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. 2022 Feb 27;55(Pt 2):271–283. doi: 10.1107/S1600576722000826

Table 1. Characteristics of the 48 m VSANS instrument.

Source m = 1 straight neutron guide 60 × 150 mm cross section, filter: 200 mm Be + 200 mm Bi
Monochromator (i) HOPG, Δλ/λ = 0.8–1.0%, 4.75 < λ < 5.5 Å
(ii) Neutron velocity selector (NVS), Δλ/λ = 12.5%, 4.5 < λ < 20.0 Å
(iii) Deflector, Δλ/λ = 44%, λ = 5.34 Å
(iv) Filter only, Δλ/λ = 80%, λ = 6.20 Å
Source–sample distance Nominally 6–24 m in 2 m steps via insertion of neutron guide segments
Sample–detector distance (i) Rear: 11.03–23.65 m
(ii) Middle: 2.85–20.87 m
(iii) Front: 0.84–10.14 m
Collimation (i) Standard circular pinhole
(ii) 18 CB with MgF2 lenses and prisms
(iii) Slits; width 1–60 mm, height 1–150 mm
Sample area 2 m-long sample area with four-axis stage and vacuum pipe
q range 2 × 10−4 to 0.7 Å−1
Detectors (i) Rear: 6LiF ZnS(Ag) scintillator with CCD, 0.85 mm resolution (FWHM), 0.21 m wide × 0.47 m tall
  (ii) Middle: 8 mm-diameter 3He tubes, 48 tube panels; four panels: left + right are 0.40 m wide × 1.00 m tall, top + bottom are 0.50 m wide × 0.40 m tall
  (iii) Front: same as middle (see above)
Polarization (i) Double-V polarizer having 99% polarization
  (ii) RF spin flipper having > 99.99% flipping efficiency
  (iii) 3He spin analyzer