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Commercial alpha counters are used in science and industry applications to screen materials for surface radon progeny contamination. In this paper, we characterize an XIA UltraLo-1800, an ionization drift alpha counter, and study the…

仪器与探测器 · 物理学 2023-02-01 Joshua Ange , Robert Calkins , Andrew Posada

The high resolution spectrograph ESPRESSO on the VLT allows measurements of fundamental constants at unprecedented precision and hence enables tests for spacetime variations predicted by some theories. In a series of recent papers, we…

宇宙学与河外天体物理 · 物理学 2023-03-08 Chung-Chi Lee , John K. Webb , Robert F. Carswell , Vladimir A. Dzuba , Victor V. Flambaum , Dinko Milaković

The Boulby UnderGround Screening (BUGS) facility, located at the Boulby Underground Laboratory, has significantly advanced its material screening capabilities by installing two XIA UltraLo-1800 alpha particle detectors. This study presents…

We present results from a study of short term variability in 19 archival observations by XMM-Newton of 16 Ultraluminous X-ray Sources (ULXs). Eight observations (six sources) showed intrinsic variability with power spectra in the form of…

高能天体物理现象 · 物理学 2015-05-13 L. M. Heil , S. Vaughan , T. P. Roberts

Initial performance of the UltraLo-1800 alpha particle detector at the 700 m deep Yangyang underground laboratory in Korea is described. The ionization detector uses Argon as a counting gas for measuring alpha events of a sample. We present…

High-resolution observations of the solar chromosphere at millimeter wavelengths are now possible with the Atacama Large Millimeter Array (ALMA), promising to tackle many open problems in solar physics. Observations from other ground and…

太阳与恒星天体物理 · 物理学 2018-12-12 João M. da Silva Santos , Jaime de la Cruz Rodríguez , Jorrit Leenaarts

Ultralight axions (ULAs) are hypothetical particles which can behave like dark matter (DM) or dark energy (DE) depending on masses generated at the symmetry-breaking scale. It remains a mystery whether the ULAs can make up a fraction of DM…

宇宙学与河外天体物理 · 物理学 2025-11-25 Qianshuo Liu , Chang Feng , Filipe B. Abdalla

We present ALMA Cycle 1 observations of the HH46/47 molecular outflow using combined 12m array and ACA observations. The improved angular resolution and sensitivity of our multi-line maps reveal structures that help us study the entrainment…

We investigate the reflectivity and optical scattering characteristics at 1064\,nm of an antireflection coated fused silica window of the type being used in the Advanced LIGO gravitational-wave detectors. Reflectivity is measured in the…

We present an analysis of HI Lyman-alpha emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at z=3.5 and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman-alpha haloes are…

We present the results obtained with an end-to-end simulator of an Extreme Adaptive Optics (XAO) system control loop. It is used to predict its on-sky performances and to optimise the AO loop algorithms. It was first used to validate a…

Absorption line systems detected in quasar spectra can be used to compare the value of the fine-structure constant, {\alpha}, measured today on Earth with its value in distant galaxies. In recent years, some evidence has emerged of small…

We consider several transitions between narrow lines that have an enhanced sensitivity to a possible variation of the fine structure constant, alpha. This enhancement may allow a search to be performed with an effective suppression of the…

原子物理 · 物理学 2009-11-11 S. G. Karshenboim , A. Yu. Nevsky , E. J. Angstmann , V. A. Dzuba , V. V. Flambaum

Wireless sensor networks usually comprise a large number of sensors monitoring changes in variables. These changes in variables represent changes in physical quantities. The changes can occur for various reasons; these reasons are…

机器学习 · 计算机科学 2017-08-29 Pelumi Oluwasanya

Extremely large-scale antenna array (ELAA) technologies consisting of ultra-massive multiple-input-multiple-output (UM-MIMO) or reconfigurable intelligent surfaces (RISs), are emerging to meet the demand of wireless systems in…

信息论 · 计算机科学 2024-02-06 Yiqin Wang , Shu Sun , Chong Han

Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, alpha, and the proton-to-electron mass ratio, mu = m_p/m_e, as…

Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes -- primarily $\alpha$ and $\beta$ activity in the uranium and thorium decay chains -- inconsequential to…

仪器与探测器 · 物理学 2015-12-24 Craig E. Aalseth , Paul H. Humble , Emily K. Mace , John L. Orrell , Allen Seifert , Richard M. Williams

The outskirts of galaxy clusters host complex interactions between the intra-cluster and circumcluster media. During cluster evolution, ram-pressure stripped gas clumps from infalling substructures break the uniformity of the gas…

星系天体物理 · 物理学 2023-06-21 Orsolya E. Kovács , Zhenlin Zhu , Norbert Werner , Aurora Simionescu , Ákos Bogdán

The study of galaxy cluster outskirts has emerged as one of the new frontiers in extragalactic astrophysics and cosmology with the advent of new observations in X-ray and microwave. However, the thermodynamic properties and chemical…

宇宙学与河外天体物理 · 物理学 2014-10-24 Camille Avestruz , Erwin T. Lau , Daisuke Nagai , Alexey Vikhlinin
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