Cosmic ray tests of a 4.6 m-long test drift chamber for JLC

Performance of a 4.6 m-long drift chamber "lled with a CO 2 iso-butane (90:10) mixture was studied using cosmic-ray data, in the course of detector R&D for JLC. After correcting the data for wire displacements due to gravitational and electrostatic forces, a spatical resolution of 100 lm per wire was achieved over the full length of the chamber. The relation between wire e$ciency and oxygen remnant in the chamber gas is also discussed. ( 2000 Elsevier Science B.V. All