Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lasers create table-top supernova

02.06.2014

Laser beams 60,000 billion times more powerful than a laser pointer have been used to recreate scaled supernova explosions in the laboratory as a way of investigating one of the most energetic events in the Universe.

Supernova explosions, triggered when the fuel within a star reignites or its core collapses, launch a detonation shock wave that sweeps through a few light years of space from the exploding star in just a few hundred years. But not all such explosions are alike and some, such as Cassiopeia A, show puzzling irregular shapes made of knots and twists.

To investigate what may cause these peculiar shapes an international team led by Oxford University scientists (groups of Professor Gregori and Professor Bell in Atomic and Laser Physics, and Professor Schekochihin in Theoretical Physics) has devised a method of studying supernova explosions in the laboratory instead of observing them in space.

'It may sound surprising that a table-top laboratory experiment that fits inside an average room can be used to study astrophysical objects that are light years across,' said Professor Gianluca Gregori of Oxford University's Department of Physics, who led the study published in Nature Physics. 'In reality, the laws of physics are the same everywhere, and physical processes can be scaled from one to the other in the same way that waves in a bucket are comparable to waves in the ocean. So our experiments can complement observations of events such as the Cassiopeia A supernova explosion.'

The Cassiopeia A supernova explosion was first spotted about 300 years ago in the Cassiopeia constellation 11,000 light years away, its light has taken this long to reach us. The optical images of the explosion reveal irregular 'knotty' features and associated with these are intense radio and X-ray emissions. Whilst no one is sure what creates these phenomena one possibility is that the blast passes through a region of space that is filled with dense clumps or clouds of gas.

To recreate a supernova explosion in the laboratory the team used the Vulcan laser facility at the UK's Science and Technology Facilities Council's Rutherford Appleton Lab. 'Our team began by focusing three laser beams onto a carbon rod target, not much thicker than a strand of hair, in a low density gas-filled chamber,' said Ms Jena Meinecke an Oxford University graduate student, who headed the experimental efforts. The enormous amount of heat generated more than a few million degrees Celsius by the laser caused the rod to explode creating a blast that expanded out through the low density gas. In the experiments the dense gas clumps or gas clouds that surround an exploding star were simulated by introducing a plastic grid to disturb the shock front.

'The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent just like the images from Cassiopeia,' said Professor Gregori. 'We found that the magnetic field is higher with the grid than without it. Since higher magnetic fields imply a more efficient generation of radio and X-ray photons, this result confirms that the idea that supernova explosions expand into uniformly distributed interstellar material isn't always correct and it is consistent with both observations and numerical models of a shockwave passing through a 'clumpy' medium.'

'Magnetic fields are ubiquitous in the universe,' said Don Lamb, the Robert A. Millikan Distinguished Service Professor in Astronomy & Astrophysics at the University of Chicago. 'We're pretty sure that the fields didn't exist at the beginning, at the Big Bang. So there's this fundamental question: how did magnetic fields arise?' These results are significant because they help to piece together a story for the creation and development of magnetic fields in our Universe, and provide the first experimental proof that turbulence amplifies magnetic fields in the tenuous interstellar plasma.

The advance was made possible by the extraordinarily close cooperation between the teams performing the experiments and the computer simulations. 'The experimentalists knew all the physical variables at a given point. They knew exactly the temperature, the density, the velocities,' said Petros Tzeferacos of the University of Chicago, a study co-author. 'This allows us to benchmark the code against something that we can see.' Such benchmarking – called validation – shows that the simulations can reproduce the experimental data. The simulations consumed 20 million processing hours on supercomputers at Argonne National Laboratory, in the USA.

A report by the team, including researchers from the University of Oxford, the University of Chicago, ETH Zurich, the Queen's University Belfast, the Science and Technology Facilities Council, the University of York, the University of Michigan, Ecole Polytechnique, Osaka University, the University of Edinburgh, the University of Strathclyde and the Lawrence Livermore National Laboratory is published in Nature Physics.

###

Funding for this research was provided by the European Research Council, the UK's Science and Technology Facilities Council, and the US Department of Energy through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program.

University of Oxford News Office | Eurek Alert!
Further information:
http://www.ox.ac.uk/

Further reports about: Cassiopeia Facilities Laboratory Oxford Physics Technology X-ray clouds dense experiments explosions images irregular waves

More articles from Physics and Astronomy:

nachricht Absorbing acoustics with soundless spirals
10.02.2016 | American Institute of Physics

nachricht Hot Science of the Cold Universe
10.02.2016 | Max-Planck-Institut für Radioastronomie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

Im Focus: Superconductivity: footballs with no resistance

Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications.

Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

From intelligent knee braces to anti-theft backpacks

26.01.2016 | Event News

 
Latest News

About injured hearts that grow back - Heart regeneration mechanism in zebrafish revealed

10.02.2016 | Life Sciences

The most accurate optical single-ion clock worldwide

10.02.2016 | Earth Sciences

Absorbing acoustics with soundless spirals

10.02.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>