Complex bend. II. A new optics solution

Abstract

In our previous publications, we introduced a concept of complex bend, which is a bending element consisting of dipole poles, interleaved with strong focusing and defocusing quadrupole poles. An electron ring built from such elements features low emittance while preserving substantial room for insertion devices and associated lattice elements. In this paper, we present two new optics solutions for the complex bend which offer to substantially reduce the device length by removing the dipole poles. In the first of the solutions, the bending is realized by shifting the quadrupole poles along the curved horizontal axis. For the second solution, we use permanent magnet quadrupole poles installed into a wide gap of the conventional electromagnet. In this case, the resulting bending field in the magnet gap is a superposition of the quadrupole field from the poles and the dipole field from the conventional magnet. We present an analysis of the particle motion and synchrotron radiation emitted in such fields, as well as an assessment of the ring linear lattice that is composed of complex bend elements.