7 March 2014 Techniques for the modelling of QUBIC: a next-generation quasi-optical bolometric interferometer for cosmology
Author Affiliations +
The expansion of the universe has red-shifted remnant radiation, called the Cosmic Microwave Background (CMB) radiation, to the terahertz band, one of the last areas of the electromagnetic spectrum to be explored. The CMB has imprinted upon it extremely faint temperature and polarisation features that were present in the early universe. The next ambitious goal in CMB astronomy is to map the polarisation characteristics but their detection will require a telescope with unprecedented levels of sensitivity and systematic error control. The QUBIC (Q&U Bolometric Interferometer for Cosmology) instrument has been specifically designed for this task, combining the sensitivity of a large array of wideband bolometers with the accuracy of interferometry. QUBIC will observe the sky through an array of horns whose signals will be added using a quasi-optical beam combiner (an off-axis Gregorian dual reflector designed to have low aberrations). Fringes will be formed on two focal planes separated by a polarising grid. MODAL (our in house simulation package) has been used to great effect in achieving a detailed level of understanding of the QUBIC combiner. Using a combination of scalar (GBM) and vector (PO) analysis, MODAL is capable of high speed and accuracy in the simulation of quasi-optical systems. There are several technical challenges to overcome but the development of MODAL and simulation techniques have gone a long way to solving these in the design and analysis phase. In this paper I outline the quasi-optical modelling of the QUBIC beam combiner and work envisaged for the future.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
S. Scully, D. Gayer, D. Bennet, C. O'Sullivan, M. L. Gradziel, "Techniques for the modelling of QUBIC: a next-generation quasi-optical bolometric interferometer for cosmology", Proc. SPIE 8985, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications VII, 898516 (7 March 2014); doi: 10.1117/12.2036259; https://doi.org/10.1117/12.2036259


Back to Top