3 He-NSF as analyser at V4 (SANS) – Magi

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					    WAPANS             February 22, 2010, Paris



3He-NSF   as analyser at V4 (SANS) – Magic Box version
                                                  L = 692 mm




    D = 130 mm
    WAPANS                     February 22, 2010, Paris



3He-NSF       as analyser at V4 (SANS) – WA version
(Collaboration with University Mainz)
                                             Filter cell between the pole shoes




                                                   (Br/r)/B0 < 7×10-
                                                   4cm-1
   WAPANS                February 22, 2010, Paris



Local refilling set-up                      Helmholtz
                                              coils


                                                    Pressure
                                                     sensor
                                                                        Throttle
                                                                         valve

                                          Storage
                                            cell



                                                                                          Filter
                                                                                           cell


                                                       Valve                  N              S
                                                    controller
                                            Valve control
                                               circuit
                                                                TMP
                                           Power               system
                                           supply

                                                                   Valve          Pneumatic
                                                                 controller       lift cylinder
     WAPANS                          February 22, 2010, Paris



 Comparison of both options

Cell in the electromagnet :                      „Magic box“ :

  No space for 2. flipper                           Smaller maximum scattering angles:
                                                    θMax ≈ ±3.5°  QMax≈ 0.64 nm-1
  External flipping of 3He polarisation 
  only once per fill                                Long relaxation times: T1 > 200 h
                                                     „time-independent“ analysing
  Actual relaxation time: T1 = 2.5 h                  efficiency
  Full polarisation analysis without 2nd
  flipper             U. Keiderling et al.,         In-situ 3He spin flipping option
  Meas. Sci. Technol. 19 (2008) 034009 (8pp)         no need for a 2nd flipper

  Large maximum scattering angles:                  No local refilling needed
  θMax ≈ ±18.6°  QMax ≈ 3.3 nm-1 (at 6
  Å)

  Small cell volume allows for quick
  and frequent gas exchange
   WAPANS                        February 22, 2010, Paris



Option with polarised neutrons at V7
Instrument: V7 (CONRAD) at HZB
Detector mode: CCD, high-resolution (0.05 mm/pixel)



Experimental sketch (view from above):



                                                            Wavelength: 0.2 - 1.0 nm

       CCD camera

                                Polariser
            Analyser

                                            Beam
                                                                                   1m
                       Sample
     WAPANS         February 22, 2010, Paris



Experimental setup for imaging with polarised
neutrons                       Analyser Camera box




                                               Sample
Helium-3
spin filter
         Beam




                     Polariser

				
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