Comparison of density matrix and spectral simulation approaches for the calculation of isotopic selectivities

Suryanarayana, M. V.; Sankari, M.

doi:10.1016/s0022-4073(99)00194-6

Cited by 5 publications

(9 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the spectral simulation (SS) approach can be used as an alternative method for the calculation of optical selectivities [10,11]. Recently, we have evaluated both DM and SS methods for the calculation of optical selectivities [12].…”

Section: Introductionmentioning

confidence: 99%

Optical selectivity calculation of calcium isotopes in a double-resonance ionization scheme

Sankari¹,

Kumar²,

Suryanarayana³

2000

J. Phys. B: At. Mol. Opt. Phys.

Self Cite

View full text Add to dashboard Cite

Optical selectivities of calcium isotopes have been calculated for the 4s 2 1 S 0 422.7 nmdouble-resonance ionization scheme using the spectral simulation (SS) approach. Optical selectivities obtained by the SS approach are in good agreement with the results obtained by the density matrix formalism. Studies on the effect of laser detuning and linewidth on optical selectivities indicate that lasers with 50 MHz linewidth for both the excitation steps can yield an optical selectivity of 2.2 × 10 5 , which is adequate for selective excitation of the 41 Ca isotope for certain applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Optical selectivity calculation of calcium isotopes in a double-resonance ionization scheme

Sankari¹,

Kumar²,

Suryanarayana³

2000

J. Phys. B: At. Mol. Opt. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand the SS approach, which is only useful for selectivity calculations based on relative excitation efficiencies, is simple but its applicability is limited to incoherent step-wise excitations owing to the fact that this approach cannot incorporate coherent effects associated with single frequency laser excitations. It is noted that, in the case of excitation with broad-band lasers, the values of the isotopic selectivity calculated from the two approaches agree well with each other [15]. In the case of laser excitation with single-frequency lasers the selectivity values from the SS approach, without taking into account the coherence effects, are not expected to agree well with the DM results [5][6][7].…”

Section: Introductionmentioning

confidence: 74%

“…It is worthwhile to estimate isotopic selectivity before making a choice of the most efficient photoionization scheme and suitable laser parameters for the experimental measurements. Isotopic selectivity for photoionization schemes using narrow-band lasers is generally calculated using either density matrix (DM) formalism [5][6][7][8][9][10][11][12] or the spectral simulation (SS) approach [13][14][15][16]. The DM approach gives the most accurate description of the multi-step photoionization process, incorporating the coherence effects due to single-frequency laser excitations.…”

Section: Introductionmentioning

confidence: 99%

Isotopic selectivity calculations for multi-step photoionization of calcium atoms using narrow-band lasers

Pulhani

Gupta

Suri

2002

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

Isotopic selectivity calculations are carried out for minor calcium isotopes against the major isotope 40Ca for the single-resonance two-step and double-resonance three-step photoionization schemes with narrow-band lasers by using spectral simulation (SS) and modified spectrum (MS) approaches. The results of these calculations are compared with the density matrix (DM) results reported in the literature. It is noted that the values of isotopic selectivity from the SS approach do not agree with those from the DM approach whereas the MS approach, considering hole burning in the Doppler-broadened atomic spectrum, predicts selectivity values which are in good agreement with the DM results. It is argued that one can adequately use the simple MS approach rather than the complex DM approach for the calculation of isotopic selectivity of multi-step photoionization with single-frequency lasers.

show abstract

“…The theoretical approach adopted for the isotopic selectivity calculations is the spectral simulation (SS) method developed by our group [14][15][16][17]. In this approach the atomic line profile is generated assuming a Lorentzian profile taking into account the appropriate abundances, isotope shifts of the constituent isotopes and hyperfine structure of the odd isotopes.…”

Section: Theoretical Approachmentioning

confidence: 99%

“…The laser linewidth and the laser line shape are incorporated in the computation. Further details of this theoretical model have been discussed in our previous publications, and hence it is not elaborated here [14][15][16][17].…”

Section: Theoretical Approachmentioning

confidence: 99%

Theoretical and Experimental Understanding of the Anomalous Odd-to-Even Isotope Ratios of Tin in a 1 + 1 Single-Colour Resonance Ionization Mass Spectrometry: Revisited

Sankari¹

2011

International Journal of Optics

View full text Add to dashboard Cite

Differences in the odd to even response for tin isotopes has been observed earlier in resonance ionization experiments, resulting in anomalous odd to even isotope ratios. I have used a theoretical approach known as the spectral simulation approach to understand the cause for such anomaly and the anomaly has also been experimentally verified and found to be in good agreement. The effects of laser parameters such as intensity, accuracy of the excitation laser wavelength and bandwidth on the determination of the tin isotope ratio have been analyzed theoretically and experimentally. The source for such anomalies was found to be the inaccuracy in the excitation laser wavelength. For the 5p 2 ( 3 P 0 ) − 5p 6s ( 3 P 0 1 ) (286.3317 nm) transition, an inaccuracy of the order of γ L in the peak frequency of the excitation laser (γ L = 15 GHz) can cause anomalies as large as ∼31% (β = 0.31). Use of a very large bandwidth laser (∼60 GHz) reduces the anomaly to as small as −0.003. Alternatively by employing a relatively narrow band laser (∼1.2 GHz), it has been observed that inaccuracy of the order of 3-4 γ L in the laser peak frequency does not induce anomalies >0.05. The isotope ratio is sensitive to the inaccuracy in the excitation laser wavelength for an intermediate linewidth laser.

show abstract

Comparison of density matrix and spectral simulation approaches for the calculation of isotopic selectivities

Cited by 5 publications

References 13 publications

Optical selectivity calculation of calcium isotopes in a double-resonance ionization scheme

Optical selectivity calculation of calcium isotopes in a double-resonance ionization scheme

Isotopic selectivity calculations for multi-step photoionization of calcium atoms using narrow-band lasers

Theoretical and Experimental Understanding of the Anomalous Odd-to-Even Isotope Ratios of Tin in a 1 + 1 Single-Colour Resonance Ionization Mass Spectrometry: Revisited

Contact Info

Product

Resources

About