NIRPS: integration and validation of thermal performance of the cryogenic near infra-red spectrograph subsystem

摘要

NIRPS is a near-infrared RV spectrograph for ESO 3.6m telescope in La Silla. At the present the instrument is in the integration phase. This new instrument will be covering YJH bands to detect and characterize low-mass planets in the habitable zone of M dwarfs, and will allow RV measurements at 1 m/s level, at 100K spectral resolution. The instrument consists of three subsystems: the front-end extracts the 700nm-2400nm band from the telescope beam, fiber link scrambles and guides light into the spectrograph, and the spectrograph itself. The cryogenic spectrograph unit, is operating at 80 K. Among key parameters is thermal stability of less than 1 mK over 24 hours. In this paper we describe as-built thermal and vacuum system design, work performed on assembly and integration of the cryo-vacuum subsystem, and validation of the thermal design, and thermal stability.