Performance of the new drift chambers for HADES @ FAIR

Seven new Multiwire Drift Chambers of plane 1 for the High - Acceptance Di - Elektron Spectrometer (HADES) are assembled in the Detector workshop of the Forschungszentrum Dresden - Rossendorf.
We present the results of test performed on the first chamber in comparison with the main design parameters .
End of 2008 one detector was completely equipped with the new generation of the readout system designed for the high multiplicity environment as provided in collisions of heavy systems at HADES @ FAIR.
The chamber was investigated with cosmic rays and β ⁹⁰Sr source. The obtained results show that the new design fulfills the equirements with respect to efficiency, accuracy and rate capability.
These chambers will be installed in 2009 to be armed for the upcoming heavy ion program.