Integration and characterization of the cryogenic system of MEGARA

MEGARA (Multi-Espectrografo en GTC de Alta ResoluciOn para AstronomIa) is an optical Integral-Field Unit and Multi-Object Spectrograph designed for the GTC (Gran Telescopio de Canarias) 10.4m telescope in La Palma, it is expected that the spectrograph will be delivered to GTC towards the end of 2016. MEGARA includes an open cycle cryostat which harbors the scientific CCD of the instrument at an operating temperature of 153 K, this cryogenic system has been designed and integrated by the "Astronomical Instrumentation Lab for Millimeter Wavelengths" at the Instituto Nacional de Astrofsica, Optica y Electronica (INAOE) in Mexico. Early this year the cryostat has finished its fabrication and now it is on AIV phases, in this paper we report the cryostat CCD-head and dewar back integration, vacuum and cryogenic test results are also reported. The final integration of the cryostat with the other components of the instrument is taking place at LICA lab at the Universidad Complutense de Madrid