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Storage Ring




The core of the SSRF complex is a 3.5 GeV storage ring with a circumference of 432 meters. The storage ring lattice is a 20-cell double bend achromat lattice structure with 4 super-periods and each super-period contains a 12 meters

long straight section and four 6.5 meters standard straight sections. Two of the long straight sections have been used

for accommodating injection elements and for installing three superconducting RF cavities respectively, the other

eighteen straight sections are used to install various insertion devices. Each of the 20 storage ring double bend lattice

cells consists of two bending dipole magnets, ten quadrupole magnets, seven sextupole magnets and seven pairs of

corrector magnets, 4 of them are slow correctors, others are fast correctors. The storage ring is equipped with

three superconducting RF cavities in a 12 m-long straight section to provide the beam with a voltage of 4-6 MV

and a total beam power up to more than 600 kW. The injection system consists of two septum magnets and four

kicker magnets and is optimized for top-up operation. The storage ring has a natural emittance of 3.9 nm-rad and

can operate at a multi-bunch current up to 300 mA or at a single bunch current of 5 mA. A sophisticated beam

diagnostic system and an orbit feedback system keep the position of the electron beam constant to less than

1 µm (RMS), which guarantees a very high stability of the electron orbit.


The main specifications are listed in the following table


Injection energy (GeV)


Extraction energy (GeV)


Beam Current (mA)

Single bunch


Multi bunch


Circumference (m)


Cell number/Super periods


Natural emittance (nm-rad)


Betatron tune ( nH /nV)


Nature Momentum spread


RF Frequency (MHz)


RF voltage (MV)


Repetition rate (Hz)