SVOM/VT: Flight Model Verification and Pre-launch Testing

TL;DR

This paper reports on the pre-launch testing and calibration of the SVOM/VT flight model, confirming it meets all design specifications through comprehensive ground and early in-orbit evaluations.

Contribution

It provides detailed validation results of the SVOM/VT flight model's performance under simulated space conditions, ensuring readiness for space deployment.

Findings

Stray light suppression achieves <10^{-7} at 30° off-axis.

Thermal control maintains CCD temperatures at -75°C and -65°C.

Detection sensitivity exceeds the limiting magnitude of 22.50.

Abstract

This paper presents pre-launch testing and calibration results for the SVOM/VT (Space-based Variable Objects Monitor, Visible Telescope) Flight Model (FM), validating its performance under simulated space conditions through thermal vacuum cycling, energy concentration analysis, stray light suppression, and CCD/electronics calibrations (gain, noise, quantum efficiency). The results confirm full compliance with design requirements: stray light suppression achieves point-source transmittance $<10^{-7}$ at $30^\circ$ off-axis, thermal control maintains stable CCD temperatures ($-75^\circ$C for the red channel, $-65^\circ$C for the blue channel), and detection sensitivity meets the limiting magnitude of 22.50 (SNR $>$ 3 with 300 seconds exposure). Early in-orbit tests further validate performance, yielding limiting magnitudes of 22.70 (V-band, red) and 22.78 (blue), consistent with pre-launch specifications.