P2.4 Align SHARK-NIR to the telescope

• Phase : 2
• Status : Draft
• Category : Daytime testing (functionality and operability) (C2)
• Recurrence : after instrument installation at telescope platform
• Duration : 3 days

Description

• SHARK-NIR is aligned to the telescope and the daytime collimation model is acquired.

Prerequisites

• All electronics and services up and running.
• SHARK-NIR shutter open, and deployable arm (dichroic + IN-TT) deployed to get the light directed into SHARK-NIR.

Procedure

• Since SHARK-NIR has the same focal station as LBTI, the telescope is set to the LBTI collimation model to start the alignment of SHARK-NIR to the telescope.
• RR is mounted on the SX side. Using RR / ARGOS on-axis calibration light source, M2 and M3 of the LBT are moved to have the on-axis spot on the reference position on SCICAM (also TECCAM), identified during the internal alignment of the instrument. (Do you want to use the IN-TT mirror for the alignment?) Coma, if present, is minimized by looking at the out-of-focus image, shifting and tilting M2, and keeping the spot fixed on SCICAM. Astigmatism, if present, can be reduced by applying the astigmatism terms to the M2 shape. Focus is adjusted shifting M2 along the optical axis. The daytime collimation model is recorded.
• Do we need to check if LBTI is getting the light in their detectors? Do we ever run both SHARK-NIR and LBTI parallelly? Maybe it is required for running the LBTI AO system?

Success criteria

• On-axis spot from the RR/ARGOS light source at the reference pixel of the SCICAM.
• The daytime SHARK-NIR collimation model recorded.
• Something with LBTI?

Notes

• SCICAM has large persistence. Avoid super-bright stars (LM: this is a daytime activity. I would move this note to P3.6. Secondly, I disagree, at least for the first part of the alignment. In fact, I would need a very very bright light source in order to see the footprint of the beam on the dichroic and IN-TT, to ensure it is fairly centered on the optics. I do not know how bright is ARGOS source as I never used it..if it is not very bright we might ask Tom Herbst if we can use Baby Argos for this phase? Of course for this activity, to preserve detectors we can close SHARK-NIR shutter). Use TECCAM first, and then SCICAM (with ND filter) later for the alignment.

LBTO support

• Working platform installed in front of the Gregorian focal-station SX.
• Argos swing arm and calibration source on SX side.
• Support from the LBTI team.

Associated SHARK-NIR personnel

Date performed and by whom

Comments

after arcetri videocon probably for alignment Argos source is the best solution. I would start also with mirrors in LBTI configuration as the light needs to go to SOUL WFS and would mostly use our internal degrees of freedom (internal of course including the dichroic). Of course some tweaking either of mirrors or SOUL WFS x-y-z is possible. [need to talk. does this mean that we need someone to look into LBTI AO system or support from SOUL Arcetri team?]

LM: absolutely, I would minimize any movement of the telescope's mirror, as that is an already commissioned focal station, so the telescope collimation is already good. We shall use our internal mirror IN-TT and DM to align SHARK-NIR to the telescope. If errors in the mechanics are too big to be only compensated by our mirrors, then we can move the telescope's mirrors. In this case, SOUL shall "chase" the beam using its XYZ linear stages. As far as I know, SHARK-NIR will not be used together with LBTI (in trinocular observations, LMIRcam receives light from DX side). However, it is worth, at the end of the alignment, to check that our deployable arm, when un-deployed, does not vignette any of the technical FoV of LBTI (which is 120 more or less). I think the latter activity can be performed only at night time (authorize LBTI night collimation). We also have to align the telescope pupil to our internal pupil, other than the PSF. Let's discuss together the details of this procedure