[ Identification | Description | Input parameters | Links ]

# The `ILL_Lagrange` Instrument

IN1-Lagrange hot neutrons spectrometer for liquids at the ILL.

## Identification

- Site: ILL
- Author: E. Farhi
- Origin: LLB/ILL
- Date: 13 Apr 2006

## Description

    IN1-Lagrange hot neutrons spectrometer for liquids at the ILL.

    The dedicated liquid and amorphous instrument Lagrange is a spectrometer with
    constant final neutron energy, and variable incoming neutron energy.
    The analyser is a focusing barrel covered with PG analyser, all focusing to
    the detector. The flux is thus very high, and the resolution is that given
    buy the PG crystal mocaicity.

    The monochromator take-off angle is 2Theta_M ~ 20-25 deg, variable. The available
    monochromators are all vertically focusing, Cu (200) for 0.7 Angs, Cu (220)
    for 0.5 Angs.

    Cu       002 DM=1.807 AA
    Cu       220 DM=1.278 AA
    PG       002 DM=3.355 AA
    --------------------------

## Input parameters

Parameters in boldface are required; the others are optional.

Name | Unit | Description | Default
lambda | Angs | Wavelength at monochromator | 0.897
DM | Angs | d-spacing of monochromator | 1.807
RV | m | Monochromator vertical curvature, 0=flat, -1=automatic | -1
coh | str | File name for sample coherent scattering contribution | "Rb_liq_coh.sqw"
inc | str | File name for sample incoherent scattering contribution | "Rb_liq_inc.sqw"
L1 | m | Source-Monochromator distance | 6.35
L2 | m | Monochromator-Sample distance | 2.55
L3 | m | Sample-Detector distance | 0.901
verbose | 1 | Print spectrometer configuration. 0 to be quiet | 1

## Links

- Source code for `ILL_Lagrange.instr`.
- The D4 diffractometer at the ILL

[ Identification | Description | Input parameters | Links ]