bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observation of gas flow around plants using Schlieren imaging system and high-refractive-index gas
Authors: Matsutani Akihiro 
Published: May 2024

Abstract
The fruits of many plant are carried and flowers are also swayed by the wind. If the flow of air around plants can be visualized, the science behind it will be interestingly illustrated. In this study, the gas flow around cherry blossom fruits, clover flowers, maple seed propellers, and dandelion pappi as spherical and propeller-shaped samples is demonstrated using a Schlieren optical system and a high-refractive-index gas. The observed gas flow corresponding to the sample shape was well characterized by fluid dynamics features such as the Coandă effect. The results of experiments in which the flow of gas around plants is visualized are useful as a scientific education material for fluidics and optics.
Combined optimization of spot positions and weights for better FLASH proton therapy
Authors: Lansonneur P , Magliari A , Rosa L , Perez J , Niemelä P , Folkerts M 
Published: May 2024

Abstract

Objective. In Intensity Modulated Proton Therapy (IMPT), the weights of individual pencil-beams or spots are optimized to fulfil dosimetric constraints. Theses spots are usually located on a regular lattice and their positions are fixed during optimization. In many cases, the range of spot weights may however be limited, leading sometimes to sub-optimal plan quality. An emblematic use case is the delivery of a plan at ultra-high dose rate (FLASH-RT), for which the spot weights are typically constrained to high values. Approach. To improve further the quality of IMPT FLASH plans, we propose here a novel algorithm to optimize both the spot weights and positions directly based on the objectives defined by the treatment planner. Main results. For all cases considered, optimizing the spot positions lead to an enhanced dosimetric score, while maintaining a high dose rate. Significance. Overall, this approach resulted in a substantial plan quality improvement compared to optimizing only the spot weights, and in a similar execution time.
Topological magnons in a non-coplanar magnetic order on the triangular lattice
Authors: Bai Linli , Chen Ken 
Published: May 2024

Abstract
The bond-dependent Kitaev interaction K is familiar in the effective spin model of transition metal compounds with octahedral ligands. In this work, we find a peculiar non-coplanar magnetic order can be formed with the help of K and next-nearest neighbor Heisenberg coupling J
2 on the triangular lattice. It can be seen as a miniature version of skyrmion crystal, since it has nine spins and an integer topological number in a magnetic unit cell. The magnon excitations in such an order are studied by the linear spin-wave theory. Of note is that the change in the relative size of J
2 and K produces topological magnon phase transitions although the topological number remains unchanged. We also calculated the experimentally observable thermal Hall conductivity, and found that the signs of thermal Hall conductivity will change with topological phase transitions or temperature changes in certain regions.
Electron-induced hydrogen desorption from selected polymers (polyacetylene, polyethylene, polystyrene, and polymethyl-methacrylate)
Authors: Dapor Maurizio 
Published: May 2024

Abstract
Elastic Peak Electron Spectroscopy, abbreviated as EPES, involves the analysis of the line shape found in the elastic peak. The reduction in the energy of electrons within the elastic peak is a result of energy being transferred to the target atoms, a phenomenon referred to as recoil energy. EPES distinguishes itself among electron spectroscopies by its unique ability to identify hydrogen in polymers and hydrogenated carbon-based materials. This distinctiveness is particularly notable because lighter elements demonstrate more pronounced energy shifts. The detection of hydrogen in polymers entails measuring the energy difference between the positions of the carbon (or carbon+oxygen) elastic peak and the hydrogen elastic peak. This difference tends to increase as the kinetic energy of the incident electrons rises. Concerning hydrogen peak intensity, electron beam-induced damage represents a critical aspect of EPES, as hydrogen desorbs under electron irradiation. In this study, the Monte Carlo method was employed to simulate EPES spectra involving electrons interacting with polyacetylene (C2H2), polyethylene (C2H4), polystyrene (C8H8), and polymethyl-methacrylate (C5H8O2) and to evaluate electron-induced hydrogen desorption from these polymers.
Crystal structure, composition and valence state of cations in mixed-valence A1−xCdxMnO3 (A=Pr, La) ceramics
Authors: Googlev K A , Kozakov A T , Kochur A G , Nikolskii A V , Rudskaya A G , Shevtsova S I 
Published: May 2024

Abstract
Complex manganites A1−xCdxMnO3 (A = Pr, La) are synthesized by solid state reaction method. X-ray diffraction, scanning electron microscopy and energy-dispersive analysis are applied to study their crystal structure, surface morphology, elemental and phase composition. X-ray photoelectron spectroscopy (XPS) methods are used to study the charge states of Pr and La cations, as well as to quantify the fractions of coexisting Mn3+ and Mn4+ ions. La3d-, La4d-, Pr4d- и Mn2p-spectra of La3+, Pr3+, Mn3+ and Mn4+ ions are calculated in the isolated–ion approximation with accounting for multiplet splitting and charge transfer effect. Good agreement with the experiment is obtained. The relative fractions of trivalent and tetravalent manganese ions in La0.45Cd0.78Mn0,9O2.86 and Pr0.50Cd0.76Mn0.86O2.88 samples are determined by fitting the Mn2p spectra by superposition of experimental spectra containing only Mn3+, and only Mn4+ ions; they were found to be 0.71Mn3+/0.29Mn4+ and 0.54Mn3+/0.46Mn4+, respectively.
Higher-order phase-space moments for off-diagonal rotating Morse oscillators
Authors: Cherroud Othmane , Yahiaoui Sid-Ahmed 
Published: May 2024

Abstract
The present paper proposes an advancement beyond the recent mathematical formulation [Cherroud O and Yahiaoui S-A 2023 Eur. Phys. J. Plus. 138 534], by extending their approach to the evaluation of off-diagonal matrix elements

〈

x

ˆ

m

p

ˆ

l

〉

n
,
n
′

J
,
J
′

for the rotation-vibration Morse oscillators. Calculations are conducted within the framework of phase-space quantum mechanics, considering (r → r
eq). This methodology facilitates the derivation of analytical expressions for

〈

x

ˆ

s

〉

n
,
n
′

J
,
J
′

and

〈

p

ˆ

s

〉

n
,
n
′

J
,
J
′

matrix elements, where s = 1, 2, …. This approach enables the evaluation of both diagonal (

n
=
n
′
,
J
=
J
′
≠
0

) and off-diagonal (

n
≠
n
′
,
J
=
J
′
≠
0

) matrix elements through a more explicit and compact analytic formula, applicable for cases where

J
≠
J
′

as well as for scenarios involving non-rotating effects

J
=
J
′
=
0

.
Theoretical investigation of NbB as an electrode material for Li/Na-ion batteries
Authors: Li Xusheng , Liu Yu , Wang Haiyan , Yu Weiwei , Fu Yiwen , Wu Qinghua , Hu Qianku , Zhou Aiguo 
Published: May 2024

Abstract
The utilization of MBenes as electrode materials for lithium/sodium-ion batteries (LIBs/NIBs) has emerged as a prominent research area. The potential application of two-dimensional niobium boride (NbB) in LIBs/NIBs was explored through first-principles calculations. The results indicate that the monolayer of NbB exhibits exceptional dynamic stability, thermodynamic stability and electrical conductivity. The migration path of Li/Na on the NbB surface was determined, revealing diffusion barriers as low as 0.034 and 0.017 eV respectively, indicating the exceptional mobility and reversibility exhibited by NbB. The theoretical capacities of Li and Na on NbB are 258 and 323 mAh g−1, respectively. The open circuit voltage (OCV) varies within the range of 0.58 to 0.71 V and 0.05 to 0.81 V for Li/Na concentrations. Meanwhile, the investigation into the influence of various functional groups of NbB on the adsorption properties of Li/Na atoms reveals that both NbBO and NbBS surfaces retain their maximum capacity for Li/Na adsorption, whereas the NbBSe surface fails to achieve complete layer adsorption of Li/Na atoms. The introduction of the S functional groups not only maintains the ultra-low diffusion barrier (0.09 eV) of Na ions but also results in a significant decrease in the average OCV of Li/Na adsorption, which is approximately 0.37 and 0.14 V, respectively. The electrochemical properties of NbB in LIBs/NIBs are exceptional, positioning it as a promising electrode material within the MBenes family.
Asymmetric dark matter and Sommerfeld enhancement
Authors: Qiu Sujuan , Iminniyaz Hoernisa , Huo Wensheng 
Published: May 2024

Abstract
We study the relic density of asymmetric dark matter with long-range interactions by considering the Sommerfeld effect. We find that the annihilation cross section of asymmetric dark matter is enhanced by the Sommerfeld effect and thus the relic density is decreased. Then we use the Planck data to constrain the asymmetry factor, coupling, and to derive the upper bounds on the dark matter mass in s-wave and p-wave annihilation cases.
Test of the Brans–Dicke theory with GW200105 and GW200115
Authors: Fei Qin , Yang Yingjie 
Published: May 2024

Abstract
We study whether it is possible to constrain the Brans–Dicke (BD) theory from the measurement of gravitational waves (GW) released in neutron star-black hole collisions. Considering the scalar field modifications through monopole and dipole radiations, we find additional contributions to the phase evolution in the emitted gravitational waveform. After effectively calculating such effect in the post-Newtonian order, we are in a position to measure the scalar field and give bounds on the BD coupling parameter ω

BD
. We derive the analytical expression for the phase modification due to the orbital eccentricity of eccentric binaries in both general relativity and BD theory. Employing the Bayesian analysis, we obtain the constraints on ω

BD
from the GW events, GW200105 and GW200115.
A high-performance passively Q-switched Tm:YAP laser with a TaSe2 saturable absorber
Authors: Feng Xu , Hao Qianqian , Wang Chen , Bai Chunyan , Li Linjun 
Published: May 2024

Abstract
In this paper, TaSe2 material was prepared and used as a saturable absorber (SA) to modulate a Tm:YAP laser. Under the continuous-wave mode, an 18.31 W diode laser was used to pump the Tm:YAP crystal, and an output power of 6.22 W was achieved at 1993.1 nm with an optical–optical conversion efficiency of 33.9%. Under the passively Q-switched mode, the Tm:YAP pulse laser was modulated by a TaSe2-based SA, and a 2.8 W average power and a 440 ns pulse width at 73.15 kHz were obtained at 1988.4 nm, corresponding to an optical–optical conversion efficiency of 15.2% and a per pulse energy of 38.2 µJ.
Intrinsic valley-polarized quantum anomalous Hall effect in a two-dimensional germanene/MnI2 van der Waals heterostructure
Authors: Dong 董 Xiao-Jing 晓晶 , Zhang 张 Chang-Wen 昌文 
Published: May 2024

Abstract
Valley-polarized quantum anomalous Hall effect (VQAHE), combined nontrivial band topology with valleytronics, is of importance for both fundamental sciences and emerging applications. However, the experimental realization of this property is challenging. Here, by using first-principles calculations and modal analysis, we predict a mechanism of producing VQAHE in two-dimensional ferromagnetic van der Waals germanene/MnI2 heterostructure. This heterostructure exhibits both valley anomalous Hall effect and VQAHE due to the joint effects of magnetic exchange effect and spin–orbital coupling with the aid of anomalous Hall conductance and chiral edge state. Moreover interestingly, through the electrical modulation of ferroelectric polarization state in In2Se3, the germanene/MnI2/In2Se3 heterostructure can undergo reversible switching from a semiconductor to a metallic behavior. This work offers a guiding advancement for searching for VQAHE in ferromagnetic van der Waals heterostructures and exploiting energy-efficient devices based on the VQAHE.
Optical storage of circular airy beam in atomic vapor
Authors: Chang 常 Hong 虹 , Yang 杨 Xin 欣 , Ma 马 Yan 燕 , Yang 杨 Xinqi 鑫琪 , Cao 曹 Mingtao 明涛 , Zhang 张 Xiaofei 晓斐 , Dong 董 Ruifang 瑞芳 , Zhang 张 Shougang 首刚 
Published: May 2024

Abstract
The realization of quantum storage of spatial light field is of great significance to the construction of high-dimensional quantum repeater. In this paper, we experimentally realize the storage and retrieval of circular Airy beams (CABs) by using the Λ-type three-level energy system based on the electromagnetically induced transparency in a hot rubidium atomic vapor cell. The weak probe beam field is modulated with phase distribution of CABs by a spatial light modulator. We store the probe circular Airy beam (CAB) into the rubidium atomic vapor cell and retrieve it after the demanded delay. We quantitatively analyze the storage results and give corresponding theoretical explanations. Moreover, we investigate the autofocusing and self-healing effect of the retrieved CAB, which indicates that the properties and beam shape of CAB maintain well after storage. Our work will have potential applications in the storage of high-dimensional quantum information, and is also useful for improving the channel capacities of quantum internet.
Steering the energy sharing of electrons in nonsequential double ionization with orthogonally polarized two-color field
Authors: Fan 樊 Guangqi 光琦 , Yang 杨 Zhijie 志杰 , Sun 孙 Fenghao 烽豪 , Zheng 郑 Jinmei 金梅 , Han 韩 Yuntian 云天 , Huang 黄 Mingqian 明谦 , Liu 刘 Qingcao 情操 
Published: May 2024

Abstract
Using the semiclassical ensemble model, the dependence of relative amplitude for the recollision dynamics in nonsequential double ionization (NSDI) of neon atom driven by the orthogonally polarized two-color field (OTC) laser field is theoretically studied. And the dynamics in two typical collision pathways, recollision-impact-ionization (RII) and recollision-excitation with subsequent ionization (RESI), is systematically explored. Our results reveal that the V-shaped structure in the correlated momentum distribution is mainly caused by the RII mechanism when the relative amplitude of the OTC laser field is zero, and the first ionized electrons will quickly skim through the nucleus and share few energy with the second electron. As the relative amplitude increases, the V-shaped structure gradually disappears and electrons are concentrated on the diagonal in the electron correlation spectrum, indicating that the energy sharing after electrons collision is symmetric for OTC laser fields with large relative amplitudes. Our studies show that changing the relative amplitude of the OTC laser field can efficiently control the electron–electron collisions and energy exchange efficiency in the NSDI process.
Physics package based on intracavity laser cooling 87Rb atoms for space cold atom microwave clock
Authors: Deng 邓 Siminda 思敏达 , Ren 任 Wei 伟 , Xiang 项 Jingfeng 静峰 , Zhao 赵 Jianbo 剑波 , Li 李 Lin 琳 , Zhang 张 Di 迪 , Wan 万 Jinyin 金银 , Meng 孟 Yanling 艳玲 , Jiang 蒋 Xiaojun 小军 , Li 李 Tang 唐 , Liu 刘 Liang 亮 , Lü 吕 Desheng 德胜 
Published: May 2024

Abstract
This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation, microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2 × 10−12
τ
−1/2 with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.
Orbit tomography in constants-of-motion phase-space
Authors: Rud M. , Moseev D. , Jaulmes F. , Bogar K. , Dong Y. , Hansen P.C. , Eriksson J. , Järleblad H. , Nocente M. , Prechel G. , Reman B.C.G. , Schmidt B.S. , Snicker A. , Stagner L. , Valentini A. , Salewski M. 
Published: May 2024

Abstract
Tomographic reconstructions of a 3D fast-ion constants-of-motion phase-space distribution function are computed by inverting synthetic signals based on projected velocities of the fast ions along the diagnostic lines of sight. A spectrum of projected velocities is a key element of the spectrum formation in fast-ion D-alpha spectroscopy, collective Thomson scattering, and gamma-ray and neutron emission spectroscopy, and it can hence serve as a proxy for any of these. The fast-ion distribution functions are parameterised by three constants of motion, the kinetic energy, the magnetic moment and the toroidal canonical angular momentum. The reconstructions are computed using both zeroth-order and first-order Tikhonov regularisation expressed in terms of Bayesian inference to allow uncertainty quantification. In addition to this, a discontinuity appears to be present in the solution across the trapped-passing boundary surface in the three-dimensional phase space due to a singularity in the Jacobian of the transformation from position and velocity space to phase space. A method to allow for this apparent discontinuity while simultaneously penalising large gradients in the solution is demonstrated. Finally, we use our new methods to optimise the diagnostic performance of a set of six fans of sightlines by finding where the detectors contribute most complementary diagnostic information for the future COMPASS-Upgrade tokamak.
Various Parameter Measurements in Single-Frequency Dual-ECR Heating on Electron Cyclotron Resonance Ion Source
Authors: Iwahara Kouki , Maenaka Takumu , Fujimura Yushi , Kato Yushi 
Published: May 2024

Abstract
We have been researching efficient generation of multi-charged ions on electron cyclotron resonance ion source (ECRIS). We can introduce microwaves from a coaxial antenna at the upstream side of the magnetic mirror field (Coaxial) and a rod antenna at the downstream side (Rod). Regardless of R-wave cutoff, ECR occurs at two resonance points by Dual-ECR heating which means introducing microwaves from both antennas and we succeeded in generating more multi-charged Ar ions. We measured beam currents and plasma parameters such as electron density and electron temperature and obtained their radial distributions. We found the beam currents of multi-charged Ar ions were highest by Dual-ECR heating.
Time-resolved measurement of optical emission line profiles from electron cyclotron resonance ion source plasma
Authors: Timonen Oskari , Koivisto Hannu , Kronholm Risto , Toivanen Ville 
Published: May 2024

Abstract
Optical emission spectroscopy provides a non-invasive method to probe the properties of hot and highly charged magnetically confined plasmas. The optical emission line profiles enable, for example, to identify the different species and characterize the relative population densities and temperatures of the ions and neutrals forming the plasma. The feasibility of this approach has been demonstrated at the University of Jyväskylä accelerator laboratory by measuring the light emitted by Electron Cyclotron Resonance Ion Source (ECRIS) plasma with a high-resolution spectrometer setup POSSU (Plasma Optical SpectroScopy Unit). In these previous studies, the emission line profiles were measured by scanning the desired wavelength range by rotating the diffraction grating of the spectrometer. This process is slow compared to many interesting plasma phenomena, thus limiting the applicability of the setup. Recently, POSSU has been upgraded by changing the light sensor from a photomultiplier tube to a position-sensitive imaging sensor. As a result, it is possible to measure simultaneously a 1 - 2 nm wavelength range, with a spectral resolution in the order of picometers, without moving the grating. This enables a time-resolved study of the optical emission line profiles. By turning the grating, the measured wavelength region can be chosen between 370 nm and 870 nm, which covers the visible light spectrum. The time-evolution of optical emission line profiles emitted from the JYFL 14 GHz ECRIS plasma, during shifting plasma conditions induced by changing the gas balance, has been measured to demonstrate this new capability. The time-evolution of temperatures and emission intensities of selected ion species, correlated with extracted ion beam currents, are presented.
Simulation of laser-plasma focusing using taper solenoid
Authors: Hosoya S , Kashiwagi H , Yamada K 
Published: May 2024

Abstract
A laser ion source can produce ion beams of various elements, including high melting point metals. Owing to its ability to switch beams rapidly by loading multiple solid targets, we are developing a laser ion source to implement it in a 400 kV ion implanter, which requires a wide range of ion species. Although a laser ion source offers above advantages, most of the plasma is lost in an ion source due to the generation of the beam from a part of the diffused plasma with a broad angular distribution. To suppress this loss and enhance beam intensity, we employ a linear solenoid to increase the amount of plasma reaching the extraction electrode by suppressing the three-dimensional plasma diffusion. However, the linear solenoid cannot suppress the loss of plasma near the target as the plasma spreads three-dimensionally from the plasma generation point. Therefore, by placing a taper solenoid near the target, it is possible to suppress the diffusion of plasma immediately after its generation and to transport most of the generated plasma to the extraction electrode. In this paper, we present the results of plasma trajectory calculations using the particle-in-cell method by the plasma simulations involving taper solenoids.
Application of Optical Emission Spectroscopy to Electron Cyclotron Resonance Ion Sources
Authors: Castro G , Reitano R , Leonardi O , Russo F , Celona L , D’Agostino G , Gammino S , Neri L , Costanzo G , Siliato D 
Published: May 2024

Abstract
Electron Cyclotron Resonance Ion Sources (ECRIS) are widely used for production of highly charged high intensity ion beams for research, medical and industrial applications.
ECRIS performances, especially the charge state distribution and beam intensity, depend significantly on the electron energy distribution function that ranges from a few eV to hundreds of keV. Further improvements of ECRIS performances require a deeper and deeper understanding of the plasma heating mechanisms and ion generation by means of opportune plasma diagnostics. Amongst others, optical emission spectroscopy (OES) is the most remarkable for application in ECRIS: it is a non-invasive diagnostics able to operate also in high-voltage conditions and it requires small room for operation. OES has been already tested for plasma diagnostics in proton sources.
This work presents the experimental set-up developed for the plasma diagnostics of the Advanced Ion Source for Hadrontherapy (AISHa), an ECRIS for medical applications, together with the strategy applied to relate plasma emission lines in the visible and near-infrared domain to plasma parameters for some ions of interest. Preliminary results and perspectives will be also discussed.