A5101924851- Atomic and Molecular Physics
- Gamma-ray bursts and supernovae
- Atomic and Subatomic Physics Research
- Pulsars and Gravitational Waves Research
- Laser-induced spectroscopy and plasma
- Cold Atom Physics and Bose-Einstein Condensates
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Educational Robotics and Engineering
- Nuclear physics research studies
- Quantum, superfluid, helium dynamics
- Geophysics and Gravity Measurements
- Laser-Plasma Interactions and Diagnostics
- NMR spectroscopy and applications
- X-ray Spectroscopy and Fluorescence Analysis
- Scientific Measurement and Uncertainty Evaluation
- Statistical and numerical algorithms
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Relativity and Gravitational Theory
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
Queen's University Belfast
2021-2023
University of Washington
1995-2019
Northwest University
2019
Columbia University
2019
New York University
2019
Northwestern University
2019
University of Oxford
2010-2011
Science and Technology Facilities Council
2010
Rutherford Appleton Laboratory
2010
University of Sussex
2010
ABSTRACT Binary neutron star mergers are thought to be one of the dominant sites production for rapid capture elements, including platinum and gold. Since discovery binary merger GW170817, its associated kilonova AT2017gfo, numerous works have attempted determine composition outflowing material, but they been hampered by lack complete atomic data. Here, we demonstrate how inclusion new data in synthetic spectra calculations can provide insights constraints on heaviest elements. We employ...
ABSTRACT A large number of $\bf{R}$-matrix calculations electron-impact excitation for heavy elements ($Z\gt 70$) have been performed in recent years applications fusion and astrophysics research. With the expanding interest ions due to kilonova (KN) events such as AT2017gfo AT2023vfi, these new data can be utilized diagnosis study observed KN spectra. In this work, recently computed effective collision strengths are used, first three ionization stages tungsten (W, $Z=74$), platinum (Pt,...
Abstract The detection of a gravitational-wave signal and subsequent electromagnetic transient from neutron star merger in 2017 is consistent with expectations mergers as an r -process element production site. Within the first few days post-merger, kilonova spectra are blackbody illuminating mix heavy, elements. With increasing time, transitions to non-LTE regime where level populations ionization balance determined by both collisional photoprocesses. Detailed cross section data for...
ABSTRACT Neutron binary star mergers have long been proposed as sufficiently neutron rich environments that could support the synthesis of rapid capture elements (r-process elements) such gold. However, literature reveals beyond neutral and singly ionized systems, there is an incompleteness atomic data for remaining ion stages importance mergers. In this work, we report on relativistic structure calculations Au i–Au iii using grasp0 codes. Comparisons to Flexible Atomic Code suggest...
We have constructed an instrument, CryoEDM, to measure the neutron electric dipole moment a precision of 10−28 e cm at Institut Laue-Langevin. The main characteristic is that it operating entirely in cryogenic environment, temperatures 0.7 K within superfluid helium. Ultracold neutrons are produced superthermal source and stored storage cell which held magnetic field. NMR measurements carried out look for any shifts Larmor precession frequency associated with field detected in-situ...
Abstract To better understand plasma wall interactions involving tungsten, accurate atomic structure and electron-impact driven collisional processes for near-neutral ion stages of tungsten are required. Complementing existing work on neutral singly ionised calculations W 2+ excitation have been completed. These an important component S/XB coefficients charge states, which may be used to spectroscopically infer re-deposition at the plasma-solid boundary fusion relevant devices. With in...
Abstract A selection of electron-impact excitation R -matrix calculations completed by the collision group at Queens University Belfast are discussed. The atomic data calculated foundation applications in a variety fields, sample which presented here. They include an analysis Fe ii emission active galactic nuclei, possible presence Pt and Au spectra binary neutron star mergers viability W ions as diagnostic tool magnetically confined tokamak plasmas. radiative were computed using most recent...
We have carried out a series of magnetic field measurements using portable three-axis SQUID magnetometer at the Laboratoire Souterrain à Bas Bruit (LSBB), Rustrel, France. The was originally developed as part cryoEDM neutron electric dipole moment experiment [1], where we need to monitor drifts in level ∼0.1 pT. system is 12-channel designed operate large cryostat with extensive shielding [3]. tested smaller prototype systems during trips LSBB [2], primarily test SQUIDs, and control DAQ...
We present results from a pilot study, using laser-produced plasma, to identify new lines in the 350 1000 nm spectral region for r-process element gold (Au), of relevance studies neutron star mergers. This was achieved via optical-IR spectroscopy Au with an target high purity (99.95 %) and low vacuum pressure remove any air contamination experimental spectra. Our data were recorded spectrometer 750 mm focal length 1200 mm-1 grating, yielding resolution 0.04 nm. find 54 not previously...
A large number of R-matrix calculations electron impact excitation for heavy elements (Z > 70) have been performed in recent years applications fusion and astrophysics research. With the expanding interest ions due to kilonova (KN) events such as AT2017gfo AT2023vfi, this new data can be utilised diagnosis study observed KN spectra. In work recently computed electron-impact effective collision strengths are used, first three ionisation stages tungsten (W, Z = 74), platinum (Pt, 78) gold (Au,...
The cryoEDM experiment at the Institut Laue-Langevin in Grenoble will measure electric dipole moment (EDM) of neutron with unparalleled precision.A EDM arises due to CP violation.The is sensitive levels violation predicted by many "beyond standard model" theories and result therefore constrain or support these theories.The current limit stands |d n | < 2.9×10 -26 e cm as measured a room temperature experiment.By operating superfluid helium below 0.9 K collecting high densities ultra cold...