Download or read book CMB Polarization Measurements with the Polarbear Experiment written by David Boettger and published by . This book was released on 2014 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: POLARBEAR is an experiment designed to measure the polarization of the cosmic microwave background (CMB). These measurements have scientific objectives spanning particle physics, cosmology, and astrophysics. The field of CMB polarization is rapidly evolving, with extraordinary progress being made on several fronts including the recently claimed detection of gravitational waves generated during cosmic inflation. This dissertation describes the POLARBEAR instrument and the measurements taken during its first season of observations. The results include the first evidence for a non-zero ClBB power spectrum at sub-degree angular scales, consistent with theoretical expectations.
Download or read book Design and Deployment of the POLARBEAR Cosmic Microwave Background Polarization Experiment written by Kam Stahly Arnold and published by . This book was released on 2010 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: POLARBEAR is a Cosmic Microwave Background (CMB) polarization experiment that will measure the CMB polarization angular power spectrum with unprecedented precision, searching for evidence of inflationary gravitational waves and the gravitational lensing of the CMB polarization by large scale structure. This dissertation presents an overview of the design of the instrument, focusing on the design and fabrication of the focal plane, and presents the results of some tests of instrument performance, both in the laboratory and from the initial engineering deployment. The structure of this thesis is as follows: Chapter 1 introduces the theoretical constructs used to describe the CMB polarization anisotropies, and the state of measurements in the field. Chapter 2 gives an overview of the choices made in the instrument design. Chapter 3 discusses the fundamental limits to the sensitivity of bolometric detectors, and chapter 4 explains the design choices involved in populating the focal plane with detectors. Chapter 5 describes the details of the detector architecture and fabrication, and chapter 6 the details of selecting the spectral band of the detectors. Finally, chapter 7 goes through some results obtained before and during the POLARBEAR engineering run in 2010, and comments on the work to be done before the Chilean deployment.
Download or read book Measuring the Polarization of the Cosmic Microwave Background with POLARBEAR 1 and Developing the Next Generation Experiment POLARBEAR 2 written by Tucker Elleflot and published by . This book was released on 2019 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the polarization of the Cosmic Microwave Background (CMB) have the potential to provide very strong evidence for cosmic inflation. However, the polarization signal that is expected to have been created by inflation is extremely small. This has motivated the construction of extremely sensitive instruments with thousands of cryogenic detectors. Simons Array is a CMB polarization experiment comprised of three telescopes located in northern Chile and each containing a cryogenic receiver. The Simons Array will observe in four frequency bands in order to measure the CMB signal as well as polarized foreground signals. The design of the detectors and readout system has been optimized to provide a low noise measurement and an experiment that can observe in varying weather conditions. Characterizing the detectors and readout system has been a crucial part of the development of the Simons Array receivers. This dissertation describes the development and deployment of the Simons Array experiment with a focus on characterization of the cryogenic detector and readout electronics.
Download or read book The POLARBEAR Cosmic Microwave Background Polarization Experiment and Anti Reflection Coatings for Millimeter Wave Observations written by Erin Quealy and published by . This book was released on 2012 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: New technology has rapidly advanced the field of observational cosmology over the last 30 years. This trend will continue with the development of technologies to measure the Cosmic Microwave Background (CMB) polarization. The B-mode component of the polarization map will place limits on the energy scale of inflation and the sum of the neutrino masses. This thesis describes the \pb instrument which will measure the CMB polarization anisotropy to unprecedented sensitivity. POLARBEAR-I is currently observing, and an upgraded version, POLARBEAR-II, is planned for the future. The first version of the experiment, POLARBEAR-I, is fielding several new technologies for the first time. POLARBEAR-I has high sensitivity due to its detector count. It employs a 1274 detector Transition-Edge Sensor (TES) bolometer array. The bolometers are coupled to a planar array of polarization sensitive antennas. These antennas are lithographed on the same substrate as the TES detectors, allowing on-chip band defining filters between the antenna and detector. The focal plane is composed of seven hexagonal detector modules. This modular scheme can be extended to create larger focal plane arrays in the future. POLARBEAR-I is observing at a single band near 150 GHz, the peak in the CMB blackbody curve. The lenslet antenna coupled detector technology, fielding for the first time in POLARBEAR-I, is naturally scalable to larger arrays with multi-chroic pixels. This broadband technology will have higher sensitivity and better capability for astronomical foreground contaminant removal. The antenna geometry can be changed to receive a wider frequency bandwidth. This bandwidth can be broken into multiple frequency bands with the on-chip band defining filters. Each band will be read out by one TES detector. A dual band instrument, \pbtwo, is in development with bands at 90 and 150 GHz. One challenge for all CMB polarization measurements is minimization of systematic errors. One source of error is polarized reflections off of the refractive optics inside the receiver. Specifically, the antenna-coupled detector scheme relies on a high dielectric lenslet for each pixel on the focal plane. A large portion of this thesis discusses development of anti-reflection (AR) coatings for the high curvature lenslet surface. The AR coating technologies discussed are also applicable to other optical elements, such as reimaging lenses and half-wave plates. A single layer coating is used on the \pbone lenslet array, and a two layer coating is presented for use in \pbtwo. The two layer coating method can be extended to wider bandwidth AR coatings.
Download or read book Cosmic Microwave Background Polarization Science and Optical Design of the POLARBEAR and Simons Array Experiments written by Frederick Takayuki Matsuda and published by . This book was released on 2017 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cosmic microwave background (CMB) radiation contains great amounts of information that allow for studying the physics of the early universe through constraining cosmological parameters in the standard [Lambda]CDM model. The CMB temperature signal has been measured to high precision, but measuring the CMB polarization signal is still in its early stages. The theoretically small primordial CMB polarization B-mode signal has not yet been measured, but has principle importance in that its existence would be strong evidence of inflation. This measurement allows one to probe the earliest state of the universe at energy scales of 10^16 GeV thought to be near the Grand Unified Theory scale. The B-mode signal arising from weak gravitational lensing by large scale structures provides information about the matter composition of the universe and puts strong constraints on the sum of the neutrino masses. This dissertation discusses the optical design, instrumentation, data analysis, and first season science results of the POLARBEAR experiment, a CMB polarization telescope aimed to measure the B-mode signal. The results show the first evidence of non-zero lensing B-modes at sub-degree angular scales on the sky. The development and measurement results of the Fourier transform spectrometer calibration instrument used to characterize the spectral response of the POLARBEAR detectors are also described. The optical design development and systematic studies for the Simons Array, the next generation installment of the experiment, are described as well. The cross polarization effect of Mizuguchi-Dragone breaking due to a prime focus half-wave plate, and the optical redesign of the Simons Array re-imaging optics for increased optical performance at higher frequencies were studied in detail. The Simons Array is planned to fully deploy in 2018 to further study the CMB with enhanced sensitivity.
Download or read book High Fidelity Maps of the CMB Polarization from the First Two Campaigns of the POLARBEAR Experiment and Their Statistical Exploitation written by Davide Poletti and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis concerns the cosmic microwave background (CMB) map-making problem in the presence of filtering. The observations of the CMB kept refining our understanding of the universe over the past decades. The characterisation of its curl-like polarisation pattern - the so-called B-modes - is expected to convey invaluable information on both the primordial and the late universe as well as on fundamental physics.In order to extract these unique constraints from the faint B-mode signal, the quality and the size of CMB datasets have been constantly increasing, posing serious challenges for data analysis. The reconstruction of the map of the observed sky compresses by many orders of magnitude the data volume, white striving for preserving ail the cosmological information. In this process, the raw data are typically filtered in order to remove unwanted signais of instrumental or astrophysical origins. This thesis illustrates the formalism for performing general filtering operations and for incorporating them in the map-making procedure. The realistic circumstances under which this unbiased estimation of the sky signal can succeed are also investigated, both in general and in the specific context of ground-based experiments. This new formalism has been innplemented in a massively parallel map-making code, capable of producing high fidelity renditions of the sky as well as their detailed statistical characterisation. The methodology and the tool are then applied to the analysis of the first and second season data POLARBEAR, one of the leading experiments in the B-modes quest.
Download or read book Measurement of the B mode Power Spectrum with POLARBEAR written by Bryan Steinbach and published by . This book was released on 2014 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the \pb experiment and its measurement of the B-mode power spectrum. \pb is a millimeter wave telescope that is measuring the Cosmic Microwave Background (CMB) polarization, using large format arrays of photon noise limited Transition-Edge Sensor (TES) bolometers. The instrument observes from the Atacama Desert at 5.2km in elevation with a 2.5m primary aperture telescope. This telescope has sufficient angular resolution (3.5' FWHM) to resolve the gravitational lensing features of the CMB, a new channel for obtaining information on fundamental physics such as the sum of the mass of neutrinos. This dissertation describes the design, integration and results of the first season of \pb observations. The receiver observed for 1 year with a noise-equivalent temperature (NET) of $22.8\mu K \sqrt{s}$ and mapped a 30 square degree area of the CMB, obtaining evidence for gravitational lensing in the BB power spectrum at a significance of $2\sigma$.
Download or read book Challenges in CMB Lensing Data Analysis and Scientific Exploitation of Current and Future CMB Polarization Experiments written by Dominic Beck and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Next-generation cosmic microwave background (CMB) measurements will further establish the field of cosmology as a high-precision science and continue opening new frontiers of fundamental physics. Cosmic-variance limited measurements not only of the CMB temperature but also its polarization down to arcminute scales will allow for precise measurements of our cosmological model, which is sensitive to the elusive physics of dark matter, dark energy and neutrinos. Furthermore, a large-scale measurement of B-mode CMB polarization permits a determination of the power of primordial gravitational waves, generated by processes potentially happening in the very early universe at energies close to the scale of the Grand Unified Theory. Entering a new sensitivity regime entails the necessity to improve our physical understanding and analysis methods of astronomical and instrumental systematics.This thesis presents within this context several analyses of potential astronomical and instrumental systematics, primarily focusing on CMB measurements related to weak gravitational lensing. The latter distorts the path of the primary CMB's photons, such that the statistical properties of the measured signal deviate from the primary signal and, hence, has to be accounted for. This thesis describes the underlying physics, analysis methods and applications to current data sets of the POLARBEAR CMB experiment in the context of CMB lensing science.This thesis shows that future high-precision measurements of CMB lensing have to account for the high complexity of this effect, primarily caused by multiple deflections within an evolving, non-linear large-scale structure distribution. Furthermore, the impact of higher-order correlations introduced by galactic foregrounds and CMB lensing when jointly analyzing CMB data sets on both large and small scales is investigated, showing the need for small-scale multi-frequency observations and foreground removal techniques to obtain an unbiased estimate of the tensor-to-scalar ratio.
Download or read book Precision Measurements of Cosmic Microwave Background Polarization to Study Cosmic Inflation and Large Scale Structure written by Darcy Riley Barron and published by . This book was released on 2015 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of cosmic microwave background (CMB) are a powerful tool to study and understand our universe. Detailed characterizations of the temperature of the CMB played a key role in the development of the current standard cosmological model, Lambda CDM. Although this model, along with the standard model of particle physics, describes much of the observed large-scale structure of the universe and its evolution, there are still gaps in our understanding. The next step for answering many of these outstanding questions in cosmology and particle physics lies in the characterization of the CMB B-mode polarization pattern. This faint signal is expected to be imprinted at the formation of the CMB by inflationary gravitational waves in the early universe. Detection of this primordial B-mode signal would not only be the first direct evidence for inflation, but would also constrain inflationary models and determine the energy scale of inflation. Gravitational lensing of CMB E-mode polarization by intervening matter also produces a secondary B-mode polarization signal at smaller angular scales. This signal traces large scale structure in the universe, with information about the distribution and composition of matter. This dissertation describes research in instrumentation, observations, and data analysis for measurements of the CMB B-mode signal, including work on three generations of experiments in this rapidly evolving field. Analysis of the galactic plane and CMB multi-frequency data from the BICEP1 CMB polarization telescope helped further our understanding of polarized CMB foregrounds by studying polarized galactic emission and the structure of the galactic magnetic field. The deployment and first season of observations with the POLARBEAR-1 instrument, a CMB polarization telescope, are described. This instrument reached a milestone in sensitivity with our measurement of a non-zero B-mode polarization power spectrum. Finally, this thesis discusses the design and development of the POLARBEAR-2 instrument, a new receiver with expanded capabilities and sensitivity, scheduled to deploy alongside POLARBEAR-1 in 2016.
Download or read book Modeling and Measuring the Weak Lensing of CMB Polarization in Current and Future Ground based Experiments written by Giulio Fabbian and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravitational lensing effect on Cosmic Microwave Background (CMB) anisotropies is sensitive to structure formation history around a redshift of 2. Therefore it allows constraining physical effects to which CMB signal of primordial origin is weakly sensitive. These include small changes of the matter power spectrum caused by the presence of massive neutrinos and dark energy, what in turn can set precise constrains on the sum of neutrino massive and the nature of dark energy. Measuring precisely the lensing effect on CMB polarization is also a mandatory step for the study of primordial signais on CMB polarization coming from inflationary gravitational waves, because the lensing-generated signal will be one of the major source of contaminant for the detection of this imprint. In order to fully exploit the entire information contained in CMB lensing, sophisticated data analysis methods have to be used and tested precise simulations of this effect will be of crucial importance. In this thesis I describe the challenges and problems involved in simulating efficiently and accurately the lensing effect on polarized CMB signais, both from a numerical and physical perspective, and introduce some new advanced algorithms and methods devised to address them. I then discuss difficulties involved in extracting CMB signals from the real data by presenting data analysis of a data set collected by a current CMB polarization experiment, POLARBeaR. I complement this latter part by presenting forecasts of the science goals, which can be attained with future upgrades of this instrument, which will target both primordial and lensing-generated B-mode signals.
Download or read book Sensitive Detection of CMB B Mode Polarization written by Stephanie Moyerman and published by . This book was released on 2013 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous experiments in the last two decades have shown that the cosmic microwave background (CMB) is a powerful cosmological probe. The temperature anisotropy of the CMB has now been mapped to exquisite precision by many experiments, yielding tight constraints on the standard LCDM cosmological model. Many current and upcoming experiments focus on measuring CMB polarization, in particular the B-mode polarization, which potentially encodes information from long before the epoch of matter-radiation decoupling. However, the magnitude of the inflationary B-mode signal is constrained by an upper limit of tens of nK, which represents a massive experimental challenge. Foreground contamination and systematic effects, among other factors, further increase the difficulty of detection. A measurement of this signal therefore requires the development of dedicated telescopes with exquisite control of systematics and large kilo-pixel arrays of background limited detectors. This thesis describes my work on Cosmic Microwave Background polarization studies. Specifically, it describes my data analysis efforts on two CMB polarization telescopes, BICEP and POLARBEAR, my contribution to hardware efforts on POLARBEAR, and my design and fabrication work on next generation detector arrays.
Download or read book Precise Measurement of B mode Polarization Signal from the Cosmic Microwave Background with Polarbear and the Simons Array written by Praween Siritanasak and published by . This book was released on 2018 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout history, human beings have always sought to answer the question "what was the origin of the universe?" The Cosmic Microwave Background (CMB) is one of the most essential scientific tools that will help us better understand the universe. The temperature maps of the CMB have allowed us to study the nature of the early universe through the standard [Lambda]CDM model as well as to describe its evolution. Nevertheless, many questions remain. The next step in finding the answer lies in the measurement of the B-mode polarization of the CMB. These faint signals from the primordial universe are expected to be key pieces of evidence of the inflationary gravitational wave. Successful detection of this B-mode polarization would not only serve as direct evidence of the inflation theory but also lead to constraining of inflationary model and the energy scale of inflation. Moreover, the gravitational lensing of CMB E-mode polarization to B-mode polarization signal at small angular scales will allow us to trace back to the distribution of matter in our universe. This dissertation describes the details of the Polarbear instrument which is designed to detect CMB B-mode polarization. The results from the first and second observational season are also described. Furthermore, this dissertation discusses the development of the Simons Array instrument, which is the expansion of Polarbear with expanded capabilities and increased sensitivity. The Simons Array is scheduled to deploy in 2018.
Download or read book Preparation and Deployment of the Telescopes and POLARBEAR 2b Receiver for the Simons Array Cosmic Microwave Background Polarization Experiment written by Lindsay Ng Lowry and published by . This book was released on 2021 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Simons Array is a polarization-sensitive cosmic microwave background (CMB) experiment located in the Atacama Desert in northern Chile. Observations of the CMB, which consists of the oldest observable light in the universe, have been invaluable for cosmological research in recent decades, producing a wealth of information regarding the universe's beginning and evolution, and providing substantial evidence in support of the Lambda-Cold Dark Matter model of cosmology. The field continues to grow as technological advances enable ever more sensitive measurements of both the intensity and polarization patterns imprinted in the CMB. The Simons Array aims to further our understanding of cosmology by measuring the polarization pattern of the CMB at angular scales ranging from a few arcminutes to a few degrees, with a focus on the faint B-mode polarization signals predicted at these scales. The Simons Array is composed of three identical telescopes, each coupled to a cryogenic receiver. The receivers are developed and characterized in laboratories before installation at the observatory site in Chile at an altitude of 5,200 m, with significant upgrades compared to POLARBEAR-1, the Simons Array's predecessor, to improve the experiment's sensitivity. In particular, the upgraded receivers employ larger focal planes with increased detector counts and sensitivity across multiple frequency bands. This dissertation describes the Simons Array experiment as a whole, with an emphasis on the telescope accessories and laboratory characterization of the POLARBEAR-2b receiver, the second receiver of the Simons Array.
Download or read book The POLARBEAR 2 Cryogenic Receiver for Cosmic Microwave Background Polarization Science written by Logan Howe and published by . This book was released on 2019 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the Cosmic Microwave Background (CMB) have proved pivotal over the last few decades in the development of [Lambda]CDM, the standard model of cosmology. Coupled with the standard model of particle physics, these two theories describe a majority of our observations of the Universe’s structure, dynamics, and evolution. Beyond discovering the specifics of how our Universe was formed, remaining open questions regarding our Universe include the masses of neutrino species, the exact nature of dark matter, and the equation of state of dark energy--to name a few. The CMB is imprinted with information that can help answer all these questions, making measurements of the temperature and polarization field of the CMB at high precision an effective path to increasing our understanding of fundamental physics. The polarization field especially, composed of parity even E-mode and parity odd B-mode patterns, possesses untapped constraining power, at both very large and very small angular scales. This dissertation describes the design and characterization of cryogenic receivers for the Simons Array CMB polarization experiment. The Simons Array is located at 5200 m elevation in the Atacama desert, Chile and consists of three off-axis Gregorian-Dragone telescopes, each coupled to a POLARBEAR-2 cryogenic receiver. Each receiver’s focal plane is comprised of 7,588 transition edge sensor (TES) bolometers cooled to 250 mK and read out using 4 K superconducting quantum interference devices (SQUIDs) using digital frequency division multiplexing (DfMUX). The POLARBEAR-2 receiver cryostat consists of an optics tube and backend cryostat, which are built and tested separately, then integrated for final testing before deployment to the Chilean site. Here we describe fabrication and cryogenic validation of two POLARBEAR-2 backends, and of the complete second POLARBEAR-2 receiver: POLARBEAR-2b. Additionally, we discuss readout and detector integration, including detailed SQUID characterization and TES array measurements, and demonstration of deployment readiness of all selected devices and subcomponents. Finally, we describe efforts and progress towards final lab validation of the POLARBEAR-2b receiver and final demonstrations of deployment readiness.
Download or read book CMB Polarization Workshop written by Scott Dodelson and published by American Institute of Physics. This book was released on 2009-06-24 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: The workshop brought together experts in astronomy and particle physics to make the science case for a satellite mission to measure the polarization of the cosmic microwave background (CMB). Detailed maps of the CMB polarization will potentially reveal clues about the origin of the universe. An early epoch of inflation typically produces a spectrum of gravitational waves and these leave a distinctive imprint on the CMB polarization field. The workshop addressed all theoretical aspects of this science: which inflationary models predict an amplitude that will be detected and which do not? What do alternatives to inflation predict? Apart from the gravitational wave signal, what other science can be gleaned from these measurements? High resolution maps should have traces of gravitational lensing which in turn is affected by dark energy and massive neutrinos. How well will a satellite mission be able to measure these effects? CMB polarization also speaks to the end of the Dark Ages; the constraints on reionzation are discussed in the context of all other probes. Finally, several articles – based on many talks and follow-up work – probe the science of and removal of Galactic foregrounds.
Download or read book Measurement of the CMB Polarization at 95GHz from Quiet written by Immanuel David Buder and published by . This book was released on 2012 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the great success of precision cosmology, cosmologists cannot fully explain the initial conditions of the Universe. Inflation, an exponential expansion in the first ≈ 10−36 s, is a promising potential explanation. A generic prediction of inflation is odd-parity (B-mode) polarization in the cosmic microwave background (CMB). The Q/U Imaging ExperimenT (QUIET) aimed to limit or detect this polarization.
Download or read book Maxipol written by Jeffrey Scott Collins and published by . This book was released on 2006 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
