Doubly excited 2 1Δg state of Na2

Abstract

The doubly excited valence (3p+3p) 2 (1)Delta(g) state of Na(2) is experimentally observed by using optical-optical double resonance spectroscopy. A single line Ar(+) laser (a total of nine lines) was used to pump the sodium dimers from thermally populated ground state X (1)Sigma(g) (+) to the intermediate B (1)Pi(u) state. Then, a single mode Ti:sapphire laser was used to probe the doubly excited 2 (1)Delta(g) state. Violet fluorescence emitted from the highly excited states (mainly 2 (3)Pi(g) or 3 (3)Pi(g) states which are transferred from 2 (1)Delta(g) state via collision) to the a (3)Sigma(u) (+) state was monitored by a filtered photomultiplier tube (PMT). A total of 582 rovibrational levels of 2 (1)Delta(g) state were observed, identified, and assigned to the vibrational and rotational quantum numbers in the range of 0< or =v< or =28 and 11< or =J< or =99, respectively. The absolute vibrational quantum number assignment was verified by comparing the totally resolved fluorescence with the calculated Franck-Condon factors between 2 (1)Delta(g) state and B (1)Pi(u) state. Dunham coefficients and Rydberg-Klein-Rees potential curve were derived from these observed quantum levels. The primary molecular constants of Na(2) 2 (1)Delta(g) state are T(e)=32 416.759(15) cm(-1), omega(e)=124.8484(36) cm(-1), B(e)=0.119 158(3) cm(-1), and R(e)=3.508 20(5) A.

Experimental study of the Na2 31Πg state

“…2 plots the block diagram of the experimental setup which is similar to that in [11]. Briefly, a single line Ar + laser (Coherent I-90, total of 9 lines) was used as the pump laser to excite from a thermally populated ground state X 1 R þ g ðv 00 ; J 00 Þ sodium dimer to the intermediate B 1 P u (v 0 , J 0 = J 00 or J 00 ± 1) state.…”

Λ-Doubling investigation of the 51Πg Rydberg state of Na2 using optical–optical double resonance spectroscopy

“…The experimental setup has been described in more detail in [10]; hence we only dwell on it briefly. As shown in Fig.…”

Observation of the 7Πg State of Na2 by Optical−Optical Double Resonance Spectroscopy

“…The details of the optical−optical double resonance experimental setup with a block diagram can be found elsewhere …”

“…In particular, the Na 2 system has been studied for understanding different types of interactions playing important roles in diatomic molecules and to search for the answers to many intriguing questions about the fundamental physical properties of atoms and molecules. Researchers have carried out many works in investigating Na 2 using high level ab initio calculations , and experimental techniques − that involve many interesting and unusual features of the interactions.…”