McXtrace - An X-ray ray-trace simulation package

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The Bending_magnet Component

Model of a bending magnet source

Identification

• Author: Erik B. Knudsen
• Origin: DTU Physics
• Date: May, 2013.

Description

A source model using the full angular distribution of synchrotron radiation from a bending magnet,
eq. (1) of K.-J. Kim, X-Ray Data Booklet, Section 2.1 (https://xdb.lbl.gov/Section2/Sec_2-1.html).
In the horizontal plane (psi=0) this reduces to eq. (28) of B.D. Patterson, Am. J. Phys. 79, 1046 (2011); doi: 10.1119/1.3614033

The ray weight p is the flux in [photons/s] emitted into the sampled solid angle and the energy
band [E0-dE, E0+dE] (i.e. NOT per mrad^2 or per 0.1% bandwidth). The energy is sampled uniformly, so dE>0
is required. In lambda0/dlambda mode the corresponding energy interval is sampled uniformly in energy.
With focus_xw/focus_yh the target window is sampled; without them, the horizontal/vertical emission angle
is sampled uniformly within +-2.5 mrad, so the total flux is then the flux into a 5 mrad horizontal fan.

Example: Bending_magnet(
E0 = 14, dE = 7, Ee = 2.75,
Ie = 0.5, B = 1.72, sigey=9.3e-6, sigex=215.7e-6)

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
E0	keV	Center of emitted energy spectrum (overrides lambda0)	0
dE	keV	Half-width of emitted energy spectrum	0
lambda0	AA	Center of emitted wavelength spectrum	0
dlambda	AA	Half-width of emitted wavelength spectrum	0
phase	rad	Initial phase of radiation.	0
randomphase	0/1	If !=0 phase will be random (I.e. the emitted radiation is completely incoherent)	1
Ee	GeV	Storage ring electron energy (typically a few GeV)	2.4
Ie	A	Ring current	0.4
B	T	Magnet field strength	1.6
sigey	m	Electron ring beam size in vertical plane (rms)	0
sigex	m	Electron ring beam size in horizontal plane (rms)	0
focus_xw	m	Width of target window	0
focus_yh	m	Height of traget window	0
dist	m	Distance from source plane to target window along the optical axis	1
gauss_t	0/1	If 0 the target window will be sampled uniformly and the weight adjusted accordingly, otherwise we will use a gaussian sampling scheme	0

AT (	,	,		) RELATIVE		Generate to clipboard
ROTATED (	,	,		) RELATIVE

Links

• Source code for Bending_magnet.comp.

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[ Identification | Description | Examples | Input parameters | Links ]

Generated on mcxtrace 3.10.2

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Last Modified: Monday, 02-Nov-2026 22:21:08 CET