bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the upper bound of non-thermal fusion reactivity with fixed total energy
Authors: Xie Huasheng , Wang Xueyun 
Published: April 2024

AbstractFusion reactivity represents the integration of fusion cross-sections and the velocity distributions of two reactants. In this study, we investigate the upper bound of fusion reactivity for a non-thermal reactant coexisting with a thermal Maxwellian background reactant while maintaining a constant total energy. Our optimization approach involves fine-tuning the velocity distribution of the non-thermal reactant. We employ both Lagrange multiplier and Monte Carlo methods to analyze Deuterium–Tritium (D–T) and proton-Boron11 (p-B11) fusion scenarios. Our findings demonstrate that, within the relevant range of fusion energy, the maximum fusion reactivity can often surpass that of the conventional Maxwellian–Maxwellian reactants case by a substantial margin, ranging from 50% to 300%. These enhancements are accompanied by distinctive distribution functions for the non-thermal reactant, characterized by one or multiple beams. These results not only establish an upper limit for fusion reactivity but also provide valuable insights into augmenting fusion reactivity through non-thermal fusion, which holds particular significance in the realm of fusion energy research.
Electrically controlled crossed Andreev reflection in altermagnet/superconductor/altermagnet junctions
Authors: Ping Niu Zhi , Mei Zhang Yong 
Published: April 2024

Abstract
Altermagnets are a novel class of magnetic materials with a significant non-relativistic spin splitting band structure but zero net macroscopic magnetization. We here investigate the interplay between altermagnetism and superconductivity and how the band structures of the altermagnet affect nonlocal transport across altermagnet/superconductor/altermagnet junctions. The two types of spin-momentum coupling: anisotropic and valley-dependent spin-momentum couplings are considered. The pure crossed Andreev reflection (CAR) can be observed by tuning the chemical potential and a switch effect between pure CAR and pure electron elastic cotunneling (EC) can be realized by reversing the Néel vector of the right altermagnet. For the anisotropic spin-momentum coupling, increasing the altermagnetism strength decreases the amplitude of EC while increases that of CAR. Furthermore, a switch between pure EC and pure CAR is predicted for the Néel vectors of the altermagnets in the parallel configuration for the valley-dependent spin-momentum coupling by tuning the on-site energy.
Experimental AC loss study on REBCO coil assemblies coupled with an iron cylinder
Authors: Wu Yue , Fang Jin , Miyagi Daisuke , Amemiya Naoyuki , Badcock Rodney A , Long Nicholas J , Jiang Zhenan 
Published: April 2024

Abstract
In high-temperature superconducting (HTS) power devices, the presence of iron cores changes the magnetic field profile around the HTS coil windings, potentially affecting their AC loss characteristics. AC loss measurements for HTS coil windings coupled with an iron core using the electrical method can lead to a significant error, owing to the indirect estimation of the iron core loss through using a copper test coil. To investigate the cause of the experimental error and the influence of an iron core on coil AC losses, transport AC losses of REBCO double pancake coil (DPC) assemblies coupled with an iron cylinder were measured. A 40-turn 1DPC and an 80-turn 2DPC assembly wound with 4 mm SuperPower wire were employed in the measurements. To ensure the same iron core loss using the HTS coil assembly and the copper coil, 2D finite element method simulations were conducted iteratively to design the iron core and the copper coil to get the same local magnetic field distributions in the designed iron core for the two cases. The main cause of the error is due to the difference in local magnetic flux densities in the iron core generated by the HTS coil assembly and the copper coil even when the ampere-turns of the coils are identical. We showed that the simulation-guided measurement method can assure accurate AC loss measurement in the HTS coil assemblies coupled with iron cores. Compared with the AC losses in the 1DPC and 2DPC coil assemblies without the iron cylinder, the presence of the iron cylinder significantly increases the coil losses. Frequency dependence is observed in the coil AC losses of the 1DPC and 2DPC assemblies when coupled with the iron cylinder. This is due to the eddy current induced in the iron cylinder generating a magnetic field, which influences the coil AC loss.
An open-source 3D FE quench simulation tool for no-insulation HTS pancake coils
Authors: Atalay Sina , Schnaubelt Erik , Wozniak Mariusz , Dular Julien , Zachou Georgia , Schöps Sebastian , Verweij Arjan 
Published: April 2024

Abstract
A new module, Pancake3D, of the open-source finite element quench simulator (FiQuS) has been developed in order to perform transient simulations of no-insulation (NI) high-temperature superconducting pancake coils in three-dimensions. FiQuS/Pancake3D can perform magnetodynamic or coupled magneto-thermal simulations. Thanks to the use of thin shell approximations, an

H
→

−
ϕ

formulation, and anisotropic homogenization techniques, each turn can be resolved on the mesh level in an efficient and robust manner. FiQuS/Pancake3D relies on pre-formulated finite-element (FE) formulations and numerical approaches that are programmatically adjusted based on a text input file. In this paper, the functionalities and capabilities of FiQuS/Pancake3D are presented. The challenges of FE simulation of NI coils and how FiQuS/Pancake3D addresses them are explained. To highlight the functionalities, the results of a magneto-thermal analysis of a double pancake coil with 40 turns per pancake with local degradation of the critical current density are conducted and discussed. Furthermore, a parameter sweep of the size of this local degradation is presented. All FiQuS input files for reproducing the simulations are provided.
Numerical study on the transport current distribution in the multi-layer CORC coil
Authors: Li Chao , Yang Wenchao , Li Quan , Li Bin , Xin Ying , Yang Jiabin 
Published: April 2024

Abstract
The conductor on round core (CORC) cable has attracted increasing attention due to its strong and high-efficient current carrying capacity. It is considered as one of ideal candidate cables for manufacturing nuclear fusion magncets. Under the circumstance, the transport current distribution of the coils wound by CORC cables has significant impacts on the operating performance of nuclear fusion magnets. Considering the difficulty in experimental tests, numerical model is an effective way to illustrate transport current distribution of the multi-layer CORC coil and provide further insights into its working performance. Therefore, in this work, A 3D finite element model based on the
H
formulation is proposed to simulate a single-turn and multi-layer CORC coil. The validity of the model has been verified by experimental results. Based on the proposed model, the transport current distribution of the multi-layer straight CORC cable and the multi-layer CORC coil is compared and discussed. In addition, the current density distribution on the superconducting tapes of the multi-layer CORC coil is also investigated. This work can provide an important reference for the design and practical application of multi-layer CORC coils.
Competition between self- and other-regarding preferences in resolving social dilemmas
Authors: Wang Chaoqian , Szolnoki Attila 
Published: April 2024

Abstract
Evolutionary game theory assumes that individuals maximize their benefits when choosing strategies. However, an alternative perspective proposes that individuals seek to maximize the benefits of others. To explore the relationship between these perspectives, we develop a model where self- and other-regarding preferences compete in public goods games. We find that other-regarding preferences are more effective in promoting cooperation, even when self-regarding preferences are more productive. Cooperators with different preferences can coexist in a new phase where two classic solutions invade each other, resulting in a dynamical equilibrium. As a consequence, a lower productivity of self-regarding cooperation can provide a higher cooperation level. Our results, which are also valid in a well-mixed population, may explain why other-regarding preferences could be a viable and frequently observed attitude in human society.
Basic and acidic electrolyte mediums impact on MnO2-Mn2O3/Poly-2-methylaniline hexagonal nanocomposite pseudo-supercapacitor
Authors: Alkallas Fatemah H , Esayed Asmaa M , Ben Gouider Trabelsi Amira , Rabia Mohamed 
Published: April 2024

Abstract
A highly efficient MnO2-Mn2O3/Poly-2-methylaniline (MnO2-Mn2O3/P2MA) hexagonal nanocomposite is synthesized using a one-pot technique involving oxidation polymerization. The hexagonal morphology and crystalline nature of this nanocomposite, as evidenced by the XRD pattern, affirm its exceptional characteristics. The electrical properties are assessed through charge/discharge behavior and cyclic voltammetry curves, elucidating the storage capabilities of this pseudo supercapacitor using different electrolytes NaOH and HCl. The fabricated supercapacitor exhibits impressive efficiency values of 22 F g−1 in a basic medium and a notably higher 72 F g−1 in an acidic medium at a current density of 0.2 A/g. Similarly, the power density values are calculated at 480 and 478 W.kg−1 for the basic and acidic electrolyte, correspondingly. In the basic medium, the series resistance (RS) and charge transfer resistance (RCT) are 5.2 and 0.7 Ω, respectively. In the acidic medium, these values are notably lower, with RS at 2.82 Ω and RCT at 0.2 Ω. Remarkably, even after 500 cycles, the supercapacitor stability remains high at 95% in both media, underscoring the enduring stability attributed to the oxides and polymer materials within the supercapacitor. The combination of cost-effectiveness, ease of fabrication, and potential for mass production positions this supercapacitor as a promising candidate for industrial applications of polymer-based supercapacitors.
Prepotential approach: a unified approach to exactly, quasi-exactly, and rationally extended solvable quantal systems
Authors: Ho Choon-Lin 
Published: April 2024

Abstract
We give a brief overview of a simple and unified way, called the prepotential approach, to treat both exact and quasi-exact solvabilities of the one-dimensional Schrödinger equation. It is based on the prepotential together with Bethe ansatz equations. Unlike the the supersymmetric method for the exactly-solvable systems and the Lie-algebraic approach for the quasi-exactly solvable problems, this approach does not require any knowledge of the underlying symmetry of the system. It treats both quasi-exact and exact solvabilities on the same footing. In this approach the system is completely defined by the choice of two polynomials and a set of Bethe ansatz equations. The potential, the change of variables as well as the eigenfunctions and eigenvalues are determined in the same process. We illustrate the approach by several paradigmatic examples of Hermitian and non-Hermitian Hamiltonians with real energies. Hermitian systems with complex energies, called the quasinormal modes, are also presented. Extension of the approach to the newly discovered rationally extended models is briefly discussed.
A cosmological sandwiched window for lepton-number breaking scale
Authors: Li Shao-Ping , Yu Bingrong 
Published: April 2024

Abstract
A singlet majoron can arise from the seesaw framework as a pseudo-Goldstone boson when the heavy Majorana neutrinos acquire masses via the spontaneous breaking of global U(1)
L
symmetry.
The resulting cosmological impacts are usually derived from the effective majoron-neutrino interaction, and the majoron abundance is accumulated through the freeze-in neutrino coalescence. However, a primordial majoron abundance can be predicted in a minimal setup and lead to distinctive cosmological effects. In this work, we consider such a primordial majoron abundance from relativistic freeze-out and calculate the modification to the effective neutrino number N
eff. We demonstrate that the measurements of N
eff will constrain the parameter space from a primordial majoron abundance in an opposite direction to that from neutrino coalescence. When the contributions from both the primordial abundance and the freeze-in production coexist, the U(1)
L
-breaking scale (seesaw scale) f will be pushed into a “sandwiched window”.
Remarkably, for majoron masses below
1 MeV and above the eV scale, the future CMB-S4 experiment will completely close such a low-scale seesaw window for f ∈ [1,105] GeV. We highlight that any new light particle with a primordial abundance that couples to Standard Model particles may lead to a similar sandwiched window, and such a general phenomenon deserves careful investigation.
Numerical 1-loop correction from a potential yielding ultra-slow-roll dynamics
Authors: Davies Matthew W. , Iacconi Laura , Mulryne David J. 
Published: April 2024

Abstract
Single-field models of inflation might lead to amplified scalar fluctuations on small scales due, for example, to a transient ultra-slow-roll phase. It was argued by Kristiano & Yokoyama in ref. [1] that the enhanced amplitude of the scalar power spectrum on small scales has the potential to induce a sizeable 1-loop correction to the spectrum at large scales. In this work, we repeat the calculation for the 1-loop correction presented in ref. [1]. We closely follow their assumptions but evaluate the loop numerically. This allows us to consider both instantaneous and smooth transitions between the slow-roll and ultra-slow-roll phases. In particular, we generate models featuring realistic, smooth evolution from an analytic inflationary potential. We find that, upon fixing the amplitude of the peak in the power spectrum at short scales, the resulting 1-loop correction is not significantly reduced by considering a smooth evolution. In particular, for a power spectrum with a tree-level peak amplitude potentially relevant for small-scale phenomenology, e.g. primordial black hole production, the 1-loop correction on large scales is a few percent of the tree-level power spectrum.
RKKY interaction in helical higher-order topological insulators
Authors: Jin 金 Sha 莎 , Li 李 Jian 健 , Li 李 Qing-Xu 清旭 , Zhu 朱 Jia-Ji 家骥 
Published: April 2024

Abstract
We theoretically investigate the Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction in helical higher-order topological insulators (HOTIs), revealing distinct behaviors mediated by hinge and Dirac-type bulk carriers. Our findings show that hinge-mediated interactions consist of Heisenberg, Ising, and Dzyaloshinskii–Moriya (DM) terms, exhibiting a decay with impurity spacing z and oscillations with Fermi energy ε
F. These interactions demonstrate ferromagnetic behaviors for the Heisenberg and Ising terms and alternating behavior for the DM term. In contrast, bulk-mediated interactions include Heisenberg, twisted Ising, and DM terms, with a conventional cubic oscillating decay. This study highlights the nuanced interplay between hinge and bulk RKKY interactions in HOTIs, offering insights into designs of next-generation quantum devices based on HOTIs.
Wavelength-interval switchable Brillouin–Raman random fiber laser through Brillouin pump manipulation
Authors: Li 李 Yang 阳 , Xu 徐 En-Ming 恩明 , Chen 陈 Rui-Jia 睿佳 , Shee Yu-Gang , Zhang 张 Zu-Xing 祖兴 
Published: April 2024

Abstract
A wavelength-interval switchable Brillouin–Raman random fiber laser (BRRFL) based on Brillouin pump (BP) manipulation is proposed in this paper. The proposed wavelength-interval switchable BRRFL has a full-open cavity configuration, featuring multiwavelength output with wavelength interval of double Brillouin frequency shifts. Through simultaneously injecting the BP light and its first-order stimulated Brillouin-scattered light into the cavity, the laser output exhibits a wavelength interval of single Brillouin frequency shift. The wavelength-interval switching effect can be manipulated by controlling the power of the first-order stimulated Brillouin scattering light. The experimental results show the multiwavelength output can be switched between double Brillouin frequency shift multiwavelength emission with a broad bandwidth of approximately 60 nm and single Brillouin frequency shift multiwavelength emission of 44 nm. The flexible optically controlled random fiber laser with switchable wavelength interval makes it useful for a wide range of applications and holds significant potential in the field of wavelength-division multiplexing optical communication.
Dynamical Dark Energy in Light of Cosmic Distance Measurements. II. A Study Using Current Observations
Authors: Wang Xiaoma , Gu Gan , Mu Xiaoyong , Yuan Shuo , Zhao Gong-Bo 
Published: April 2024

Abstract
We extract key information on dark energy from current observations of BAO, OHD and H
0, and find hints of dynamical behavior of dark energy. In particular, a dynamical dark energy model whose equation of state crosses −1 is favored by observations. We also find that the Universe has started accelerating at a lower redshift than expected.
High-temperature annealing of (
) β-Ga2O3 substrates for reducing structural defects after diamond sawing
Authors: Butenko Pavel , Boiko Michael , Sharkov Mikhail , Almaev Aleksei , Kitsay Aleksnder , Krymov Vladimir , Zarichny Anton , Nikolaev Vladimir 
Published: April 2024

Abstract
A commercial epi-ready (

) β-Ga2O3 wafer was investigated upon diamond sawing into pieces measuring 2.5 × 3 mm2. The defect structure and crystallinity in the cut samples has been studied by X-ray diffraction and a selective wet etching technique. The density of defects was estimated from the average value of etch pits calculated, including near-edge regions, and was obtained close to 109 cm−2. Blocks with lattice orientation deviated by angles of 1−3 arcmin, as well as non-stoichiometric fractions with a relative strain about (1.0−1.5) × 10−4 in the [

] direction, were found. Crystal perfection was shown to decrease significantly towards the cutting lines of the samples. To reduce the number of structural defects and increase the crystal perfection of the samples via increasing defect motion mobility, the thermal annealing was employed. Polygonization and formation of a mosaic structure coupled with dislocation wall appearance upon 3 h of annealing at 1100 °C was observed. The fractions characterized by non-stoichiometry phases and the block deviation disappeared. The annealing for 11 h improved the homogeneity and perfection in the crystals. The average density of the etch pits dropped down significantly to 8 × 106 cm−2.
Observation of avalanche-like transport in Heliotron J and JT-60U plasmas
Authors: Kin F. , Inagaki S. , Nagasaki K. , Luo M. , Itoh K. , Shinohara K. , Terakado A. , Minami T. , Kado S. , Kobayashi S. , Ohshima S. , Bando T. , Oyama N. , Yoshida M. 
Published: April 2024

Abstract
The avalanche type of transport can induce a long-radial transport and thus can contribute to the global profile formation. In this study, we observed the heat perturbations exhibiting avalanche-like transport in the stellarator/heliotron device, Heliotron J, and the tokamak device, JT-60U. We found that the electron heat propagation in Heliotron J is mainly generated from the heating source region. The relatively high value of the Hurst exponent, which is a signature of avalanches, depends on the total heating power. On the other hand, the electron and ion heat avalanches measured in JT-60U tend to spread from the local peak of the temperature gradient and are not influenced by the heating source profiles. The contrasting features of avalanches in stellarator/heliotrons and tokamaks potentially imply the difference in the temperature profile formation, such as the presence of stiffness.
Simultaneous measurements for fast neutron flux and tritium production rate using pulse shape discrimination and single crystal CVD diamond detector
Authors: Kobayashi M.I. , Yoshihashi S. , Ogawa K. , Isobe M. , Aso T. , Hara M. , Sangaroon S. , Tamaki S. , Murata I. , Toyama S. , Miwa M. , Matsuyama S. , Osakabe M. 
Published: April 2024

Abstract
This paper presents the development of a simultaneous measurement method for fast neutron energy spectra and tritium production rates within mixed radiation fields using a single crystal chemical vapour deposition diamond detector combined with a lithium fluoride (LiF) foil. The method involves the separation of pulses with rectangular shapes and the determination of the depth position within the single crystal diamond (SCD) struck by fast neutrons or nuclear reaction products including recoil tritons from the LiF foil based on pulse width, extracting pulse events occurred at the specific bulk region and the surface region of the SCD. Subsequently, unfolding techniques were employed to analyse the energy deposition spectrum of pulses at the specific bulk region which are induced only by fast neutrons, allowing the deduction of the fast neutron energy spectrum. To evaluate the tritium production rate, the energy deposition spectrum of pulses from events occurring at the SCD surface facing the LiF foil was analysed. By estimating the energy deposition spectrum solely induced by fast neutrons striking the SCD surface and subtracting it from the energy deposition spectrum of events at the SCD surface, the contribution of energetic ions, such as recoil tritons generated by the 6Li(n,α)3H reaction in the LiF foil, was determined. The fast neutron flux and tritium production rate obtained through this study were consistent with particle transport calculations, demonstrating the successful development of a method suitable for performance testing of fusion reactor blankets.
Investigation of fast ion effects on core turbulence in FIRE mode plasmas
Authors: Kim D. , Park S.J. , Choi G.J. , Cho Y.W. , Kang J. , Han H. , Candy J. , Belli E.A. , Na Y.-S. , Hahm T.S. , Sung C. 
Published: April 2024

Abstract
Further investigation of fast ion effects on turbulence and transport in the fast ion regulated enhancement (FIRE) mode discharge (Han et al 2022 Nature
609 269–275) was performed in this work as a continuation of a previous study (Kim et al 2023 Nucl. Fusion
63 124001) that showed that the dominant turbulence suppression mechanism by fast ions is the dilution effect in the FIRE mode discharge. The current study includes (i) the impact of the fast ion relevant mode observed in the simulation of thermal energy flux, (ii) dilution effects by fast ions compared to dilution effects by other species, and (iii) fast ion effects on electron-scale turbulence. First, nonlinear gyrokinetic simulation results show that turbulence is significantly suppressed even without the fast ion relevant mode, indicating that the impact of this mode on thermal transport is not significant in this discharge. Second, further analysis on the dilution effects shows the three following results: Turbulence is not completely suppressed by the reduced main ion density fraction effect due to impurities; the reduction in energy flux can be limited by a certain impurity mode that is destabilized by a high impurity density gradient from adjusting the main ion density gradient; electrons can contribute to turbulence suppression through the main ion density gradient change, although this effect is less significant compared to other species. Third, we observe that two fast ion effects can influence the linear growth rate of the electron-scale turbulence mode. The growth rate decreases by an increase in

β
∗

(

≡

(

−
8
π

/

B
2

)

d

p

/

d

r

)

and increases by dilution effects, suggesting that fast ion effects on electron-scale turbulence can differ depending on the operation scenario, such as the fast ion fraction. The comprehensive analysis performed in this study can enhance our understanding of fast ion physics, required for burning plasma operation in the future.