[ Identification | Description | Input parameters | Links ]

The ILL_H15_SAM Instrument

The small-angle diffractometer SAM at the ILL.

Identification

• Site: ILL
• Author: Nicolas MARTIN
• Origin: LLB
• Date: 2026/04/08

Description

SAM is a CRG instrument built through a collaboration between the LLB & the ILL between
June 2023 and February 2024. After hot commissioning, first user experiments took place
in June 2024. SAM stands for "Small-Angle Modular instrument". It is a compact SANS
devoted to the study of mesostructures found in various contexts (soft matter, biophysics,
material sciences and magnetism), which also features polarized neutrons capabilities
(not included in this model). The beamline is fed by the completely renewed H15 cold
neutrons guide.

Instrument parameters:

Typical wavelength range: 3.25-24 AA
Guides cross section: 30 x 30 mm2 (three moveable elements within collimator)
Collimation lengths: [9, 7, 5, 2.5] m
Adjustable 'reflectometer-type' diaphragms located at [9, 5, 2.5] m upstream of sample position.
Sample-to-detector distance: 0.75-6.85 m
Detector: 64 x 64 cm2 monoblock 3He PSD
See the instrument page on the ILL website for more details.

Example (typical "real-life" measurement sequence):

mcrun ILL_H15_SAM.instr --gravity -n1e7 -dLargeQ lambda=5.2
mcrun ILL_H15_SAM.instr --gravity -n1e7 -dSmallQ guide1=0 guide2=0 guide3=0 lsd=6.8

(Corresponding test-suite entries:)

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
lambda	AA	Wavelength mean value	5.2
dlambda	1	Wavelength range, full width	0.2
lambdasel	AA	Mean wavelength selected by the NVS	-1.0
guide1	1	0 = out, 1 = in	1
guide2	1	0 = out, 1 = in	1
guide3	1	0 = out, 1 = in	1
s1w	mm	Width of the 1st adjustable diaphragm	30
s1h	mm	Height of the 1st adjustable diaphragm	30
s2w	mm	Width of the 2nd adjustable diaphragm	30
s2h	mm	Height of the 2nd adjustable diaphragm	30
s3w	mm	Width of the 3rd adjustable diaphragm	30
s3h	mm	Height of the 3rd adjustable diaphragm	30
ssw	mm	Width or diameter of sample slit	7
ssh	mm	Height of sample slit (0 for circular slit)	10
sampleno	1	Choice of sample: 0 = none, 1 = liquid water, 2 = powder ring, 3 = hard spheres in solution	3
lsd	m	Sample-to-detector distance	0.85

Links

• Source code for ILL_H15_SAM.instr.

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[ Identification | Description | Input parameters | Links ]

Generated for mcstas 3.6.14

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Last Modified: Monday, 13-Apr-2026 11:30:07 CEST