We present the construction of a planar drift chamber with wires stretched between two arms of a c-shaped aluminium frame. The special shape of the frame allows to extend the momentum acceptance of the COSY-11 detection system towards lower momenta without suppressing the high momentum particles. The proposed design allows for construction of tracking detectors covering small angles with respect to the beam, which can be installed and removed without dismounting the beam-pipe. For a three-dimensional track reconstruction a computer code was developed using a simple algorithm of hit preselection.
Publication: Nucl.Inst.& Meth. A 541 (2005) 574-582