Kraken OTR Procedure

Authors: Oliver Williams, Brendan O’Shea, Esperanza Arab, Christine Clarke

06/23/2012

It’s important to remove the backgrounds caused by the OTR “donut” coming off the KOTR Al turning mirror. This procedure isnt perfect and if you drop the bit depth you can still see something, but with the OTR foil in, it is very faint. It does contribute to over estimates in beam sizes, but we haven't an alternative.

  1. Park beam
  2. Turn Kraken light on

  1. Change Kraken camera trigger to 43 (always present regardless of beam) and look at the KRAKENOTR profile monitor.
  2. Remove the sample holder/OTR foil. Drive the X stage to -5 using “increment”.X does not have a limit switch- it should not be driven more positive than -1 mm. -5 mm is plenty for getting out of the beam path no matter what Y is set to.
  3. Put in the KOTR pop in (mirror)
  4. Turn off the Kraken light.
  5. Set the Kraken OTR trigger to 213 (beam synchronous).
  6. Set to average over 10 frames. Hit 'single' and let it take the frames.
  7. Bring back beam to FACET.
  8. Make background.(Grab background turns off the beam so don’t do that).
  9. Use background.Reset averaging to 1.
  10. Park beam.
  11. Turn the Kraken light on.
  12. Set the Kraken OTR camera trigger to 43. You may need to crank up the width too to see the block.
  13. Move x and y to the OTR foil- watch the holder move across the screen until the OTR foil is centred on the camera. The foil is 1 cm in diameter so you shouldn’t have to move too much.
  14. Set Kraken OTR camera trigger to 213.
  15. Turn the Kraken light off.
  16. Bring beam back.
  17. Tune!

Troubleshooting

Q: I have beam on IP2A and the dump, I loaded a known working config but I don’t see the beam on IP2B or KrakenOTR?

A: Check the trigger, as in point 3 above. Is it set to beam synchronous? The trigger panel can be found under FACETHome->Profile Monitor -> LI20 in the bottom right corner, “Trigger Config…”. The current beam timing codes can be found at the bottom of the “Trigger Config…” panel.

Q: I have beam on IP2A and IP2B, but nothing, or something silly (like below), on KrakenOTR, what is up?

A: This most likely means camera trouble or the alignment of beam to KrakenOTR is poor. The camera’s Field of View (FoV) is something like 2.5x2.5mm, with a Depth of Focus (DoF) on the order of 100 microns. Add in the fact that OTR has an opening angle of the inverse of gamma and the camera alignment is very sensitive. Below is shown a configuration in which the turning mirror halo can be barely seen to get into the camera’s FoV. A green box next to KrakenOTR in FACETHome->Profile Monitor ->LI20 indicates the camera is working properly. If you have a green box and still see nothing, or see poorly align light, as below, then the Kraken camera system needs to be realigned (not covered here, it requires tunnel access).