Laboratory astroparticle physics

Abstract:

Data for the plots in Measurement of turbulent velocity and bounds for thermal diffusivity in laser shock compressed foams by X-ray photon correlation spectroscopy

Abstract:

Recent archaeological research in the Valle Sabbia in the territory of Brescia (BS-Northern Italy) has led to the discovery of a new place of worship from the Roman era, possibly built on an ancient indigenous sanctuary. The Valle Sabbia is one of the alpine valleys of Lombardy, north of Brescia (the Colonia Augusta Civica Brixia). The territory, crossed by the river Chiese, stretches between Lake Idro and Lake Garda, in a favourable geographical position that puts it in direct contact with the plain on one side and the Alps on the other. Since 2000, campaigns of archaeological excavations have led to the discovery of different contexts that can be interpreted as sacred, with frequenting from prehistoric times to Roman times and which have as recurrent characteristic a close relationship with the surrounding landscape, with a clear preference for mountainous and wooded contexts. The most important novelties, concerning the Roman period, emerge in Villanuova sul Clisi, where on a panoramic hill overlooking the entire Valle Sabbia and Garda Lake, various wall structures have emerged that define a complex built on several levels, with a rectangular main room of about 11×4,20 m, made with large structures confining the summit plateau, and other lateral ones. The recovered materials indicate a visitation from the 1st to the 4th century A.D.: in addition to coins, fibulae and ceramics, some miniature metal ex-voto with dedications to Iuppiter Aeternus, various graffiti on plaster and a stone altar also inscribed have been uncovered.

Abstract:

Abstract Recent experiments aiming to measure phenomena predicted by strong-field quantum electrodynamics (SFQED) have done so by colliding relativistic electron beams and high-power lasers. In such experiments, measurements of collision parameters are not always feasible. However, precise knowledge of these parameters is required to accurately test SFQED. Here, we present a novel Bayesian inference procedure that infers collision parameters that could not be measured on-shot. This procedure is applicable to all-optical non-linear Compton scattering experiments investigating radiation reaction. The framework allows multiple diagnostics to be combined self-consistently and facilitates the inclusion of known information pertaining to the collision parameters. Using this Bayesian analysis, the relative validity of the classical, quantum-continuous and quantum-stochastic models of radiation reaction was compared for several test cases, which demonstrates the accuracy and model selection capability of the framework and highlight its robustness if the experimental values of fixed parameters differ from their values in the models.

Abstract:

The pursuit of inertial confinement fusion ignition target designs requires precise experimental validation of the conditions within imploding capsules, in particular the density and temperature of the compressed shell. Previous work has identified x-ray Thomson scattering (XRTS) as a viable diagnostic tool for inferring the in-flight compressed deuterium-tritium shell conditions during capsule implosions (Poole et al 2022 Phys. Plasmas 29 072703). However, this study focused on one-dimensional simulations, which do not account for the growth of hydrodynamic instabilities. In this work, two-dimensional DRACO simulations incorporating intermediate-mode perturbations up to Legendre mode ℓ=50 were used to generate synthetic XRTS spectra with the SPECT3D code. The analysis employed Markov-Chain Monte Carlo techniques to infer plasma conditions from these spectra. The results demonstrate that the XRTS diagnostic platform can effectively discern the in-flight compressed shell conditions for targets with varying adiabats, even in the presence of intermediate-mode perturbations. This work underscores the potential of XRTS for realistic inertial confinement fusion experiments, providing a robust method for probing the complex dynamics of fusion implosions.