View upon the diffractometer:
   Set up adjusted for transmission geometry
   Left:  Translation (XS,YS) and rotation (Omega S)
          for the sample support  
   Right: Monochromator (M)
   Diffractometer with two counters
   with special degree of freedom (Omega C) to keep
   the two counters C1,C2 oriented towards the sample (ST)
   Magnified setup (127 kB)

  Diagram of the beam path
  Legend see above and:
  F1 Focus of the X-ray tube
  F2 Focus of the Johannson bent
     monochromator
  XC Translation of the counter circle
  ST Sample position for transmission 
  SR          "          reflection  
  R  Radius of the diffractometer
  Inset:
  R1:R2=1:2, gear for the counter
             orientation