Role of some selected intermediate states of ca i in the collisional excitation of 4p 2p states of ca h in a laser-pumped ca vapour

The role of some intermediate states, e.g. 4s5p³P, 3d4p (¹D,³F) of Ca i in the collisional excitation of the 4p3P_{3/2, 1/2}states of Can (located at 74 720.35 and 74 497.46cm”1 above the ground state of Cat) following pulsed-laser pumping of the 4s4p 3PS state of Ca i (E_cx= 15 210.063 cm^-1), is investigated. A ‘pump’ and ‘probe’ technique is employed together with the study of fluorescent emission. The ‘probe’ laser selectively prepares a substantially higher population of a specific intermediate state in Ca t and the increase in the fluorescent intensity of the 4p 2P_3/2-4s²S_t/2transition of Ca n is read as the relative strength of the particular collision channel utilizing that intermediate state. It is found that the 3d4p¹D₂state has the strongest influence.