neutronpy.instrument.Instrument.ana

Instrument.ana

A structure that describes the analyzer and contains fields as in mono plus optional fields.

Parameters:

thickness: float

The analyzer thickness in cm for ideal-crystal reflectivity corrections (Section II C 3). If no reflectivity corrections are to be made, this field should remain unassigned or set to a negative value.

Q : float

The kinematic reflectivity coefficient for this correction. It is given by

\[Q = \frac{4|F|**2}{V_0} \frac{(2\pi)**3}{\tau**3},\]

where V0 is the unit cell volume for the analyzer crystal, F is the structure factor of the analyzer reflection, and τ is the analyzer reciprocal lattice vector. For PG(002) Q = 0.1287. Leave this field unassigned or make it negative if you don’t want the correction done.

horifoc : bool

A flag that is set to 1 if a horizontally focusing analyzer is used (Section II D). In this case hcol[2] (see below) is the angular size of the analyzer, as seen from the sample position. If the field is unassigned or equal to -1, a flat analyzer is assumed. Note that this option is only available with the Cooper-Nathans method.

dir : int

Direction of the crystal (left or right, -1 or +1, respectively). Default: -1 (left-handed coordinate frame).

rh : float

Horizontal curvature of the analyzer in cm.

rv : float

Vertical curvature of the analyzer in cm.