First Polarised Light with the NIKA Camera
- 113 Downloads
NIKA is a dual-band camera operating with 315 frequency multiplexed LEKIDs cooled at 100 mK. NIKA is designed to observe the sky in intensity and polarisation at 150 and 260 GHz from the IRAM 30-m telescope. It is a test-bench for the final NIKA2 camera. The incoming linear polarisation is modulated at four times the mechanical rotation frequency by a warm rotating multi-layer half- wave plate. Then, the signal is analyzed by a wire grid and finally absorbed by the lumped element kinetic inductance detectors (LEKIDs). The small time constant (\(<\)1 ms ) of the LEKIDs combined with the modulation of the HWP enables the quasi-simultaneous measurement of the three Stokes parameters I, Q, U, representing linear polarisation. In this paper, we present the results of recent observational campaigns demonstrating the good performance of NIKA in detecting polarisation at millimeter wavelength.
KeywordsMillimeter astronomy Polarisation KIDs NIKA
We would like to thank the IRAM staff for their support during the campaign. This work has been partially funded by the Foundation Nanoscience Grenoble, the ANR under the contracts ”MKIDS” and ”NIKA.” This work has been partially supported by the LabEx FOCUS ANR-11-LABX-0013. This work has benefited from the support of the European Research Council Advanced Grant ORISTARS under the European Union’s Seventh Framework Program (Grant Agreement no. 291294). The NIKA dilution cryostat was designed and built at the Institut Neel. A. R. would like to thank the FOCUS French LabEx doctoral fellowship program. A. R. acknowledges support from the CNES doctoral fellowship program. R. A. would like to thank the ENIGMASS French LabEx doctoral fellowship program. B. C. acknowledges support from the CNES post-doctoral fellowship program.