With a new 3D-model for energy simulation scientists from Bochum and Huntsville, USA, are studying the 'physical mystery' of the Voyager.
Over 30 years ago the spacecraft detected particles in solar wind which were 'hotter' than they should have been according to the existing theory expounded by the mathematician Andrey Kolmogorov in 1941.
The Bochum plasma physicists Prof. Padma Kant Shukla and Dr. Dastgeer Shaikh from the University of Alabama are thereby the first to verify by means of computer simulation that the non-linear characteristics of turbulences in the plasma carried by the solar wind differs from the familiar model for dynamic fluids. The scientists have published their results in 'Physical Review Letters.'
Recognized for over 60 years: The 5/3 law.
According to Kolmogorov's theory there is a relationship between the size of eddies and the amount of energy released or dissipated by hot solar particles. The smaller an eddy gets the more it interacts with its surroundings, so the greater the energy loss.
For example this can be observed in the turbulent wake caused by a bridge piling in a flowing river. The energy of the tumbling wake dissipates only at the edges, where the smallest eddies interact with the smooth flowing water. The Kolmogorov law set the exponents for the relationship between eddy size and energy at 5/3: In a dynamic fluid, the amount of energy released should increase by a factor of x5/3 when the size of the eddy is reduced by a factor of x.
7/3 law: Efficiency increases by 40 percent
Observations made by the Voyager, other spacecraft and satellites show that the energy flow in plasma tends to follow a 7/3 law rather than the so-called 5/3 law proposed by Kolmogorov.
The dynamic spectrum of the wave lengths in plasma is therefore significantly greater than in other hydrodynamic systems. The efficiency of energy transfer between hot particles carried in the solar wind and cooler particles increases by 40 percent. The computer model developed by Shukla and Shaikh explains the sudden increase by the interaction between magnetic fields and the outward flowing currents of hot atoms, ions and electrons.
The magnetic field is responsible for energy cascades. Influenced and 'constrained' by magnetic fields, the small eddies serve to "damp" the energy in them.
Explanation for gigantic quantities of cosmic energy
"This is the same kind of thing that happens in a microwave oven," Shaikh said. "If there is nothing there, the microwaves go out without releasing their energy. But the microwaves are absorbed by the food, causing them to release the energy and heat the food."
"This development of the two scientists helps us to understand how the particles in the solar wind contain enormous quantities of energy. Prof. Shukla continued "It might also explain where the fastest and most powerful cosmic rays get their boost." Scientists have struggled for decades to find plausible natural processes that could explain how some cosmic rays (atoms stripped of their electrons) are accelerated to almost the speed of light.
3D simulations of fluctuation spectra in the Hall-MHD plasma, Dastgeer Shaikh and P K Shukla, Physical Review Letters 102, 045004 (2009): DOI:10.1103/PhysRevLett.102.045004
Further informationProf. Dr. Dr. h.c. mult. Padma Kant Shukla
Dr. Josef König | idw
Further reports about: > 3D-model > Plasma > RUB > cosmic ray > dynamic spectrum > electrons > energy flow > energy simulation scientists > familiar model for dynamic fluids > hot atoms > hot solar wind turbulences > ions > magnetic field > non-linear characteristics of turbulences > physical mystery > solar particles > solar wind > spacecraft
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Life Sciences
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology