Massive dynamic q-range small-angle diffractometer

Guide hall n°1, cold guide H142

Wavelength Definition

Monochromatic Mode:

Velocity selector (Astrium)

Δλ/λ = 10 % (standard)

Wavelength range

4.5 < λ/Å < 40 (for Δλ/λ = 10 %)

Time-of-Flight (TOF) Mode:

4-chopper system (Astrium)


Wavelength cut-offs

14 Å and 20 Å

Wavelength resolutions

Δλ/λ  = 2 % to 26 % (depending on chopper pair & detector distance)


4 movable guide sections

2.5 m

Beam nose

2.8 m

Guide cross-section

30 x 30 mm

Source-to-sample distances (m)

2.8, 5.3, 7.8, 10.3, 12.8

Source apertures

30x50 mm (off-centre), 30x30 mm
diameters: 5, 10, 20, 30 mm

Sample area

Maximum flux at sample 
(for Δλ/λ = 10%)

4.1x107 n cm-2 s-1

Brightness (flux / unit solid angle)

3.57x1011 n cm-2 s-1 strd-1

Maximum sample dimensions

15 mm x 15 mm

Sample environments

Sample changer, Electromagnet, Cryostat, Cryomagnet, Furnace, Stopped-flow, Shear cell


Sample - Detector distances

1.2 ... 12.8 m

Detector 1 (rear):

Single panel monoblock

640 x 640 mm

Pixel size

5 x 5 mm2 (128 x 128 pixels)

Maximum count rate

4 MHz (global) ; 3 kHz/pixel (local)

Detector 2 (front):

4-panel monoblock

160 x 640 mm each panel

Pixel size

5 x 5 mm2 (32 x 128 pixels)

Maximum count rate

4 MHz (global) ; 3 kHz/pixel (local)

Instrument Description

Scientific goals

Modern trends in materials science, physics and in particular nano-structured materials require that D33 provides both high resolution and a wide dynamic range of measured scattering vector, q.


The instrument offers both ‘monochromatic’ and ‘time-of-flight’ (TOF) mode.
Monochromatic mode: a velocity selector and flexible system of inter-collimation apertures defines the neutron beam.

TOF mode: a chopper system allows an enhanced dynamic q-range (qmax / qmin) and flexible wavelength resolution.
Two large multitube detectors extend the dynamic q-range further giving qmax / qmin = 20 in monochromatic mode and massive qmax / qmin > 1000 in TOF mode.

Beam polarization and 3He spin analysis facilitate and expand studies of magnetism and allow a more quantitative analysis of spin incoherent samples. The position of D33 allows high magnetic fields and bulky environments at the sample position.


  1. "The small-angle neutron scattering instrument D33 at the Institut Laue–Langevin", Dewhurst C.D., Grillo I., Honecker D., Bonnaud M., Jacques M., Amrouni C., Perillo-Marcone A., Manzin G., Cubitt R., Journal of Applied Crystallography 49, 1-14 (2016)