arXiv subjects

John Anthony Murphy

Publications and source records attributed to John Anthony Murphy.

4 recordsLinked to original sources

arXiv2019

QUBIC: Exploring the primordial Universe with the Q\&U Bolometric Interferometer

In this paper we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the art bolometric detectors with the systematic effects control typical of interferometers. QUBIC unique features are the so-called "self-calibration", a technique that allows us to clean the measured data from instrumental effects, and its spectral imaging power, i.e. the ability to separate the signal in various sub-bands within each frequency band. QUBIC will observe the sky in two main frequency bands: 150 GHz and 220 GHz. A technological demonstrator is currently under testing and will be deployed in Argentina during 2019, while the final instrument is expected to be installed during 2020.

astro-ph.IM↗

arXiv2006

PTD vs. PO effects in power and polarisation of PLANCK HFI 100 beams

A method of accelerated computation of broadband far off boresight patterns of telescope beams is extended and applied to the 100 GHz channels of Planck HFI (HFI 100). Far off boresight angle power patterns are computed with both GRASP PTD and NUIM PO software, considering cuts with an angular size of 10 degrees. The former reveal secondary oscillations of radial power distribution as compared with the latter. The difference for power patterns of a/b polarisation channels is also investigated.

astro-ph↗

arXiv2004

Ultrafast multireflector physical-optics beam simulations for the HFI instrument on the ESA PLANCK Surveyor

We present the latest results of our fast physical optics simulations of the ESA PLANCK HFI beams. The main beams of both polarized and non-polarized channels have been computed with account of broad frequency bands for the final design and positions of the HFI horns. Gaussian fitting parameters of the broadband beams have been presented. Beam polarization characteristics and horn defocusing effects have been studied.

astro-ph↗

arXiv2002

Optimization of the Coupling of High-Frequency Horn Antenna Array to the ESA PLANCK Submillimeter-Wave Telescope

We study the electromagnetic coupling of the array of Gaussian and multi-moded horn antennas to the dual-reflector submillimeter-wave telescope on the ESA PLANCK Surveyor designed for measuring the temperature anisotropies and polarization characteristics of the cosmic microwave background. In this paper, we present the results of our analysis concerning the measurement of polarization with tilted off-axis dual-reflector Gregorian telescope and the propagation of multi-moded beams through such a system.

astro-ph↗