Beam dynamics and expected performance of Sweden’s new storage-ring light source: MAX IV

Abstract

MAX IV will be Sweden's next-generation high-performance synchrotron radiation source. The project has recently been granted funding and construction is scheduled to begin in 2010. User operation for a broad and international user community should commence in 2015. The facility is comprised of two storage rings optimized for different wavelength ranges, a linac-based short-pulse facility and a freeelectron laser for the production of coherent radiation. The main radiation source of MAX IV will be a 528 m ultralow emittance storage ring operated at 3 GeV for the generation of high-brightness hard x rays. This storage ring was designed to meet the requirements of state-of-the-art insertion devices which will be installed in nineteen 5 m long dispersion-free straight sections. The storage ring is based on a novel multibend achromat design delivering an unprecedented horizontal bare lattice emittance of 0.33 nm rad and a vertical emittance below the 8 pm rad diffraction limit for 1 Å radiation. In this paper we present the beam dynamics considerations behind this storage-ring design and detail its expected unique performance.

Perspectives for future light source lattices incorporating yet uncommon magnets

“…It is planned to correct for the influence of insertion devices both locally (matching of the achromat optics to the insertion device) and globally (restoring the working point) [3]. This can be done almost exclusively by adjusting the nondispersive matching quadrupoles at the end of the achromat.…”

“…Nevertheless, we believe the MBA approach as applied to the design of MAX IV [3] to be superior to TME and LGB for building an ultralow-emittance lattice within a limited circumference.…”

“…The MAX IV 3 GeV storage ring lattice design is detailed elsewhere [3] and only a very brief overview will be given here. The storage ring lattice was tailored to match the requirements of state-of-the-art x-ray insertion devices: a 528 m circumference multibend achromat lattice with 20-fold periodicity that achieves an ultralow emittance of 0.33 nm rad for the bare lattice; a reduction by 50% can be achieved if all straights are occupied with insertion devices.…”

“…Assuming an isomagnetic lattice, i.e., all bending magnets are of same type, with constant curvature h and a bending angle È ¼ hL, the TME is obtained by solving integral I 5 over H from Eqs. (2) and (3) and minimizing the result with respect to the values of x , x , , and 0 at some point [11][12][13][14][15]-cf. Appendix A for details.…”

“…A new generation of rings (PETRA III [1], NSLS-II [2], MAX IV [3]) is characterized by a natural emittance 1 nm rad and significant impact of insertion devices on the radiation equilibrium. Lattices for an ''ultimate light source'' with emittance in the pm rad range providing fully diffraction-limited photon beams are being studied (see, for example, [4][5][6][7][8]).…”