(1) Atomic Physics Laboratory, Physics Department, Banaras Hindu University, Varanasi 221 005, India, IN;(2) Nuclear Science Center, P.O. Box 10502, Aruna Asaf Ali Marg, New Delhi 110 067, India, IN
Abstract:
Measurements were carried out to deduce the transverse kinetic energies of highly charged argon recoil ions produced in single
collisions of 120 MeV ions with argon atoms in which the post collision charge states of the projectiles were not determined. A time of flight
spectrometer was designed and fabricated to detect the charge states of recoils. Experimental procedures for optimizing the
spectrometer for extraction, transmission and detection of recoils are described. A simple approach for determining the transverse
kinetic energy of the recoil ions from FWHM of the peaks is reported. This method is shown to be independent of the choice
of collision partners and requires only the knowledge of the physical values of “optimized parameters” of time-of-flight spectrometer
used in the experiment. The transverse kinetic energy of the recoil ions determined from the present approach is found to
vary from 0.03 eV for to 4.02 eV for Ar10+. These values are compared with the results reported by earlier workers and are shown to follow a q2-behaviour up to a charge state q=8+ of the recoil ions.
Received: 5 February 1998 / Revised: 8 June 1998 / Accepted: 11 June 1998