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Titolo:
The collisional behaviour of Ba[6s5d(D-3(J))] generated following pulsed dye-laser excitation at lambda=553.5 nm {Ba[6s6p(P-1(1))] <- Ba[6s(2)(S-1(0))]} in the presence of noble gases and ground state atomic barium by atomicspectroscopic marker emission measurements in the time-domain
Autore:
Adams, JW; Lei, J; Husain, D;
Indirizzi:
Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England Univ Cambridge Cambridge England CB2 1EW hem, Cambridge CB2 1EW, England
Titolo Testata:
ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS
, volume: 215, anno: 2001,
parte:, 9
pagine: 1205 - 1230
SICI:
0942-9352(2001)215:<1205:TCBOBG>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
TRANSITION-PROBABILITIES; NEUTRAL BARIUM; VAPOR; BA<6S6P(P-1(1))><-BA<6S(2)(S-1(0))>; SR<5S5P(P-3(J))>; FLUORESCENCE; POPULATION; RESONANCE; KINETICS; LINES;
Keywords:
Ba[6s5d(D-3(1,2,3))]; pulsed laser generation; spectroscopic marker monitoring; collisions with noble gases and Ba;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Husain, D Univ Cambridge, Dept Chem, Lensfield Rd, Cambridge CB2 1EW, England Univ Cambridge Lensfield Rd Cambridge England CB2 1EW , England
Citazione:
J.W. Adams et al., "The collisional behaviour of Ba[6s5d(D-3(J))] generated following pulsed dye-laser excitation at lambda=553.5 nm {Ba[6s6p(P-1(1))] <- Ba[6s(2)(S-1(0))]} in the presence of noble gases and ground state atomic barium by atomicspectroscopic marker emission measurements in the time-domain", Z PHYS CHEM, 215, 2001, pp. 1205-1230

Abstract

We present a kinetic study of the collisional behaviour of Ba[6s5d(D-3(J))], 1.151 eV above the 6s(2)(S-1(0)) ground state (J = 1, 1.120, 1 = 2, 1.143, J = 3, 1.190 eV) in the time-domain. This optically metastable atom was generated following the pulsed dye-laser excitation of atomic barium vapourat elevated temperatures at lambda = 553.5 nm {Ba[6s6p(P-1(1))] <-- Ba[6s(2)(S-1(0))]}. Ba(D-3(J)) was then produced in the long-time domain following a complex series of collision and radiative processes within the energy manifold of atomic barium. The collisional behaviour of this species in the presence of neon and argon, and ground state Ba[6s(2)(S-1(0))] itself, was then monitored using spectroscopic marker emission measurements at lambda =877.4 nm {Ba[6s5d(D-1(2))] --> Ba[6s(2)(S-1(0))]}, lambda = 791.1 nm {Ba[6s6p(P-3(1))] --> Ba[6s(2)(S-1(0))]} and lambda =553.5 nm {Ba[6s6p(P-1(1))] --> Ba[6s(2)(S-1(0))]} following energy transfer by collision and energy pooling. As in previous investigations with other noble gases, first-order rate coefficients for the emission profiles at 553.5 nm, 791.1 mn and 877.4 nm, which demonstrate exponential decay, were found to be in the ratio 2: 1 : I in the long-time regime. These 'long times', typically 1-2 msec, may becontrasted particularly with the mean radiative lifetimes of Ba[6s6p(P-1(1))] (tau (e) = 8.37 +/-0.38ns) and Ba[6s6p(P-3(1))] (tau (e) = 1.2 +/-0.1 mus). A computerised kinetic model is presented to account for these emission profiles in the 'Iong-time' domain. The decay coefficients resulting fromthese measurements are used to describe quantitatively the collisional anddiffusional processes undergone by Ba(D-3(J)) with Ne and Ar, which are considered within the context of all the noble gases, particular attention isgiven to the collisional removal of Ba(D-3(J)) by Ba( ISO) where all rate measurements, which have hitherto employed a variety of vapour density datafor atomic barium at elevated temperatures, are normalised to common vapour pressure data. Finally, an estimate is made of the mean radiative lifetime, tau (c)((BaD1)-D-3) = 1.5 +/-0.2ms.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/04/20 alle ore 01:58:50