• A. Jankowiak, K. Aulenbacher, O. Chubarov, M. Dehn, H. Euteneuer, R.G. Heine, P. Jennewein, H.-J. Kreidel, U. Ludwig-Mertin, O. Ott, G.S. Stephan, V. Tioukine
  IKP, Mainz

Funding: Work supported by DFG (CRC443) and the German Federal State of Rheinland-Pfalz

In December 2006 the maximum output energy of the cw race track microtron cascade MAMI B was increased to 1508MeV by the successful commissioning of the world wide first Harmonic-Double-Sided-Microtron (HDSM)* as a new fourth stage. Since then MAMI C was in operation for more than 15000 hours, delivering approx. 10000 hours the maximum beam energy of 1508MeV. We will report about our operational experiences and the recent machine developments concerning e.g. the increase of the energy and stabilisation of the output energy down to 10^-6. Topics of machine reliability and stability will be addressed and the operation under different demands of nuclear physics experiments described.

*K.-H. Kaiser et al., NIM A 593 (2008) 159 - 170, doi:10.{10}16/j.nima.2008.05.018

• M. Dehn, H. Euteneuer, A. Jankowiak
  IKP, Mainz

Funding: Work supported by DFG (CRC 443) and the German Federal State of Rheinland-Pfalz.

The 1.5GeV Harmonic Double Sided Microtron (HDSM)* as the fourth stage of the Mainz Microtron (MAMI) is now in routine operation for two and a half years**. Simulations predicted a wide range of applicable longitudinal parameters with which the machine can be run. Measurements of the longitudinal acceptance proved that. The reproducibility of different configurations is sufficient to support a fast and reliable set-up of the machine and to guarantee a stable long-term operation. But in order to optimise the configuration a reliable measurement of the phases and accelerating voltages in both linacs is essential. Each turn’s phase information is provided by low-Q-TM010 resonators at both linacs when operating the machine with 10ns diagnostic pulses. The HDSM’s four bending magnets are designed with a field gradient to compensate the vertical fringe defocusing. The decreasing field integral results in less synchronous energy gain per turn, automatically causing a change of the longitudinal phase. The calibration of the phase signals which in case of the RTMs could be easily done by exciting a synchrotron oscillation was improved to deliver precise phase data.

*K.-H. Kaiser et al., NIM A 593 (2008) 159 - 170, doi:10.{10}16/j.nima.2008.05.018
**A. Jankowiak et al., ID 2689, this conference