@conference{10902/19298, year = {2012}, month = {10}, url = {http://hdl.handle.net/10902/19298}, abstract = {The QUIJOTE-CMB project has been described in previous publications. Here we present the current status of the QUIJOTE multi-frequency instrument (MFI) with five separate polarimeters (providing 5 independent sky pixels): two which operate at 10-14 GHz, two which operate at 16-20 GHz, and a central polarimeter at 30 GHz. The optical arrangement includes 5 conical corrugated feedhorns staring into a dual reflector crossed-draconian system, which provides optimal cross-polarization properties (designed to be < -35 dB) and symmetric beams. Each horn feeds a novel cryogenic on-axis rotating polar modulator which can rotate at a speed of up to 1 Hz. The science driver for this first instrument is the characterization of the galactic emission. The polarimeters use the polar modulator to derive linear polar parameters Q, U and I and switch out various systematics. The detection system provides optimum sensitivity through 2 correlated and 2 total power channels. The system is calibrated using bright polarized celestial sources and through a secondary calibration source and antenna. The acquisition system, telescope control and housekeeping are all linked through a real-time gigabit Ethernet network. All communication, power and helium gas are passed through a central rotary joint. The time stamp is synchronized to a GPS time signal. The acquisition software is based on PLCs written in Beckhoffs TwinCat and ethercat. The user interface is written in LABVIEW. The status of the QUIJOTE MFI will be presented including pre-commissioning results and laboratory testing.}, publisher = {SPIE Society of Photo-Optical Instrumentation Engineers}, publisher = {Proceedings of SPIE, 2012, 8452, 845233}, publisher = {Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VI, Amsterdam, 2012}, title = {The status of the Quijote multi-frequency instrument}, author = {Hoyland, Roger J. and Aguiar González, Marta and Aja Abelán, Beatriz and Ariño, Javier and Artal Latorre, Eduardo and Barreiro Vilas, Rita Belén and Blackhurst, E. J. and Cagigas Ibañez, Jaime and Cano de Diego, Juan Luis and Casas Reinares, Francisco Javier and Davis, R. J. and Fernández Cobos, Raúl and Fuente Rodríguez, Luisa María de la and Herranz Muñoz, Diego and López-Caniego Alcarria, Marcos and Martínez González, Enrique and Mediavilla Sánchez, Ángel and Ortiz García, David and Vielva Martínez, Patricio and Villa Benito, Enrique}, }