Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shortest flashes from ultra-hot matter

06.10.2009
High-energy heavy ion collisions, which are studied at RHIC in Brookhaven and soon at the LHC in Geneva, can be a source of light flashes of a few yoctoseconds duration (a septillionth of a second, 10-24 s, ys) - the time that light needs to traverse an atomic nucleus.

This is shown in calculations of the light emission of so-called quark-gluon plasmas, which are created in such collisions for extremely short periods of time. Under certain conditions, double flashes are created, which could be utilized in the future to visualize the dynamics of atomic nuclei. (Physical Review Letters, 07.10.2009)


Collisions of heavy ions in a large accelerator facility (schematic). Under certain conditions, double light flashes of a few yoctoseconds duration can be emitted. MPI for Nuclear Physics


Temporal evolution of the quark-gluon plasma. Two ions (colored disks) collide along the beam collision axis (black double arrow). Image (a) shows the time immediately after the collision. The plasma (orange area) shines light (wavy arrows) in all directions, so that a first pulse in the direction of the detector (green semi-circle) is formed. (b) After some time, the inner dynamics of the plasma will cause light to be preferentially radiated perpendicular to the direction of flight of the ions. During this time no light is emitted into the direction of the detector which is placed close to the collision axis. In (c) the plasma radiates again in all directions, so that the second pulse is emitted in the direction of the detector. MPI for Nuclear Physics

For high-precision spectroscopy and structural studies of molecules, short light flashes with lowest possible wavelength, i.e., high photon energy, are required. Currently, x-ray flashes of some attosecond (a quintillionth of a second, 10-18 s) duration are accessible experimentally. Even shorter pulses with even higher photon energy would improve the temporal and spatial resolution, or would allow for the investigation of even smaller structures, such as for example atomic nuclei. In so-called pump-probe experiments, two light pulses of exactly controllable distance are utilized to observe rapid system changes in slow motion.

Calculations at the Max Planck Institute for Nuclear Physics have now shown that high-energy heavy ion collisions at large particle accelerators are suitable as light sources for the desired single and double pulses. This is due to the remarkable properties of quark-gluon plasmas.

The quark-gluon plasma is a state of matter of which the universe consisted right after the big bang. In this state, the temperatures are so high that even the constituents of atomic nuclei, the neutrons and protons, are split into their constituents, the quarks and gluons. Such a state of matter can nowadays be realized in modern colliders.

In the collision of heavy ions (i.e. atoms of heavy elements from which all electrons have been removed) at relativistic velocities, such a quark-gluon plasma is created for a few yoctoseconds at the size of a nucleus (Figure 1). Among many other particles, it also creates photons of a few GeV (billion electron volts) energy, so-called gamma radiation. These high-energy flashes of light are as short as the lifetime the quark-gluon plasma and consist of only a few photons.

The researchers have simulated the time-dependent expansion and internal dynamics of the quark-gluon plasma. It was found that at some intermediate time the photons are not emitted in all directions, but preferably perpendicular to the collision axis. A detector that is placed close to the collision axis will measure practically nothing during this period. Therefore, overall it detects a double pulse (Figure 2). By suitable choice of geometry of the setup and observing direction, the double pulses can in principle be selectively varied. Thus, they open up the possibility of future pump-probe experiments in the yoctosecond range at high energies. This could lead to a time-resolved observation of processes in atomic nuclei. Conversely, a detailed analysis of the gamma-ray flashes would allow to draw conclusions about the quark-gluon plasma.

Contact:

PD Dr. Jörg Evers
Max-Planck-Institut für Kernphysik, Heidelberg
Tel: +49-6221-516-177
E-Mail: joerg.evers@mpi-hd.mpg.de
Prof. Dr. Christoph H. Keitel
Max-Planck-Institut für Kernphysik, Heidelberg
Tel: +49-6221-516-150
E-Mail: christoph.keitel@mpi-hd.mpg.de

Dr. Bernold Feuerstein | Max-Planck-Gesellschaft
Further information:
http://link.aps.org/doi/10.1103/PhysRevLett.103.152301
http://www.mpi-hd.mpg.de/keitel/
http://www.mpi-hd.mpg.de/keitel/evers/

More articles from Physics and Astronomy:

nachricht Four elements make 2-D optical platform
26.09.2017 | Rice University

nachricht The material that obscures supermassive black holes
26.09.2017 | Instituto de Astrofísica de Canarias (IAC)

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 fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>