Storage Ring


The SESAME Storage Ring is a 133.2 circumference and 2.5GeV energy one. The 8-fold Storage Ring lattice is a simple Double Bend Achromat (DBA) one composed of 16 mirror-image cells with 16 dispersive sections.  Each cell contains one combined-function Bending Magnet (BM) flanked by two Focusing Quadrupoles (QF), two Defocusing   ones (QD), two Focusing Sextupoles (SF) and two Defocusing ones (SD).

The Storage Ring offers a maximum capacity of 25 beamlines. The storage ring is filled with electrons at 800MeV at a repetition rate 1Hz, then its energy is ramped to the operational value 2.5 GeV.

One cell and the main parameters of the Storage Ring are shown and listed in the Figure and Table below respectively.


Parameter Unit Value
Energy GeV 2.5
Circumference m 133.2
Betatron tunes Qx / Qz   7.23 / 6.19
Number of super-periods   8
Bending Dipole field T 1.45545
Field gradient T/m -2.794
Natural Chromaticities H / V   -15.15 / -20.56
Energy loss / turn keV 590.2
Damping time   τE / τx / τz msec 2.74/2.32/3.76
RMS energy spread  σE % 0.1073
Natural emittances ɛx / ɛy nm.rad 25.74 / 0.2574
Betatron coupling % 1


RF Parameters Unit Value
Frequency MHz 499.654097
Harmonic Number   222
Peak Voltage MV 2.4
RF acceptance (ɛRF) % 1.463
Synchrotron tune   0.0165
Synchrotron frequency (νs) kHz 37.147
Natural bunch length (σL) mm 11.42
Max current (200 bunch) mA 400