P3.4 Pupil alignment

• Phase : 3
• Status : Draft
• Category : Nighttime testing (functionality and operability) (C5) + Nighttime calibration (C6)
• Recurrence : before every observing target (CI, LSS), starting from commissioning.
• Duration : 1 night

Description

• Alignment of the internal pupil image with apodizer (at PP1) or Lyot stop (at PP2) in the coronagraphic mode

Prerequisites

• Bad pixel map, Background or Dark, Flat-field, detector RON

Procedure

• The position of the first tip-tilt mirror (IN_TT) is optimized in order to have the first pupil image centered with the apodizer/Lyot stop. This is obtained comparing the pupil image, formed on the SCICAM, with the image of the apodizer, obtained on the SCICAM using the calibration fiber as a source.

Success criteria

• Expected accuracy: 0.25% of pupil image diameter ~17arcsec of the TTM ~1.5pixel SCICAM ~30μm at the level of the SCICAM.

Notes

• Same as activity 8.2 in AD4

LBTO support

• AO support

Associated SHARK-NIR personnel

Date performed and by whom

Comment

KR, EC, DV: Should we do this also for Lyot Stops (Lyot_Grism_W) or PP2? Do we need to do the pupil alignment for the Prism or Grism (we think not)? Considering 5 cases (3 + 2) and 30 mins / case, we put 2.5 hours in total above. DV: yes, I confirm we need this procedure also for Lyot Stops on PP2. We started iterations with Depa/DavideR to adapt the template. DG: No fine alignment should be required for prism and grism every time we need them in night-time. We do not expect flectures strong enough to introduce vignetting, but we will have to ckeck it with tests.