Radiative Lifetime Measurements Of Highly Excited Odd-parity Levels Of Pt I

Astrospectroscopy is a method to identify the stellar formation and evolution of stars by analyzing the stellar spectroscopy obtained in astronomy observation events. These lines in spectrum are used to comprehend the stellar structure of matter in Kirchhoff’s thoery and evaluate the stellar temperature according relative intensity classification of lines. And spectral lines broadening and splitting respond the stellar temperature and the magnetic intensity. Determinations of astronomical radial velocity as well as autogiration correlate to spectrographic analysis. Astrospectroscopyanalysis is based on a mount of radiative data of atoms and ions. Oscillator strengths deduced by combining radiative lifetime and branching fraction can help to study element abundance in stellar. The element abundance is a key to explore the origins of the universe and the stars evolutional mechanism. In sum, the study of radiative lifetime influences basic research of astrophysics.Benefiting from the process of Space exploration technologies, the detection range expanded to near ultraviolet region, even the far ultraviolet scope. Some heavy neutron-capture elements, such as Ge, As, Se, Mo, Cd, Te, Lu, Os, Ir, Pt, Au, Pb, were first distinguished in stellar spectrum. But these elements were hardly recorded in papers determining radiative parameters, which were restricted with laser energy and measurement instruments. So the determinations of radiative lifetime in atoms and ions need to be solved.Radiative lifetime measurements of 15 highly excited odd-parity levels in Pt I were performed using time-resolved laser-induced fluorescence(TR-LIF) technique in this paper. TR-LIF is recognized to be in high-precision. The free platinum atoms in the ground state and the metastable states generated by laser-induced plasma spectroscopy(LIPS) were motivated by excitation light from a Nd: YAG laser and then emission fluorescence generated in spontaneous radiative transition from the target level. The fluorescence signal was obtaned and recorded by monochromator and oscilloscope in the experiment. Radiative lifetime values of the aimed levels could be evaluationed by fluorescence curve analysed with an exponential fitting. This paper has performed measurements of 15 highly excited odd-parity levels of Pt I which covers some electron configurations(5d96 p、5d 6s6p、5d 6p、5d 7p、5d 6s 6p) in Pt I. The measured lifetime values range between 6.1 and 116 ns with an uncertainty of 10% or less. Comparison with previous results reveals a good agreement. To our knowledge, five of these excited levels, which approach 60000 cm, were measured for the first time.Radiative data influence many aspects such as plasma diagnostics, performance evaluation of laser medium, studying nonconservation of parity in atomic physics and so on. In sum, radiation parameter derminations are of significance in astronomy and physics.