Biomedical subjects

Viatcheslav Kokoouline

Publications and source records attributed to Viatcheslav Kokoouline.

3 recordsLinked to original sources

PubMed2004

Triatomic dissociative recombination theory: Jahn-Teller coupling among infinitely many Born-Oppenheimer surfaces.

The coupling of many Rydberg surfaces poses a stringent challenge for theoretical description. Yet simplifications arise because quantum defect ideas can be applied, which circumvents some of the usual difficulties that arise. We describe a theoretical technique capable of handling these complex interactions, which has already been applied with success to the dynamics of H3 Rydberg states. The extensions necessary to treat the other isotopomers H2D+ and HD2+ are then discussed, along with a preliminary application.

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PubMed2003

Multichannel cold collisions between metastable Sr atoms.

We present a multichannel-scattering calculation of elastic and inelastic cold collisions between two low-field seeking, metastable 88Sr [(5s5p)3P2] atoms in the presence of an external magnetic field. The scattering physics is governed by strong anisotropic long-range interactions, which lead to pronounced coupling among the partial waves of relative motion. As a result, nonadiabatic transitions are shown to trigger a high rate of inelastic losses. At relatively high energies, T>100 microK, the total inelastic collision rate is comparable with the elastic rate. However, at lower collisional energy, the elastic rate decreases, and at T approximately 1 microK, it becomes substantially smaller than the inelastic rate. Our study suggests that magnetic trapping and evaporative cooling of 88Sr [(5s5p)3P2] atoms, as well as 40Ca [(4s4p)3P2], in low-field seeking states will prove difficult to achieve experimentally.

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PubMed2003

Theory of dissociative recombination of d(3h) triatomic ions applied to h+3.

We propose a fully quantal description of H+3 dissociative recombination. The new method combines multichannel quantum defect theory, the adiabatic hyperspherical approach, and the techniques of outgoing-wave Siegert pseudostates. The vibrational, rotational, nuclear spin degrees of freedom of the ion, in their full dimensionality, are all taken into account for the first time in any calculation of polyatomic dissociative recombination. Our calculation of the recombination rate confirms that the Jahn-Teller effect is responsible for the large rate in H+3. The resulting theoretical rates for dissociative recombination of H+3 are in good general agreement with experiment.

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