Powder dictionary (pdCIF) version 1.0.1

_pd_instr_monochr_

Names:
'_pd_instr_monochr_pre_spec' '_pd_instr_monochr_post_spec'

Definition:

   Indicates the method used to obtain monochromatic radiation.
   Use _pd_instr_monochr_pre_spec to describe the primary beam
   monochromator (pre-specimen monochromation). Use
   _pd_instr_monochr_post_spec to specify the
   post-diffraction analyser (post-specimen monochromation).

   When a monochromator crystal is used, the material and the
   indices of the Bragg reflection are specified.

   Note that monochromators may have either 'parallel' or
   'antiparallel' orientation. It is assumed that the
   geometry is parallel unless specified otherwise.
   In a parallel geometry, the position of the monochromator
   allows the incident beam and the final post-specimen
   and post-monochromator beam to be as close to parallel
   as possible. In a parallel geometry, the diffracting
   planes in the specimen and monochromator will be parallel
   when 2\q~monochromator~ is equal to 2\q~specimen~.
   For further discussion see R. Jenkins & R. Snyder (1996).
   Introduction to X-ray Powder Diffraction, 
   pp. 164-165. New York: Wiley.

Examples:

'Zr filter'

'Ge 220'

none

'equatorial mounted graphite (0001)'

'Si (111), antiparallel'

May appear in list

Type: char

Category: pd_instr

---