Realizing a human-centered digitalization of the energy sector.

The digitalization of the energy sector is in progress, but Europe is about to fall behind. A human-centered design approach ensures that it takes place with, and for the benefit of, people, for which this letter puts forward policy recommendations. People need access to tailored and ready-for-use tools that help the realization of societal co-benefits, bring individual gains, remove human burdens, and ensure just participation of all societal groups.

Statistical evidence for the contribution of citizen-led initiatives and projects to the energy transition in Europe.

Statistical accounting of the impacts of citizen-led energy initiatives is absent, despite their impact on increased energy self-sufficiency and ramping up of renewable energies, local sustainable development, greater citizen engagement, diversification of activities, social innovation, and acceptance of transition measures. This paper quantifies the aggregate contributions of collective action in pursuit of the sustainable energy transition in Europe. We estimate the number of initiatives (10,540), projects (22,830), people involved (2,010,600), installed renewable capacities (7.

A Europe-wide inventory of citizen-led energy action with data from 29 countries and over 10000 initiatives.

Numerous case studies show that citizens engage in various ways in renewable and low carbon energy projects, thereby contributing to the sustainable energy transition. To date, however, a systematic and cross-country database on citizen-led initiatives and projects is lacking. By performing a major compilation and reviewing copious data sources from websites to official registries, we provide a Europe-wide inventory with over 10,000 initiatives and 16,000 production units in 29 countries, focusing on the past 20 years.

Current state and call for action to accomplish findability, accessibility, interoperability, and reusability of low carbon energy data.

With the continued digitization of the energy sector, the problem of sunken scholarly data investments and forgone opportunities of harvesting existing data is exacerbating. It compounds the problem that the reproduction of knowledge is incomplete, impeding the transparency of science-based targets for the choices made in the energy transition. The FAIR data guiding principles are widely acknowledged as a way forward, but their operationalization is yet to be agreed upon within different research domains.

Wave-number dependent current correlation for a harmonic oscillator.

The wave-number k dependent current-correlation function is considered for a harmonic oscillator model. An explicit analytic expression for the Laplace transformed correlation function is derived. It is compared with numerical solutions and results obtained by the recurrence relation method.

Influence of local-field corrections on Thomson scattering in collision-dominated two-component plasmas.

The dynamic structure factor, which determines the Thomson scattering spectrum, is calculated via an extended Mermin approach. It incorporates the dynamical collision frequency as well as the local-field correction factor. This allows to study systematically the impact of electron-ion collisions as well as electron-electron correlations due to degeneracy and short-range interaction on the characteristics of the Thomson scattering signal.

Bremsstrahlung and line spectroscopy of warm dense aluminum plasma heated by xuv free-electron-laser radiation.

We report the creation of solid-density aluminum plasma using free-electron laser (FEL) radiation at 13.5nm wavelength. Ultrashort pulses were focused on a bulk Al target, yielding an intensity of 2x10;{14}Wcm;{2} .

Plasmon resonance in warm dense matter.

Collective Thomson scattering with extreme ultraviolet light or x rays is shown to allow for a robust measurement of the free electron density in dense plasmas. Collective excitations like plasmons appear as maxima in the scattering signal. Their frequency position can directly be related to the free electron density.

Neutral helium spectral lines in dense plasmas.

Shift and broadening of isolated neutral helium lines 7281 angstroms (2(1)P-3(1)S), 7065 angstroms (2(3)P-3(3)S), 6678 angstroms (2(1)P-3(1)D), 5048 angstroms (2(1)P-4(1)S), 4922 angstroms (2(1)P-4(1)D), and 4713 angstroms (2(3)P-4(3)S) in a dense plasma are investigated. Based on a quantum statistical theory, the electronic contributions to the shift and width are considered, using the method of thermodynamic Green functions. Dynamic screening of the electron-atom interaction is included.

Molecular dynamics simulations of optical conductivity of dense plasmas.

The optical conductivity sigma (omega) for dense Coulomb systems is investigated using molecular dynamics simulations on the basis of pseudopotentials to mimic quantum effects. Starting from linear response theory, the response in the long-wavelength limit k=0 can be expressed by different types of autocorrelation functions (ACF's) such as the current ACF, the force ACF, or the charge density ACF. Consistent simulation data for transverse as well as longitudinal ACF's are shown which are based on calculations with high numerical accuracy.

Response function including collisions for an interacting fermion gas.

The response function of an interacting fermion gas is considered in the entire (k-->,omega) space. Applying a generalized linear response theory, it is expressed in terms of determinants of equilibrium correlation functions, which allow for a systematic perturbative treatment. The relation to dynamical local-field factors is given.

Dynamic structure factor for a two-component model plasma.

Analytical results for the structure factor of a two-component model plasma that describe an electron-ion plasma with modified interaction are derived from a Green function approach in different approximations. The random-phase approximation is improved by including the dynamic collision frequency, and results for the long-wavelength limit are extended to arbitrary wave numbers using the Mermin ansatz. After taking the classical limit of the resulting expressions, they are compared with molecular dynamics simulation results for the classical two-component model plasma.

Long-wavelength limit of the dynamical local-field factor and dynamical conductivity of a two-component plasma.

A systematic approach to the optical conductivity is given within a dielectric function formalism. The response function as well as the dynamical local-field factor G(k-->,omega) of an electron-ion plasma can be expressed in terms of determinants of equilibrium correlation functions which allow for a perturbative treatment. The dynamical collision frequency nu(omega)=-iomega(2)(pl)G(0,omega)/omega for fully ionized weakly coupled plasmas is evaluated in the low-density limit.