The `Brilliance_monitor` Component

Special "Brilliance" monitor.

Identification

Site:
Author: Peter Willendrup, derived from TOF_lambda_monitor.comp
Origin: DTU Physics
Date: May 23, 2012

Description

If used in the right setting, will output "instantaneous" and "mean" brilliances in units of Neutrons/cm^2/ster/AA/s. Conditions for proper units:

Use a with a source of area 1x1cm
The source must illuminate/focus to an area of 1x1cm a 1m distance
Parametrise the Brilliance_monitor with the frequency of the source
To not change the source TOF distribution, place the Brilliance monitor close to the source!


with a source of area 1x1cm illuminating/focusing to an area of 1x1cm a 1m distance, this monitor will output "instantaneous" and "mean" brilliances in units of Neutrons/cm^2/ster/AA/s

Here is an example of the use of the component. Note how the mentioned Unit conditions are implemented in instrument code.

COMPONENT Source = ESS_moderator_long(
l_low = lambdamin, l_high = lambdamax, dist = 1, xw = 0.01, yh = 0.01,
freq = 14, T=50, tau=287e-6, tau1=0, tau2=20e-6,
n=20, n2=5, d=0.00286, chi2=0.9, I0=6.9e11, I2=27.6e10,
branch1=0, branch2=0.5, twopulses=0, size=0.01)
AT (0, 0, 0) RELATIVE Origin

COMPONENT BRIL = Brilliance_monitor(nlam=196,nt=401,filename="bril.sim",
t_0=0,t_1=4000,lambda_0=lambdamin,
lambda_1=lambdamax, Freq=14)
AT (0,0,0.000001) RELATIVE Source

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
nlam	1	Number of bins in wavelength	101
nt	1	Number of bins in TOF	1001
nowritefile	1	If set, monitor will skip writing to disk	0
lambda_0	AA	Minimum wavelength detected	0
lambda_1	AA	Maximum wavelength detected	20
restore_neutron	1	If set, the monitor does not influence the neutron state	0
Freq	Hz	Source frequency. Use freq=1 for reactor source
tofcuts	1	Flag to generate TOF-distributions as function of wavelength	0
toflambda	1	Flag to generate TOF-lambda distribution output	0
xwidth	m	width of monitor	0.01
yheight	m	height of monitor	0.01
source_dist	m	Distance from source. Beware when transporting through neutron optics!	1
filename	string	Defines filenames for the detector images. Stored as: Peak_<filename> and Mean_<filename>	0
t_0	us	Minimum time	0
t_1	us	Maximum time	20000
srcarea		Source area [cm^2]	1

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

The Brilliance_monitor Component

Identification

Description

Input parameters

Links

The `Brilliance_monitor` Component