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[ Identification | Description | Input parameters | Links ]
The Molecule_2state Component
Disordered optical-excitable molecule sample.
Identification
- Site:
- Author: Erik B Knudsen
- Origin: DTU Physics
- Date: October 2012
Description
A sample model for pump probe experiments which models disordered molecules in a volume (rectangular, cylindrical, or spherical). Molecules can be in one of two states (0 and 1). Scattering is either specified through F vs. q scattering curves or as a set of atom positions from which F vs. q is computed. At t=-delta_t, a fraction of the molecules are put in state 1, from which they decay exponentially, with time constant t_relax, into state 0. For t<-delta_t all of the molecules are in the state specified by initial_state. To improve statistics, scattering may be limited to a "forward" cone with opening angle in [psimin, psimax]. Furthermore, scattering may be restricted to the azimuthal segment between [etamin,etamax].
Input parameters
Parameters in boldface are required; the others are optional.| Name | Unit | Description | Default | |
| form_factors | ( ) File from which to read atomic form factors. Defualt amounts to use the one shipped with McXtrace. | "FormFactors.txt" | ||
| state_0_file | ( ) Isotropic scattering factors (parameterized by q), or atom positions are specified for state 0. | NULL | ||
| state_1_file | ( ) Isotropic scattering factors (parameterized by q), or atom positions are specified for state 1. | NULL | ||
| nq | ( ) Number of q-bins if F is to be computed from atom positions (Debye formalism). | 512 | ||
| material_datafile | ( ) Where to read f1 and f2 factors from in order to handle absorption. | "Be.txt" | ||
| delta_t | (s) Delay between the exciting event t=0. delay is negative, i.e. delta_t>0 means the exciting event happens before t=0. | 100e-9 | ||
| excitation_yield | ( ) Mean fraction of molecules that get excited. | 0.2 | ||
| t_relax | (s) Mean relaxation time (into state 0) of excited molecules. | 100e-9 | ||
| initial_state | ( ) Which state is Molecule_2state in for t| 0 | | ||
| psimin | (rad) Minimum scattering angle off the optical axis. | 0 | ||
| psimax | (rad) Maximum scattering angle off the optical axis. | M_PI_2 | ||
| etamin | (rad) Minimum scattering angle around the optical axis. | -M_PI | ||
| etamax | (rad) Maximum scattering angle around the optical axis. | M_PI | ||
| radius | (m) Radius of cylindrical of spherical sample. | 0 | ||
| yheight | (m) Height of rectangular or cylindrical sample. | 0 | ||
| xwidth | (m) Width of rectangular sample. | 0 | ||
| zdepth | (m) Depth (thickness) of rectangular sample. | 0 | ||
| concentration | (m) Concentration or packing factor of sample. | 1 | ||
| p_transmit | (m) Fraction of statistics devoted to sample direct (unscattered) beam. | 0.1 | ||
| q_parametric | ( ) 0: Assume that datafiles contains atom positions. 1: datafiles contains F vs. q data. | 0 | ||
| Emax | ( ) Maximal energy for which scattering factors are computed. Must be larger than the maximal impinging energy. | 80 |
| AT ( | , | , | ) RELATIVE | |||
|---|---|---|---|---|---|---|
| ROTATED ( | , | , | ) RELATIVE |
Links
- Source code for
Molecule_2state.comp.
[ Identification | Description | Input parameters | Links ]
Generated on 2023-12-19 19:37:45
