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McStas: ILL_H8_IN1

[ Identification | Description | Input parameters | Links ]

The ILL_H8_IN1 Instrument

Hot neutron three-axis spectrometer IN1@ILL

Identification

Description

IN8 is installed on beamtube H10 (diameter F = 200 mm).

IN1 works in a time-sharing mode. This means that the same monochromator is
also used by the Be-filter spectrometer IN1-BeF and by the liquids
diffractometer D4. Changing over between the three different instruments can be
done without difficulty in about two hours.

The monochromator unit carries three different vertically focussing
monochromators built from copper single crystals (available reflecting planes
Cu(200), Cu(220) and Cu(331)). The exchange of the monochromator planes is
controlled by the instrument computer. The radius of curvature can be
automatically adjusted as function of reflected energy in order to maintain
maximal flux at the sample position in the course of energy scans. The
scattering angles on the monochromator cover a range of 10<2theta_m <90
allowing for scanning neutron energies from 13 meV to more than 1 eV..

The IN1-TAS spectrometer: the scattering angles at the sample and the analyser
can be changed in the intervals -115<2theta_S<115 and -120<2theta_S<120. Three
different analysers (PG(002), Cu(200), Cu(220)) can be installed in order to
optimise intensity and resolution for a given experiment. Various resonance
absorption filters (e.g. Er, Sm, Hf ...) can be used to suppress higher order
contaminations from the incident beam or in the scattered beam. An oriented
Pyrolytic Graphite filter is designed for experiments eventually demanding
thermal neutron energy range.

In this TAS configuration, Cu220 are used as monochromator and analyser,
with a single type detector.

Input parameters

Parameters in boldface are required; the others are optional.
NameUnitDescriptionDefault
KFAngs-1Outgoing neutron wavevector10
KIAngs-1Incoming neutron wavevector0
QMAngs-1Wavevector transfer in crystal0.5
ENmeVEnergy transfer in crystal0
verbose1print TAS configuration. 0 to be quiet1
WMmWidth of monochromator0.18
HMmHeight of monochromator0.20
RMHmMonochromator horizontal curvature, 0 for flat, -1 for automatic setting-1
RMVmMonochromator vertical curvature, 0 for flat, -1 for automatic setting-1
DMAngsMonochromator d-spacing1.278
NHM1Number of horizontal slabs composing the monochromator15
NVM1Number of vertical slabs composing the monochromator15
WAmWidth of analyzer0.16
HAmHeight of analyzer0.12
RAHmAnalyzer horizontal curvature, 0 for flat, -1 for automatic setting-1
RAVmAnalyzer vertical curvature, 0 for flat, -1 for automatic setting-1
DAAngsAnalyzer d-spacing1.278
NHA1Number of horizontal slabs composing the analyzer15
NVA1Number of vertical slabs composing the analyzer15
L1mSource-Monochromator distance. Contains 1st Collimator of length 5.347
ALF1arc minHorizontal collimation from Source to Monochromator120
ALF2arc minHorizontal collimation from Monochromator to Sample A120
ALF3arc minHorizontal collimation from Sample to Analyzer120
ALF4arc minHorizontal collimation from Analyzer to Detector120
BET1arc minVertical collimation from Source to Monochromator120
BET2arc minVertical collimation from Monochromator to Sample A120
BET3arc minVertical collimation from Sample to Analyzer120
BET4arc minVertical collimation from Analyzer to Detector120

Links

  • Source code for ILL_H8_IN1.instr.
  • Rescal for Matlab at http://www.ill.eu/instruments-support/computing-for-science/cs-software/all-software/matlab-ill/
  • Restrax at http://omega.ujf.cas.cz/restrax/

[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43


Last Modified: Tuesday, 16-Apr-2024 20:05:21 CEST
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