Spectral line shape in the limit of frequent velocity-changing collisions
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , |
|---|---|
| Format: | Preprint |
| Publié: |
2023
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866910385014046720 |
|---|---|
| author | Stolarczyk, Nikodem Wcisło, Piotr Ciurłyo, Roman |
| author_facet | Stolarczyk, Nikodem Wcisło, Piotr Ciurłyo, Roman |
| contents | The speed-dependent spectral line profiles collapse into a simple Lorentz profile in the regime dominated by the velocity-changing collisions. We derive general formulas for the effective width and shift of the Lorentzian for arbitrary speed-dependent collisional broadening and shift and velocity-changing collision operators. For a quadratic speed dependence of collisional broadening and shift, and the billiard ball model of velocity-changing collisions, we provide simple analytical expressions for the effective Lorentzian width and shift. We show that the effective Lorentzian width and shift split into components originating from the: well-known Dicke-narrowed Doppler width, speed-averaged collisional broadening and shift, their speed dependencies, and a product term that mixes the contributions of the broadening and shift speed dependencies. We show how the components depend on rates of speed-changing and velocity-changing collisions related to the perturber/absorber mass ratio. We validate analytical formulas numerically on example of H$_{2}$ transition perturbed by He. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2305_11885 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Spectral line shape in the limit of frequent velocity-changing collisions Stolarczyk, Nikodem Wcisło, Piotr Ciurłyo, Roman Statistical Mechanics Chaotic Dynamics Atomic Physics Optics The speed-dependent spectral line profiles collapse into a simple Lorentz profile in the regime dominated by the velocity-changing collisions. We derive general formulas for the effective width and shift of the Lorentzian for arbitrary speed-dependent collisional broadening and shift and velocity-changing collision operators. For a quadratic speed dependence of collisional broadening and shift, and the billiard ball model of velocity-changing collisions, we provide simple analytical expressions for the effective Lorentzian width and shift. We show that the effective Lorentzian width and shift split into components originating from the: well-known Dicke-narrowed Doppler width, speed-averaged collisional broadening and shift, their speed dependencies, and a product term that mixes the contributions of the broadening and shift speed dependencies. We show how the components depend on rates of speed-changing and velocity-changing collisions related to the perturber/absorber mass ratio. We validate analytical formulas numerically on example of H$_{2}$ transition perturbed by He. |
| title | Spectral line shape in the limit of frequent velocity-changing collisions |
| topic | Statistical Mechanics Chaotic Dynamics Atomic Physics Optics |
| url | https://arxiv.org/abs/2305.11885 |