ACCELERATORS OF THE CENTRAL JAPAN SYNCHROTRONRADIATION FACILITY PROJECT

N. Yamamoto∗1, Y. Takashima1, M. Hosaka1, H. Morimoto1, K. Takami1,Y. Hori3, S. Sasaki4, S. Koda5, M. Katoh2,1

1. Synchrotron Radiation Research Center, Nagoya University, Chikusa-ku, Nagoya, Japan2. UVSOR, Institute for Molecular Science, Myodaiji-cho, Okazaki, Aichi, Japan

3. High Energy Accelerator Research Organization, KEK, Tsukuba, Japan4. JASRI/SPring-8, Sayo-gun, Hyogo, Japan

5. Saga Light Source, Tosu, Saga, Japan

Abstract

The construction of Central Japan Synchrotron Radia-tion Facility has started at Aichi in Japan and the servicewill start in 2012. The facility is designed to be usednot only for basic research, but also for engineering andindustry-oriented research and development.

One of the key equipments of this facility is a compactelectron storage ring that is able to supply hard X-rays. Thecircumference of the storage ring is 72 m with the energy of1.2 GeV, the beam current of 300 mA and the natural emit-tance of about 53 nmrad. The configuration of the storagering is based on the Triple Bend Cell including 5 T super-conducting magnet.

INTRODUCTION

Synchrotron radiation (SR) facilities have been used suc-cessfully for basic researches in the world. Recently, anSR facility as a tool not only for basic research, but alsofor engineering and industrial research and development isstrongly required. For this purpose, an SR facility projecthas been proposed at Nagoya University since 1991 [1].

In the meantime, the Aichi Prefectural government hasbeen planning a new research and development complexhKnowledge Hubh for industries in the Tokai area (oneof middle parts of Japan) and the SR facility proposed atNagoya University has been considered to be one of theleading facilities for ”Knowledge Hub”. Therefore, the pre-fecture, industries, universities, and research institute in theTokai area have been working together to realize this plan.After a long effort the construction was started last year andthe service will start in 2012.

The SR facility, consisting of accelerators, beamlines(BLs), peripheral equipments, and housing, has been de-signed at the Nagoya University Synchrotron Radiation Re-search Center (NUSR)1 in collaboration with Aichi pre-fectural government, Aichi Science & Technology Founda-tion (ASTF)2, industries, and other universities in this area[2, 3, 4].

∗E-mail:naoto@nagoya-u.jp1*URL:http://www.nusr.nagoya-u.ac.jp/2*URL:http://www.astf.or.jp/english/index.html

Storage ring

Booster Synchrotron

Experiment hall

Superbend (5T, 12˚)

Linac

12 m

Undulator

Superbend

Superbend

Superbend

Figure 1: Schematic view of the accelerators and radiationshielding wall.

ACCELERATORS

The design of the accelerators and building has almostbeen finished, and the schematic view is shown in Fig. 1.The accelerators consist of an electron storage ring, abooster synchrotron ring (booster), and an injector linac.The booster and injector linac are located inside of the stor-age ring, and the accelerators are separated from the exper-iment hall by a single shielding wall. The parameters ofaccelerators are summarized in Table 1.

The circumference of the storage ring is 72 m with theenergy of 1.2 GeV, and the natural emittance is 53 nm-rad.The lattice configuration is Triple Bend Cell, which consistof a super-conducting magnet (superbend) and two normalconducting magnets (normal bends). Optical functions ofthe storage ring are shown in Fig. 2. In order to minimizethe multi-pole effects of the superbends, the horizontal be-tatron and dispersion functions are set to be relatively small

Proceedings of IPAC’10, Kyoto, Japan WEPEA036

02 Synchrotron Light Sources and FELs

A05 Synchrotron Radiation Facilities 2567

Superbend

Longitudinal Distance (m)0 5 15 20

0.2

1.0

0.6

0

5

34

21

Figure 2: Optical functions of the storage ring.

0

5

10

15

20

-100 -50 0 50 100

Ver

tical

Dis

tanc

e [m

m]

Horizontal Distance [mm]

dE/E=0dE/E=8.4e-3

dE/E=-8.4e-3

Figure 3: Dynamic apertures of the storage ring.

at the superbend sections (see Table 1). Calculated dy-namic apertures that take into account the multi-pole com-ponents of the superbends, are shown in Fig. 3,

There are twelve bending magnets at the storage ring.Eight of them are normal bends of 1.4 T and four of themare 5 T superbends, respectively. The critical energy of theSR from the superbends is 4.8 keV. Spectra of photon Fluxfrom the bending magnets are shown in Fig. 4. The bendingangle of superbends is 12 degree and two or three hard X-ray BLs can be constructed at each superbend, so that tenor more hard X-ray BLs can be constructed. The numberof BLs from normal bends is more than 16. In addition, anAPPLE-II type undulator will be also installed in straightsections for VUV experiments.

Superbend

For the design of superbends, operation stability andmaintenance cost are important. The parameters of the su-perbend are listed in Table 2. The basic design is similarto that of the Advanced Light Source in USA[5]. The mainpole is directly cooled by 2-stage 4K-GM cryocooler, andliquid helium is not used during normal operation or main-

Table 1: Parameters of AcceleratorsStorage ringElectron energy 1.2 GeVCircumference 72 mCurrent >300 mANatural emittance 53 nm-radBetatron tune (4.72, 3.23)RF frequency 499.654 MHzRF voltage 500 kVRF bucket height >0.990 %Harmonics number 120Energy spread 8.41 × 10−4

Magnetic lattice Triple Bend Cell × 4Normal bend 1.4 T, 39◦

Superbend 5 T, 12◦

(βx, βy, ηx) @superbend (1.63, 3.99, 0.179)(βx, βy, ηx) @straight section (30.0, 3.77, 1.20)

Booster synchrotronElectron energy 50 MeV – 1.2 GeVCircumference 48 mCurrent >5 mANatural emittance <250 nm-radRF frequency 499.654 MHzHarmonics number 80Injection scheme On-axis (single turn)Repetition rate ∼1Hz

Injector linacBeam energy 50 MeVCharge per pulse >1 nCPulse length 1 nsRF frequency 2,856 MHzRepetition rate ∼1Hz

Table 2: Parameters of the Superbend

Return york C-ShapedConductor type NbTi/CuCryo-system 2-stage GM cryocoolerOperating current 150 APeak field 5 TBending angle 12◦

Warm bore gap 42 mmPole gap 80 mmPole length along beam 70 mmPole length transverse to beam 180 mmDimensions

Length 840 mmHeight 2000 mmWidth 1140 mm

Total mass <3500 kgCritical Energy @1.2GeV 4.8 keV

WEPEA036 Proceedings of IPAC’10, Kyoto, Japan

2568

02 Synchrotron Light Sources and FELs

A05 Synchrotron Radiation Facilities

108

109

1010

1011

1012

1013

1014

104 1054 54 5

Photon energy (eV)

Flux

(ph/

s/m

rad/

0.1%

b.w

.)

103102

Normal BendSuperbend

(300 mA)

Figure 4: Spectra of photon Flux from the bending mag-nets.

tenance. The cryocooler has a cooling capacity of 1.5 W at4.2 K and 45 W at 50 K. To decrease leak fields, two fieldclamps are equipped at outside of coil and iron core. Tostudy the details of the fields and beam envelops in the su-perbend, we have used the add-in program ”Radia”, whichis developed in ESRF [6]. Field calculation model by thisprogram is shown in Fig. 5.

Injectors

The electron beam will be injected from the booster withthe full energy from the first phase of the operation, and thetop-up operation will be introduced as early as possible inour project.

The maximum repetition rates of the injectors are 1 Hzand the beam from the booster is injected to the bumpedclose orbit excited by four kicker magnets at the storagering. The on-axis single turn schemes are employed for theinjection and extraction at the booster. The timing systemof accelerators is based on that of SPring-8 [7].

SUMMARY

Central Japan Synchrotron Radiation Facility is underconstructed not only for basic research but also for engi-neering and industrial research and development. The ac-celerators of this facility consist of a compact storage ring,that is able to supply more than ten hard X-ray BLs, and afull energy injector for the top-up operation.

Currently, six BLs are considered to be constructed inthe first phase. Those are BLs for a hard X-ray XAFS, asoft X-ray XAFS, a soft X-ray to ultraviolet spectroscopy,a small angle scattering, X-ray diffraction, and an X-rayfluorescence analysis.

ASTF is responsible for the operation and management,and NUSR is responsible to run the equipments and supportthe users technically and scientifically. The commissioning

-200

0

200

400-400

-2000

200

400

Y [m]

-400

-200

0

200

400

Z [m]

0

200

400

X [m]

Figure 5: Filed calculation model of the superbend.

of accelerators will start in the spring of 2012 and the startof the service is scheduled in the same year.

REFERENCES

[1] Y. Takashima, T. Yamane, Y. Takeda, K. Soda, S. Yagi,T. Takeuchi, et.al., AIP Conference Proceedings, 879, 75-78(2007)

[2] Y. Takeda, N. Watanabe, M. Katoh, M. Hosaka,Y. Takashima, N. Yamamoto and H. Morimoto, 3rdAsia Oceania Forum for Synchrotron Radiation Research,4-5 December, 2008, Melbourne, Australia.

[3] N. Yamamoto, Y. Takashima, M. Katoh, M. Hosaka,K. Takami, et. al., The 10th International Conference on Syn-chrotron Radiation Instrumentation, 27 September - 2 Octo-ber, 2009 , Melbourne, Australia.

[4] N. Yamamoto, Y. Takashima, M. Katoh, M. Hosaka,K. Takami, et. al., The 14th Hiroshima International Sympo-sium on Synchrotron Radiation, 3-4 March, 2010, Hiroshima,Japan.

[5] D. Robin, J. Krupnick, R. Schlueter, C. Steier, S. Marks,et.al., Nuclear Instruments and Methods in Physics ResearchSection A, 538, 65 - 92 (2005)

[6] URL:http://www.esrf.eu/Accelerators/Groups/InsertionDevices/Software/Radia

[7] Y. Kawashima, T. Asaka and T. Takashima, Physical ReviewSpecial Topics - Accelerators and Beams, 4, 082001 (2001)

Proceedings of IPAC’10, Kyoto, Japan WEPEA036

02 Synchrotron Light Sources and FELs

A05 Synchrotron Radiation Facilities 2569