The Munich Heavy Ion Post Accelerator

Abstract

The post accelerator in the Munich MP-tandem laboratory is a linear radio-frequency accelerator of the Interdigital-H-structure (IH). This structure has a particular high shunt impedance for particle velocities in the range 0.05 ß < 0.106. In this velocity range the effective shunt impedance is empirically well described by Z<_eff=13(±1)M&#x003A9;/m·ß<sup-0.84</sup>. The drift tube configuration is changeable in order to adjust the structure to the different particle velocities of the ion beams from the tandem accelerator. The eigenfrequency of different configurations varies between 55 and 80 MHz. With an applied rf-power of 50 kW. in continuous operation it is possible, to increase the energy of the ion beam by a factor of 1.5-2. Acceleration tests have been performed with &#x022C9;-particles from a radioactive ²⁴¹Am &#x022C9;-source. The &#x022C9;-particles were accelerated with 50 kW rf-power from 4.1 MeV to 14.9 MeV. A beam of ³²S ions from the tandem with charge state 14+ was accelerated from 100 MeV to 160 MeV with an applied rf-power of 40 kW.