「加速器」Vol. 3, No. 4, 2006 (400402)

話題

THE AUSTRALIAN SYNCHROTRON PROJECT

G. LeBlanc

Abstract This paper will give an overview of the Australian Synchrotron Project (ASP) storage ring1). The ASP storage ring is a 3 GeV machine with 14 identical cells and a circumference of 216 m. The injection system is commissioned and the storage ring is currently being commissioned. The facility is expected to be in operation by March 20072).

straight sections are used for RF cavities, one for the STORAGE RING injection septum, and the remaining eleven will be A single cell of the ASP lattice is shown below in available for full length insertion devices. Splitting the Figure 1. The two bending magnets are identical and cavities between two straight sections leaves 2.5 m are gradient dipoles with a focusing strength of k＝ available for insertion devices in those straight sec- －0.335 m－2. There are three families of quadrupoles tions. The machine functions for one cell in the lattice and four families of sextupoles. Horizontal and vertical are shown in Figure 2 and the design speciˆcations corrector and skew quadrupole coils are wound into are shown in Table 1. the sextupole magnets to make the lattice more The injection system is a 100 MeV linac feeding a compact3). The design of the vacuum system is 0.13 GeV booster. The injection system runs at 1 Hz detailedinRef.4). The storage ring RF system uses and can deliver up to 3 mA per shot into the storage HOM damped cavities developed for the Australian ring. The layout for the injection system and storage Synchrotron project detailed in Ref. 5). ring can be seen in Figure 3. The nominal lattice tunes are n ＝13.3 and n ＝5.2, x y BEAMLINES but the machine can be tuned over a large range by us- ing the outer two of the quadrupole families. The inner Diagnostic Beamlines quadrupoles are used to distribute the dispersion to al- There are two diagnostic beamlines to monitor the low it to leak into the straight sections. Two of the synchrotron light from dipoles in the storage ring; one

Fig. 1 A unit cell of the 14 cell double bend achromat ASP storage ring lattice.

Australian Synchrotron Project, Melbourne, Australia. (E-mail: greg.leblanc＠synchrotron.vic.gov.au)

58 J. Particle Accelerator Society of Japan, Vol. 3, No. 4, 2006 ― 400 ― THE AUSTRALIAN SYNCHROTRON PROJECT

Fig. 2 Machine functions for one cell of the ASP storage ring with zero dispersion in the straight sections. Fig. 3 The storage ring and injector ‰oor plan

Table 1 ASP storage ring speciˆcations.

Energy 3 [Gev] A ˆll pattern monitor is also implemented and will be Circumference 216 [m] RF Frequency 499.654 [MHz] used to target individual bunches in top-up mode. Harmonic Number 360 Experimental Beamlines Peak RF Voltage 3.0 [MV] An initial suite of nine beamlines is included in the Current 200 [mA] design of the ASP. Four of these are expected to be Critical Photon Energy 7.8 [keV] under commissioning at the completion of the storage Betatron Tune (h/v) 13.3/5.2 ring in 2007. Two beamlines will be from bend magnet Momentum Compaction 0.002 sources and two from insertion devices2). Natural Chromaticity (h/v) －28/－27 Radiation Damping (h/v/l) 3/5/3 [ms] COMMISSIONING RESULTS Energy Spread 0.1 [] Radiation Loss 932 [keV] First Light Horizontal Emittance 16 [nm･rad] The ˆrst electrons were stored and the synchrotron light observed on the X-ray diagnostic beamline on July 14, 2006. This was according to the project sched- for X-rays and one for optical light. The X-ray beam- ule set out in 2002. The next commissioning shift after line has been designed to ˆt entirely within the shield- that saw stacking up to 10 mA. ing walls of the storage ring to simplify the design and Matlab Tools remove the need for a hutch. An X-ray pinhole camer- The Accelerator Toolbox6) tools have been used ex- a, a YAG screen and a CCD camera are used to meas- tensively during commissioning. The control system is ure the beam size from a dipole source to determine based on EPICS and the process variables are availa- the beam stability and the emittance. ble to the Matlab tools. These include orbit control, The optical diagnostic beamline is used to measure response matrix measurements and analyses, as well the bunch length and study longitudinal beam dynam- as the ability to easily script up experiments in the ics. This design consists of an optical chicane to bring Matlab environment and treat the data with all of the the visible light out through the shielding wall and ab- standard Matlab tools. sorb the unwanted X-rays. A hutch containing an opti- Beam Position Monitor System cal bench houses a streak camera and a high speed The Libera7) beam position monitor system was CCD to measure the longitudinal beam characteristics. chosen for all of the beam position monitors. This gave

― 401 ― J. Particle Accelerator Society of Japan, Vol. 3, No. 4, 2006 59 G. LeBlanc turn-by-turn, and averaged orbit data simultaneously commissioning has gone very smoothly. With most of from the start of commissioning. The orbit interlock to the ˆnal performance criteria already demonstrated, protect the vacuum chamber from a miss-steered in- thetimeremaininguntiltheMarch2007startofoper- sertion device beam is also being implemented using ations will be spent continuing to optimize the perfor- the hardware on the Libera units. mance and work will begin on characterizing and cor- Storage Ring Performance recting for the eŠects of insertion devices on the elec- All of the electron beam performance criteria set out tron beam. for the project that can be demonstrated at present REFERENCES have been met or exceeded. As of 27 November 2006, the beam orbit has been corrected to 26 mmRMSin 1) http:// synchrotron.vic.gov.au the horizontal plane and 17 mmRMSinthevertical 2) A. Jackson, ``The Australian Synchrotron ProjectUp- date'', EPAC04. plane. Injection from 0160 mA (highest current 3) E. Huttel, A. Jackson, G. LeBlanc and J. Tanabe, ``The achieved so far with the design current of 200 mA) Storage Ring Magnets for the Australian Synchrotron'', takes ～3 min. The lifetime at 100 mA is 11 hours af- EPAC04. ter a total integrated current of 17 Ahrs. The emit- 4) E. Huttel, W. Barg, A. Jackson and B. Mountford, ``The Vacuum System for the Australian Synchrotron'', tance has been measured at 18.7 nmrad with an emit- EPAC04. tance coupling to the vertical of 0.5.Thebeam 5) J. Watanabe et al., ``Design and cold model test of 500 stability is less than 6 ofthebeamsizeatthesource MHz Damped Cavity for ASP Storage Ring RF Sys- point for the x-ray diagnostic beamline. tem'', PAC 2005. 6) A. Terebilo, ``Accelerator modelling with Matlab Ac- CONCLUSIONS celerator Toolbox'', PAC 2001, p. 3203. 7) http:// www.i-tech.si The storage ring is performing as expected and the

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