Laboratório Nacional
de Luz Síncrotron

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ACCELERATORS PARAMETERS

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Sirius’ Storage Ring uses a 20-cell 5BA magnetic lattice to achieve a very low beam emittance of 0.25 nm.rad. The 518 m circumference contains 20 dispersion-free straight sections of alternating 6.5 and 7.5 meters in length, to be used for insertion devices as well as injection and RF systems. The central dipole of the 5BA cell is a permanent magnet with transverse and longitudinal field gradients to reduce the emittance and provide a hard X-ray radiation source. The thin high field section at its center of approximately 3.2 T provides radiation with critical energy of 19 keV with a modest contribution to the total energy loss. The other low field dipoles (0.58 T), responsible for the main beam deflection, will be electromagnetic.

The Booster lattice consists of 50 modified FODO cells with combined-function magnets suitable to provide low emittance. The main difference from other booster designs is that the Sirius booster contains only arc sections: no long dispersion-free straight sections are provided. This means that injection and extraction, as well as the Petra 5-cell RF cavity, are located in these dispersive straight sections. With this concept a very high lattice symmetry for the booster is obtained and only a few magnet families are necessary.

PARAMETERS OF THE ELECTRON BEAM


ParametersValueUnit
Energy3.0GeV
Gamma Factor5870.854-
Beta Factor0.999999985-
Velocity$ 2.9979 \times 10^{8}$m/s
Magnetic Rigidity10.0069T.m
Nominal Current350.0mA

PARAMETERS OF THE STORAGE RING


ParametersValueUnit
Lattice
Type5BA-
Circunference518.396m
Revolution period1.729$ \mu \rm s$
Revolution frequency0.5783MHz
Long Straight Sections5 x 7.5m
Short Straight Sections15 x 6.5m
Optics
Linear Momentum Compaction$1.630 \times 10^{-4}$-
Transverse coupling1.0%
Betatron Tunes49.110 (h) x 14.165 (v)-
Natural Chromaticities-119.2 (h) x -79.1 (v)-
Beam size at center of SS-A64.9 (h) x 3.4 (v)$ \mu \rm m$
Beam size at center of SS-B19.1 (h) x 2.0 (v)$ \mu \rm m$
Beam size at center of BC9.5 (h) x 3.5 (v)$ \mu \rm m$
Beam divergence at center of SS-A3.8 (h) x 0.7 (v)$ \mu \rm rad$
Beam divergence at center of SS-B13.0 (h) x 1.3 (v)$ \mu \rm rad$
Beam divergence at center of BC26.9 (h) x 0.7 (v)$ \mu \rm rad$
Equilibrium Parameters
Natural Emittance0.251nm.rad
Natural Energy Spread0.085%
Natural bunch length2.5 (8.2)mm (ps)
Energy loss from Dipoles per turn475.3keV
Energy loss from IDs per turn400.0keV
Radiation power from Dipoles237.6kW
Radiation power from IDs200.0kW
Damping partition number1.30 (h) x 1.00 (v) x 1.70 (L)-
Damping time (dipoles only)16.78 (h) x 21.83 (v) x 12.83 (L)ms
RF Parameters
Frequency499.658MHz
Harmonic Number864-
Cavity Peak Voltage3.0MV
Synchronous phase163.0°
Synchronous tune$ 4.6 \times 10^{-3}$-
Synchronous frequency2.68kHz
Energy Acceptance5.1%
Low Filed Dipoles
Magnetic Field0.5812T
Bending Radius17.218m
Critical Energy3.48keV
Number of Dipoles40 (B1) / 40 (B2) / 40 (BC_LF)-
Hard-edge length of dipoles0.8280 (B1) / 1.2310 (B2) / 0.4250 (BC_LF)m
Deflection angle2.76 (B1) / 4.10 (B2) / 1.58 (BC_LF)°
High Filed Dipoles
Magnetic peak field3.2T
Bending Radius at peak3.127m
Critical energy at peak19.15keV
Number of dipoles20 (BC_HF)-
Deflection angle1.14°

PARAMETERS OF THE BOOSTER


ParametersValueUnit
Beam extraction energy3.0GeV
Beam Injection energy0.150GeV
Beam current2.0mA
Circunference496.800m
Revolution frequency0.603MHz
Revolution period1.657$ \mu \rm s$
Cycling frequency2Hz
Betatron Tunes19.204 (h) x 7.314 (v)-
Momentum compaction factor$ 7.19 \times 10^{-4}$-
Natural cromaticities-33.70 (h) x -13.95 (v)-
Natural emittance3.47nm.rad
Natural energy spread0.087%
Damping time11.3 (h) x 13.8 (v) x 7.7 (L)ms
RF frequency499.654MHz
Harmonic number828-