Laser excitation of the In(62S1/2−52P1/2) atomic transition in a Hg-In-Ne gaseous mixture results in HgIn excimer emission near the In atomic resonance lines at 410.3 nm and 451.1 nm as well as HgIn bound-bound transitions at 499 nm and 522 nm. The spectrum, including the fluorescence lifetimes of the various features, are interpreted in terms of analagous states extrapolated from high resolution spectroscopic observations of HgTl.
Laser excitation of the In(62S1/2−52P1/2) atomic transition in a Hg-In-Ne gaseous mixture results in HgIn excimer emission near the In atomic resonance lines at 410.3 nm and 451.1 nm as well as HgIn bound-bound transitions at 499 nm and 522 nm. The spectrum, including the fluorescence lifetimes of the various features, are interpreted in terms of analagous states extrapolated from high resolution spectroscopic observations of HgTl.
Laser excitation of In atoms at the 62S1/2−−52P1/2 atomic resonance transition wavelength of 410.3 nm in the presence of Hg vapor produces several types of emission features: HgIn excimer satellites on the red wings of the In resonance fluorescence transitions at 410.3 and 451.1 nm, bound-bound HgIn molecular fluorescence at 499 and 522 nm resulting from photoassociation of In(62S1/2) with Hg(61S0), and UV atomic fluorescence from the In(52D) states that lie at energies above the In(62S1/2−−52P1/2) excitation. These various spectral features are interpreted in terms of a proposed HgIn potential-energy level diagram with additional information from measured excited-state lifetimes and the power dependence of the laser excitation at 410.3 and 522 nm. Direct excitation of the 499 and 522 nm HgIn bound-bound transitions also produces emission at 410.3 and 451.1 nm resulting from collisional dissociation of the excited HgIn states.
We report the first observation of laser-induced fluorescence of the CsHg molecule. Cs/Hg vapor mixtures contained in a heat-pipe oven were excited by several different argon ion laser lines. Following these excitations, we observed three distinct peaks at λ=492.8, λ=498.3, and λ=521.5 nm in addition to the well-known fluorescence of the Cs2 molecule. Based on an analysis using ab initio potential energy curves of Cs2 and CsHg, we identified the origin of these three distinct peaks as bound–free transitions of CsHg (λ=492.8: IV3/2→X1/2, λ=498.3: VII1/2→X1/2, and λ=521.5 nm: VI1/2→X1/2). Furthermore, we could show that two different production channels are responsible for the formation of the CsHg molecules in the excited states. The excitation of the Cs/Hg vapor mixtures with wavelengths λexc=476–514 nm of the argon ion laser results in the production of the CsHg molecules via a photoassociation process, whereas the CsHg molecules are produced in a three-body collision following an excitation with λexc=457 nm. These results are confirmed by subsequent quantum-mechanical simulations of the observed laser-induced fluorescence spectra of CsHg.
After excitation of the 7 1 S 0 mercury state by two photon absorption of a laser radiation at 313 nm the time integrated intensities of the 407.8 (I 0 ) and 404.7 nm (I 1 ) lines emitted from the 7 1 S 0 and 7 3 S 1 states were determined as functions of the pump laser intensity, I, and mercury pressure. At high pump laser intensities I 0 and I 1 do not follow anymore a quadratic law in I, I 0 weakens to I n<2 while, in contrast, I 1 increases to I n>2 . The time evolutions of the populations of these 7 1 S 0 , 7 3 S 1 states and of the 6 1 P 1 , 6 3 P 0,1,2 states were determined. The set of experimental results is well reproduced by introducing collisions of two Hg(6P) atoms as well as two Hg(7 1 S 0 ) collisions. Effects of these collisions are discussed.
Collisional transfer of excitation from mercury to sodium was investigated using methods of sensitized fluorescence. A mixture of mercury and sodium vapors at low pressure was irradiated with Hg 2537 Å resonance radiation, producing a population of Hg(63P1) atoms whose inelastic collisions with ground-state sodium atoms resulted in a transfer of excitation energy to close-lying S, P, and D states in sodium. The subsequent decay of these states manifested itself in the emission of a sensitized fluorescent spectrum. Absolute intensity measurements on the components of the spectrum yielded 21 cross sections whose magnitudes range from 0.02 to 38.5 Å2 and which exhibit a pronounced resonance with ΔE, the energy defect between Hg (63P1) and the appropriate level in sodium.
The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg–Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 Å resonance radiation which caused the mercury atoms to become excited to the 63P1, state. Subsequent collisions between the Hg(63P1) and Tl(62P1/2) atoms resulted in the population of the 82S1/2, 62D, and 72S1/2 thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 Å. Intensity measurements on the sensitized fluorescence and on the Hg 2537 Å resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 Å2 for collisional excitation transfer from Hg(63P1) to the 82S1/2, 62D, and 72S1/2 states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.
We present studies on monoisotopic Hg+ ions generation and trapping at room temperature. An ultraviolet laser system, including a frequency-controlled 194 nm laser and a 254 nm laser, is constructed. Mercury atoms are isotope-selectively excited by the 254 nm laser. The spectrum of the 6s2–6s6p transition lines for natural mercury isotopes is measured, and the uncertainty is less than 100 MHz. Then, the selected mercury isotopes are ionized by the 194 nm laser and trapped in a linear Paul trap. The fluorescence of the ion crystal at 194 nm is detected, and the temperature of the ions is estimated to be less than 10 mK.