“…Pulse energies were typically 150 mJ for the excimer, 20 μJ for λ 12 , 200−300 μJ for λ 23 , and 0.1−1 mJ for λ 34 . Laser pulse durations, as reported in our previous work, were ∼34 ns (fwhm). 1 Experimental setup, with the three-step excitation scheme shown in the inset.…”
Section: Methodsmentioning
confidence: 72%
“…In our previous, time-resolved ionization study, it was shown that direct photoionization from the 7s 3 S 1 level occurred, as the ionization wave form observed without λ 34 (λ 12 + λ 23 only) resembled the exciting laser pulse shape. The behavior observed here as a result of increasing the laser energy of λ 34 indicates that the excitation cross section for the 7s 3 S 1 → n p 3 P 0 2 transitions ( n = 10, 11, and 12) cannot differ from the photoionization cross section from the same 7s 3 S 1 level in the absence of λ 34 by more than ∼1 order of magnitude.…”
Section: Resultsmentioning
confidence: 88%
“…In the resonance ionization literature, it is well-known that the two factors influencing the rate of collisional ionization are (1) the energy difference between the excited atomic levels of different principal quantum number (from which ionization is occurring) and the ionization continuum and (2) the number of ionizing collisions, which depends on the temperature in and around the interaction region. The former factor was studied in our previous work, in which we observed the behavior of the rate of collisional ionization when different atomic levels, of increasing principal quantum number, were reached by laser excitation …”
Section: Resultsmentioning
confidence: 99%
“…The experimental setup used in this work, shown in Figure for the sake of clarity, is similar to the one described in our previous paper . The inset gives a schematic representation of the stepwise excitation scheme.…”
A new method for laser-enhanced ionization detection of mercury atoms in an inert gas atmosphere is described. The method, which is based on the avalanche amplification of the signal resulting from the ionization from a selected Rydberg level reached by a three-step laser excitation of mercury vapor in a simple quartz cell, can be applied to the determination of this element in various matrices by the use of conventional cold atomization techniques. The overall (collisional + photo) ionization efficiency is investigated at different temperatures, and the avalanche amplification effect is reported for Ar and P-10 gases at atmospheric pressure. It is shown that the amplified signal is related to the number of charges produced in the laser-irradiated volume. Under amplifier noise-limited conditions, a detection limit of ∼15 Hg atoms/laser pulse in the interaction region is estimated.
“…Pulse energies were typically 150 mJ for the excimer, 20 μJ for λ 12 , 200−300 μJ for λ 23 , and 0.1−1 mJ for λ 34 . Laser pulse durations, as reported in our previous work, were ∼34 ns (fwhm). 1 Experimental setup, with the three-step excitation scheme shown in the inset.…”
Section: Methodsmentioning
confidence: 72%
“…In our previous, time-resolved ionization study, it was shown that direct photoionization from the 7s 3 S 1 level occurred, as the ionization wave form observed without λ 34 (λ 12 + λ 23 only) resembled the exciting laser pulse shape. The behavior observed here as a result of increasing the laser energy of λ 34 indicates that the excitation cross section for the 7s 3 S 1 → n p 3 P 0 2 transitions ( n = 10, 11, and 12) cannot differ from the photoionization cross section from the same 7s 3 S 1 level in the absence of λ 34 by more than ∼1 order of magnitude.…”
Section: Resultsmentioning
confidence: 88%
“…In the resonance ionization literature, it is well-known that the two factors influencing the rate of collisional ionization are (1) the energy difference between the excited atomic levels of different principal quantum number (from which ionization is occurring) and the ionization continuum and (2) the number of ionizing collisions, which depends on the temperature in and around the interaction region. The former factor was studied in our previous work, in which we observed the behavior of the rate of collisional ionization when different atomic levels, of increasing principal quantum number, were reached by laser excitation …”
Section: Resultsmentioning
confidence: 99%
“…The experimental setup used in this work, shown in Figure for the sake of clarity, is similar to the one described in our previous paper . The inset gives a schematic representation of the stepwise excitation scheme.…”
A new method for laser-enhanced ionization detection of mercury atoms in an inert gas atmosphere is described. The method, which is based on the avalanche amplification of the signal resulting from the ionization from a selected Rydberg level reached by a three-step laser excitation of mercury vapor in a simple quartz cell, can be applied to the determination of this element in various matrices by the use of conventional cold atomization techniques. The overall (collisional + photo) ionization efficiency is investigated at different temperatures, and the avalanche amplification effect is reported for Ar and P-10 gases at atmospheric pressure. It is shown that the amplified signal is related to the number of charges produced in the laser-irradiated volume. Under amplifier noise-limited conditions, a detection limit of ∼15 Hg atoms/laser pulse in the interaction region is estimated.
“…-December 31. 1998 The progress report is divided into 8 sections including (1) laser ionization, (2) laser fluorescence in a glow discharge, (3) glow discharge ernissiotifluorescence, (4) magnetically enhanced glow discharges for optical err&sion spectrometry, (5) electrothermal atomization-laser excited atomic fluorescence, (6) 3-dimensional number density profiles of species in a glow discharge, (7) laser induced breakdown spectroscopy, LIBS, (8) fimdamental studies, and (9) other studies.…”
Section: Overview Of Past Four Years Workmentioning
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
