bluuebunny/crossref_metadata_2025_split huggingface dataset:
High performance of an innovative cable-in-conduit conductor with CWS cable pattern
Authors: Guo Zichuan , Liu Yunhao , Dai Chao , Nijhuis Arend , Wang Wei , Zhou Chao , Qin Jinggang 
Published: May 2024

Abstract
Cable-in-conduit conductors, known as CICCs, were developed for constructing superconducting coils in tokamak fusion reactors. To achieve large currents in high magnetic field, CICCs were utilized with a short-twist-pitch (STP) cable pattern to prevent irreversible performance degradation, but also inducing higher AC losses. Institute Of Plasma Physics Chinese Academy Of Sciences (ASIPP) designed and manufactured three innovative CICCs, all featuring CWS (copper wire with a STP wound around superconducting strands with a long-twist-pitch) structure to increase both the current density and structure stiffness of CICC cable. These CICCs had the same new CWS cable pattern but the Nb3Sn superconducting strands were from different suppliers. All samples were subsequently tested under electromagnetic cycling tests in SULTAN. For similar electromagnetic performance degradation, the Lorentz load threshold of the CWS cable pattern exhibited to be higher than that of STP cable pattern. Moreover, the AC losses of CWS were 15% lower than that of STP cable pattern for low frequencies of the applied alternating magnetic field. Both results indicated that the CWS cable pattern has a higher margin of engineering safety and lower AC losses than STP cable pattern under the target operating conditions. This provides new insights in finding solutions for optimizing the CICCs’ cable pattern and preventing its electromagnetic performance degradation.
Crossover from Cooper-pair hopping to single-electron hopping in Pb
x
(TiO2)

1
−
x

granular films
Authors: He Zhi-Hao , Han Zi-Yan , Gao Kuang-Hong , Wang Zi-Wu , Li Zhi-Qing 
Published: May 2024

Abstract
The electrical transport properties of Pb
x
(TiO2)

1
−
x

(x being the Pb volume fraction and ranging from ∼0.45 to ∼0.72) granular films are investigated experimentally. The charging energy of the Pb granules is reduced to less than the superconducting gap of Pb granules for the low temperature insulating films by using high-k dielectric TiO2 as the insulating matrix. For the insulating films in the vicinity of the superconductor-insulator transition, Cooper-pair hopping governs the low-temperature hopping transport. For these films, the low-temperature magnetoresistance is positive at low field and the resistivity vs temperature for Cooper-pair hopping obeys an Efros–Shklovsii-type variable-range-hopping law. A crossover from Cooper-pair-dominated hopping to single-electron-dominated hopping is observed with decreasing x. The emergence of single-electron-dominated hopping in the more insulating films is due to the causation that the intergrain Josephson coupling becomes too weak for Cooper pairs to hop between adjacent Pb granules.
Facile synthesis of eco-friendly mango peel-derived porous carbon for optimizing microwave absorption
Authors: Qamar Tauqeer Haidar , Ma Lei , Hassan Sibt ul , Ahmed Nouman , Jamali Sain Bux , Huang Shengxiang , Deng Lianwen 
Published: May 2024

Abstract
An environment-friendly and cost-effective method to deal with electromagnetic pollution is fabricating porous carbon from biomass as a raw material with a simple technique. The purpose of this research is to create porous carbon from mango peel biomass for optimizing microwave absorption. The resulting porous carbon (PC) has the potential to be an effective microwave absorber. Scanning Electron Microscopy (SEM) depictions also revealed the porous carbon with homogeneous shapes and uniform size distribution. Complex permittivity studies were performed to evaluate their microwave absorption capabilities, resulting in a high reflection loss of −50.2 dB at a thickness of 2.1 mm and an effective absorption bandwidth (EAB) of 3.39 GHz for the sample carbonized at 800 °C. The exceptional microwave absorption ability of porous carbon (PC) can be attributed to its effective impedance matching and consequent attenuation of microwaves through dielectric loss. This research introduces a novel biomass source, readily available in nature, which can be easily processed to enhance microwave absorption properties.
A sensitive methane gas sensor based on sagnac interferometer with a cryptophane-A film-coated birefringent photonic crystal fiber : design and FEM simulation
Authors: Li Yuxin , Chen Hailiang , Li Hongwei , Yin Zhiyong , Gu Mingqi 
Published: May 2024

Abstract
As being sensitive to methane gas, cryptophane-A is widely used in fiber optic methane gas sensors. In order to further improve the sensitivity, a Sagnac interference (SI) was constructed with a cryptophane-A film coated birefringent photonic crystal fiber (PCF) to realize the methane gas sensing. Cryptophane-A film absorbs the methane gas and as a result its refractive index decreases linearly with the increasing of methane gas concentration. Simulation results utilizing the finite element method demonstrate that sensitivity reaches 124.4 nm/% when the methane concentration ranges from 0% to 3.5%. The sensor is relatively simple to prepare and can achieve high sensitivity, which has potential application in the field of monitoring methane gas leakage.
Revisiting the stochastic QCD axion window: departure from equilibrium during inflation
Authors: Briaud Vadim , Kadota Kenji , Mukohyama Shinji , Talebian Alireza , Vennin Vincent 
Published: May 2024

Abstract
If dark matter is made of QCD axions, its abundance is determined by the vacuum expectation value acquired by the axion field during inflation. The axion is usually assumed to follow the equilibrium distribution arising from quantum diffusion during inflation. This leads to the so-called stochastic window under which the QCD axion can make up all the dark matter. It is characterised by 1010.4 GeV ≤ f ≤ 1017.2 GeV and H
end > 10-2.2 GeV, where f is the axion decay constant and H
end is the Hubble expansion rate at the end of inflation. However, in realistic inflationary potentials, we show that the axion never reaches the equilibrium distribution at the end of inflation. This is because the relaxation time of the axion is much larger than the typical time scale over which H varies during inflation. As a consequence, the axion acquires a quasi-flat distribution as long as it remains light during inflation. This leads us to reassessing the stochastic axion window, and we find that 1010.3 GeV ≤ f ≤ 1014.1 GeV and H
end > 10-13.8 GeV.
Laser beam effect on the entanglement of elastic collisions in quantum plasma
Authors: Roozehdar Mogaddam Ramin , Sepehri Javan Nasser , Mohammadzadeh Hosein 
Published: May 2024

Abstract
In the quantized field formalism, using Kramers–Henneberger unitary transformation as the semi-classical counterpart of Block–Nordsieck transformation, the dynamics of entanglement during the low energy scattering processes in bi-partite systems at the presence of a laser beam fields are studied. The stationary-state Schrodinger equation for the quantum scattering process is obtained for such systems. Then, using partial wave analysis, we introduce a new form of entanglement fidelity considering the effect of high-intensity laser beam fields. The effective potential of hot quantum plasma including plasmon and quantum screening effects is used to obtain the entanglement fidelity ratio as a function of the laser amplitude, and plasmon and Debye length parameters for the elastic electron-ion collisions. It is shown that the plasma free electrons oscillations under interaction with laser beam fields improve the correlations between charged particles and consequently lead to the increase in the system entanglement.
Two-dimensional Sb net generated nontrivial topological states in SmAgSb2 probed by quantum oscillations
Authors: Yuan 袁 Jian 健 , Shi 石 Xian-Biao 贤彪 , Du 杜 Hong 红 , Li 李 Tian 田 , Xi 郗 Chuan-Ying 传英 , Wang 王 Xia 霞 , Xia 夏 Wei 威 , Wang 王 Bao-Tian 保田 , Zhong 钟 Rui-Dan 瑞丹 , Guo 郭 Yan-Feng 艳峰 
Published: May 2024

Abstract
The REAgSb2 (RE = rare earth and Y) family has drawn considerable research interest because the two-dimensional Sb net in their crystal structures hosts topological fermions and hence rich topological properties. We report herein the magnetization and magnetotransport measurements of SmAgSb2 single crystal, which unveil very large magnetoresistance and high carrier mobility up to 6.2 × 103% and 5.58 × 103 cm2⋅V−1⋅s−1, respectively. The analysis of both Shubnikov–de Haas and de Haas–van Alphen quantum oscillations indicates nontrivial Berry phases in the paramagnetic state while trivial Berry curvature in the antiferromagnetic state, indicating a topological phase transition induced by the antiferromagnetic order. It is also supported by the first-principles calculations. The results not only provide a new interesting topological material but also offer valuable insights into the correlation between magnetism and nontrivial topological states.
Initial Experimental Results on Ion Cyclotron Resonance Heating Selectively Mixed Low Z Ions to Enhance Production Efficiency of Multicharged Ions on Electron Cyclotron Resonance Ion Source
Authors: Kato Y , Harisaki S , Kubo W , Fujimura Y , Iwahara K 
Published: May 2024

Abstract
According to the accessibility conditions of wave propagation in the magnetized plasma of an electron cyclotron resonance (ECR) ion source (ECRIS), it is speculated that the essential factor that determines the limitations in the multiply charged ion currents is the left-hand polarization wave cutoff (L-cutoff). It is necessary to overcome this limitation, we proposed the introduction of ion cyclotron resonance (ICR) or lower hybrid resonance (LHR) by lower frequency waves. We conduct heating low-mass ions selectively in enhanced producing multiply charged ion by mixing low-mass element gas, which has been conventionally performed in ECRIS, or relaxation of the potential well based on the existence of resonant electron particles by ECR. This paper will describe the initial experimental results of ICR application by introducing low-frequency RF electromagnetic waves in the ECRIS.
First numerical evidence of the two-close frequency heating effect on electron cyclotron resonance ion sources
Authors: Galatà A , Biri S , Finocchiaro G , Gallo C S , Mascali D , Mishra B , Naselli E , Pidatella A , Rácz R , Torrisi G 
Published: May 2024

Abstract
The two-close frequency heating (TCFH) is a new implementation of the well-known two frequency heating. In TCFH, the two frequencies differ around 200-300 MHz each other in order to establish two contiguous ECR resonance zones. TCFH has been proved to be a powerful technique to suppress plasma instabilities in Electron Cyclotron Resonance Ion Sources (ECRIS), as well as to improve their performances. Its beneficial effect, compared to the application of a single frequency, is always deduced from the extracted charge states distributions and from the detection of the plasma self-emission in the X-ray and microwave ranges. This paper presents the first approach to a numerical description of the two-close frequency effect, based on the relevant plasma parameters of the ECRIS setup operating at ATOMKI-Debrecen. Simulations have been performed by our PIC-Full Wave code, joining electron kinetics and FEM solution of Maxwell equations in a cold plasma model. Results on plasma electron density and energy distribution will be shown, together with a direct comparison with the already published data on X ray emission.
Design of a novel ECR ion trap facility for nuclear physics and fundamental plasma processes studies
Authors: Naselli E. , Santonocito D. , Biri S. , Celona L. , Finocchiaro G. , Galatà A. , Mauro G.S. , Mishra B. , Pidatella A. , Rácz R. , Torrisi G. , Mascali D. 
Published: May 2024

Abstract
An innovative ECR ion trap facility, called PANDORA (Plasma for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry), was designed for fundamental plasma processes and nuclear physics investigations. The overall structure consists of three subsystems: a) a large (70 cm in length, 28 cm in inner diameter) ECR plasma trap with a fully superconducting B-minimum magnetic system (Bmax = 3.0 T) and an innovative design to host detectors and diagnostic tools; b) an advanced non-invasive plasma multidiagnostics system to locally characterize the plasma thermodynamic properties; c) an array of 14 HPGe detectors. The PANDORA facility is conceived to measure, for the first time, in-plasma β-decaying isotope rates under stellar-like conditions. The experimental approach consists in a direct correlation of plasma parameters and nuclear activity by disentangling - by means of the multidiagnostic system that will work in synergy with the γ-ray array - the photons emitted by the plasma (from microwave to hard X-ray) and γ-rays emitted after the isotope β-decay. In addition to nuclear physics research, fundamental plasma physics studies can be conducted in this unconventional ion source equipped with tens of detection and diagnostic devices (RF polarimeter, optical emission spectroscopy (OES), X-ray imaging, space and time-resolved spectroscopy, RF probes, scope), with relevant implications for R&D of ion sources for accelerator physics and technology. Several studies have already been performed in downsized nowadays operating ECRIS. Stable and turbulent plasma regimes have been described quantitatively, studying the change of plasma morphology, confinement, and dynamics of losses using space resolved X-ray spectroscopy.
Recent experiments on photo-assisted negative ion production in caesium sputter ion source at the JYFL Pelletron facility
Authors: Hossain A. , Tarvainen O. , Reponen M. , Kronholm R. , Julin J. , Kalvas T. , Toivanen V. , Kivekäs M. , Laitinen M. 
Published: May 2024

Abstract
We have measured the effect of a 15 W, 445 nm laser on Br− beam current produced by a SNICS ion source by systematically varying the ion source parameters, most importantly the target holder material, and temperatures of the ioniser and Cs oven. The target holder material has no significant effect on the observed photoenhancement of the beam current. The evidence shows that the laser allows reaching higher beam currents at low ioniser temperatures compared to running the source without the laser but at higher ioniser temperature. We have observed a priming effect, i.e. applying a number of laser pulses at certain ion source settings causes the beam current measured without the laser to increase significantly and remain high after ceasing the laser pulsing. These observations suggest that the photo-assisted effect is related to changes of the cathode caesium coverage. Finally, we report the results of our first attempts to sustain a stable beam current at the elevated level over several hours, achieved through active control of the laser power.
Plasma homogeneity over the extraction beamlet groups at the half size ITER negative ion source at ELISE test facility
Authors: Yordanov D. , Wünderlich D. , Wimmer C. , Riedl R. , Navarro A. , Fantz U. ,   NNBI Team
Published: May 2024

Abstract
The negative ion source for neutral beam injection at ITER has to provide high-intensity and low-divergence negative hydrogen and deuterium ion beams. Extracting the negative ions from the plasma is inevitably accompanied by co-extraction of electrons, which can limit the source performance, especially in deuterium. Reducing the co-extracted electrons is done by applying a magnetic filter field. On the one hand, the filter field reduces the electron temperature and the amount of co-extracted electrons, on the other hand, it introduces ×

B
→

drifts. The drifts create a vertical plasma inhomogeneity in front of the extraction area and, consequently, an asymmetry of the co-extracted electrons. This motivated detailed studies on the vertical plasma inhomogeneity over the beamlet groups in the ELISE ion source using a movable Langmuir probe in deuterium plasma. It is demonstrated that the vertical distribution of the plasma potential changes together with the sheath, forming at the plasma grid – from electron repelling to attracting sheath. A repelling sheath reduces the flux of electrons from the plasma to the grid surface and consequently, more electrons are co-extracted. The attracting sheath collects the majority of electrons on the grid and reduces the co-extracted electrons.
The extraction of both positive and negative ions from a volume cusp H− ion source
Authors: Melanson Stephane , George Anand , Dehnel Morgan 
Published: May 2024

Abstract
The TRIUMF licensed H− ion source is known to produce 15 mA of H− ions, but some applications, such as cyclotrons, require the injection of both positive and negative ions. Furthermore, when using a tandem accelerator, there would be a benefit in using an ion source that can directly extract H− and He+. A charge exchange chamber would only have to be used with the He+ beam for the production of He−. In this paper, we present the conversion of the H− ion source to allow for the extraction of both positive (He+, H+,

H
2
+

and

H
3
+

) and negative (H− and D−) ions. In the modified design, up to 3 mA of protons and 2 mA of He+ can be extracted when using positive extraction power supplies and up to 5 mA of H− can be extracted when the polarity of the power supplies switched to negative extraction. We study how the ion source parameters affect the proton fraction and we look at the influence of the magnetic filter field in the plasma chamber.
Beam Optics Study during Long-Pulse MeV-Class Beam Operation for the ITER HNB
Authors: Tanaka Y , Kisaki M , Suzuki K , Hiratsuka J , Murayama M , Ichikawa M , Tobari H , Kashiwagi M 
Published: May 2024

Abstract
Neutral beam injectors for ITER require the beam divergence to be less than 7 mrad for both D− and H− negative ion beams. The time evolution of beam optics parameters of ITER-relevant high intensity has not been well understood due to the material capabilities of heat load. In this study, the time evolution of beam divergence has been successfully observed with the ITER-relevant perveance beam parameter for 0.5 MeV and 100 seconds pulse. For this purpose, a beam monitoring system based on a visible camera, which has been newly developed and installed in the MeV Test Facility, is used. As a result of this experiment, it is experimentally found that the time evolution of beam divergence exists even if the Iacc
and heat load to beam dump are stable. To reduce the time evolution of beam optics, the feed-back control of Iext
is under development in order to suppress the variation of conditions in the ion source.
Gas mixing and double frequency operation of the permanent magnet quadrupole minimum-B electron cyclotron resonance ion source CUBE-ECRIS
Authors: Toivanen Ville , Kalvas Taneli , Koivisto Hannu , Kosonen Sami , Tarvainen Olli 
Published: May 2024

Abstract
CUBE-ECRIS is a recently commissioned permanent magnet electron cyclotron resonance (ECR) ion source developed at the university of Jyväskylä accelerator laboratory. The special features of the new ion source design include an unconventional quadrupole minimum-B magnetic field structure and a slit beam extraction system necessitated by the line-shaped plasma loss fluxes. Gas mixing and double frequency operation are widely used methods to optimize high charge state ion production of conventional ECR ion sources. The work presented here demonstrates the applicability of these methods for boosting the high charge state beam currents of argon, krypton and xenon extracted from CUBE-ECRIS. Oxygen and helium were used as mixing gases and microwave frequencies between 10 and 11 GHz were used for single and double frequency operation. Gas mixing has a strong impact on the high charge state beam currents. For example, the highest observed charge state increased from 15+ to 19+ for krypton and from 16+ to 23+ for xenon with oxygen gas mixing. Double frequency operation provides an additional performance improvement, for example the currents of argon 9+ and 11+ beams, produced with gas mixing, increased 30% and 100% in double frequency operation at the same total power.
European effort to improve highly charged heavy ion beam capabilities with ECR ion sources (invited)
Authors: Koivisto H. , Andreev A. , Asfari Z. , Biri S. , Celona L. , Charbonnière L. , Charpentier C. , Dubois M. , Filliger M. , Galatà A. , Gall B. , Gallo C. S. , Galonska M. , Gammino S. , Gerbershagen A. , Jones B.N. , Kalvas T. , Kremers H.R. , Kronholm R. , Lang R. , Lemagnen F. , Leonardi O. , Maimone F. , Mascali D. , Mäder J. , Naselli E. , Pidatella A. , Rácz R. , Thuillier T. , Timonen O. , Toivanen V. , Torrisi G. 
Published: May 2024

Abstract
The European Electron Cyclotron Resonance Ion Source (ECRIS) community has more than 20 years of experience working together in various EU-funded projects. In the recent project, called ERIBS (European Research Infrastructure – Beam Services), the community will focus on improving ion beam services for the EURO-LABS (European-Laboratories for Accelerator Based Sciences) research infrastructures. The EURO-LABS is a four-year project funded by the Horizon Europe program of the European Commission for years 2022 - 2026. In the ERIBS collaboration the best expertise, know-how and practices of the ECRIS community will be exploited and transferred between the partners to take full advantage of the European ion source infrastructure. The aim is to extend the beam variety available for the European user community by developing beam production methods and techniques. This development includes further improvement of technologies related to high temperature ovens, axial sputtering and MIVOC method for all the participating laboratories. We will also aim to improve both short- and long-term plasma and beam stability, as well as methods for online monitoring of these conditions. This can be realized, for example, by optical emission spectroscopy, identifying kinetic plasma instabilities by means of hard x-ray detection and using online beam current monitoring systems. An example of the recent developments is the new collaboration proposed by the CNRS-IPHC team to synthesize enriched MIVOC compounds for the other ERIBS partners. For example, the team successfully prepared an enriched chromocene compounds, which were needed to produce intensive 54Cr and 50Cr beams for the JYFL and GANIL nuclear physics programs, respectively.
Evolution of ALISES 3 Light Ion Source at CEA Saclay
Authors: Dubois A , Delferriere O , Gauthier Y , Sauce Y , Tuske O 
Published: May 2024

Abstract
Since 1995, the Laboratory for Accelerator Studies and Development at CEA Saclay specializes in producing ECR intense Light Ion Sources, for high intensity proton or deuteron. The initial source SILHI (Source d’Ions Légers Haute Intensité) designed for IPHI accelerator in 1995 was the root of sources provided to laboratories worldwide, such as IFMIF, FAIR or SPIRAL2. In parallel, the Ion Source team started a new R&D program on high intensity ECR compact ion sources with the ALISES source family (Advanced Light Ion Source Extraction System). The years spent testing and improving ALISES v1&2 led us to design a new source, named ALISES v3. The development of this source gathers the advantages of each improvement tested on ALISES v1&2, to achieve an even smaller and pragmatic configuration. The manufacturing of ALISES v3 took place during the improvement of the BETSI test bench in 2018, from 50 kV to 100 kV. The goal of this source is to obtain the same characteristics as the original SILHI, with fewer parts and easier maintenance. This article describes the evolution of ALISES v3 and the beam characteristics at every stage. BETSI test bench is equipped with an Allison Scanner and a Faraday cup to analyse the emittance and the beam current.