Nuclear physic

The ion beams produced by very intense lasers make it possible to observe and experimentally study changes in the properties of the nuclear states, and their population, in hot and dense plasmas. This studies are in full development with the construction and the commissioning of very high energy and/or very high intensity laser facilities, such as NIF, LMJ, APOLLON or ELI facilities.

Lasers are used to create plasmas with a density and a temperature which are impossible to generate with conventional nuclear physic accelerators. The extreme thermodynamic conditions of temperature and density prevailing here are likely to affect the coupling between the nucleus and its electronic cloud. The excitation reaction rates as well as the nuclear properties, such as excited states’ lifetime, then can be modified;
The lasers with short pulses (up to 100 picoseconds) allow to produce high-flow, short-lived accelerated particle (ions, but also neutrons produced in a secondary way) pulses. These new compact sources are interesting for both fundamental physics and applications;
These ion and neutron beams produced by the APOLLON Laser Facility, coupled with the ability to inject them into a laser-produced plasma, will open a wide range of applications: flash radiography of objects or fields in rapid evolution, detection of composition of materials by spectroscopy, temperature measurement in dense plasmas, measure of the influence of a plasma medium on nuclear reactions, or the evaluation of nuclear reactions havin small cross-sections (of crucial importance for nuclear astrophysics and the stellar evolution cycle).

Nuclear physic studies (such as neutron production with the ERC project GENESIS), or the studies of nuclear excitation mechanisms in plasmas such as “indirects”, wich are based on a coupling between the nucleus and its electronic cloud (http://www.cenbg.in2p3.fr/Excitations-nucleaires-dans-des,1011#neet).