number of reflecting surfaces number of wavelengths NXguide is used by neutron instruments to describe a guide consists of several mirrors building a shape through which neutrons can be guided or directed. The simplest such form is box shaped although elliptical guides are gaining in popularity. The individual parts of a guide usually have common characteristics but there are cases where they are different. For example, a neutron guide might consist of 2 or 4 coated walls or a supermirror bender with multiple, coated vanes. To describe polarizing supermirrors such as used in neutron reflection, it may be necessary to revise this definition of NXguide to include NXpolarizer and/or NXmirror. When even greater complexity exists in the definition of what constitutes a guide, it has been suggested that NXguide be redefined as a NXcollection of NXmirrors each having their own NXgeometries describing their location(s). For the more general case when describing mirrors, consider using NXmirror. NOTE: The NeXus International Advisory Committee welcomes comments for revision and improvement of this definition of NXguide. A description of this particular instance of NXguide. Reflectivity as function of reflecting surface and wavelength reflectivity of each surface as a function of wavelength Use signal="1" to indicate that this is the plottable data for NeXus. NeXus basic motivation default plot Use axes="surface:wavelength" to indicate the dimension scales to be used when plotting this data. List of surfaces. Probably best to use index numbers but the specification is very loose. wavelengths at which reflectivity was measured external material outside substrate The m value for a supermirror, which defines the supermirror regime in multiples of the critical angle of Nickel. number of substrate sections (also called nsurf as an index in the NXguidespecification)