Science Current Events | Science News | Brightsurf.com
 

Researchers create 'MRI' of the sun's interior motions

July 09, 2012
A team of scientists has created an "MRI" of the Sun's interior plasma motions, shedding light on how it transfers heat from its deep interior to its surface. The result, which appears in the journal the Proceedings of the National Academy of Sciences, upends our understanding of how heat is transported outwards by the Sun and challenges existing explanations of the formation of sunspots and magnetic field generation.

The work was conducted by researchers from NYU's Courant Institute of Mathematical Sciences and its Department of Physics, Princeton University, the Max Planck Institute, and NASA.

The Sun's heat, generated by nuclear fusion in its core, is transported to the surface by convection in the outer third. However, our understanding of this process is largely theoretical-the Sun is opaque, so convection cannot be directly observed. As a result, theories largely rest on what we know about fluid flow and then applying them to the Sun, which is primarily composed of hydrogen, helium, and plasma.

Developing a more precise grasp of convection is vital to comprehending a range of phenomena, including the formation of sunspots, which have a lower temperature than the rest of the Sun's surface, and the Sun's magnetic field, which is created by its interior plasma motions.

In order to develop their "MRI" of the Sun's plasma flows, the researchers examined high-resolution images of the Sun's surface taken by the Helioseismic and Magnetic Imager (HMI) onboard NASA's Solar Dynamics Observatory. Using a 16-million pixel camera, HMI measures motions on the Sun's surface caused by convection.

Once the scientists captured the precise movement waves on the Sun's surface, they were able to calculate its unseen plasma motions. This procedure is not unlike measuring the strength and direction of an ocean's current by monitoring the time it takes a swimmer to move across the water-currents moving against the swimmer will result in slower times while those going in the same direction will produce faster times, with stronger and weaker currents enhancing or diminishing the impact on the swimmer.

What they found significantly departed from existing theory--specifically, the speed of the Sun's plasma motions were approximately 100 times slower than scientists had previously projected.

"Our current theoretical understanding of magnetic field generation in the Sun relies on these motions being of a certain magnitude," explained Shravan Hanasoge, an associate research scholar in geosciences at Princeton University and a visiting scholar at NYU's Courant Institute of Mathematical Sciences. "These convective motions are currently believed to prop up large-scale circulations in the outer third of the Sun that generate magnetic fields."

"However, our results suggest that convective motions in the Sun are nearly 100 times smaller than these current theoretical expectations," continued Hanasoge, also a postdoctoral fellow at the Max Plank Institute in Katlenburg-Lindau, Germany. "If these motions are indeed that slow in the Sun, then the most widely accepted theory concerning the generation of solar magnetic field is broken, leaving us with no compelling theory to explain its generation of magnetic fields and the need to overhaul our understanding of the physics of the Sun's interior."

###

The study's other co-authors were Thomas Duvall, an astrophysicist at NASA, and Katepalli Sreenivasan, University Professor in NYU's Department of Physics and Courant Institute. Sreenivasan is also Senior Vice Provost for Science and Technology for the Global Network University at NYU and Provost of Polytechnic Institute of NYU.

New York University


Related Plasma Current Events and Plasma News Articles


Calming the plasma edge: The tail that wags the dog
Experiments on the DIII-D tokamak that General Atomics operates for the U.S. Department of Energy (DOE) have demonstrated the ability of lithium injections to transiently double the temperature and pressure at the edge of the plasma and delay the onset of instabilities and other transients.

Using radio waves to control the density in a fusion plasma
Recent fusion experiments on the DIII-D tokamak at General Atomics (San Diego) and the Alcator C-Mod tokamak at MIT (Cambridge, Massachusetts), show that beaming microwaves into the center of the plasma can be used to control the density in the center of the plasma, where a fusion reactor would produce most of its power.

Helping general electric upgrade the US power grid
When researchers at General Electric Co. sought help in designing a plasma-based power switch, they turned to the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL).

Laser experiments mimic cosmic explosions and planetary cores
Researchers are finding ways to understand some of the mysteries of space without leaving earth.

IU researchers: Blood test may help to diagnose pancreatic cancer
Indiana University cancer researchers have found that a simple blood test might help diagnose pancreatic cancer, one of the most deadly forms of the disease.

Postcards from the plasma edge
For magnetic fusion energy to fuel future power plants, scientists must find ways to control the interactions that take place between the volatile edge of the plasma and the walls that surround it in fusion facilities.

Insights into the physics of space weather that disrupts cell phones and creates Earthly havoc
Each second, the sun hurls millions of tons of hot, charged plasma gas into space. This volatile "solar wind" buffets the magnetosphere, the magnetic field that surrounds the Earth, and can whip up geomagnetic storms that disrupt cell phone service, damage satellites and blackout power grids.

Genetic predisposition to elevated LDL-C associated with narrowing of the aortic valve
In an analysis that included approximately 35,000 participants, genetic predisposition to elevated low-density lipoprotein cholesterol (LDL-C) was associated with aortic valve calcium and narrowing of the aortic valve, findings that support a causal association between LDL-C and aortic valve disease, according to a study appearing in JAMA.

International Group Publishes Updated Criteria for Diagnosing Multiple Myeloma
The International Myeloma Working Group (IMWG) today announced that it has updated the criteria for diagnosing multiple myeloma.

A 'Star Wars' laser bullet -- this is what it really looks like
Action-packed science-fiction movies often feature colourful laser bolts. But what would a real laser missile look like during flight, if we could only make it out?
More Plasma Current Events and Plasma News Articles

Plasma Physics (Dover Books on Physics)

Plasma Physics (Dover Books on Physics)
by James E. Drummond (Author)


A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and '70s.
Hailed by Science magazine as a "well executed venture," the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwave plasma physics. Highlights include Klimontovich's article on quantum plasmas, Buneman's writings on how to distinguish between attenuating and amplifying waves, and Yoler's clear and cogent...

Plasma Engineering: Applications from Aerospace to Bio and Nanotechnology

Plasma Engineering: Applications from Aerospace to Bio and Nanotechnology
by Michael Keidar (Author), Isak Beilis (Author)


Plasma engineering applies the unique properties of plasmas (ionized gases) to improve processes and performance over many fields, such as materials processing, spacecraft propulsion, and nanofabrication. Plasma Engineering considers this rapidly expanding discipline from a unified standpoint, addressing fundamentals of physics and modeling as well as new real-word applications in aerospace, nanotechnology, and bioengineering. The book starts by reviewing plasma particle collisions, waves, and instabilities, and proceeds to diagnostic tools, such as planar, spherical, and emissive probes, and the electrostatic analyzer, interferometric technique, and plasma spectroscopy. The physics of different types of electrical discharges are considered, including the classical Townsend mechanism of...

Introduction to plasma physics and controlled fusion. Volume 1, Plasma physics

Introduction to plasma physics and controlled fusion. Volume 1, Plasma physics
by Francis F. Chen (Author)


TO THE SECOND EDITION In the nine years since this book was first written, rapid progress has been made scientifically in nuclear fusion, space physics, and nonlinear plasma theory. At the same time, the energy shortage on the one hand and the exploration of Jupiter and Saturn on the other have increased the national awareness of the important applications of plasma physics to energy production and to the understanding of our space environment. In magnetic confinement fusion, this period has seen the attainment 13 of a Lawson number nTE of 2 x 10 cm -3 sec in the Alcator tokamaks at MIT; neutral-beam heating of the PL T tokamak at Princeton to KTi = 6. 5 keV; increase of average ß to 3%-5% in tokamaks at Oak Ridge and General Atomic; and the stabilization of mirror-confined plasmas at...

Fundamentals of Plasma Physics

Fundamentals of Plasma Physics
by Paul M. Bellan (Author)


This rigorous explanation of plasmas is relevant to diverse plasma applications such as controlled fusion, astrophysical plasmas, solar physics, magnetospheric plasmas, and plasma thrusters. More thorough than previous texts, it exploits new powerful mathematical techniques to develop deeper insights into plasma behavior. After developing the basic plasma equations from first principles, the book explores single particle motion with particular attention to adiabatic invariance. The author then examines types of plasma waves and the issue of Landau damping. Magnetohydrodynamic equilibrium and stability are tackled with emphasis on the topological concepts of magnetic helicity and self-organization. Advanced topics follow, including magnetic reconnection, nonlinear waves, and the...

Plasma Physics: An Introduction

Plasma Physics: An Introduction
by Richard Fitzpatrick (Author)


Encompasses the Lectured Works of a Renowned Expert in the Field Plasma Physics: An Introduction is based on a series of university course lectures by a leading name in the field, and thoroughly covers the physics of the fourth state of matter. This book looks at non-relativistic, fully ionized, nondegenerate, quasi-neutral, and weakly coupled plasma. Intended for the student market, the text provides a concise and cohesive introduction to plasma physics theory, and offers a solid foundation for students wishing to take higher level courses in plasma physics. Mathematically Rigorous, but Driven by Physics This work contains over 80 exercises—carefully selected for their pedagogical value—with fully worked out solutions available in a separate solutions manual for professors. The...

Plasma Physics and Fusion Energy

Plasma Physics and Fusion Energy
by Jeffrey P. Freidberg (Author)


Considering the worldwide increase of interest in fusion research over the last decade - the recognition that a large number of new, environmentally attractive, sustainable energy sources will be needed to meet ever-increasing demands for electrical energy, is obvious. This book serves up the latest interest in alternative energy. Based on a series of graduate course notes in plasma physics and fusion energy at MIT, the text begins with an overview of world energy needs, current methods of energy generation, and the potential role that fusion may play in the future. It covers energy issues such as the production of fusion power, power balance, the design of a simple fusion reactor, and the basic plasma physics issues faced by the developers of fusion power. This book is suitable for...

Plasma At Work

Plasma At Work
by George A Sites (Author)


Description: THE PURPOSE OF THIS BOOK IS TO INTRODUCE THE READER TO MANY OF THE APPLICATIONS OF THE PLASMA ARC. THE APPLICATIONS ARE ALMOST ENDLESS AND IT IS ONE OF THE EMERGING TECHNOLOGIES OF TOMORROW. Synopsis: According to Geoplasma, Municipal Waste Disposal is one of the most pressing environmental problems of the 21st centruy. According to the United States EPA, over 245 million tons of Municipal Solid Waste (MSW) were generated in the United States in 2005. Population growth has consequently resulted in a significant increase in Municipal waste for disposal. Simultaneously, there has been increased pressure on business and civic leaders for better land use, environmental stewardship and sustainable development. Plasma Arc processing of waste materials is an innovative solution. It...

Platelet-Rich Plasma: Regenerative Medicine: Sports Medicine, Orthopedic, and Recovery of Musculoskeletal Injuries (Lecture Notes in Bioengineering)

Platelet-Rich Plasma: Regenerative Medicine: Sports Medicine, Orthopedic, and Recovery of Musculoskeletal Injuries (Lecture Notes in Bioengineering)
by José Fábio Santos Duarte Lana (Editor), Maria Helena Andrade Santana (Editor), William Dias Belangero (Editor), Angela Cristina Malheiros Luzo (Editor)


Platelet-Rich Plasma (PRP) has gained tremendous popularity in recent years as a treatment option for specialties including Orthopedics, Dentistry, Sports Medicine, Otorhinolaryngology, Neurosurgery, Ophthalmology, Urology, Vascular, Cardiothoracic and Maxillofacial Surgery, and Veterinarian Medicine. Nowadays, PRP and Stem Cell Science have added an exciting dimension to tissue repair. This book begins by giving the reader a broad overview of current progress as well as a discussion of the technical aspects of preparation and therapeutic use of autologous PRP. It is followed by a review of platelet structure, function and major growth factors in PRP (PDGF and TGFβ).The third chapter outlines the basic principles of biochemical cellular metabolism that increases the efficacy of PRP....

Plasma Physics via Computer Simulation (Series in Plasma Physics)

Plasma Physics via Computer Simulation (Series in Plasma Physics)
by C.K. Birdsall (Author), A.B Langdon (Author)


Divided into three main parts, the book guides the reader to an understanding of the basic concepts in this fascinating field of research. Part 1 introduces you to the fundamental concepts of simulation. It examines one-dimensional electrostatic codes and electromagnetic codes, and describes the numerical methods and analysis. Part 2 explores the mathematics and physics behind the algorithms used in Part 1. In Part 3, the authors address some of the more complicated simulations in two and three dimensions. The book introduces projects to encourage practical work Readers can download plasma modeling and simulation software — the ES1 program — with implementations for PCs and Unix systems along with the original FORTRAN source code. Now available in paperback, Plasma Physics via...

Laser-Plasma Interactions (Scottish Graduate Series)

Laser-Plasma Interactions (Scottish Graduate Series)
by Dino A. Jaroszynski (Editor), R.A. Bingham (Editor), R.A Cairns (Editor)


A Solid Compendium of Advanced Diagnostic and Simulation Tools Exploring the most exciting and topical areas in this field, Laser-Plasma Interactions focuses on the interaction of intense laser radiation with plasma. After discussing the basic theory of the interaction of intense electromagnetic radiation fields with matter, the book covers three applications of intense fields in plasma: inertial fusion, wakefield accelerators, and advanced radiation sources. Collecting contributions from a host of international experts, the book provides a thorough grounding in the fundamental concepts of the interaction of electromagnetic radiation with matter, before moving on to selected advanced topics from the field. It describes state-of-the-art diagnostic tools and experimental techniques used...

© 2014 BrightSurf.com