double_rowland_from_channel_distance

marxs.design.rowland.double_rowland_from_channel_distance(d_BF, R, f)

This prescription is borne out of the engineering needs where it turns out that the spacing between channels d_BF is actually an important parameter so it makes sense to use that here to parameterize the torus, too.

f is the distance between a theoretical on-axis CAT grating and the focal point. It’s default is a little smaller than 12 m, to leave space to mount the SPOs.

Parameters:

d_BFfloat

Distance between the optical axes of two channels measured in the dispersion direction.

Rfloat

Radius of Rowland torus.

ffloat

Distance between a theoretical on-axis CAT grating and the focal point.

Returns:

geometrydict

Dictionary with the keys that hold the input parameters, derived dimensions of the geometry, and the constructed Rowland tori. Three Rowland tori are constructed: One for each channel called (rowland_central, rowland_central_m) and one for the detector (rowland_detector).