Prijenos energije pobude između 6s5d 1D2 i 6s5d 3DJ stanja barija u sudarima s atomima helija, argona i ksenona

The cross sections for the Ba 6s5d 1D2 → 6s5d 3DJ excitation energy transfer, induced by collisions with He, Ar and Xe, were measured using laser absorption and fluorescence methods in the steady-state regime. The populations of the barium metastable 6s5d 1D2 and Ba 6s5d 3DJ states were created by subsequent radiative and collisional relaxation of the optically excited 6s6p 3P01 level. The four-level model, comprising 6s2 1S0, 6s6p 3P10, 6s5d 1D2 and 6s5d 3DJ states, is proposed for the description of the population and depopulation processes of the Ba metastable states in noble gas atmosphere. The analysis of the experimental results, within the assumed model, yields the following cross-section values for the investigated processes: σHe = 1.5×10-20 m2, σAr = 2×10-22 m2 and σXe = 8×10-21 m2, with an accuracy of ±50%.Metodom laserske apsorpcije i fluorescencije određeni su udarni presjeci za prijenos energije pobude u procesu Ba 6s5d 1D2 → 6s5d 3DJ uzrokovanom sudarima s atomima helija, argona i ksenona. Metastabilni nivoi 6s5d 1D2 i 6s5d 3DJ napučivani su radijativnom i sudarnom relaksacijom optički pobuđenog 6s6p 3P 0 1 stanja. U okviru predloženog modela sa četiri nivoa, koji uključuje 6s2 1S0, 6s6p 3P 0 1 , 6s5d 1D2 i 6s5d 3DJ stanja, opisani su procesi napučivanja i pražnjenja barijevih metastabila u atmosferi plemenitog plina. Analiza eksperimentalnih rezultata daje slijedeće udarne presjeke za istraživane procese: σHe = 1.5 × 10−20 m2 , σAr = 2 × 10−22 m2 σXe = 8 × 10−21 m2 , s točnošću od ±50