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Tag: Nuclear Physics & Engineering

  • Proton resonance radii show an early-time plateau and threshold increase

    What the study found

    The study found that the radius of a proton resonance can coincide with the real-energy radius during an early-time plateau. It also found a nonmonotonic dependence of the complex radius on decay energy and a local increase of the charge radius across the threshold, described as a halolike enhancement.

    Why the authors say this matters

    The authors say nuclear radius is a fundamental structural observable that informs properties of atomic nuclei and nuclear matter. They also note that charge radii of proton-unbound nuclei are of particular interest because they will soon be approached in laser spectroscopy.

    What the researchers tested

    The researchers used a complex-energy approach and direct time propagation to investigate the radius of a proton resonance. They studied a proton resonance, including its Gamow resonance form, where the size is described as ill defined in the standard stationary quantum-mechanical description.

    What worked and what didn't

    The analysis identified an early-time plateau during which the Gamow resonance radius matches the real-energy radius accessible experimentally. The study also demonstrated a nonmonotonic dependence of the complex radius on decay energy and a local increase in charge radius across the threshold. The abstract does not describe any approach that failed.

    What to keep in mind

    The abstract does not provide detailed numerical results, sample systems, or quantitative uncertainty estimates. It also does not describe limitations beyond noting that the resonance size is ill defined in the standard stationary quantum-mechanical description.

    • A proton resonance radius can match the experimentally accessible real-energy radius during an early-time plateau.
    • The complex radius changes nonmonotonically with decay energy.
    • The charge radius shows a local increase across the threshold, described as a halolike enhancement.
    • The authors used a complex-energy approach and direct time propagation.
    • The abstract says nuclear radii are fundamental observables for nuclei and nuclear matter.

  • Greedy strategy balances emissions, cost, and grid reliability

    What the study found

    The study found that a greedy heuristic-based strategy produced a more balanced trade-off among cumulative carbon dioxide emissions, total system cost, and power supply reliability than the other scenarios tested. In the abstract, the minimum-carbon and maximum-power scenarios had the lowest emissions, while the minimum-cost scenario had the highest emissions.

    Why the authors say this matters

    The authors conclude that their framework is useful for exploring practical, path-dependent energy transition strategies under uncertainty. They also suggest that dispatchable low-carbon technologies, especially nuclear power, are important in carbon-constrained electricity systems.

    What the researchers tested

    The researchers examined Taiwan's long-term energy transition over the 2025–2050 planning horizon. They compared four optimization frameworks: Min Carbon, Min Cost, Max Power, and a greedy heuristic-based strategy, using activity-based costing to attribute long-run system costs to technology-specific capacity expansion decisions.

    What worked and what didn't

    The Min Carbon and Max Power scenarios achieved the lowest cumulative emissions, at 200 Mt, but at higher system costs. The Min Cost scenario minimized expenditure but produced the highest emissions, at 8000 Mt. The greedy heuristic reduced emissions to approximately 1000 Mt while keeping costs moderate and maintaining long-term reliability; sensitivity analyses found these relative patterns remained robust under alternative electricity demand growth assumptions.

    What to keep in mind

    The abstract notes that the results are conditional on the assumed availability of small modular reactors, or SMRs. Beyond that, limitations are not described in the available summary.

    • The study compared four energy transition scenarios for Taiwan: Min Carbon, Min Cost, Max Power, and a greedy heuristic-based strategy.
    • The Min Carbon and Max Power scenarios had the lowest cumulative emissions, at 200 Mt, but higher system costs.
    • The Min Cost scenario had the highest emissions, at 8000 Mt, while minimizing expenditure.
    • The greedy heuristic produced a more balanced outcome, with emissions of about 1000 Mt and moderate costs.
    • Sensitivity analyses reported that the overall performance patterns were robust under alternative demand growth assumptions.
    • The findings are conditional on the assumed availability of small modular reactors.