Two-color photoionization spectroscopy of uranium in a U–Ne hollow cathode discharge tube

Dev, Vas; Shah, M.L.; Pulhani, A. K.; Suri, B. M.

doi:10.1007/s00340-005-1747-z

Cited by 11 publications

(8 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have also developed what is called photoionization optogalvanic spectroscopy. In this technique, cathode dark space is explored using resonant laser(s) [4]. In this case, a distinctive nanosecond laser-induced photoionization signal can be observed.…”

Section: Optogalvanic Spectroscopymentioning

confidence: 98%

See 1 more Smart Citation

High-Resolution Spectroscopy

Suri¹

2014

Springer Proceedings in Physics

Self Cite

View full text Add to dashboard Cite

Classical high-resolution spectroscopy had been of interest for the sake of studies related to isotope shifts and hyperfine interactions and for resolving complex spectra associated with heavy elements like lanthanides and actinides. In this chapter, some of the history of classical high-resolution spectroscopy has been described. The highest-resolution laser spectroscopy is usually performed with CW lasers which have inherent ultra-narrow linewidths. Pulsed dye lasers though have relatively large linewidth because of Fourier transform limit but can still be usefully employed for multicolor laser spectroscopy of various elements with complex spectra. We have demonstrated the utility of pulsed dye lasers for studying lanthanides and actinides by employing techniques like multicolor optogalvanic spectroscopy in hollow cathode discharges, multicolor laser-induced fluorescence, and resonance ionization spectroscopy in atomic beams. We have for the first time utilized ICCD-based spectrograph for some of the measurements. These techniques have yielded excellent new information on atomic parameters like radiative lifetimes, branching ratios, and absolute transition probabilities of singly or multiply excited atomic levels. These techniques have inherent simplicity and may offer themselves as excellent alternative to conventional techniques and have universal applications of interest to wide cross section of atomic spectroscopists.

show abstract

Section: Optogalvanic Spectroscopymentioning

confidence: 98%

“…Using this technique, multiphoton ionization spectroscopy can be performed. We have employed this for exploring highly excited states of uranium atom [4]. All these studies have been carried out in a home-built hollow cathode discharge tube as shown in Fig.…”

Section: Optogalvanic Spectroscopymentioning

confidence: 99%

High-Resolution Spectroscopy

Suri¹

2014

Springer Proceedings in Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Using two-color, two-step optogalvanic spectroscopy, Kujirai et al [12][13][14] studied extensively the AI states of rareearth elements, such as Lu, Pr, and Sm. Dev et al [15] reported investigations on the high-lying odd-parity atomic states and even-parity AI states of uranium in the energy regions 34;500-34;813 cm −1 and 51;400-51;703 cm −1 , respectively, using two-color, three-photon photoionization optogalvanic spectroscopy in a U-Ne HCDL. By employing a similar twocolor, three-photon photoionization technique, Marathe et al [16] reported the observation of even-parity AI levels of uranium in the energy region 51;425-51;760 cm −1 and defined the J values of about 20 AI levels.…”

Section: Introductionmentioning

confidence: 99%

Study of even-parity autoionization resonances of atomic uranium by three-color optogalvanic spectroscopy

et al. 2012

Self Cite

View full text Add to dashboard Cite

We report our investigation on the even-parity autoionization (AI) resonances of atomic uranium in the energy region 52;850-53;350 cm −1 , using the three-color optogalvanic spectroscopy technique in a U-Ne hollow cathode discharge lamp with three pulsed dye lasers. To the best of our knowledge, this is the first report of observation of even-parity AI states in atomic uranium lying more than 2000 cm −1 above the ionization limit. We have used four different excitation schemes, starting from the lowest metastable state of uranium at 620 cm −1 ( 5 K 0 5 ). We have identified 102 new even-parity AI resonances in atomic uranium and assigned probable total angular momentum (J) values to these resonances. By observing 25 out of these 102 AI resonances through more than one excitation pathway, the ambiguity in the assignment of their J values has been reduced considerably.

show abstract

“…Multi-step resonance ionization spectroscopy using pulsed tunable lasers has played a key role in the investigations of complex atomic structure in basic research, especially the high-lying excited levels of atoms [1][2][3][4][5][6][7], which are not the photoionization (PI) signal as a function of laser fluence in that particular step whose cross section is to be measured while keeping the fluence of the other two lasers constant. Here, λ i represents the wavelength of the laser for the ith step.…”

Section: Introductionmentioning

confidence: 99%

Understanding photoexcitation dynamics in a three-step photoionization of atomic uranium and measurement of photoexcitation and photoionization cross sections

et al. 2015

Self Cite

View full text Add to dashboard Cite

accessible with the conventional spectroscopic techniques such as absorption and emission spectroscopy, and in many laser-based applications such as isotope-selective photoionization processes, elemental ultra-trace analysis, etc. [8][9][10][11]. For the effective implementation of the processes mentioned above, identification of an efficient multi-step photoionization scheme is a prerequisite [1,11,12]. Precise information on photoexcitation and photoionization cross sections is necessary in the selection of an efficient multi-step photoionization scheme. It also helps in the distribution of the available tunable laser powers between various steps for efficient photoionization of atom.Several laser-based methods such as transition saturation [1,9,12], branching ratio and life time [12][13][14][15][16], Rabi oscillations [12], Autler-Towns [12,17] are reported in the literature by various research groups worldwide for the measurement of photoexcitation cross sections. With the exception of Mclaughlin et al. [18] who have measured the absolute photoionization cross section of Ti from the second excited level by observing the depletion in the fluorescence signal, the saturation method is the most suitable for the measurement of photoionization cross section [19][20][21][22]. The saturation in the photoionization signal represents the complete transfer of atomic population from the last excited level in the stepwise photoionization scheme. In this method, one has the advantage of measuring photoexcitation and photoionization cross sections using the same apparatus.The ionization potential of uranium is ~6.19 eV. Hence, a three-step photoionization of atomic uranium is the most appropriate using visible lasers whose photon energy is ~2 eV. In a three-color three-step photoionization process, i.e., λ 1 + λ 2 + λ 3 , where two-color photoionization, i.e., λ 1 + 2λ 2 , as shown in Fig. 1a, is not possible, photoexcitation and photoionization cross sections of the transitions used in a scheme are measured by observing saturation in Abstract Photoexcitation dynamics in a three-step photoionization of atomic uranium has been investigated using time-resolved two-color three-photon and delayed threecolor three-photon photoionization signals. Investigations are carried out in an atomic beam of uranium coupled to a high-resolution time-of-flight mass spectrometer using three tunable pulsed dye lasers. Dependence of both the signals on the second-step laser photon fluence is studied. Excited-level-to-excited-level photoexcitation cross section and photoionization cross section from the second excited level are simultaneously determined by analyzing the two-color three-photon and three-color three-photon photoionization signals using population rate equation model. Using this methodology, photoexcitation and photoionization cross sections at seven values of the second-step laser wavelength have been measured. From the measured values of the photoexcitation cross sections, we have obtained excited-level-to-excited-level transiti...

show abstract

Two-color photoionization spectroscopy of uranium in a U–Ne hollow cathode discharge tube

Cited by 11 publications

References 20 publications

High-Resolution Spectroscopy

High-Resolution Spectroscopy

Study of even-parity autoionization resonances of atomic uranium by three-color optogalvanic spectroscopy

Understanding photoexcitation dynamics in a three-step photoionization of atomic uranium and measurement of photoexcitation and photoionization cross sections

Contact Info

Product

Resources

About