< 0.1 nC
> 1 nC

170

The BESSY (and MLS) Low Alpha Optics and the Generation of
Coherent Synchrotron Radiation
J. Feikes, K. Holldack, H.-W. Huebers¹, P. Kuske, G. Wuestefeld
BESSY, and ¹DLR, Berlin (Germany)
The BESSY II optics is tuned to a low alpha optics for bunch shortening.
This machine mode is offered 4 times per year for 3 days for users
experiments. About 1mm short bunches emit coherent synchrotron radiationin the THz range and short x-ray pulses. Characteristics of the machine
optics and measured THz signals are discussed. Limitations to produce ultra
short bunches and a possible upgrading scheme for intense, short bunches
are discussed.
The presently commissioned Metrology Light Source (MLS) next to the
BESSY site includes the option for low alpha operation. Plans for the shortbunch generation are presented.

171

NewSUBARU

Coherent THz radiation at NewSUBARU
Y. Shoji
NewSUARU, LASTI, University of Hyogo, Kamigori-cho, Ako-gun, 678-1205, Japan
Abstract

1.5 A/bunch
0.5 A/bunch

0-10

2 fs fs

-20
-30
-40
-50
-4

-3

-2

-1

0

1 2
f - fRF (kHz)3

short-pulsed radiation for every turn. It would supply
a strong coherent radiation pulse train in THz region
for beam lines in the storage ring. This plan will bepresented in the other presentation titled "Bunch
compression at the SPring-8 linac for successive
generation of THz pulse train in the isochronous ring"at the workshop.
The third type was a radiation burst from ahigh-density, single-bunch beam. Although its
radiation power is extremely high and easy to beobtained in any electron storage ring, this type is not
used for experiments. This is because the source of
the CSR burst is a fine time structure in the bunch
due to longitudinal beam instabilities, and is notstable. However, it could be used for some kind of
application experiments with an appropriate time
averaging. We investigated the time structure of the
CSR burst using Schottky diode detector, which had ahigh time resolution. When we took an averaging
period of 10ms (=25250 revolutions), the fluctuationof the integrated power was about 10% (standard
deviation). In this time range, the relative fluctuation
decreases with the period length faster than the squareroot scaling law as shown in Fig. 2. It is thought that
the CSR burst can be obtained in most storage rings.
This type does not require fine and delicate machine
tuning as the quasi-isochronous operation does.
However for a user operation, two accelerator
techniques, an accurate bucket selection in theinjection process, and the top-up operation are
required. These two techniques are not common at theexisting storage rings but coming to be a standard of
new rings.
fuluctation of averaged power(r.m.s / average)

Relative Power of CSR (dB)

NewSUBARU is a 1.5 GeV synchrotron radiation
ring at the SPring-8 site. Laboratory of Advanced
Science and Technology for Industry (LASTI) at the
University of Hyogo is in charge of its operation,
collaborating with SPring-8. The beam is injectedfrom the SPring-8 linac with 1.0 GeV of electronenergy. Three types of CSR (coherent synchrotron
radiation) from three types of electron beam weredetected in the storage ring, NewSUBARU.
One was quasi-dc CSR (in other wards, steadystate CSR) from a low-current, short-bunched beam,
which is used for application experiment at BESSY-II.
The ring was operated in a quasi-isochronous mode(with a low momentum compaction factor), in which
it a short-bunched beam can be stored stationary. At
NewSUBARU a quasi-dc CSR was obtained at low
current of 1 pC/bunch and short bunch length of 3.4
ps FWHM. In this state, the longitudinal coherent
oscillation amplitude depended on the stored beam
current probably because of a burst of CSR by alongitudinal instability. Burst CSR could produce asudden energy loss and excite a coherent synchrotron
oscillation. Fig. 1 shows the FFT power spectrum of
the pulsed CSR signal. This quasi-isochronous
operation requires delicate tuning and high stability ofthe storage ring.

4

Fig. 1. Beam current dependence of the power
spectrum of CSR signal. The main peak (rf frequency
fRF) is normalized to 0dB.

averaged time length (ms)
0.001

10

0.01

0.1

1

10
-0.8

time length
1

0.1

1

10

100

1000

10000

averaged number of revolutions

Fig. 2. Fluctuation of time-averaged power of
CSR burst. The broken line is a guide which shows
the dependence of period-0.8.

The second type was a radiation pulse following
injection. A short-bunch linac beam, with a basewidth of 20 ps and a charge of 50 pC/bunch, emitted
short-pulse CSR in the storage ring. It was almost
impossible to store short and high-charged electron
bunch in a storage ring but the production of shortand intense bunch at a linac is not difficult. When the
short bunch is injected into an ideal isochronous ring,
the time structure of the bunch is frozen and it emits

172

UVSOR-II

Observation of THz CSR burst at UVSOR-II
M. Shimada1, M. Katoh1,2, M. Hosaka2, A. Mochihashi1*, Y. Takashima2,
S. Kimura1, T. Takahashi3
1
UVSOR Facility, Institute for Molecular Science, Japan
2
Graduate School of Engineering, Nagoya University, Japan
3
Research Reactor Institute, Kyoto University, Japan*Present affiliation : JASRI Spring-8, Japan

173

10

Intensity (arb. units)

In 2004, we reported the first result from theobservation of bursts of Terahertz Coherent
Synchrotron Radiation (THz CSR) at UVSOR-II
[1]. In this experiment, UVSOR-II electron storage
ring was operated in a single-bunch mode with theelectron beam energy of 600 MeV. The bursts wereobserved at the infrared/THz beamline BL6B which
has a large solid angle, 215 × 80 mrad2 [2]. A
hot-electron bolometer, which is sensitive from a few
cm-1 to 50 cm-1, was used as a detector.
Figure 1 shows the average intensity of theterahertz radiation measured by using a mechanicalchopper and a lock-in-amplifier, in the single bunchmode (black circles) and in the multi-bunch mode(gray circles) against the average beam current.Large
fluctuations can be seen in two beam current regions
around 80 mA and above 130 mA. In these regions,very intense bursts were observed. They appeared
quasi-periodically at the lower current whilechaotically at the extremely higher current. The time
structure of each burst sometimes showed periodicity
which was approximately same as twice ofsynchrotron frequency..
After the upgrade of RF cavity at 2005 [3], acorrelation between the bursts and a vertical beam
instability was discovered. The threshold beam
current came to be lower down to around 40 mA. The
quisi-periodic structure in each burst cannot be seen.
At 2006, a schottky THz diode detector was
introduced for measurement with high time resolutionof around 100 ps. We have successful in observing
the THz CSR at each revolution of the electron bunch(5.6 MHz). The bursts seems to contain rapid
temporal structure which could not resolved with thebolometer.
We have constructed a laser bunch slicing
system by introducing a Titanium Sapphire (Ti:Sa)
femto-second laser [4]. The minimum duration of
Ti:Sa laser is 130 fs and the maximum power per
pulse is 2 mJ. We could observe both bursting THz
CSR and CSR produced by the bunch slicing
simultaneously in some beam current region. So far,
we have not observed that the slicing induced thebursts.

1

30

40

50

60 70 80 90100

200

Beam current (mA)

Fig. 1. Average intensity of the terahertz radiation in
the single bunch mode (black circles) and in themulti-bunch mode (gray circles) as a function of theaverage beam current, measured by using amechanical chopper and a lock-in-amplifier.

Fig. 2. THz CSR produced by the laser bunch slicing
with the CSR bursts.

Reference[1] Y. Takashima, et. al., Jpn. J. Appl. Phys., 44,(2005) L1131[2] S. Kimura, et. al., Infrared Phys. Tech., 49,(2006) L 147[3] A. Mochihashi et. al., Proc. EPAC2006 (2006,
Edinburgh), 1268-1270[4] M. Shimada et al., accepted for publication by
Jpn. J. Appl. Phys.

STATUS OF THE ANKA SHORT BUNCH OPERATION
A.-S. Müller, I. Birkel, E. Huttel, S. Casalbuoni, B. Gasharova,
Y.-L. Mathis, D.A. Moss, P. Wesolowski
Karlsruhe Research Center, Germany

σs / mm

The ANKA electron storage ring located at the Research Centre Karlsruhe in Germany operates inthe energy range from 0.5 to 2.5 GeV. To generate coherent radiation in the far IR (THz) region, a
dedicated operation mode with reduced momentum compaction factor is used. The beam behaviour
with short bunches has been studied under various conditions and at different beam energies (seeFig. 1). This presentation gives an overview over the status and perspectives of the operation of the
ANKA storage ring with short bunches.

1510αc scan at 0.8 GeV
αc scan at 1.0 GeV
αc scan at 1.3 GeV
αc scan at 1.6 GeV
αc scan at 1.8 GeVfrom fit with VRF=0.6 MV
from fit with VRF=1.2 MV

5

0
1000

2000

Ebeam / MeV
Figure 1: RMS Bunch length derived from measurements of the syn-chrotron frequency as a function of beam energy. The hatched regions are error bands obtained by a full error Monte Carlo. The
markers represent bunch lengths derived from synchrotron frequency
measurements for different beam energies.

174

Generation of THz CSR with laser-bunch slicing in UVSOR-II electron
storage ring
A. Mochihashi1*, M. Shimada1, M. Katoh1, S. Kimura1, M. Hosaka2, Y. Takashima2,
T. Hara3, T. Takahashi4, S. Bielawski5, C. Szwaj5 and C. Evain5
1
UVSOR Facility, Institute for Molecular Science, Japan
2
Graduate School of Engineering, Nagoya University, Japan
3
RIKEN/SPring-8, Japan
4
Research Reactor Institute, Kyoto University, Japan
5
Universite des Science et Technologies de Lille, France* Prsent affilation : JASRI/SPring-8, Japan
abstract
We have performed experiments for generation of THz CSR with laser-bunch slicing
in UVSOR-II electron storage ring. A mode-locked Ti:Sa laser system generates
femto-second high power laser pulse and injects the pulses into an undulator section of
the UVSOR-II electron storage ring. The laser pulse induces energy modulation on anelectron bunch in the undulator section and the energy modulation changes tolongitudinal density modulation on the bunch by passing through a bending magnet
section which is beyond the undulator section. The THz radiation generates at thebending magnet section where infra-red beam line (BL6B) is settled. Quadratic
dependence of the intensity of the intense THz radiation on the peak bunch current
indicates the coherent synchrotron radiation (CSR). Spectral measurement with aninterferometer settled in the beam line shows dependence of the bandwidth and spectral
range on the laser pulse duration; that indicates possibility to control the frequency andbandwidth of the THz CSR. To control both the frequency and the bandwidth of the
THz CSR, we have performed a bunch-slicing experiment with amplitude-modulated
laser pulse. The amplitude-modulated pulse laser is generated by ‘chirped pulse beating’method[1]. The THz CSR spectral bandwidth by the modulated laser pulse becomesnarrower than that by single laser pulse. Because the spectral peak frequency and the
bandwidth depend on the modulation of the laser pulse, it is possible to tune the THz
CSR frequency and bandwidth only by adjusting the optics for the laser modulation.
Introduction of the laser-bunch slicing system in UVSOR-II, experimental results of thebunch-slicing with single and amplitude-modulated laser pulses are presented in theworkshop.
[1] Weling, A.S. & Auston, D. H., J. Opt. Soc. Am. B 13, 2783-2791 (1996)

175

Applications of Intense CSR from a cw Linac at Jefferson Lab
Gwyn P. Williams, Mike Klopf & The Jefferson Lab Team
Jefferson Lab
Newport News, Virginia 23606
At Jefferson Lab we operate a superconducting linac with continuous-wave radiofrequency excitation to produce 135 pC sub-ps bunches of electrons at repetition rates

up to 75 MHz. CSR, or multiparticle coherently enhanced emission is produced bymodulating this bunch in a Free Electron Laser cavity, and is also produced forwavelengths that are longer than twice the bunch length. With electron beam energiesof 100 MeV, the electron beam energy is 1 MW. Therefore we energy recover theelectrons in a return loop.
We will describe the operation of the facility, and then applications of this intense
beam. The applications fall into 2 categories, real-time imaging, and out-ofequilibrium dynamics.
G.R. Neil et al “The JLab High Power ERL Light Source”, Nucl. Instr. & Methods
A557 9 (2006).
J.M. Klopf, et al., Nucl. Instr. and Meth. A (2007), doi:10.1016/j.nima.2007.08.081.
This work supported by the Office of Naval Research, the Joint Technology Office,
the Commonwealth of Virginia, the Air Force Research Laboratory, The US Army
Night Vision Lab, and by DOE under contract DE-AC05-060R23177.

176

An Intense Terahertz Radiation Source at the Compact ERL
Kentaro Harada, Photon Factory, High Energy Accelerator Research Organization (KEK),
Oho, Tsukuba, Ibaraki 305-0801, Japan
Miho Shimada, UVSOR, Institute for Molecular Science, National Institutes of Natural
Sciences, Myodaiji-cho, Okazaki, Aichi 444-8585, Japan
Ryoichi Hajima, ERL Development Group , Japan Atomic Energy Agency (JAEA),
Tokai, Naka, Ibaraki 319-1195, Japan(Insertion device)

Beam dump

MergerMain linac(module 2)

Main linac(module 1)

Injector
linac
Electron gun

Fig. 1. Lattice of the Compact ERL.
Table 1 Tentative parameters of the test facility
Parameters (final goal)
Injection energy
5 MeV (10-15 MeV)
Injectorbeam 500 kW (1 MW)
power
Beam energy in the ~60 MeV
recirculation path(160-200 MeV)SC cavities for 9 cells x 4: single module
main linac(two modules)
Normalized
1 mmmrademittance(0.1 mmmrad)
Beam current
10 mA (100 mA)
RMS bunch length Usual mode : VW = 1-2 ps(Short bunch : VW = 0.1 ps)
Figure 1 shows the plan of the Compact ERL and
Table 1 lists the tentative parameters. In order togenerate the CSR of the wavelength OCSR , theelectron bunch length should be shorter than

Vz

OCSR
2

.

For example, the electron bunch with the bunch
length of 0.2 ps (60Pm) can generate the CSR of theenergy 10 meV (120 Pm). In order to achieve such

1.E+18
Photon Flux Density

Extractor

2

Recirculation pathshort bunch length, however, the bunch compression
is inevitable.
For the bunch compression [1],[2], the off-crest
acceleration at the main acceleration module firstly
generates the energy gradient in the electron bunch.
Then the difference of the orbit length depending on
the particle energy at the arc section can compress thebunch length. The linear path length difference of thearc, R56, can be optimized by the quadrupoles and thesecond order effect, T566, by the sextupoles.
Furthermore, in order to suppress the emittance
growth by the CSR, Twiss parameter D at the end of
the arc section is fixed. Finally, the simulation results
show that, if the bunch charge is smaller than about
0.5nC, the bunch length can be compressed to about
0.2ps at the 65MeV beam energy [3]. The estimatedphoton flux from the bending magnet at the arc of the
ERL test facility is shown in Fig. 2.

[photons/sec/mrad /0.1%b.w.]

The Compact ERL is the energy recovery linac(ERL) test facility that will be constructed at KEK
Tsukuba campus as a joint project of the KEK, JAEA,
and other institutes. The Compact ERL has a great
feasibility of producing intense terahertz radiation
using coherent synchrotron radiation (CSR) from its
electron beams. Although the primary purpose of the
facility is the demonstration of the key technologies
that are essential to build ultra-brilliant new
synchrotron light source based on the ERL, thelimited user operation with the terahertz CSR is now
examined. In this presentation, we show theparameters of the Compact ERL and discuss expected
performances of the terahertz radiation.

1.E+15Enhancement by
the CSR effect

1.E+12
1.E+09
1.E+06
1.E+030.00001

0.001
0.1
Photon Energy [eV]10

Fig. 2. Radiation spectrum from the bending magnetof the arc section of the Compact ERL. The beam
current is 100 mA (= 77 pC x 1.3 GHz), the bunch
length 0.2ps, and the beam energy 65MeV.
[1] M. Shimada, K. Yokoya, T. Suwada and A.
Enomoto, ”Lattice and beam optics design forsuppression of CSR-induced emittance gowth at
the KEK-ERL test facility”, NIM A 575, (2007)
315[2] R. Hajima, ”Emittance commpensation in a returnarc of an energy recovery linac”, NIM A 528,
(2004) 335[3] M. Shimada, K. Harada, R. Hajima, ”Bunch
compression and the emittance growth dur to
CSR”, Proc. of ERL 2007

Scientific Experiments at BESSY using Coherent Synchrotron Radiation
U. Schade
Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m.b.H. (BESSY)
Albert-Einstein-Strasse 1512489 Berlin, Germany
ulrich.schade@bessy.de
Coherent synchrotron radiation (CSR) from a storage ring is a new spectroscopic source
between microwaves and thermal black body radiation offering broadband radiation in theTHz range. During the past few years, this new technique to generate powerful, stable,
coherent sub-THz and THz radiation from the electron storage ring has been established at theelectron storage ring in Berlin (BESSY). The spectral range between 3 and 30 wavenumbers(0.1 – 1 THz) which can be only poorly accessed by conventional sources is now covered byoperating BESSY in special machine modes. Here, up to 108 more brilliance than from a
black body source has been achieved. The production of stable, high power, coherent
synchrotron radiation at THz and sub-THz frequencies at BESSY opens a new region in theelectromagnetic spectrum offered at synchrotron radiation sources which now can be applied
for imaging, spectroscopic and microscopic methods in solid state physics, material sciences
and life sciences. The feasibility of using the coherent synchrotron radiation in scientificapplications has been proven at the infrared beamline IRIS. Beside the characterization of thecoherent synchrotron radiation source this talk will present a couple of applications spanningfrom spectroscopic investigations of new superconducting materials to scanning near-fieldmicrospectroscopy.

178