Component Manual for the Xray-Tracing Package McXtrace, version 3.8.6

6.5  The TwinKB_ML McXtrace Component

Montel optic model (aka side-by-side Kirkpatrick Baez)

Identification

Description

Models a Montel optic, or Twin Kirkpatrick Baez mirror optic (hence the component name). The mirror are fully abutting, i.e. there’s is no gap between them, and perfectly elliptic.

Reads reflectivity values from a data input file for a W/B4C multilayer. The multilayer code reflects ray in an ideal geometry, the reflectivity datafile accounts for surface roughness, sigma.

The mirror is positioned such that the long axis of the mirror elliptical surface coincides with the z-axis.

The algorithm: Incoming photon’s coordinates and direction (k-vector) are transformed into an elliptical reference frame (elliptical parameters are calculated according to the mirror’s position and its focusing distances and the * incident angle), the intersection point is then defined. A new, reflected photon is then starting at the point of intersection.

Example: TwinKB_ML( theta=1.2, s1=.045 , s2=.9 , length=0.06 , width=0.2 , R0=0 , reflectivity_datafile=”Ref_W_B4C.txt”)

Input parameters

Parameters in boldface are required; the others are optional.

Name

Unit

Description

Default

reflectivity_datafile

str

File which contains reflectivities as a function of q.

”Ref.txt”

theta

deg

Incident angle

1.2

s1

m

Distance from the source to the multilayer

s2

m

Focusing distance of the multilayer

length

m

Length of the mirrors

0.6

width

m

Width of the mirror along x-axis

0.2

R0

0-1

Constant reflectivity, R0=1 for an ideal situation. If R0=0, the code reads the reflectivity from the datafile

0

Links

Side-by-side Kirkpatrick-Baez mirror pair

Models a pair of perpendicular, elliptically curved mirrors, known as a Montel-mirror or Side-by-side Kirkpatrick-Baez mirror.