# Stochastic approach to laser-induced ultrafast dynamics: the desorption of H(2)/D(2) from Ru(0001).
> フェムト秒レーザー誘起H₂/D₂脱離ダイナミクスの確率論的シミュレーション：Ru(0001)表面における多重電子遷移過程の解析


## Abstract

This theoretical study examined the femtosecond-laser-induced desorption of H2 and D2 from a Ru(0001) surface through the DIMET (Desorption Induced by Multiple Electronic Transitions) mechanism. Classical Monte Carlo trajectory (CMCT) simulations were performed on ground and excited state potential energy surfaces, incorporating up to six adsorbate degrees of freedom. The CMCT approach was first validated against quantum mechanical Monte Carlo wavepacket calculations using a two-mode model. Extending to full six-dimensional simulations enabled direct comparison with experimental data. Key findings included: qualitative agreement between CMCT and quantum wavepacket methods; accurate reproduction of a pronounced isotope effect; nonlinear yield scaling with laser fluence; translationally hot desorbing products reaching several thousand Kelvin; and non-equipartitioned energy distributions following E(trans) > E(vib) > E(rot). Additionally, a strong angular dependence of translational energies at large observation angles was predicted.

### Mechanism

Hot electrons generated by femtosecond laser pulses transfer energy from the metal surface to adsorbed H2/D2 molecules via multiple electronic transitions, driving desorption with non-equipartitioned energy distributed preferentially into translational over vibrational and rotational modes.

## Bibliographic

- **Authors**: Füchsel G, Klamroth T, Tremblay JC, Saalfrank P
- **Journal**: Phys Chem Chem Phys
- **Year**: 2010 (2010-11-14)
- **PMID**: [20856974](https://pubmed.ncbi.nlm.nih.gov/20856974/)
- **DOI**: [10.1039/c0cp00895h](https://doi.org/10.1039/c0cp00895h)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 20856974. https://h2-papers.org/en/papers/20856974
> **Source**: PubMed PMID [20856974](https://pubmed.ncbi.nlm.nih.gov/20856974/)