Universality of the Collins-Soper kernel in lattice calculations

The Collins-Soper (CS) kernel is a nonperturbative function that characterizes the rapidity evolution of transverse-momentum-dependent parton distribution functions (TMDPDFs) and wave functions. In this Letter, we calculate the CS kernel for pion and proton targets and for quasi-TMDPDFs of leading and next-to-leading power. The calculations are carried out on the CLS ensemble H101 with dynamical $N_f=2+1$ clover-improved Wilson fermions. Our analyses demonstrate the consistency of different lattice extractions of the CS kernel for mesons and baryons, as well as for twist-two and twist-three operators, even though lattice artifacts could be significant. This consistency corroborates the universality of the lattice-determined CS kernel and suggests that a high-precision determination of it is in reach.Comment: 10 pages, 7 figures, published versio

Solar Thermochemical Hydrogen Production in the USA

Hydrogen produced from renewable energy has the potential to decarbonize parts of the transport sector and many other industries. For a sustainable replacement of fossil energy carriers, both the environmental and economic performance of its production are important. Here, the solar thermochemical hydrogen pathway is characterized with a techno-economic and life-cycle analysis. Assuming a further increase of conversion efficiency and a reduction of investment costs, it is found that hydrogen can be produced in the United States of America at costs of 2.1–3.2 EUR/kg (2.4–3.6 USD/kg) at specific greenhouse gas emissions of 1.4 kg CO2-eq/kg. A geographical potential analysis shows that a maximum of 8.4 × 1011 kg per year can be produced, which corresponds to about twelve times the current global and about 80 times the current US hydrogen production. The best locations are found in the Southwest of the US, which have a high solar irradiation and short distances to the sea, which is beneficial for access to desalinated water. Unlike for petrochemical products, the transport of hydrogen could potentially present an obstacle in terms of cost and emissions under unfavorable circumstances. Given a large-scale deployment, low-cost transport seems, however, feasible

Climate Impact and Economic Feasibility of Solar Thermochemical Jet Fuel Production

Solar thermochemistry presents a promising option for the efficient conversion of H₂O and CO₂ into liquid hydrocarbon fuels using concentrated solar energy. To explore the potential of this fuel production pathway, the climate impact and economic performance are analyzed. Key drivers for the economic and ecological performance are thermochemical energy conversion efficiency, the level of solar irradiation, operation and maintenance, and the initial investment in the fuel production plant. For the baseline case of a solar tower concentrator with CO₂ capture from air, jet fuel production costs of 2.23 €/L and life cycle greenhouse gas (LC GHG) emissions of 0.49 kg_{CO₂‑equiv}/L are estimated. Capturing CO₂ from a natural gas combined cycle power plant instead of the air reduces the production costs by 15% but leads to LC GHG emissions higher than that of conventional jet fuel. Favorable assumptions for all involved process steps (30% thermochemical energy conversion efficiency, 3000 kWh/(m² a) solar irradiation, low CO₂ and heliostat costs) result in jet fuel production costs of 1.28 €/L at LC GHG emissions close to zero. Even lower production costs may be achieved if the commercial value of oxygen as a byproduct is considered

Universality of the Collins-Soper kernel in lattice calculations

2023 Descuento SCOAPThe Collins-Soper (CS) kernel is a nonperturbative function that characterizes the rapidity evolution of transverse-momentum-dependent parton distribution functions (TMDPDFs) and wave functions. In this paper, we calculate the CS kernel for pion and proton targets and for quasi-TMDPDFs of leading and next-To-leading power. The calculations are carried out on the CLS ensemble H101 with dynamical Nf=2+1 clover-improved Wilson fermions. Our analyses demonstrate the consistency of different lattice extractions of the CS kernel for mesons and baryons, as well as for twist-Two and twist-Three operators, even though lattice artifacts could be significant. This consistency corroborates the universality of the lattice-determined CS kernel and suggests that a high-precision determination of it is in reach.National Natural Science Foundation of ChinaDeutsche ForschungsgemeinschaftChinese Academy of SciencesComunidad de MadridMinisterio de Ciencia e Innovación (España)United States Department of EnergyDepto. de Física TeóricaFac. de Ciencias FísicasInstituto de Física de Partículas y del Cosmos (IPARCOS)TRUEpubDescuento UC

Universality of the Collins-Soper kernel in lattice calculations

The Collins-Soper (CS) kernel is a nonperturbative function that characterizes the rapidity evolution of transverse-momentum-dependent parton distribution functions (TMDPDFs) and wave functions. In this paper, we calculate the CS kernel for pion and proton targets and for quasi-TMDPDFs of leading and next-to-leading power. The calculations are carried out on the CLS ensemble H101 with dynamical Nf=2+1 clover-improved Wilson fermions. Our analyses demonstrate the consistency of different lattice extractions of the CS kernel for mesons and baryons, as well as for twist-two and twist-three operators, even though lattice artifacts could be significant. This consistency corroborates the universality of the lattice-determined CS kernel and suggests that a high-precision determination of it is in reach

Solar-Driven Thermochemical Production of Sustainable Liquid Fuels from H2O and CO2 in a Heliostat Field

The technology presented has as main goal to produce for the first time fuels from concentrated sunlight, water and carbon dioxide under real-world conditions and to promote the technology to a readiness level of 5. For this purpose, a solar fuel research facility comprising a high-flux solar concentrating heliostat field and tower, a solar thermochemical reactor system, and a gas-to-liquid conversion plant have been installed at a sunny site. Ceria is used as the reactive material, which undergoes a temperature and pressure swing in a redox cycle, splitting water and carbon dioxide into hydrogen and carbon monoxide. This synthesis gas is then converted into hydrocarbons via a Fischer-Tropsch conversion plant. The customized heliostat field has been able to provide irradiances above 3000 kW/m2 onto the aperture of the 50kW reactor, producing up to 300 l/hour solar syngas subsequently converted into liquid fuel

Future wavelength calibration standards at ESO : the Laser Frequency Comb

A new technique for precise wavelength calibration of high-resolution spectrographs using frequency combs has recently been proposed. After introducing the basic concepts and advantages of this technique, we describe the ongoing development between ESO and the Max-Planck Institute for Quantum Optics for a novel wavelength calibration system that aims, within three years, to construct a laboratory demonstrator

A solar tower fuel plant for the thermochemical production of kerosene from H2O and CO2

Developing solar technologies for producing carbon-neutral aviation fuels has become a global energy challenge, but their readiness level has largely been limited to laboratory-scale studies. Here, we report on the experimental demonstration of a fully integrated thermochemical production chain from H2O and CO2 to kerosene using concentrated solar energy in a solar tower configuration. The co-splitting of H2O and CO2 was performed via a ceria-based thermochemical redox cycle to produce a tailored mixture of H2 and CO (syngas) with full selectivity, which was further processed to kerosene. The 50-kW solar reactor consisted of a cavity-receiver containing a reticulated porous structure directly exposed to a mean solar flux concentration of 2,500 suns. A solar-to-syngas energy conversion efficiency of 4.1% was achieved without applying heat recovery. This solar tower fuel plant was operated with a setup relevant to industrial implementation, setting a technological milestone toward the production of sustainable aviation fuels.ISSN:2542-4351ISSN:2542-478