High Intensity Physics
The use of high power lasers to create hot plasmas is common to laboratories around the world. The advantage of lasers is that very high powers can be delivered, with focussed intensities onto target in excess of 1020 Wcm -2. To get a sense of perspective we can note that this intensity is more than 20 orders of magnitude higher than what delivered by bright sunlight . The electric field in such a beam is more than 1013 Vm-1. This is enough to rip electrons from atoms directly. When laser light is absorbed by a solid, the matter is evaporated and heated into a plasma with a temperature that can easily be in excess of 108 K. The sort of lasers in which we are interested range from the very large systems, with nanosecond (10-9s) pulses delivering kilojoules of energy, to smaller systems with ultra-fast pulses of less than 10-13 s which can be focussed to high intensities. Some of the physical phenomena associated with laser-matter interactions are:
- Driving strong shock waves in excess of 100 million atmospheres pressure.
- Generating beams of electrons or protons with energies of MeV.
- Pumping a plasma to generate X-ray lasers operating in the soft X-ray regime.
- Generating high energy density matter with energy densities in excess of 10 11 Jm -3.
- Compression of laser-fusion capsules to investigate inertial confinement fusion.
- Generation of ultra-high magnetic fields in excess of 1000T.
- Generating plasmas that can be used as models of astrophysical systems.
- Driving atoms in a gas jet or electrons in a solid foil non-linearly to generate high harmonics of the incident laser up to in excess of the 200th harmonic.
Our group has an active interest in all of these types of physics experiments. Experimental activity in these and other areas is carried out by our group at Large facilities worldwide. These currently include:
- Central Laser Facility at the Rutherford Appleton Laboratory,
- the Laboratoire pour l'Utilisation des Lasers Intenses in Palaiseau, France.
- the PALS system in Prague, Czech Republic.
Our own in house TARANIS laser allows us to carry out experiments hee at Queen's.
We have ongoing collaborations with many University and Laboratory groups worldwide. Following the links of individual researchers will lead you to recent publications with more details of our work.