P1.8 Complete system functional verification, filter artifacts/defects verification, NCPA measurement, and internal tip-tilt loop verification

• Phase : 1
• Status : COMPLETE
• Category : Unpack, Assemble, and Verification (C1)
• Recurrence : once
• Duration : 1.5 days

Description

• Checking the working of motors and light sources within SHARK-NIR using optical feedback. Finding the filter defects/artifacts using an internal calibration source (flat-field) within the instrument. Measure the NCPA internal to the SHARK-NIR and correct using the ALPAO-DM. Check the working of the internal tip-tilt loop using calibration unit light sources, C-RED2, and ALPAO-DM.

Prerequisites

• SHARK-NIR is connected to the LBT network.
• Electronics racks on.
• DM best shape uploaded (shape minimizing internal aberrations)
• The cryostat should be running and cooled down.
• P1.7 should be completed.

Procedure

• When the services are up and running, after the motors are sent to home positions, each of the individual motors is individually tested for their different named/nominal positions.
• The light sources within SHARK-NIR are used simultaneously to check the working of the motors by looking at the optical feedback.
• Check the CRED-2 and ALPAO-DM SW using optical feedback.
• Take the images of all the filters using the internal calibration source (flat-field) within the instrument to locate/find out the filter defects/artifacts, if any. You may take short- and long exposures to get better contrast of the features if required.
• Check the filter wheel position monitoring script detailed in SNM1. Save the data in the repository.
• Run the Phase-diversity routine using the images taken with the SHARK-NIR internal calibration sources to measure the NCPA within (excluding the deployable arm).
• Run the internal tip-tilt loop routine for a defined (or set of) brightness of the source (star).
• Check its efficiency in keeping the PSF at the C-RED2 hot-pixel.
• Save data to the repository and analyze them.

Templates

• SHARKNIR_di_mon_MaskRepeatability
• SHARKNIR_di_cal_NCPA_PD (Phase Diversity approach)
• SHARKNIR_di_cal_NCPA_trial (Trial & Error approach)
• SHARKNIR_gen_tec_CloseLoop
• SHARKNIR_gen_tec_OpenLoop

Success criteria

• All the motors can reach the named positions / nominal positions.
• All the light sources are working and confirmed through optical feedback at the SCICAM.
• Filter wheel position monitoring script is run successfully and data is saved in the repository.
• CRED-2 AND ALPAO-DM working normally.
• All the filter images are saved.
• Internal NCPA is measured and the PSF shows improvement in its quality after the NCPA correction using the ALPAO DM.
• Internal tip-tilt routine works fine and the PSF at the C-RED2 is stable within the required precision.
• All the data and analysis are saved in the repository
• Completed. The data can be found in this ​link.

Notes

LBTO support

• Liquid Nitrogen refill is required in the cleanroom.

Date performed and by whom Elena, Luca