Innovative Analytical Method for X-ray Imaging and Space-Resolved Spectroscopy of ECR Plasmas

Condensed Matter

Sandor Biri¹  Zoltan Perduk¹  Richard Rácz¹  Luigi Celona²  Maria Mazzaglia²  Santo Gammino²  Giuseppe Torrisi²  David Mascali²  Eugenia Naselli²  Alessio Galatà³ 

[1] Institute for Nuclear Research (Atomki), Bem Square 18/c, 4026 Debrecen, Hungary;Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania, Italy;Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Viale dell’Università 2, 35020 Legnaro, Italy;

关键词: X-ray imaging;    plasma diagnostics;    Electron Cyclotron Resonance ion sources;    High Dynamical Range analysis;    Single-Photon-Counted images;    X-ray spatially resolved spectroscopy;   

DOI  :  10.3390/condmat7010005

来源: DOAJ

【 摘 要 】

At the Italian National Institute for Nuclear Physics-Southern National Laboratory (INFN-LNS), and in collaboration with the ATOMKI laboratories, an innovative multi-diagnostic system with advanced analytical methods has been designed and implemented. This is based on several detectors and techniques (Optical Emission Spectroscopy, RF systems, interfero-polarimetry, X-ray detectors), and here we focus on high-resolution, spatially resolved X-ray spectroscopy, performed by means of a X-ray pin-hole camera setup operating in the 0.5–20 keV energy domain. The diagnostic system was installed at a 14 GHz Electron Cyclotron Resonance (ECR) ion source (ATOMKI, Debrecen), enabling high-precision, X-ray, spectrally resolved imaging of ECR plasmas heated by hundreds of Watts. The achieved spatial and energy resolutions were 0.5 mm and 300 eV at 8 keV, respectively. Here, we present the innovative analysis algorithm that we properly developed to obtain Single Photon-Counted (SPhC) images providing the local plasma-emitted spectrum in a High-Dynamic-Range (HDR) mode, by distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar). This method allows for a quantitative characterization of warm electrons population in the plasma (and its 2D distribution), which are the most important for ionization, and to estimate local plasma density and spectral temperatures. The developed post-processing analysis is also able to remove the readout noise that is often observable at very low exposure times (msec). The setup is now being updated, including fast shutters and trigger systems to allow simultaneous space and time-resolved plasma spectroscopy during transients, stable and turbulent regimes.

【 授权许可】

Unknown