The principle of polarizing cavities is based on the spin-dependent transmission of the neutrons through a polarizing supermirror on a silicon substrate (polarizing wafer). One spin orientation is transmitted. The other is reflected out of the beam. The polarizing wafers are arranged in a V shape in order to shorten the device for a given width. Multiple, parallel channels, each equipped with a polarizing V allow to cover a larger beam width. Using two (or more) Vs in a serial arrangement increases the polarization efficiency of the device.

Particular features are:

• Fe/Si polarizing coatings with large m-values and excellent reflectivity

• single-/multi-channel

• serial Vs

• thin Si wafer (t = 0.3mm) for high transmission

• overlap of Si wafer at the tip of the V and intrusion into sides to avoid streaming of neutrons of the wrong spin state

Download: Flyer polarizing devices

• V-cavity design
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 4: Critical wavelength:	1 15 0.7° 560 mm single crystal Si, t = 0.3 mm Fe/Si, m = 4, double-sided Rave = 0.81 λ* = 2.15 Å
  Body design
  	Cross-section: Length: Width of channel: Substrate dividing wall: Coating:	100 mm (w) x 214 mm (h) -> 52 mm (w) x 214 mm (h) 642 mm 14 mm borosilicate glass, t = 0.3mm none
  Specials
  	Magnetic casing with B = 450 G

• V-cavity design
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 4.5: Critical wavelength:	1 25 0.6875° 154 mm single crystal Si, t = 0.3 mm Fe/Si, m = 4.5, double-sided Rave = 0.76 λ* = 1.5 Å
  Body design
  	Cross-section: Length: Coating:	60 mm (w) x 60 mm (h) 185 mm TiB
  Specials
  	3 identical cavities were delivered

• V-cavity design
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 4.2: Critical wavelength:	1 1 logarithmic spiral 225 mm single crystal Si, t = 0.3 mm Fe/Si, m = 4.2, double-sided Rave = 0.79 λ* = 2 Å
  Body design
  	Cross-section: Length: Coating:	50 mm (w) x 50 mm (h) 225 mm none
  Specials
  	Additional Ni coating on top of polarizing supermirror as frame overlap mirror

• V-cavity design
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 3: Critical wavelength:	1 1 1.03° 2000 mm single crystal Si, t = 0.3 mm Fe/Si, m = 3, double-sided Rave = 0.86 λ* = 3.5 Å
  Body design
  	Cross-section: Length: Coating:	36.7 mm (w) x 36.7 mm (h) 2000 mm Ni/Ti m = 1.2

• V-cavity design polarizer
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 5: Critical wavelength:	2 6 0.3° 750 mm single crystal Si, t = 0.3 mm Fe/Si, m = 5, double-sided Rave = 0.72 λ* = 1.2 Å
  Body design polarizer
  	Cross-section: Length: Width of channel: Substrate dividing walls: Coating:	30 mm (w) x 100 mm (h) -> 30 mm (w) x 50 mm (h) 750 mm 4.75 mm borosilicate glass, t = 0.3 mm Ni/Ti m = 2.5, non-magnetic
  Specials polarizer
  	Magnetic casing with B = 500 G
  V-cavity design analyzer
  	Number of serial V: Number of channels: Taper angle of V: Length of V: Substrate: Coating: Measured reflectivity @ m = 5: Critical wavelength:	2 11 0.63° 500 mm single crystal Si, t = 0.3 mm Fe/Si, m = 5, double-sided Rave = 0.86 λ* = 1.2 Å
  Body design analyzer
  	Cross-section: Length: Width of channel: Substrate dividing walls: Coating:	42 mm (w) x 74 mm (h) -> 30 mm (w) x 74 mm (h) 500 mm 6.45 mm borosilicate glass, t = 0.3 mm Ni/Ti m = 2, non-magnetic
  Specials analyzer
  	Magnetic casing with B = 500 G