The `Powder_process` Component

Identification

Site:
Author: Mads Bertelsen
Origin:
Date: 20.08.15

Description

This Union_process is based on the PowderN.comp component originally written
by P. Willendrup, L. Chapon, K. Lefmann, A.B.Abrahamsen, N.B.Christensen,
E.M.Lauridsen.

Part of the Union components, a set of components that work together and thus
sperates geometry and physics within McStas.
The use of this component requires other components to be used.

1) One specifies a number of processes using process components like this one
2) These are gathered into material definitions using Union_make_material
3) Geometries are placed using Union_box / Union_cylinder, assigned a material
4) A Union_master component placed after all of the above

Only in step 4 will any simulation happen, and per default all geometries
defined before the master, but after the previous will be simulated here.

There is a dedicated manual available for the Union_components*
Algorithm:
Described elsewhere

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
format	no quotes	Name of the format, or list of column indexes (see Description).	Undefined
reflections		Input file for reflections. Use only incoherent scattering if NULL or "" [string]	"NULL"
packing_factor	1	How dense is the material compared to optimal 0-1	1
Vc		Volume of unit cell=nb atoms per cell/density of atoms [AA^3]	0
delta_d_d	0/1	Global relative delta_d_d/d broadening when the 'w' column is not available. Use 0 if ideal.	0
DW	1	Global Debye-Waller factor when the 'DW' column is not available. Use 1 if included in F2	0
nb_atoms	1	Number of sub-unit per unit cell, that is ratio of sigma for chemical formula to sigma per unit cell	1
d_phi	deg	Angle corresponding to the vertical angular range to focus to, e.g. detector height. 0 for no focusing	0
density	g/cm^3	Density of material. rho=density/weight/1e24*N_A.	0
weight	g/mol	Atomic/molecular weight of material	0
barns	1	Flag to indicate if \|F\|^2 from 'reflections' is in barns or fm^2 (barns=1 for laz, barns=0 for lau type files).	1
Strain	ppm	Global relative delta_d_d/d shift when the 'Strain' column is not available. Use 0 if ideal.	0
interact_fraction	1	How large a part of the scattering events should use this process 0-1 (sum of all processes in material = 1)	-1

AT (	,	,		) RELATIVE
ROTATED (	,	,		) RELATIVE

The Powder_process Component

Identification

Description

Input parameters

Links

The `Powder_process` Component