COLLISIONAL EXCITATION AMONG THE 7 LOWEST STATES OF TIXII

Collision strengths have been calculated for electron impact excitatio n of sodium-like TiXII for all 21 transitions amongst its lowest seven states. Configuration interaction wave functions have been used to re present the target states. The standard and no-exchange R-matrix codes have been used to calculate the contribution of partial waves with L less than or equal to 8 and L>8 respectively. Collision strengths are tabulated at selected energies in the range 26 to 50 Ryd. Effective co llision strengths are tabulated for electron temperatures in the range log T-e = 4.0 to log T-e = 6.0, with T-e in K. This is the first deta iled calculation on this ion in which the effects of exchange, channel couplings and short-range correlation are taken into account.