Nav: Home

As hot as the sun's interior

June 05, 2019

The three classic physical states - solid, liquid and gaseous - can be observed in any normal kitchen, for example when you bring an ice cube to the boil. But if you heat material even further, so that the atoms of a substance collide and the electrons separate from them, then another state is reached: plasma. More than 99 per cent of material in space is present in this form, inside stars for instance. It is therefore no wonder that physicists are keen to study such material. Unfortunately, creating and studying plasmas on Earth using the high temperature and pressure that exist inside stars is extremely challenging for various reasons. Physicists at Friedrich Schiller University in Jena have now managed to solve some of these problems, and they have reported on their results in the renowned research journal Physical Review X.

Nanowires let light through

"To heat material in such a way that plasma is formed, we need correspondingly high energy. We generally use light in the form of a large laser to do this," explains Christian Spielmann of the University of Jena. "However, this light has to be very short-pulsed, so that the material does not immediately expand when it has reached the appropriate temperature, but holds together as dense plasma for a brief period." There is a problem with this experimental setup, though: "When the laser beam hits the sample, plasma is created. However, it almost immediately starts to act like a mirror and reflects a large part of the incoming energy, which therefore fails to penetrate the matter fully. The longer the wavelength of the laser pulse, the more critical the problem," says Zhanna Samsonova, who played a leading role in the project.

To avoid this mirror effect, the researchers in Jena used samples made of silicon wires. The diameter of such wires - a few hundred nanometres - is smaller than the wavelength of around four micrometres of the incoming light. "We were the first to use a laser with such a long wavelength for the creation of plasma," says Spielmann. "The light penetrates between the wires in the sample and heats them from all sides, so that for a few picoseconds, a significantly larger volume of plasma is created than if the laser is reflected. Around 70 per cent of the energy manages to penetrate the sample." Furthermore, thanks to the short laser pulses, the heated material exists slightly longer before it expands. Finally, using X-ray spectroscopy, researchers can retrieve valuable information about the state of the material.

Maximum values for temperature and density

"With our method, it is possible to achieve new maximum values for temperature and density in a laboratory," says Spielmann. With a temperature of around 10 million Kelvin, the plasma is far hotter than material on the surface of the Sun, for example. Spielmann also mentions the cooperation partners in the project. For the laser experiments, the Jena scientists used a facility at the Vienna University of Technology; the samples come from the National Metrology Institute of Germany in Braunschweig; and computer simulations for confirming the findings come from colleagues in Darmstadt and Düsseldorf.

The Jena team's results are a ground-breaking success, offering a completely new approach to plasma research. Theories on the state of plasma can be verified through experiments and subsequent computer simulations. This will enable researchers to understand cosmological processes better. In addition, the scientists are carrying out valuable preparatory work for the installation of large-scale apparatus. For example, the international particle accelerator, 'Facility for Antiproton and Ion Research' (FAIR), is currently being set up in Darmstadt and should become operational around 2025. Thanks to the new information, it will be possible to select specific areas that merit closer examination look.
-end-
Original publication: Zhanna Samsonova, et al.: Relativistic Interaction of Long-Wavelength Ultrashort Laser Pulses with Nanowires, Physical Review X, 2019, DOI: 10.1103/PhysRevX.9.021029

Contact:
Dr Zhanna Samsonova / Prof. Christian Spielmann
Institute of Optics and Quantum Electronics of Friedrich Schiller University, Jena
Max-Wien-Platz 1, 07743 Jena, Germany
Tel.: +49 (0)3641/947214, +49 (0)3641/947231
E-mail: zhanna.samsonova@uni-jena.de, christian.spielmann@uni-jena.de

Friedrich-Schiller-Universitaet Jena

Related Plasma Articles:

Plasma-driven biocatalysis
Compared with traditional chemical methods, enzyme catalysis has numerous advantages.
How bacteria protect themselves from plasma treatment
Considering the ever-growing percentage of bacteria that are resistant to antibiotics, interest in medical use of plasma is increasing.
A breakthrough in the study of laser/plasma interactions
Researchers from Lawrence Berkeley National Laboratory and CEA Saclay have developed a particle-in-cell simulation tool that is enabling cutting-edge simulations of laser/plasma coupling mechanisms.
Researchers turn liquid metal into a plasma
For the first time, researchers at the University of Rochester's Laboratory for Laser Energetics (LLE) have found a way to turn a liquid metal into a plasma and to observe the temperature where a liquid under high-density conditions crosses over to a plasma state.
How black holes power plasma jets
Cosmic robbery powers the jets streaming from a black hole, new simulations reveal.
Give it the plasma treatment: strong adhesion without adhesives
A Japanese research team at Osaka University used plasma treatment to make fluoropolymers and silicone resin adhere without any adhesives.
Chemotherapeutic drugs and plasma proteins: Exploring new dimensions
This review provides a bird's eye view of interaction of a number of clinically important drugs currently in use that show covalent or non-covalent interaction with serum proteins.
The coming of age of plasma physics
The story of the generation of physicists involved in the development of a sustainable energy source, controlled fusion, using a method called magnetic confinement.
Intense microwave pulse ionizes its own channel through plasma
More than 30 years ago, researchers theoretically predicted the ionization-induced channeling of an intense microwave beam propagating through a neutral gas (>103 Pa) -- and now it's finally been observed experimentally.
Plasma thruster: New space debris removal technology
A Japanese and Australian research group has discovered new technology to remove space debris using a single propulsion system in a helicon plasma thruster.
More Plasma News and Plasma Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.