The MAX IV 3 GeV storage ring (R3) is based on a novel multi-bend achromat lattice (MBA) for the production of ultra-bright hard x-ray radiation. The storage ring has a circumference of 528 m, comprises 20 achromats, and provides 19 straight sections of roughly 5 m length for insertion devices. As of today R3 serves 10 beamlines, as detailed here. The ultra-low emittance is the result of the strong focusing provided by the multi-bend achromat lattice. A fully NEG-coated copper vacuum system and highly compact magnets machined from common iron yokes provide the technical basis for the realization of this optics. The 3 GeV storage ring is the workhorse of the MAX IV facility and was the world’s first light source based on an MBA technology.
| Circumference | 528 m |
| No. of long straight sections / no. of available ID straights | 20 / 19 |
| Injection | Full-energy top-up from MAX IV Linac |
| Nominal current | 500 mA |
| Horizontal emittance | ~200 - 330 pm rad (depending on ID gap settings) |
| Vertical emittance | 2 - 8 pm rad (depending on user demand) |
| Typical horizontal beam size at ID center | 42 - 54 micron (depending on horizontal emittance) |
| Typical horizontal beam divergence at ID center | 4.7 - 6.1 urad (depending on ID gap settings) |
| Typical vertical beam size at ID center | 2 - 4 micron (depending on choice of vertical emittance) |
| Typical vertical beam divergence at ID center | 1 - 2 urad (depending on choice of vertical emittance) |