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High-power PW laser systems (HPLS) provide intense beams of accelerated reaction-driving protons simultaneously with spatially localized keV-plasmas. We herein depict our groundwork and strategy to use these unique features of the HPLS at the Extreme Light Infrastructure (ELI-NP) by exposing the long-lived nuclear isomer 93 m Mo at 2.425 MeV ( t 1 / 2 = 6.85 h) to plasma facilitating the local petawatt beamlines. An intermediate short-lived ( t 1 / 2 = 3.52 ns) state situated only 4.85 keV above 93 m Mo constitutes a gateway to allow for its prompt release. The controllable release of the nuclear isomer energy will henceforth enable harvesting energy densities in the nuclear regime of GJkg - 1 (‘Nuclear Battery’). The campaign was inspired by the observation of the triggered release of 93 m Mo via the intermediate state by Chiara et al. [1] published in Nature. They assigned the hitherto elusive Nuclear Excitation by Electron Capture (NEEC) as the driving process and claimed a very high probability of P NEEC exp = 0.010 (3) . However, these claims are challenged by experimentalists [2-3] and theory [4]. We herein outline our strategy following bespoke theoretical guidance in the quest to unambiguously and independently demonstrate the onset of NEEC in 93 m Mo . With the yield estimations derived for our forthcoming HPLS experiment at ELI-NP, we draw optimism to resolve the current conundrum between the conflicting experimental observations and theoretical interpretations as discussed in world-leading journals and to pave the way for the future utilization of isomer depopulation in applied physics. [ABSTRACT FROM AUTHOR]

Latest developments in the field of high power ultra-short pulse lasers have led to intensive studies dedicated to the fabrication possibility of new antireflective coatings which exhibit high damage threshold. Therefore, this study is focused on the deposition and characterization of metal oxide heterostructures followed by laser-induced damage threshold tests which evidence their application in high power laser optics. Al2O3, SiO2, and HfO2 layers are combined to obtain different heterostructures, i.e. HfO2/Al2O3/HfO2/Al2O3/HfO2 and HfO2/SiO2/HfO2/SiO2/HfO2. The metal oxide heterostructures are deposited in a controllable oxygen atmosphere, either at room temperature or high temperatures (600 °C) by pulsed laser deposition (PLD). The morphological, structural and optical properties of the as-deposited heterostructures are first investigated. Atomic force microscopy and spectroscopic ellipsometry investigations reveal a lower roughness of the heterostructures based on HfO2/Al2O3 layers grown at 600 °C as compared to those grown at room temperature. Furthermore, following the laser-induced damage threshold (LIDT) tests carried out with a Ti–Sapphire laser, higher LIDT values are obtained for the HfO2/Al2O3-based heterostructures than for the HfO2/SiO2-based heterostructures. The ability to control the morphological and structural properties of the antireflective coatings by modifying the deposition parameters of the metal oxide heterostructures demonstrates that PLD is a suitable technique for the manufacturing of antireflective coatings for high power ultra-short laser systems. [ABSTRACT FROM AUTHOR]