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20130220 Laser Tuning

RGA Tuning

Green Output

Don't have attenuator so can't measure output energy. Going by the 'crack' though, I'd say about 200mJ, maybe even 250mJ. Could optimise the green on both the camera and the crack on the beam dumps at the same time.

  • Beam size different at VIP - most likely because of different mode in RGA.
  • Initially 4 sigma 2.8mm x 1mm. Way too small!
  • Telescope currently at 14mm on actuator and manual micrometer at 0.0mm
  • Setting telescope actuator to 10mm takes 4 sigma to around 3.5. Looks like the actuator won't be enough on it's own
  • Telescope actuator to 5mm -> 4 sigma of 3.7mm. Need to adjust lens holder position

  • Larger telescope actuator number corresponds to LARGER lens separation -> SMALLER beam size at VIP.
  • Set telescope actuator to 12.5 (middle of range). Set manual micrometer to 15mm.

Ok, camera wasn't recognised properly with pixel multiplication factor of 3.1 for camera number 3. Going to Dataray>settings and clicking ok refreshed this and sizes are much more realistic. Beam was filling at least three quarters of camera before which was suspicious for such a small size.

  • Manual: 15mm, Actuator: 12.5 4 sigma: 12.7mm approximately.
  • Manual: 10mm, Actuator: 12.5 4 sigma: 12.0mm approximately.

Telescope Calibration

  • Telescope set at 12.5mm in the end. Was quite accurate to start with!

  • Verified over the range 5mm to 20mm centre does move.
  • Aligned well to iris at VIP.


  • Laser at 100us flash lamp delay - ie full power.

Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg 20130220_green_100us_VIP.jpg r1 manage 30.6 K 20 Feb 2013 - 17:04 LaurieNevay green 100us at vip before telescope calibration
JPEGjpg after_spatial_filter.jpg r1 manage 15.9 K 20 Feb 2013 - 17:03 LaurieNevay after spatial filter
JPEGjpg vertical.jpg r1 manage 199.2 K 20 Feb 2013 - 17:03 LaurieNevay Telescope Calibration

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Topic revision: r1 - 20 Feb 2013 - LaurieNevay

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