.. _throughput:
************
throughput
************
:author: Stanislav Stoupin
:email:
calculate throughput of a multicrystal configuration
(dynamical theory of x-ray diffraction for perfect crystals)
SYNOPSIS
============
throughput [options] func dpsi Ec dEx ne input_file
DESCRIPTION
============
A program to calculate throughput of a multicrystal configuration given by input_file using dynamical theory of
x-ray diffraction for perfect crystals
For a brief summary of options and parameters run::
throughput -h
PARAMETERS
============
:func: angular divergence distribution function for incoming x-rays:
==== ============ ==================
func description dpsi meaning
==== ============ ==================
g Gaussian rms
l Lorentzian fwhm
f flat interval :math:`\pm` 3*dpsi
1r single ray ignored
==== ============ ==================
:dpsi: angular divergence in units of [urad]
* rms for Gaussian distribution
* fwhm for Lorentzian distribution
* interval :math:`\pm` 3*dpsi for flat
* any value (ignored) for single ray
:Ec: central energy for energy distribution in units of [keV] (corrected automatically depending on the
choice of source and presence of crystals in backscattering configuration in the input file)
:dEx: energy half-range in units of [meV]
:ne: number of points in the energy grid (max 1000)
OPTIONS
============
:-v, --version:
show version of program.
:-h, --help:
show summary of options.
:-o FILENAME, --output FILENAME:
write results to file (default to stdout)
:-w FILENAME, --write FILENAME:
write data to file (default - no action)
:-p, --pi:
:math:`\pi` polarization for incident wave (default - :math:`\sigma` polarization)
:-a NTH, --angular_scan NTH:
perform crystal rotation (angular scan) with NTH points
:-s SRC, --source SRC:
type of energy distribution for the source:
==== ===============================================
SRC description
==== ===============================================
0 flat distribution (default)
1 Cu K-alpha source
9 energy distribution from file source_e.dat
==== ===============================================
A point source is assumed. Source size is not included to the calculation at the moment.
For throughput calculation the source size can be modeled as additional divergence.
:-n NPSI, --npsi NPSI:
number of points in the angular grid (default NPSI=200)
EXAMPLES
===========
1. Throughput (intensity as function of photon energy) of a multicrystal configuration (double-crystal diamond monochromator)
:download:`thru_hhlmC.in <../../examples/throughput/thru_hhlmC.in>`
.. literalinclude:: ../../examples/throughput/thru_hhlmC.in
:language: guess
:linenos:
To perform the calculation ::
throughput g 5 23.7 5000 250 thru_hhlmC.in
.. image:: ../../examples/snapshots/thru_2xC111_23.7keV.png
:width: 70 %
:alt: Throughput of C111 DCM
2. Calculation of a rocking curve in a multicrystal configuration (the same double-crystal diamond monochromator, rocking curve of the 2nd crystal).
:download:`c2rc_hhlmC.in <../../examples/throughput/c2rc_hhlmC.in>`
.. literalinclude:: ../../examples/throughput/c2rc_hhlmC.in
:language: guess
:linenos:
The code is not vectorized at present, calculations can take from a few minutes to a few hours.
The progress of the rocking curve calculation is displayed interactively (the plot is updated as each additional point is calculated).
Hint: prior to full simulation using divergent x-rays ("g", "l", or "f"), try quick estimation using single ray ("1r") ::
throughput -a 100 -w c2rc_hhlmC_23keV.dat 1r 0 23.7 5000 250 c2rc_hhlmC.in
.. image:: ../../examples/snapshots/rc_1r_2xC111_23.7keV.png
:width: 70 %
:alt: Rocking curve of C111 DCM
To perform the full calculation using divergent (Gaussian) beam ::
throughput -a 100 -w c2rc_hhlmC_23keV.dat g 5 23.7 5000 250 c2rc_hhlmC.in
.. image:: ../../examples/snapshots/rc_g5_2xC111_23.7keV.png
:width: 70 %
:alt: Rocking curve of C111 DCM
SEE ALSO
============
* :ref:`dtxrd`
* :ref:`rcpeak`
:author: Stanislav Stoupin
:email:
:date: |today|