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Featured researches published by A. Gault.


Astroparticle Physics | 2011

QUBIC: The QU Bolometric Interferometer For Cosmology

E. S. Battistelli; A. Baù; D. Bennett; L. Bergé; J.-Ph. Bernard; P. de Bernardis; G. Bordier; A. Bounab; Eric Bréelle; Emory F. Bunn; M. Calvo; R. Charlassier; S. Collin; A. Coppolecchia; A. Cruciani; G. Curran; M. De Petris; L. Dumoulin; A. Gault; M. Gervasi; A. Ghribi; M. Giard; C. Giordano; Y. Giraud-Héraud; Marcin Gradziel; L. Guglielmi; Jean-Christophe Hamilton; Victor Haynes; J. Kaplan; Andrei Korotkov

The primordial B-mode polarisation of the Cosmic Microwave Background is the imprints of the gravitational wave background generated by inflation. Observing the B-mode is up to now the most direct way to constrain the physics of the primordial Universe, especially inflation. To detect these B-modes, high sensitivity is required as well as an exquisite control of systematics effects. To comply with these requirements, we propose a new instrument called QUBIC (Q and U Bolometric Interferometer for Cosmology) based on bolometric interferometry. The control of systematics is obtained with a close-packed interferometer while bolometers cooled to very low temperature allow for high sensitivity. We present the architecture of this new instrument, the status of the project and the self-calibration technique which allows accurate measurement of the instrumental systematic effects.


Bulletin of the American Astronomical Society | 2009

The Millimeter-Wave Bolometric Interferometer

Andrei Korotkov; Jaiseung Kim; Gregory S. Tucker; A. Gault; P. Hyland; Siddharth Malu; Peter T. Timbie; Emory F. Bunn; E. M. Bierman; Brian Keating; J. Anthony Murphy; Créidhe M. O'Sullivan; Peter A. R. Ade; C. Calderon; L. Piccirillo

We report on the design and tests of a prototype of the Millimeter-wave Bolometric Interferometer (MBI). MBI is designed to make sensitive measurements of the polarization of the cosmic microwave background (CMB). It combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. The prototype, which we call MBI-4, views the sky directly through four corrugated horn antennas. MBI ultimately will have ~ 1000 antennas. These antennas have low sidelobes and nearly symmetric beam patterns, so spurious instrumental polarization from reflective optics is avoided. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines, determined by placement of the four antennas, results in sensitivity to CMB polarization fluctuations over the multipole range ℓ = 150 - 270. The signals are combined with a Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Initial tests and observations have been made at Pine Bluff Observatory (PBO) outside Madison, WI.


Journal of Low Temperature Physics | 2013

Latest Progress on the QUBIC Instrument

A. Ghribi; J. Aumont; E. S. Battistelli; A. Baù; Benoit Bélier; L. Bergé; J.-Ph. Bernard; M. Bersanelli; Marie-Anne Bigot-Sazy; G. Bordier; E. T. Bunn; F. Cavaliere; P. Chanial; A. Coppolecchia; T. Decourcelle; P. de Bernardis; M. De Petris; A.-A. Drilien; L. Dumoulin; M. C. Falvella; A. Gault; M. Gervasi; M. Giard; Marcin Gradziel; Laurent Grandsire; D. Gayer; J.-Ch. Hamilton; Victor Haynes; Y. Giraud-Héraud; N. Holtzer

QUBIC is a unique instrument that crosses the barriers between classical imaging architectures and interferometry taking advantage from both high sensitivity and systematics mitigation. The scientific target is to detect primordial gravitational waves created by inflation by the polarization they imprint on the cosmic microwave background—the holy grail of modern cosmology. In this paper, we show the latest advances in the development of the architecture and the sub-systems of the first module of this instrument to be deployed at Dome Charlie Concordia base—Antarctica in 2015.


Proceedings of SPIE | 2006

The millimeter-wave bolometric interferometer (MBI)

Gregory S. Tucker; Andrei Korotkov; A. Gault; P. Hyland; Siddharth Malu; Peter T. Timbie; Emory F. Bunn; Brian Keating; E. M. Bierman; Créidhe M. O'Sullivan; Peter A. R. Ade; L. Piccirillo

The Millimeter-Wave Bolometric Interferometer (MBI) is designed for sensitive measurements of the polarization of the cosmic microwave background (CMB). MBI combines the differencing capabilities of an interferometer with the high sensitivity of bolometers at millimeter wavelengths. It views the sky directly through corrugated horn antennas with low sidelobes and nearly symmetric beam patterns to avoid spurious instrumental polarization from reflective optics. The design of the first version of the instrument with four 7-degree-FOV corrugated horns (MBI-4) is discussed. The MBI-4 optical band is defined by filters with a central frequency of 90 GHz. The set of baselines determined by the antenna separation makes the instrument sensitive to CMB polarization fluctuations over the multipole range l=150-270. In MBI-4, the signals from antennas are combined with a Fizeau beam combiner and interference fringes are detected by an array of spider-web bolometers with NTD germanium thermistors. In order to separate the visibility signals from the total power detected by each bolometer, the phase of the signal from each antenna is modulated by a ferrite-based waveguide phase shifter. Observations are planned from the Pine Bluff Observatory outside Madison, WI.


IEEE Microwave and Wireless Components Letters | 2012

Measurements of a Cryogenic Linear Polarization Modulator for mm-Wavelengths

A. Gault; E. M. Bierman; P. O. Hyland; Brian Keating; S. S. Malu; Peter T. Timbie

Cryogenic Faraday phase modulators have been implemented in waveguide and tested in both a constant current mode and an alternating current mode. The loss of the phase shifter for DC currents that results in either a or phase shift is on average 1.45 dB over the entire W-band. In the modulating mode, it operates at frequencies as high as 4 Hz with transition times between the two phase states of 1.32 x 10-2 s.


Proceedings of SPIE | 2016

Optical design and modelling of the QUBIC instrument, a next-generation quasi-optical bolometric interferometer for cosmology

S. Scully; David Burke; Créidhe M. O'Sullivan; D. Gayer; Marcin Gradziel; J. A. Murphy; M. De Petris; D. Buzi; M. Zannoni; A. Mennella; M. Gervasi; A. Tartari; B. Maffei; J. Aumont; S. Banfi; P. Battaglia; E. S. Battistelli; A. Baù; Benoit Bélier; D. Bennet; L. Bergé; J.-Ph. Bernard; M. Bersanelli; Marie-Anne Bigot-Sazy; N. Bleurvacq; G. Bordier; J. Brossard; Emory F. Bunn; D. Cammileri; F. Cavaliere

Big Bang cosmologies predict that the cosmic microwave background (CMB) contains faint temperature and polarisation anisotropies imprinted in the early universe. ESAs PLANCK satellite has already measured the temperature anisotropies1 in exquisite detail; the next ambitious step is to map the primordial polarisation signatures which are several orders of magnitude lower. Polarisation E-modes have been measured2 but the even-fainter primordial B-modes have so far eluded detection. Their magnitude is unknown but it is clear that a sensitive telescope with exceptional control over systematic errors will be required. QUBIC3 is a ground-based European experiment that aims to exploit the novel concept of bolometric interferometry in order to measure B-mode polarisation anisotropies in the CMB. Beams from an aperture array of corrugated horns will be combined to form a synthesised image of the sky Stokes parameters on two focal planes: one at 150 GHz the other at 220 GHz. In this paper we describe recent optical modelling of the QUBIC beam combiner, concentrating on modelling the instrument point-spread-function and its operation in the 220-GHz band. We show the effects of optical aberrations and truncation as successive components are added to the beam path. In the case of QUBIC, the aberrations introduced by off-axis mirrors are the dominant contributor. As the frequency of operation is increased, the aperture horns allow up to five hybrid modes to propagate and we illustrate how the beam pattern changes across the 25% bandwidth. Finally we describe modifications to the QUBIC optical design to be used in a technical demonstrator, currently being manufactured for testing in 2016.


New Astronomy Reviews | 2006

The Einstein polarization interferometer for cosmology (EPIC) and the millimeter-wave bolometric interferometer (MBI)

Peter T. Timbie; Gregory S. Tucker; Peter A. R. Ade; S. Ali; E. M. Bierman; Emory F. Bunn; C. Calderon; A. Gault; P. Hyland; Brian Keating; J Kim; Andrei Korotkov; Siddharth Malu; Philip Daniel Mauskopf; J. A. Murphy; Créidhe M. O'Sullivan; L. Piccirillo; Benjamin D. Wandelt


Journal of Low Temperature Physics | 2016

QUBIC: A Fizeau Interferometer Targeting Primordial B-Modes

A. Tartari; J. Aumont; S. Banfi; P. Battaglia; A. Baù; Benoit Bélier; D. Bennett; L. Bergé; Ph. Bernard J.; M. Bersanelli; N. Bleurvacq; G. Bordier; J. Brossard; D. Buzi; D. Cammilleri; F. Cavaliere; P. Chanial; C. Chapron; A. Coppolecchia; G. D'Alessandro; P. de Bernardis; T. Decourcelle; F. Del Torto; M. De Petris; L. Dumoulin; C. Franceschet; A. Gault; D. Gayer; M. Gervasi; A. Ghribi


arXiv: Instrumentation and Methods for Astrophysics | 2016

QUBIC Technological Design Report

J. Aumont; S. Banfi; P. Battaglia; E. S. Battistelli; A. Baù; Benoit Bélier; D. Bennett; L. Bergé; J.-Ph. Bernard; M. Bersanelli; Marie-Anne Bigot-Sazy; N. Bleurvacq; G. Bordier; J. Brossard; Emory F. Bunn; D. Buzi; A. Buzzelli; D. Cammilleri; F. Cavaliere; P. Chanial; C. Chapron; Gabriele Coppi; A. Coppolecchia; F. Couchot; Rocco D'Agostino; G. D'Alessandro; P. de Bernardis; G. de Gasperis; M. De Petris; T. Decourcelle


arXiv: Instrumentation and Methods for Astrophysics | 2016

QUBIC Technical Design Report

J. Aumont; Benoit Bélier; A. Lowitz; D. Cammilleri; A. Tartari; A. Ghribi; A. Coppolecchia; Nicola Vittorio; Marcin Gradziel; R. Puddu; M. Giard; G. Bordier; M. Tristram; G. de Gasperis; J. Brossard; F. Pajot; Laurent Grandsire; L. Dumoulin; J.-Ph. Bernard; Créidhe M. O'Sullivan; M. Salatino; P. Chanial; G. D'Alessandro; C. Franceschet; A. Mennella; Antonio Zullo; Y. Giraud-Héraud; Alessandro Pelosi; O. Rigaut; P. Battaglia

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L. Bergé

Centre national de la recherche scientifique

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E. S. Battistelli

Sapienza University of Rome

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M. Gervasi

Sapienza University of Rome

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P. de Bernardis

Sapienza University of Rome

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L. Dumoulin

Centre national de la recherche scientifique

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