Speaker
Description
In this WP we have developed two facilities, one experimental, the other one theoretical, based on the expertise of the Bari group in the diagnostics and modelling of non-equilibrium plasmas.
The experimental facility is a projection of our consolidated expertise in the optical diagnostics of gas discharges into applications to fusion-relevant studies and the development of new diagnostic strategies. In particular, we have acquired instrumentations for three main diagnostic applications:
1. Installation for studies on Laser Induced Breakdown Spectroscopy (LIBS) by fs laser, for the in-situ elemental analysis of surface modifications and, in particular, fuel retention in plasma facing materials. The relevant instrumentation is a fs laser facility, a state-of-the arts spectrograph and a set of optical microscope/optical profilometer to characterize the craters made by the laser for a quantitative depth profilometry;
2. Installation for optical emission spectroscopy, to support CR models of hydrogen emission. The relevant instrumentation is a fast gated optical spectrograph;
3. Installation for laser spectroscopy studies, with a double aim. One is the study of the kinetics of electronic states of hydrogen, to support the CR models, for which a tuneable ps OPO laser has been acquired. The other aim is the analytical application of Laser Induced Fluorescence (LIF) to the detection of transient species and, in particular H atoms, for which a ns tuneable laser has been acquired capable of wavelengths down to 204 nm.
Studies and developments of diagnostic techniques require small scale plasma test facilities that can run continuously and every day, on which the diagnostics can be tested, improved and adapted to the final user’s demands. To this end we have developed and built two discharge systems based on a DC reflex IBC discharge scheme which is capable of high-density plasma production even at low, order of 1 Pa, gas pressure. One of these discharges, with two cathodes, is used for loading with deuterium test samples for LIBS and for discharge-assisted LIBS. The other, with 8 cathodes, will be used for spectroscopy studies.
An important part of the project has been the refurbishment of new laboratory space, with technical installations, to accomodate the huge amount of new instrumentation. This operation has been made in the building of the Department of Physics of the University of Bari, where we were already present with smaller labs and with teaching activities on discharge and plasma physics. The increase of space and facilities in the Physics Department paves the way for a penetration of nuclear fusion issues into the University of Bari and for a fruitful exchange in terms of both scientific expertise and availability of new research personnel.
The Computational lab pursued two objectives:
1. Numerical simulation of negative ion source for neutral beam Injection, with the development of s three-dimensional PIC code and of a Collisional-Radiative model for the interpretation of emission spectra, in close connection with the OES experimental activities.
2. Numerical simulation of plasma-wall interaction in the Divertor region.
The numerical laboratory has enriched its calculus facilities by the acquisition of two workstations where the codes can be tested prior to launching them of large supercomputers.
This modelling facility will project its work beyond the present project, in close connection with the experimental activity in the infrastructure, along four topical areas: i) calculation of state selective cross section for elementary processes in bulk and surface; ii) interface between plasma and solid-state physics; iii) control of plasma-external power coupling, iv) coherent structures in magnetized plasma.