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and H.Humblot (middle) working on the 3He polariser. The 3He filling station uses laser light to polarise metastable 3He atoms by optical pumping at low pressure (1.3 mbar). The resulting electronic po ... First test of an 3He neutron spin filter The nuclei of a helium-3 gas (3He) can be polarised. Thanks to the strong spin-dependancy of the ...

First experiment with the 3He neutron spin filter During this first test of an 3He neutron spin filter, the neutron-beam polarisation transmitted by the filter could be determined with high accuray from ... The team: E. Bourgeat-Lami, H. Humblot, W. Heil, F. Tasset The cell filled with polarised 3He arrives on D3. The transport container ...

4-circle diffraction with a 3He dilution cryostat In the four-circle mode, the offset C-shaped Eulerian cradle can be equipped with a helium-flow cryostat (1.6 K to 450 K, or 0.1 K to 10 K in dilution

The detector The position sensitive neutron detector (PSD) is a set of 3He tubes. The assembly can be moved inside the detector tank to adjust the instrument resolution. When the photo was taken, not all

detector This very large banana PSD is of innovative design and works at high gas pressure (5 atm 3He + 1 atm CF4) for high efficiency coupled with high resolution (2.50 mm horizontally and 1.56 mm vertically;

momentum transfer range 3·10 -3 ≤ q [nm -1 ] ≤ 6 detector type (since January 2021) 3He gas detector (256 1-m long, 8 mm outer diameter stacked tubes from Reuter-Stokes, installed in 3 panels, shaped as a ... 47.65 mm -> 46.10 mm from 4.1 to 3.1 m 46.10 mm -> 38.0 mm from 3.1 to 1.6 m guide-to-sample distances 1.6, 3.1, 4.1, 5.6, 6.7, 7.7, 10.2, ...

in 10 6 n cm -2 s -1 PG (002) 3.355 1.3 - 3.3 2.662 9.3 Cu (111) 2.087 2.0 - 5.3 2.662 3.6 Heusler (111) 3.452 1.3 - 3.2 2.662 2.0 Collimation α1 = (0.015/ki) rad/Å -1 α2, α3, α4 = 10', 20', 30', 40', 60' ... adjustable by soller collimators Analyser horizontally focussing PG(002) 3He detector 50 mm Ø x 12 cm Instrument description IN3 is a classic ...

Monochromators PG 002: 2.20 ... 3.60 Å PG 004: 1.10 ... 1.80 Å Cu 220: 0.85 ... 1.50 Å Cu 111: 1.25 ... 2.24 Å take-off angle 2θM 39 ° ... 65° resolution δ> E i / E i 3 ... 6 % flux on sample 5 x 105 cm ... cm -2 s -1 background choppers ν max 5 000 rpm Fermi chopper ν max 32 000 rpm duty cycle 3 x 10 -3 beam size on sample 2 x 4 cm 2 primary ...

geometry also play a crucial role in optimising performance. POLARISED 3He ³He only absorbs neutrons with the opposite spin to that of the ³He nucleus, while its scattering cross-section is extremely small and ... times of the polarised ³He gas. ADVANCED POLARISATION ANALYSIS: PASTIS3 The ability to control the polarisation direction of ³He nuclei ...

respectiveley a 1536 cell (since 2000) curved position sensitive detector (PSD) filled with a mixture of 3He (3.1 bars) and CF4 (0.8 bar). Microstrip plates (invented by Anton Oed) replace the conventional wires ... due to Cadmium shielding and beam-stop inside. cryostat alignment liquid N2 refill liquid He refill liquid He gauge sample change and ...