McXtrace - An X-ray ray-trace simulation package

[ Identification | Description | Input parameters | Links ]

The Fluo_detector Component

Detector for fluorescence, e.g. Silicon Drift Detector (SDD) or High Purity Germanium (HPGe).

Identification

• Site:
• Author: E. Farhi
• Origin: Synchrotron SOLEIL
• Date: May 2025

Description

A detector that records energy spectrum from e.g. fluorescence.
This component handles:
- fluorescence detector escape  (energy shift from detector K-alpha)
- fluorescence detector pile-up (sum aka time-coincidence aka pile-up within detector dead-time)
- energy resolution (above Fano level)

The detector geometry can be a rectangle xwidth*yheight, or a disk of given 'radius'.
When the radius is given negative, a 4PI detector sphere of given radius is assumed.

The detector escape corresponds with a fluorescence excitation within the detector itself
that subtracts the K-alpha detector level from the sample scattered energy.
The level of escape peaks in set as 'escape_ratio', e.g. 1-2 %.

The detector pile-up is related to the detector dead-time, within which time coincidence
between two fluorescence photons are summed-up.
The level of pile-up is set as 'pileup_ratio', e.g. 1-2 % which can increase for high
count rates that saturate the detector.

Last, the fluorescence peak shape is broadened using an electronic noise (at E=0) and
a nominal resolution at E=resolution_energy (in keV). You may set the electronic_noise
to zero for a perfect detector (Fano limit). To use a constant resolution, set the
resolution_energy=0.

Example: Fluo_detector(xwidth=0.1, yheight=0.1,
Emin=1, Emax=50, nE=20, filename="Output.nrj")

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
radius	m	Radius of disk detector (in XY plane). When given as negative, a 4PI sphere is assumed.	0
xwidth	m	Width of rectangle detector.	0
yheight	m	Height of rectangle detector.	0
Emin	keV	Minimum energy to detect.	1
Emax	keV	Maximum energy to detect.	39
nE	m	Number of energy channels.	2000
filename	str	Name of file in which to store the detector image.	0
restore_xray	0/1	If set, the monitor does not influence the x-ray state.	0
escape_ratio	1	Detector escape peak ratio, e.g. 0.01-0.02. Zero inactivates.	0.01
escape_energy	keV	Detector escape peak energy, e.g. 1.739 for Si, 9.886 for Ge.	1.739
pileup_ratio	1	Sum aka time coincidence aka pile-up detector peak ratio, e.g. 0.01-0.02. This is e.g. the dead-time ratio. Zero inactivates.	0.01
electronic_noise	keV	Electronic noise at E=0, FWHM in keV. Use electronic_noise=0 for Fano limit.	0.1
resolution_energy	keV	Energy at which resolution is given, e.g. 5.9 keV Mn K-alpha.	6
resolution	keV	Resolution FWHM in keV at resolution_energy.	0.2
flag_lorentzian	1	When 1, the line shapes are assumed to be Lorentzian, else Gaussian.	0

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

Links

• Source code for Fluo_detector.comp.
• Fluorescence https://en.wikipedia.org/wiki/Fluorescence

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[ Identification | Description | Input parameters | Links ]

Generated on mcxtrace 3.5.32

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Last Modified: Tuesday, 17-Jun-2025 20:12:04 CEST