78 research outputs found
The microwave sky after one year of Planck operations
The ESA Planck satellite, launched on May 14th, 2009, is the third generation
space mission dedicated to the measurement of the Cosmic Microwave Background
(CMB), the first light in the Universe. Planck observes the full sky in nine
frequency bands from 30 to 857 GHz and is designed to measure the CMB
anisotropies with an unprecedented combination of sensitivity, angular
resolution and control of systematic effects. In this presentation we summarise
the Planck instruments performance and discuss the main scientific results
obtained after one year of operations in the fields of galactic and
extragalactic astrophysics.Comment: Invited presentation at the 13th ICATPP Conference on Astroparticle,
Particle, Space Physics and Detectors for Physics Applications (Villa Olmo,
Como 3-7 October 2011
Current Status and Perspectives of Cosmic Microwave Background Observations
Measurements of the cosmic microwave background (CMB) radiation provide a
unique opportunity for a direct study of the primordial cosmic plasma at
redshift z ~1000. The angular power spectra of temperature and polarisation
fluctuations are powerful observational objectives as they encode information
on fundamental cosmological parameters and on the physics of the early
universe. A large number of increasingly ambitious balloon-borne and
ground-based experiments have been carried out following the first detection of
CMB anisotropies by COBE-DMR, probing the angular power spectrum up to high
multipoles. The recent data from WMAP provide a new major step forward in
measurements percision. The ESA mission Planck Surveyor, to be launched in
2007, is the third-generation satellite devoted to CMB imaging. Planck is
expected to extract the full cosmological information from temperature
anisotropies and to open up new fronteers in the CMB field.Comment: 6 pages, 1 figure, to appear in "Proc of International Symposium on
Plasmas in the Laboratory and in the Universe: new insights and new
challenges", September 16-19, 2003, Como, Ital
QUBIC: the Q&U Bolometric Interferometer for Cosmology. A novel way to look at the polarized Cosmic Microwave Background
In this paper we describe QUBIC, an experiment that takes up the challenge posed by the detection of primordial gravitational waves with a novel approach, that combines the sensitivity of state-of-the art bolometric detectors with the systematic effects control typical of interferometers. The so-called ``self-calibration'' is a technique deeply rooted in the interferometric nature of the instrument and allows us to clean the measured data from instrumental effects. The first module of QUBIC is a dual band instrument (150 GHz and 220 GHz) that will be deployed in Argentina during Fall 2018
QUBIC: the Q&U Bolometric Interferometer for Cosmology. A novel way to look at the polarized Cosmic Microwave Background
In this paper we describe QUBIC, an experiment that takes up the challenge posed by the detection of primordial gravitational waves with a novel approach, that combines the sensitivity of state-of-the art bolometric detectors with the systematic effects control typical of interferometers. The so-called ``self-calibration'' is a technique deeply rooted in the interferometric nature of the instrument and allows us to clean the measured data from instrumental effects. The first module of QUBIC is a dual band instrument (150 GHz and 220 GHz) that will be deployed in Argentina during Fall 2018
Generalized adhesion maps for predicting thin film transitions
Abstract Ž . Thin film transition TFT phenomena are of special interest to the petroleum industry. After crude-oil is trapped in reservoir rocks, it can alter the wettability of the rock surface, with profound implications for the subsequent transport of fluids. Correlation between the TFT and wettability alteration is qualitatively evident from many experiments. It is not clear, however, whether the TFT is a sufficient condition for wettability alteration. In this work we describe a generalized adhesion map, which locates the TFT in parameter space. Comparison of these maps with laboratory studies indicates that wettability alteration involves other mechanisms in addition to the TFT.
LFI Optical Interfaces
The aim of this technical note is to translate the scientific requirements of LFI, when applicable, into requirements on the Optical Interfaces and specifically into requirements on the instrument and satellite designs and thermal stabilities
Report on the Pre- and Post-Cryogenic Warm Functional Test
This document presents the analysis of the two Warm Functional Tests (WFT) performed in the
Centre Spatial du Li´ege before and after the cryogenic test campaign held in summer 2008. The
procedure followed during the WFT is reported in [RD1]. Refer also to [AD1] for finer detail
Preliminary evaluation of the impact of temperature fluctuations in the HFI 4Kstage on LFI
In this technical note we provide a preliminary analysis of the effect of temperature fluctuations at the level
of the HFI 4K stage on the scientific performances of the Planck-LFI instrument. The stability of this stage is
of crucial importance for the LFI, as it impact directly the stability of the measured signal through its
reference load. The availability of the first simulations of the 4K temperature stability from the HFI team has
prompted a quick assessment of the expected effect, which is found to be large enough to require the
application of software removal algorithms to maintain the residual effect in the final maps within the
required levels. Clearly it is of crucial importance the availability in a short time of measurements from the HFI 4K cooler in order to be able to perform robust estimates of the final expected systematic effect
Temperature stability requirements at the interface between the ECCOSORB sky-load and its support in the LFI cryofacility
During the testing phase of the QM and FM LFI instrument, the integrated radiometer chain assemblies
(RCAs) will be tested in a dedicated cryo facility. The input signal will be provided by an eccosorb load
placed in front of the LFI feed horns that simulates the sky signal; the thermal stability of this sky load
needs to be of the same order of the stability that is expected in flight for the primary and secondary mirrors,
in order not to introduce uncertainties in the test results that may be difficult to interpret. In this document
we derive the thermal stability requirements at the interface between the ECCOSORB sky load and its
support starting from the signal stability requirements and considering the current knowledge concerning
thermal conduction properties of the ECCOSORB at 20 K
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