deerlab.ex_4pdeer¶

ex_4pdeer(tau1, tau2, pathways=[1, 2, 3, 4], pulselength=0.016)[source]¶

Generate a 4-pulse DEER dipolar experiment model.

The figure below shows the dipolar pathways in 4-pulse DEER. The observer (black) and pump (grey) pulses and their interpulse delays are shown on the top. The middle table summarizes all detectable modulated dipolar pathways $p$ along their dipolar phase accumulation factors $\mathbf{s}_p$ , harmonics $\delta_p$ and refocusing times $t_{\mathrm{ref},p}$ . The most commonly encountered pathways are highlighted in color. The bottom panel shows a decomposition of the dipolar signal into the individual intramolecular contributions (shown as colored lines).

The dipolar time axis is defined such that $t=0$ right after the second observer pulse.

../_images/ex_4pdeer_pathways.png — Source: L. Fábregas-Ibáñez, Advanced data analysis and modeling in dipolar EPR spectroscopy, Doctoral dissertation, 2022¶

Parameters:

tau1float scalar: 1st static interpulse delay $\tau_1$ .
tau2float scalar: 2nd static interpulse delay $\tau_2$ .
pathwaysarray_like, optional: Pathways to include in the model. The pathways are specified as a list of pathways labels $p$ . By default, pathways 1-4 are included as shown in the table above.
pulselengthfloat scalar, optional: Length of the longest microwave pulse in the sequence in microseconds. Used to determine the uncertainty in the boundaries of the pathway refocusing times.

Returns:

experimentExperimentInfo object: Experiment object. Can be passed to dipolarmodel to introduce better constraints into the model.