====== Image Intensifier Couplings ======

To guide the image from the phosphor screen of the image intensifier to the CCD camera, two different couplings are used at GSI.

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===== Taper Coupling =====
The taper coupling was our 'standard' until we had problems with radiation damage of the CCD cameras.
The advantages of the taper coupling are:\\
  * high light transmission
  * low image distortion
  * compact size \\
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Some details of the taper:
  * quartz glass
  * magnification 25:14 (10µm>6µm  &  6µm>4µm)
  * image transferred in same direction (not flipped)
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Replacing a damaged CCD is very time- and cost-intensive. Therfore we switched to the relay lens coupling.
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===== Relay Lens Coupling =====
The relay lens coupling enables flexible change of the CCD camera. 
But it has some disadvantages:
  * less light transmission than taper
  * image distortion (esp. on boundaries)
  * image is flipped
  * size ~15cm longer than taper
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Some details of the relay optics:
  * Iris: Componon 35/2,8 (Schneider Kreuznach)
  * Unifog 12 helical mount
  * magnification: 0.6
  * distance Phosphorscreen > CCD: 147 mm
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{{:fair-rnd:gsi_18.08.2009_small.png?600|}}\\
**Image Intensifier with relay lens coupling**\\
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{{:fair-rnd:gsi_13.08.2009_relay_cut_smaller.png?600|}}\\
**Image Intensifier with relay lens coupling, cut **\\
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====== Technical drawings ======
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**Dimensions of the Taper-Coupling**\\
{{:fair-rnd:bv_masse_eingangsseite.pdf|}} \\
Auflagenmaß:\\ 
Aussenkante BV - Glasfenster : 9,5 +/-0,5 mm  in Luft\\
Glasfenster    - Photokathode: 5,5 mm         in Quartzglas mit n=1,558 @400nm\\
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**Dimensions of the Relay-Coupling**\\
{{:fair-rnd:bv_masse_relaisoptik.pdf|}}