American Physical Society Division Research Articles

Rayleigh-Taylor instability in drop impact experiments

This paper is associated with a video winner of a 2020 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2020.GFM.V0019.

Fluid dynamics of COVID-19 spread

This paper is associated with a poster winner of a 2020 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2020.GFM.P0017.

Spectral landscapes of flow instabilities in brain aneurysms

This paper is associated with a poster winner of a 2020 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2020.GFM.P0004.

Turbulence in space plasmas: Who needs it?

The complex nonlinear dynamical phenomenon described as turbulence, is known to have a great impact on fluids, magnetohydrodynamic systems, and on plasmas. This paper reviews selected topics on turbulence in these systems, emphasizing the multiscale space-time properties of the turbulence cascade as it transfers energy from large scale reservoirs, through the inertial range, finally dissipating at kinetic scales and producing internal or thermal energy. Application to space and astrophysical plasmas is a pervasive theme. This paper is based on the Maxwell Prize address given at the 2019 American Physical Society Division of Plasma Physics meeting in Fort Lauderdale.

Hydrodynamic tweezing: Using water waves to push and pull

This paper is associated with a poster winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.P0031.

Gas escape behavior from bursting bubbles

This paper is associated with a video winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.V0072.

Breaking waves: To foam or not to foam?

This paper is associated with a video winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.V0018.

Unraveling the interplay of two counter-rotating helical vortices

This paper is associated with a video winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.V0067.

Droplets impaling on a cone

This paper is associated with a video winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.V0013.

Blooming flowers from drying drops

This paper is associated with a video winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.V0082.

Rico and the jets: Direct numerical simulations of turbulent liquid jets

This paper is associated with a poster winner of a 2019 American Physical Society's Di- vision of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.P0020 The breakup of an interface into a cascade of droplets and their subsequent coalescence is a generic problem of central importance to a large number of industrial settings. Examples of these applications include the atomisation of propellants in engines, the formation of droplets in injectors, mixers, separators, and the generation of droplets in multiphase flow regime transitions [2, 3, 12]. In all of these situations, it is important to predict the evolving droplet size distribution that results from a competition between breakup and coalescence, which are influenced by a range of multi-scale physics; this includes the interaction of turbulence with interfaces, capillarity, viscosity, and gravity. Therefore, it is unsurprising that the breakup of liquid jets during injection (i.e. atomisation) has received great scientific interest [4, 8, 10, 11, 13]. To the best of our knowledge, the transient dynamics of turbulent liquid/liquid systems have not been reported in the literature. Temporal instabilities and the resulting spatio-temporal interfacial structures are predicted by solving the full three-dimensional two-phase Navier-Stokes system in the context of a hybrid front-tracking/level-set method [14-16].

Fluid dynamics of millefiori: Mixing ferrofluid with watercolor

This paper is associated with a poster winner of a 2019 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.P0034.

Gas giant–like zonal jets in the laboratory

This paper is associated with a poster winner of a 2019 American Physical Society Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2019.GFM.P0015.

Special Issue on Machine Learning, Data Science, and Artificial Intelligence in Plasma Research

This Special Issue of the IEEE Transactions on Plasma Science (TPS) follows the first American Physical Society Division of Plasma Physics (APS-DPP) mini-conference on Machine Learning, Data Science, and Artificial Intelligence in Plasma Research held during the 60th APS-DPP Meeting in Portland, OR, USA (November 5–9, 2018). It contains selected highlights from not only the mini-conference but also the broader plasma physics community. Although data science has a long and rich history in plasma physics, dating back at least three decades, it is experiencing a renaissance, thanks in large part to the advances outside of plasma physics. Novel algorithms, hardware, and analytic techniques (buoyed by the open source software ecosystem) have led plasma scientists to explore ways in which the data revolution could accelerate and inform scientific discovery. Emerging data-driven methods could have a transformative effect across the full spectrum of plasma research. For fusion energy research, some areas of opportunities [item 1) in the Appendix] include using machine learning (ML) or data methods for scientific discoveries, augmented instrumentation, accelerated model development and simulations, data-informed intelligent controls of the experiment, and data-enhanced predictions. The DPP mini-conference and the articles herein represent only a tiny cross section of contemporary research on data-driven plasma science. The 3rd International Conference on Data-Driven Plasma Science (ICDDPS-3) will be held in Okinawa, Japan, in April 2020 [item 2) in the Appendix], with expected presentations on fusion plasmas and low-temperature plasmas and beyond. Furthermore, Plasma Science is not unique in its exploration of Scientific Machine Learning: the Second Workshop on Machine Learning and the Physical Sciences (NeurIPS 2019, Vancouver, BC, Canada, December 2019) and it illustrates a trend in cross disciplinary collaboration with contributions from plasma research.

Dripping down the rivulet

This paper is associated with a video winner of a 2018 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2018.GFM.V0070.

Exploring the crossover between high-energy-density plasma and ultracold neutral plasma physics

In this paper, we present ideas that were part of the miniconference on the crossover between High Energy Density Plasmas (HEDP) and Ultracold Neutral Plasmas (UNPs) at the 60th Annual Meeting of the American Physical Society Division of Plasma Physics, November 2018. We give an overview of UNP experiments with an emphasis on measurements of the time-evolving ion density and velocity distributions, the electron-ion thermalization rate, and plasma self-assembly—all just inside the strongly coupled plasma regime. We also present theoretical and computational models that were developed to understand a subset of HEDP experiments. However, because HEDP experiments display similar degrees of strong coupling, many aspects of these models can be vetted using precision studies of UNPs. This comparison is important because some statistical assumptions used for ideal plasmas are of questionable validity in the strongly coupled plasma regime. We summarize two theoretical approaches that extend kinetic theories into the strong-coupling regime and show good agreement for momentum transfer and self-diffusion. As capabilities improve, both computationally and experimentally, UNP measurements may help guide the ongoing development of HEDP-appropriate plasma models. Future opportunities in viscosity, energy relaxation, and magnetized plasmas are discussed.

9th International Particle Accelerator Conference, IPAC18

PrefaceIntroductionThe ninth International Particle Accelerator Conference, IPAC’18, took place at the J.W. Marriott Parq Hotel, Vancouver, British Columbia, Canada from Sunday to Friday, April 29 to May 04, 2018. IPAC’18 was attended by 1,276 delegates from 31 countries on all continents. The tally includes 125 industry delegates, but excludes the 88 exhibitor registrations. Hosted by the TRIUMF Laboratory, the conference was organized under the auspices of the Institute of Electrical and Electronics Engineers (IEEE), and the American Physical Society Division of Physics of Beams (APS‐DPB). Established in 1968 in Vancouver, TRIUMF is Canada’s particle accelerator centre. Delegates and Exhibitors were supported by a 26‐ member Local Organizing Committee (LOC) volunteered by TRIUMF.214 young scientists from all over the globe attended the conference. 99 of these students received travel grants thanks to the sponsorship of societies, institutes and laboratories worldwide. The Americas region sponsors are: APS, NSF and TRIUMF. The Asia region sponsors are: ANSTO, IHEP, RIKEN, KEK, SSRF and PAL. The Europe region sponsors are: CEA, CELLS, CERN, Cockcroft, DESY, Diamond, ELETTRA, ESRF, ESS, GANIL, GSI, HZB, INFN, in2p3, KIT, MAXIV, PIS, SOLEIL, STFC. The IPAC’18 budget contributed $20,000 student grants to each region. The organizers of IPAC’18 are grateful to all sponsors for their valued support of students.

Special Issue on Measuring and Modeling of Plasma-Material Interactions

The 57th Annual Meeting of the American Physical Society (APS) Division of Plasma Physics (DPP) took place November 16–20, 2015, in Savannah, Georgia, at the Savannah International Trade Convention...

Summary of the second workshop on liquid argon time projection chamber research and development in the United States

The second workshop to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States was held at Fermilab on July 8-9, 2014. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in six topical plenary sessions: i) Argon Purity and Cryogenics, ii) TPC and High Voltage, iii) Electronics, Data Acquisition and Triggering, iv) Scintillation Light Detection, v) Calibration and Test Beams, and vi) Software. This document summarizes the current efforts in each of these areas. It primarily focuses on the work in the US, but also highlights work done elsewhere in the world.

Liquid Argon Time Projection Chamber research and development in the United States

A workshop was held at Fermilab on March 20-21, 2013 to discuss the development of liquid argon time projection chambers (LArTPCs) in the United States. The workshop was organized under the auspices of the Coordinating Panel for Advanced Detectors, a body that was initiated by the American Physical Society Division of Particles and Fields. All presentations at the workshop were made in seven topical plenary sessions: i) Argon Purity, ii) Cryogenics, iii) TPC and High Voltage, iv) Electronics, Data Acquisition and Triggering, v) Scintillation Light Detection, vi) Calibration and Test Beams, and vii) Software. This document summarizes the current efforts in each of these areas. It also highlights areas in LArTPC research and development that are common between neutrino experiments and dark matter experiments.