AU0221622 Australian Synchrotron Light Source - (Boomerang) PROFESSOR JOHN BOLDEMAN, Centre for Synchrotron Science, University of Queensland, Queensland 4072, Australia, (Senior Advisor to the Victorian Government) SUMMARY The Australian National Synchrotron Light Source - (Boomerang) is to be installed at the Monash University in Victoria. This report provides some background to the proposed facility and discusses aspects of a prospective design. This design is a refinement of the design concept presented to the SRI -2000, Berlin (Boldeman, Einfeld et al), to the meeting of the 4th Asian Forum and the Preliminary Design Study presented to the Australian Synchrotron Research Program. 1 INTRODUCTION was always intended that this in principle design would be refined. A Feasibility Study (AUGUST 1997)" has recommended that the most appropriate More recently, significant effort was devoted synchrotron light facility for Australia would to refining this in principle design and a lattice have providing an emittance of 18 nm rad was • an energy of 3 GeV, obtained with a distributed dispersion (nj in • that it should be competitive in the straight sections of 0.29m. However it is now apparent that if some aspects of the design performance with other third generation 4 compact facilities currently under of the Canadian Light Source ' are construction and incorporated an even higher performance can be obtained with no additional cost. • that it should have adequate beam line and experimental stations to satisfy 95% of the research requirements of an expected The design goal of the desired storage ring has now been extended and the target parameters Australian community of 1200 different are listed below. researchers Beam Energy 3 GeV • and provide internationally competitive Beam Current at least 200 mA in performance for essentially all Australian Phase I industry requirements. Emittance better than 12 nm rad for a dispersion of less than 0.3 m Thus the minimum parameters of the Long Straights more than 9 recommended facility can be extended to Life Time greater than 20 hrs include Circumference less than 200m • an emittance of better than 18 nmrad, Instrument Stations 9 in Phase I • a beam current of at least 200 mA, • at least 8 useable straight sections for Exhaustive studies have been made of the insertion devices and economic benefits that would accrue to • a management policy which encouraged Australia following the installation of a facility front line research and a strong industrial with the design parameters listed above. In focus. addition to the studies within the ASRP, the Victorian Industrial Synchrotron RoundTable With such a facility, competitive synchrotron evaluated economic opportunities from 1996 radiation could be delivered to the various and funded several Workshops dealing with experimental stations to almost 100 keV via potential opportunities within areas such as the appropriate insertion devices. biotechnology industries and mining and mineral extraction. Three independent bodies A proposal was submitted to the Federal were funded to evaluate the economic benefit. Government in December 1999 to construct These comprised such a facility - the Boomerang Proposal Parts 2) • Centre for International Economics I - VII . The Boomerang Proposal Parts II and III described an in-principle storage ring • Centre for Strategic and Economic design which was based on an extended Studies version of the ANKA facility at the • PricewaterhouseCoopers. Forchungszentrum Karlsruhe in Germany3'. It 102 Recently, the three Eastern Australian States cell. The lattice also incorporates additional submitted proposals to the Federal sextupoles to allow the lattice to operate at a Government seeking funding to build a third higher distributed dispersion. The sextupoles generation light source in Australia. can also be double function elements as they Subsequently the Victorian Government incorporate correctors thereby minimising committed $100M towards the construction of space requirements. the facility and has underwritten the balance. A site at Monash University has been selected. The Boomerang lattice is shown in Figure 1. This report details the proposed design of the To calculate the performance of the selected facility. storage ring, three different codes have been used. These are 2. Lattice 1. Beta Code developed at the ESRF 2. WinAgile from CERN A Double Bend Achromat (DBA) has been 3. Beam Optics from Stanford. adopted, similar to the designs of the CLS and ANKA facilities and is a refinement of the AH three codes provided similar performance design presented to SRI-2000 and the 2nd (i.e. optical functions and emittance) for very Asian Forum5). Each cell comprises two similar design parameters and unchanged dipoles, six quadrupoles (Q), and six lattice dimensions if account is taken of the sextupoles (S) separated by appropriate drift different units for the specified parameters. spaces (D). The chosen lattice differs from the This was important as each of the codes has ANKA facility in that all straight sections are some aspects which makes their use more of equal length. In addition, the dipoles have a convenient that that of others. For example the gradient magnet field as in the CLS and thus dynamic aperture is more conveniently function as quadrupole elements as well as calculated in the Beta Code while for tune bending the electron beam. The chosen facility variations the WinAgile Code is more differs from the Canadian lattice in that the appropriate. The WinAgile Code is gradient field of the dipole is more modest. particularly useful for orbit correction Additional vertical focussing is provided by schemes. two small vertically focussing dipoles in each Straight Secfai /BeamPbrt 7.697m Radius 7.697m Radius Figure 1. Proposed lattice 3. Distributed Dispersion Beta Code - Distributed Dispersion The minimum value for the emittance and The optical functions calculated using the Beta maximum brightness is achieved with code are shown for one cell for distributed distributed dispersion. The performance and dispersion in Figure 2. The emittance under parameters associated with the lattice have these conditions is 11.7 nm rad. been calculated allowing a maximum of approximately 0.29m dispersion in the straight The lattice functions calculated with the Beta sections. Code for distributed dispersion are shown in Figure 2. Table 1 presents a comparison of the settings of the various magnets as derived in the three programs. 103 Figure 2. Lattice functions - Beta Code Table 1. Comparison of the Magnet Settings Parameter Beta Code WinAgile Code Beam Optics 01 1.724 -1.7240 1.724 02 -0.9083 0.9083 -0.9083 03 1.5726 -1.5726 1.5726 SI 24.5 -51.70 24.00 S2 -25.0 51.7 -25.02 sv -5.27 12.53 -10.18 SH 6.28 -9.03 7.10 The values for the three quadrupole families aperture while maintaining a slightly positive are exactly identical as expected. The values value for the chromaticity. (These calculations for the sextupoles are similar after allowance is were performed by M.Abo-Bakr using a made for the difference in the units. For routine developed at BESSY II). Within the example the values for the Beta Code need to WinAgile Code particles were followed for be multiplied by a factor of 2 for comparison 4000 revolutions of the Ml lattice to determine with the values for the WinAgile code. The the best values for the Dynamic aperture. As optimisation of the sextupole settings before the chromaticities were maintained proceeded as follows. Within the Beta Code, slightly positive. The dynamic aperture an iterative scan was made of the SI and S2 calculated with the Beta Code is shown in sextupoles settings to maximise the dynamic Figure 3. o.ro K - \ '•• 0.02S \ v \ 0.Q2 \ 0.013 . \ \ ( 0.01 \ \ \ 0.005 • 0 -ac* -&O4 -ace 0.02 CUM 0.06 Fig.3 Dynamic Aperture calculated with the Beta Code for an ideal lattice Table 2 presents a comparison of synchrotron data calculated with the three codes. Data from the CLS are presented for comparison. 104 Table 2. Comparison of the Calculated Synchrotron Data Parameter Beta Code WinAgile Beam Optics CLS Energy 3GeV 3GeV 3GeV 2.9 GeV Circumference 184.07 m 184.07 m 184.07 m 170.88 m Periodicity 12 12 12 12 Emittance 11.7 nmrad 11.5 nmrad 11.5 nmrad 18.1 nmrad Current 200 mA 200 mA 200 mA 500 mA Horizontal Tune 11.11 11.11 11.11 10.22 Vertical Tune 4.18 4.18 4.18 3.26 Hor Nat Chrom -23.3 -23.6 -13.9 Vert Nat Chrom -17.7 -15.8 -17.7 Corrected Chrom H 0.072 0.1 0.1 Corrected Chrom V 0.160 0.1 0.1 Momentum Com 0.0034 0.0034 0.0034 0.0038 Length Straight 4.57 m 4.57 m 4.57 m 5.2 m Betax 7.5 m 7.43 m 7.50 m 8.5 m Betay 2.85 m 2.84 m 2.84 m 4.6 m Dispersion 0.285 m 0.285 m 0.285 m 0.15 m Dipole Field 1.3 T 1.3 T 1.3 T 1.354 T Damping Time x 2.84 ms 2.84 ms 2.85 ms 2.4 ms Damping Time y 3.85 ms 3.95 ms 3.95 ms 3.8 ms Damping Time E 2.35 ms 2.46 ms 2.45 ms 2.7 ms Energy Loss/turn 931keV 931keV 931 keV 876 keV Total Rad Power 186 kW 186 kW 186 kW 438 kW Energy Spread % 0.103 % 0.103% 0.103% 0.111% Energy Acceptance +6% ±5% ±5% 1.54% Full Bunch Length 9.84 mm 54 ps Dynamic Aperture H ±50 mm + 36 nun + 33 mm ±29 mm Dynamic Aperture V 27 mm 14 mm 18 nun 21mm 4 Zero Dispersion The parameters of the lattice for each of the of the central quadrupoles from 1.5726 to three codes have been calculated for zero 1.5938.