© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Journal of Physics B Atomic Molecular and Optical Physics

Spectroscopy of autoionizing states using state-selective ion detection

G. T. Xu, Xinqiang Wang, William E. Cooke

Published Mar 14, 1993• 2 citations

Abstract

The authors have measured the population in each of the 5d 3/2 (m j ) ion states following autoionization of the (6p 3/2 nd) J=MJ=3 state by using a circularly polarized laser to excite the Ba + 5d 3/2 to 6p 1 2/ transition, and observing the polarized fluorescence of the Ba + 6p 1/2 to 6s 1/2 transition. The branching ratios for autoionization into each of the 5d 3/2 in l j channels can be related to these ion populations by using angular momentum algebra. The fractions of ions found in the m j =+3/2, +1/2, -1/2 and -3.2 state of the 5d 3/2 ion states were 5.9(+or-2.6)%, 4.5(+or-1.9)%, 3.2(+or-1.3)% and 1.9(+or-0.6)% respectively. This method can easily be generalized to measure the branching ratio for autoonization into other ion states.

DOI: 10.1088/0953-4075/26/5/003

Related papers

A new technique to study Rydberg states by multiphoton ionization spectroscopy

R. D. Verma, Alak Chanda

A new technique to study the Rydberg states of the Ba atom has been developed. In this technique a Multiphoton Ionization signal is detected by selective excitation of the ground state ion (6s) to an excited state (6p), which results in a collimated Amplified Spontaneous Emission (ASE) signal at the 6p→5d transition of Ba+. Discrete Rydberg states, 6snl (l=0,2), as well as autoionizing Rydberg states, 5dnl (l=0,2) and 6pnl (l=0,2) are observed by this novel but very simple method.

AIP conference proceedings•Jan 1, 1988•0 citations

Residual-ion orientation after autoionization

G. T. Xu, Xiao Wang, J. G. Story +1 more

We have measured the relative population in the two ${\mathit{m}}_{\mathit{j}}$ states of barium 6${\mathit{p}}_{1/2}$ ions produced by the autoionization of (6${\mathit{p}}_{3/2}$nd${)}_{\mathit{J}=\mathit{M}\mathit{J}}$=3 states by detecting the helicity of the emitted fluorescence. These populations can be related to the relative branching ratio into the 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{d}}_{5/2}$ and 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{g}}_{7/2}$ continuum channels. Rydberg states with n=16--23 have similar branching ratios, producing approximately six times as much 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{d}}_{5/2}$ population as 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{g}}_{7/2}$ population.

Physical Review A•Apr 1, 1993•4 citations

Electric field-induced changes in the autoionization branching ratios of the 6p{sub 1/2}nd J = 3 states of barium

William E. Cooke, G. T. Xu

We report a measurement of the branching ratio for production of 5d{sub 3/2} ions in various m{sub j} states following the autoionization of the (6{sub p1/2}nd{sub 5/2})J=M{sub J}=3 states of barium in an electric field. By detecting the population in different ion states, rather than the electron distribution, we are able to measure the decay routes even in the presence of an electric field. These branching ratios show pronounced new structure, even at fields as low as 30 V/cm.

Bulletin of the American Physical Society•May 1, 1993•0 citations

Technique to study Rydberg states by multiphoton ionization spectroscopy

R. D. Verma, Alak Chanda

A new technique to study the Rydberg states of the barium atom has been developed. In this technique a multiphoton ionization signal is detected by selective excitation of the ground-state ion (6s) to an excited state (6p), which results in a collimated amplified spontaneous emission signal at the 6p → 5d transition of Ba+. Discrete Rydberg states, 6snl (l = 0, 2), as well as autoionizing Rydberg states, 5dnl (l = 0, 2) and 6pnl (l = 0, 2) are observed by this novel but simple method.

Journal of the Optical Society of America B•Jan 1, 1988•6 citations

A NEW TECHNIQUE TO STUDY RYDBERG STATES BY MULTIPHOTON IONIZATION SPECTROSCOPY

R. D. Verma, Alak Chanda

A new technique to study the Rydberg states of the Ba atom has been developed. In this technique a Multiphoton Ionization signal is detected by selective excitation of the ground state ion (6s) to an excited state (6p), which results in a collimated Amplified Spontaneous Emission (ASE) signal at the 6p→5d transition of Ba*. Discrete Rydberg states, 6snℓ (ℓ=0,2), as well as autoionizing Rydberg states, 5dnℓ (ℓ=0,2) and 6pnℓ (ℓ=0,2) are observed by this novel but very simple method.

Le Journal de Physique Colloques•Dec 1, 1987•1 citation

Photoionization polarization spectroscopy of complex atoms

Koichi Nittoh, K Nakayama, Jun Watanabe +3 more

An improved method for the angular momentum measurement of autoionizing levels of complex atoms based on photoionization polarization spectroscopy is reported. In this method, a variation of the ion yield is measured as a function of the combination of the polarizations of the lasers used to excite the autoionizing level through a ladder of intermediate resonant states. Here, eight combinations of different polarizations in three lasers are used, which include not only circular but also linear polarizations. It has been confirmed that the angular momentum of the autoionizing level can be determined uniquely by relative ion-yield measurements for any combination of angular momenta of the levels of the excitation ladders by choosing appropriate intensities of the lasers.

Journal of Physics B Atomic Molecular and Optical Physics•May 28, 1994•9 citations

The authors have measured the population in each of the 5d 3/2 (m j ) ion states following autoionization of the (6p 3/2 nd) J=MJ=3 state by using a circularly polarized laser to excite the Ba + 5d 3/2 to 6p 1 2/ transition, and observing the polarized fluorescence of the Ba + 6p 1/2 to 6s 1/2 transition. The branching ratios for autoionization into each of the 5d 3/2 in l j channels can be related to these ion populations by using angular momentum algebra. The fractions of ions found in the m j =+3/2, +1/2, -1/2 and -3.2 state of the 5d 3/2 ion states were 5.9(+or-2.6)%, 4.5(+or-1.9)%, 3.2(+or-1.3)% and 1.9(+or-0.6)% respectively. This method can easily be generalized to measure the branching ratio for autoonization into other ion states.

We have measured the relative population in the two

{\mathit{m}}_{\mathit{j}}

states of barium 6

{\mathit{p}}_{1/2}

ions produced by the autoionization of (6

{\mathit{p}}_{3/2}

nd

{)}_{\mathit{J}=\mathit{M}\mathit{J}}

=3 states by detecting the helicity of the emitted fluorescence. These populations can be related to the relative branching ratio into the 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{d}}_{5/2}

and 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{g}}_{7/2}

continuum channels. Rydberg states with n=16--23 have similar branching ratios, producing approximately six times as much 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{d}}_{5/2}

population as 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{g}}_{7/2}

population.

An improved method for the angular momentum measurement of autoionizing levels of complex atoms based on photoionization polarization spectroscopy is reported. In this method, a variation of the ion yield is measured as a function of the combination of the polarizations of the lasers used to excite the autoionizing level through a ladder of intermediate resonant states. Here, eight combinations of different polarizations in three lasers are used, which include not only circular but also linear polarizations. It has been confirmed that the angular momentum of the autoionizing level can be determined uniquely by relative ion-yield measurements for any combination of angular momenta of the levels of the excitation ladders by choosing appropriate intensities of the lasers.