PROPORTIONAL CHAMBERS WITH A 2X1-M(2) WORKING AREA FOR THE EXCHARM SPECTROMETER

The structure and electronic hardware of three-coordinate proportional chambers with a working area of 2 x 1 m(2) and a spacing between sign al wires of 2 mm are described. Characteristics of the chambers operat ing at the Serpukhov accelerator are given. The detection efficiency o f the chamber filled with the Ar+20%C4H10+3%C4H7OH+0.3%CF3Br mixture w ith respect to charged particles reaches 98%. The curve of the chamber efficiency versus high voltage has a plateau 350 V wide. The chamber space resolution ranges from 0.69 to 0.75 mm, depending on the inciden ce angle of a charged particle with respect to the coordinate planes.