Search

The PETAL system (PETawatt Aquitaine Laser) is a high-energy short-pulse laser, currently in an advanced construction phase, to be combined with the French Mega-Joule Laser (LMJ). In a first operational phase (beginning in 2015 and 2016) PETAL will provide 1 kJ in 1 ps and will be coupled to the first four LMJ quads. The ultimate performance goal to reach 7PW (3.5 kJ with 0.5 ps pulses). Once in operation, LMJ and PETAL will form a unique facility in Europe for High Energy Density Physics (HEDP). PETAL is aiming at providing secondary sources of particles and radiation to diagnose the HED plasmas generated by the LMJ beams. It also will be used to create HED states by short-pulse heating of matter. Petal+ is an auxiliary project addressed to design and build diagnostics for experiments with PETAL. Within this project, three types of diagnostics are planned: a proton spectrometer, an electronspectrometer and a large-range X-ray spectrometer.

Theoretical predictions as well as experiments performed at storage rings have shown that the lifetimes of β-radionuclides can change significantly as a function of the ionization state. In this paper we describe an innovative approach, based on the use of a compact plasma trap to emulate selected stellar-like conditions. It has been proposed within the PANDORA project (Plasmas for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry) with the aim to measure, for the first time in plasma, nuclear β-decay rates of radionuclides involved in nuclear-astrophysics processes. To achieve this task, a compact magnetic plasma trap has been designed to reach the needed plasma densities, temperatures, and charge-states distributions. A multi-diagnostic setup will monitor, on-line, the plasma parameters, which will be correlated with the decay rate of the radionuclides. The latter will be measured through the detection of the γ-rays emitted by the excited daughter nuclei following the β-decay. An array of 14 HPGe detectors placed around the trap will be used to detect the emitted γ-rays. For the first experimental campaign three isotopes, 176Lu, 134Cs, and 94Nb, were selected as possible physics cases. The newly designed plasma trap will also represent a tool of choice to measure the plasma opacities in a broad spectrum of plasma conditions, experimentally poorly known but that have a great impact on the energy transport and spectroscopic observations of many astrophysical objects. Status and perspectives of the project will be highlighted in the paper.