• M. Abo-Bakr, B.C. Kuske, A.N. Matveenko
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin

The Helmholtz Zentrum Berlin (HZB) is proposing to build an Energy Recovery Linac Prototype, called BERLinPro, at its site in Berlin Adlershof. A gun test stand for a superconducting RF gun is already under construction at HoBiCaT. In this paper we concentrate on the recirculator part of the ERL and discuss the ERL requirements to the magnet optics. The current design of the magnet lattice will be described and main parameters and simulation results introduced. Since BERLinPro aims to demonstrate high current operation at short pulses according optics aspects will be also discussed. The focus here will be on longitudinal phase space manipulations and lattice layout options, suppressing the BBU instability and increasing its threshold currents.

• B.C. Kuske, M. Abo-Bakr, A.N. Matveenko
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin

The Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) proposes to construct an ERL test facility. To provide different operational modes for different scientific applications is one of the advantages of these new, linac-driven radiation sources. In contrast to the linear machine layouts of FELs, new challenges arise from incorporating the linac into a circular machine. One of them is the so called merger, a magnetic chicane that threads the low energy, low emittance, but high current bunch from the gun into the recirculator. The preservation of the ambitious gun parameters, the optimal collimation of dark current and flexibility to suit all user demands are the dominant design goals. Different design criteria and possible layouts are discussed and a preliminary merger design is proposed.