Table 1. Parameters for pump probe experiments.
| Comment | ||
|---|---|---|
| Laser parameters | Pulse energy (µJ) | |
| Beam profile | Gaussian, top hat | |
| Beam diameter (µm) | Indicate FWHM or 1/e 2 | |
| Pulse duration (fs) | ||
| Spatial offset of laser and X-ray foci (µm) | ||
| Pump wavelength λP (nm) | ||
| Laser polarization | ||
| Laser fluence (mJ cm−2)† | ||
| Laser power (GW cm−2)† | ||
| Sample parameters | Extinction coefficient at λP (M −1 cm−1) | |
| Average sample thickness (µm)‡ | ||
| Unit-cell parameters: a, b, c, α, β, γ (Å,°) | ||
| Number of chromophores per unit cell | ||
| Chromophore concentration (mM) | Derived quantity for crystals | |
| λP extinction length (µm)† | Calculated quantity | |
| Photoexcitation | Nominal number of absorbed photons per chromophore† |
†
These cells indicate data derived from the experimental values. They provide fast feedback on the photoexcitation regime and need to be listed somewhere in the manuscript. It makes sense to add them to this table. The extinction length of the pump laser light has direct implications for the design of the experiment.
‡
For the calculation of an average path length through crystals see page 9 of the supporting information of Nass Kovacs et al. (2019 ▸).