HI all, I thought I might pass on the reference to D.C. Christial et al, High Rate Drift Chambers NIM A345 (1994) 62-71. This describes work that David has been involved in at Fermilab. Cheers, Elton. Elton Smith Jefferson Lab MS 12H5 12000 Jefferson Ave Suite # 16 Newport News, VA 23606 elton@jlab.org (757) 269-7625