On-site performance of GroundBIRD, a CMB polarization telescope for large angular scale observations

GroundBIRD Experiment: Detecting CMB Polarization Power in a Large Angular Scale from the Ground

Journal of Low Temperature Physics ◽

10.1007/s10909-014-1138-0 ◽

2014 ◽

Vol 176 (5-6) ◽

pp. 691-697 ◽

Cited By ~ 5

Author(s):

S. Oguri ◽

◽

J. Choi ◽

M. Hazumi ◽

M. Kawai ◽

...

Keyword(s):

Angular Scale ◽

Cmb Polarization ◽

Polarization Power

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GroundBIRD: an experiment for CMB polarization measurements at a large angular scale from the ground

10.1117/12.925816 ◽

2012 ◽

Cited By ~ 11

Author(s):

Osamu Tajima ◽

Jhoon Choi ◽

Masashi Hazumi ◽

Hikaru Ishitsuka ◽

Masanori Kawai ◽

...

Keyword(s):

Polarization Measurements ◽

Angular Scale ◽

Cmb Polarization

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Two Year Cosmology Large Angular Scale Surveyor (CLASS) Observations: Long Timescale Stability Achieved with a Front-end Variable-delay Polarization Modulator at 40 GHz

The Astrophysical Journal ◽

10.3847/1538-4357/ac2235 ◽

2021 ◽

Vol 922 (2) ◽

pp. 212

Author(s):

Kathleen Harrington ◽

Rahul Datta ◽

Keisuke Osumi ◽

Aamir Ali ◽

John W. Appel ◽

...

Keyword(s):

Focal Plane ◽

Optical Element ◽

Precipitable Water ◽

Variable Delay ◽

Microwave Background ◽

Polarization Modulator ◽

Front End ◽

Angular Scale ◽

Cmb Polarization ◽

Low Levels

Abstract The Cosmology Large Angular Scale Surveyor (CLASS) is a four-telescope array observing the largest angular scales (2≲ ℓ ≲ 200) of the cosmic microwave background (CMB) polarization. These scales encode information about reionization and inflation during the early universe. The instrument stability necessary to observe these angular scales from the ground is achieved through the use of a variable-delay polarization modulator as the first optical element in each of the CLASS telescopes. Here, we develop a demodulation scheme used to extract the polarization timestreams from the CLASS data and apply this method to selected data from the first 2 yr of observations by the 40 GHz CLASS telescope. These timestreams are used to measure the 1/f noise and temperature-to-polarization (T → P) leakage present in the CLASS data. We find a median knee frequency for the pair-differenced demodulated linear polarization of 15.12 mHz and a T → P leakage of <3.8 × 10−4 (95% confidence) across the focal plane. We examine the sources of 1/f noise present in the data and find the component of 1/f due to atmospheric precipitable water vapor (PWV) has an amplitude of 203 ± 12 μ K RJ s for 1 mm of PWV when evaluated at 10 mHz; accounting for ∼17% of the 1/f noise in the central pixels of the focal plane. The low levels of T → P leakage and 1/f noise achieved through the use of a front-end polarization modulator are requirements for observing of the largest angular scales of the CMB polarization by the CLASS telescopes.

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RECOVERY OF LARGE ANGULAR SCALE CMB POLARIZATION FOR INSTRUMENTS EMPLOYING VARIABLE-DELAY POLARIZATION MODULATORS

The Astrophysical Journal ◽

10.3847/0004-637x/818/2/151 ◽

2016 ◽

Vol 818 (2) ◽

pp. 151 ◽

Cited By ~ 12

Author(s):

N. J. Miller ◽

D. T. Chuss ◽

T. A. Marriage ◽

E. J. Wollack ◽

J. W. Appel ◽

...

Keyword(s):

Variable Delay ◽

Angular Scale ◽

Cmb Polarization

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The imprint of GWs on the CMB

10.1093/oso/9780198570899.003.0011 ◽

2018 ◽

Author(s):

Michele Maggiore

Keyword(s):

Boltzmann Equation ◽

Cmb Polarization

CMB multipoles. Photon geodesics in perturbed FRW. Temperature anisotropies. Sachs-Wolfe, ISW and Doppler contributions. Boltzmann equation. CMB polarization. E and B modes

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A design study of a CMB polarization satellite Sampan and bolometric camera developments

New Astronomy Reviews ◽

10.1016/j.newar.2006.11.047 ◽

2007 ◽

Vol 51 (3-4) ◽

pp. 260-265 ◽

Cited By ~ 3

Author(s):

F.-X. Désert

Keyword(s):

Design Study ◽

Cmb Polarization

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Probing primordial gravitational waves: Ali CMB Polarization Telescope

National Science Review ◽

10.1093/nsr/nwy019 ◽

2018 ◽

Vol 6 (1) ◽

pp. 145-154 ◽

Cited By ~ 15

Author(s):

Hong Li ◽

Si-Yu Li ◽

Yang Liu ◽

Yong-Ping Li ◽

Yifu Cai ◽

...

Keyword(s):

Gravitational Waves ◽

High Energy Physics ◽

Transition Edge Sensor ◽

High Energy ◽

Cpt Symmetry ◽

Joint Project ◽

Current Limit ◽

Scientific Goal ◽

Primordial Gravitational Waves ◽

Cmb Polarization

Abstract In this paper, we will give a general introduction to the Ali CMB Polarization Telescope (AliCPT) project, which is a Sino–US joint project led by the Institute of High Energy Physics and involves many different institutes in China. It is the first ground-based Cosmic Microwave Background (CMB) polarization experiment in China and an integral part of China's Gravitational-wave Program. The main scientific goal of the AliCPT project is to probe the primordial gravitational waves (PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 5250 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with more than 20 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years' observation. Besides the PGWs, AliCPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years' observation will improve the current limit by two orders of magnitude.

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