One central subject is the development of linear ion accelerators for fundamental and applied research. Ion source development is focused on the production of high current ion beams at low charge states. The volume plasma is generated by a cathode driven discharge. Alternative microwave heating techniques are under investigation.

200 mA Proton source; Courtesy: Klaus Volk

Low energy beam transport at high beam current is investigated by beam simulations and by experiment. Space charge effects and their modification by trapped electrons have to be studied in detail to reduce the deterioration of beam quality along transport lines.


Visualization of a proton beam by rest gas interaction; Courtesy: Klaus Volk


One main focus is put on the development of linear accelerators. Beam dynamics concepts and drift tube structures are studied, which allow to reach specified beam parameters at reasonable facility size and expenses. Injectors for fundamental and applied research have been developed and were delivered to numerous accelerator facilities around the world.

10 MegaVolt Drift tube accelerator during production; Courtesy: Uli Ratzinger


Currently, a compact 68 MeV proton linear accelerator for GSI/FAIR in Darmstadt is under development. A new type of Radio Frequency Quadrupole "Ladder-RFQ" as well as a well-suited drift tube cavity of the H-Type "CH-DTL" are developed within that project and should pave the way towards simplified ion injectors for future synchrotron facilities.

Prototype Ladder-RFQ, vacuum tank opened; Courtesy: Max Schütt


A neutron source FRANZ is under construction at IAP. The pulsed high current proton driver beam allows developments in the fields of beam diagnostics, radio frequency and operation controls, detailed investigations on the particle distribution in phase space and beam experiments in applied research (besides the main research program on FRANZ by the Nuclear Astrophysics group).

A Figure Eight – type storage and collider ring for intense low energy beams is studied by beam simulations and investigated experimentally at a 60 degree bending section. This "two-beam setup" allows the study of different beam injection schemes into such a toroidal magnetic array.

Experimental test array for the "Figure Eight Ring"; Courtesy Heiko Niebuhr

Beam dynamics aspects at a large variety of beam parameters, focusing lenses and accelerator structures have to be investigated by beam simulation codes, which are suited for individual cases. Our group has to improve existing codes and to develop new codes for new challenges in beam development.
LORASR code: Beam envelopes in energy and phase; Courtesy: R. Tiede