FIRST RESULTS OF PULSED SUPERCONDUCTING HALF-WAVE RESONATORS

A pulsed linac for the cooler synchrotron COSY was projected based on superconductive half-wave resonators (HWRs)[1]. The concept of single phased resonators is a great challenge related to the requirement of accelerating protons and deuterons up to a similar energy. A cryomodule, which houses four cavities was designed taing into account the restricted space and the special requirements of a linear accelerator. Two prototypes of the 160MHz, niobium made Half-Wave Resonators (HWRs) were built at different companies. The fabrication methods differ slightly concerning the top and bottom parts of the cavities as well as the welding of the inner and outer conductors. First results of warm and cold measurements will be presented. The behaviour of the adjustable 4kW main coupler as well as the mechanical tuner can be tested together with the HWR in a new vertical test-cryostat. HALF-WAVE RESONATORS The design of the HWRs was dominated by the parameters of a Linac concept to fill the synchrotron COSY at FZ-Juelich with polarized protons and deuterons up to the space charge limit. The first prototype of the 160 MHz HWRs was tested at room-temperature (RT) prior to any chemical preparation. Figure 1 shows the good conformity between the field profile measurements in comparison to the calculated accelerating field by the simulation tool MicrowaveStudio [2]