Atkinson, T.; Dirsat, M.; Dressler, O.; Kuske, P.; Rast, H.: Development of a Non-Linear Kicker System to Facilitate a New Injection Scheme for the BESSY II Storage Ring. In: Proceedings of IPAC2011, 4 - 9 September 2011, San Sebastián, SpainHamburg: DESY, 2011. - ISBN 978-92-9083-366-6, p. 3394-3396
Abstract:
Top-Up injections without noticeable motion of the stored beam is a challenge. The common method of beam accumulation with a local bump formed by four independent pulsed dipole kicker magnets usually causes beam oscillations. The matching of the four independent kicker systems regarding pulse jitters and shapes is technologically limited. Afterward the beam excitation was reduced more when two kicker magnets on each side of the septum were powered in series by one pulser unit. An even more promising approach is to adopt an alternative injection method deploying a single non-linear kicker magnet with zero Bx,y-field in the center and an off-axis maximum, By, which is horizontally displaced by 10-12 mm. There the injected beam gets kicked and looses half of its transverse momentum. Such a magnet was designed and built as a short in-vacuum magnet with a small vertical gap height. For first beam tests the kicker was placed in the second straight section after the injection point, and the 1.5 4s pulse was designed to deflect the 1.72 GeV beam by 1 mrad. In this paper, the calculations of the magnetic fields, the mechanical design as well as the electrical pulser circuit are described.