bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predictive fluid model for self-consistent description of inductive RF coupling in powerful negative hydrogen ion sources
Authors: Zielke D , Briefi S , Lishev S , Fantz U 
Published: April 2022

Abstract
RF-driven negative hydrogen ion sources are typically operated at low frequencies around 1 MHz, gas pressures around or below 1 Pa and large power densities up to 10 Wcm-3. Owing to these conditions as well as the current discharge geometries and antenna layouts, the RF power coupling is far from optimized, i.e. only a fraction η of the power delivered by the generator is absorbed by the plasma. This considerably limits the performance and reliability of RF-driven ion sources. To study the bidirectional RF power coupling a self-consistent fluid model is introduced. Taking into account the interplay between the nonlinear RF Lorentz force and the electron viscosity (usually neglected in state-of-the-art fluid models) a steady state solution is obtained, where the trends reflect the experimental data. Solutions calculated in hydrogen but with increased ion masses indicate that the latter are responsible for the systematically increased η, which is observed experimentally when deuterium instead of hydrogen is used as feed gas.
Ion source developments at IPP: On the road towards achieving the ITER-NBI targets and preparing concepts for DEMO
Authors: Fantz U , Briefi S , Fröschle M , den Harder N , Heiler A , Heinemann B , Hurlbatt A , Hopf C , Lindqvist M , Merk F , Mimo A , Nocentini R , Orozco G , Riedl R , Starnella G , Wimmer C , Wünderlich D , Yordanov D , Zielke D 
Published: April 2022

Abstract
The large ion source of ITER’s neutral beam injection (NBI) systems (0.9 m×1.9 m) with 1280 apertures has to deliver 57 A D- for 3600 s (286 A/m2) and 66 A H- for 1000 s (329 A/m2). The RF ion source test facilities ELISE and BUG at IPP are aimed to demonstrate the ion source parameters, the homogeneity of large beams (up to 1 m×1 m) and to perform beam optic studies. While the ITER parameters could be demonstrated in hydrogen, the achievement in deuterium for long pulses is still pending due to the large fraction of co-extracted electrons, their temporal dynamics, and inhomogeneity in vertical direction, limiting the ion source performance. Biasing of the bias plate in the vicinity of the plasma grid improves the symmetry of the co-extracted electrons and contributes to its stabilzation being thus a promising alternative to potential rods formerly used to achive high performance. With the replacement of the high-voltage power supply at ELISE first 100 s steady state extraction is demonstrated increasing the relevance of the test facility for ITER and DEMO studies. For the latter, the IPP contributions focus on improvement of the RF coupling, the caesium management and conceptual studies of a beam driven plasma neutraliser as alternative to the gas neutraliser system.
Overview of recent and upcoming activities at the BATMAN Upgrade test facility
Authors: Wimmer C. , Briefi S. , Fröschle M. , Heinemann B. , den Harder N. , Hurlbatt A. , Mimo A. , Nocentini R. , Orozco G. , Fantz U. 
Published: April 2022

Abstract
The BATMAN Upgrade (BUG) test facility at IPP is contributing to the development of RF-driven H- sources towards the ITER neutral beam injection and beyond. BUG is equipped with an 1/8 size of the ITER NBI ion source and thus is highly flexible for setup changes or diagnostic access. The present strategy for BUG is aligned along two paths: (i) BUG is continuing to be upgraded upgrading for long pulse operation (up to 1 hour, both in H and D) to identify measures for the stabilization of long pulses. For pulses > 100 s a cooling of the plasma grid (first grid of the extraction system) is required in order to avoid the dominance of thermal Cs desorption. A Cs evaporation concept with evaporation close to the extraction system is being tested, showing a stabilization of co-extracted electrons in 100 s H pulses, (ii) BUG is used for investigations of whole beam and beamlet optics for which the beam diagnostics have been massively upgraded. The beam diagnostics have been used to characterize a newly installed MITICA-like extraction system including asymmetric deflection compensation magnets.
Difference of co-extracted electron current and beam acceleration in a negative ion source with hydrogen-isotope ions
Authors: Ikeda K. , Tsumori K. , Nakano H. , Nagaoka K. , Takeiri Y. , Masaki S. , Rattanawongnara E. , Osakabe M. 
Published: April 2022

Abstract
Improvement of the performance on a hydrogen/deuterium negative ion source for a nuclear fusion device is reported. In particular, the suppression of the co-extracted electron current, Ie, is an important issue to ensure the stable beam acceleration. Improvement of the Ie
has been confirmed by optimizing the magnetic field of the electron deflection magnet in the extraction grid. Two other new methods for reduction of the Ie
were validated. The first was an electron fence whose rods were set between the rows of apertures on a plasma grid. The electron and negative ion current ratio, approximately Ie/I
acc, was greatly improved from 0.7 to 0.25 in deuterium. The second was an outer iron yoke which enhanced the magnetic flux density 19% inside the arc discharge chamber. The Ie/Iacc
using the outer yoke decreased by 0.1 compared with using a normal magnetic filter in a deuterium operation. These attempts have improved the total deuterium injection beam power of 8.4 MW by three negative ion based NBIs.
Optimization of ion transport in a combined RFQ Cooler with axial magnetic field
Authors: Cavenago M. , Romé M. , Maero G. , Bellan L. , Cavaliere F. , Comunian M. , Galatà A. , Maggiore M. , Panzeri N. , Pisent A. , Pranovi L. , Sattin M. 
Published: April 2022

Abstract
The accurate mass spectrometry (with resolution goal 1:20000) of exotic ions requests beams with low energy spread (goal is about 0.5 eVrms or lower) and low transverse emittance, so it is necessary to cool ions produced by a fission source. In a radiofrequency (rf) quadrupole cooler (RFQC), collisions decrease ion kinetic energy, while rf and DC voltages confine and reaccelerate ions towards the extraction, where the cold ion beam is formed. Operation is based on carefully chosen tunings of voltages and of gas pressure p
g, which requires an adequate pumping system; efficient simulations of extraction systems, which critically depend on residual speed of ions, are also important. Progresses in the experimental setup are described. Indications from simple ray tracing and ‘ray+collision’ tracing are compared. Results are applied to a simple triode extraction system, and more flexible configurations are considered.
Production of C-14 and stable ion beams at the Argonne Tandem Linac Accelerator System with the ECR3 ion source
Authors: Scott R H , McLain J , Vondrasek R C 
Published: April 2022

Abstract
The Argonne Tandem Linac Accelerator System (ATLAS) at Argonne National Laboratory (ANL) paused production of carbon-14 ion beams with the removal of the Tandem Van de Graaff in 2013. Installation of ECR3, an Electron Cyclotron Resonance Ion Source, returned that production capability to ATLAS, with the first C-14 beam delivered in December 2020. Information is presented on C-14 beam current, gas consumption and N-14 filtering techniques using stripping foils at different sections of ATLAS. ECR3 also fulfilled the operational goal of adding flexibility to ATLAS stable beam production capabilities. Beneficial impacts to ATLAS operation, beam development and experimental programs are discussed.
Anomalous Ionization Regime in a Forced Electron Beam Induced Arc Discharge Ion Source for Singly Charged Radioactive Ion Beam Production
Authors: Maldonado Millan F , Babcock C , Day Goodacre T , Gottberg A 
Published: April 2022

Abstract
At TRIUMF’s ISAC facility, 1+ Radioactive Ion Beams (RIBs) of noble gases, halogens, and molecules are created using a Forced Electron Beam Induced Arc Discharge (FEBIAD) ion source. Reported ionization efficiencies for FEBIADs range from 10% to 25% for 40Ar+, while TRIUMF-FEBIAD ionization efficiency seems to be < 1% with a 90% emittance <15 μm. As RIB ion sources aim for a high ionization efficiency, an experimental and numerical campaign was conducted to investigate the comparably low efficiencies observed. The experimental results for 40Ar+ indicate that up to a 10% ionization efficiency is possible by operating the source at different parameters. The measurements agree with theoretical estimations; however, certain combinations of parameters produce an anomalously high electron current which enhances the ionization efficiency threefold. Present investigations aim to characterize and model the anomalous electron current because, if proven reliable, the argon ionization efficiency could reach 30% with no significant impact on beam emittance.
Simulations of a new electron gun for the TITAN EBIT
Authors: Cardona J D , Dietrich K , Mukul I , Dilling J , Gwinner G , Kester O , Kwiatkowski A A 
Published: April 2022

Abstract
Penning trap mass spectrometry is the tool of choice for mass measurements to test the Standard Model or lay the nuclear-physics foundation of neutrino physics due to the high precisions achievable. This precision can be further boosted by higher charge states (Ettenauer et al 2011). For this purpose, an electron beam ion trap (EBIT) provides radioactive HCIs at the TITAN facility at TRIUMF. To improve the electron beam properties and its control, a new electron gun is under development. The electron gun within its TITAN EBIT environment was simulated using Field Precision’s TRAK software. A new electrode geometry was chosen and optimized to extract up to 5A, 66 keV electron beams. Due to the strong fringe field of the unshielded 6T magnet, options for the passive and active shielding of the gun were explored to compress the electron beam. During the design process, careful attention was paid to safety and mechanical considerations. Simulations and the status of the new electron gun will be presented.
Analysis of electron behaviour around a spring-shape filament inside a low-energy electron gun
Authors: Matsumoto Y , Nakano H , Kisaki M , Shinto K , Sasao M , Wada M 
Published: April 2022

Abstract
Electron behaviour inside a low-energy electron gun based on a spring-shape filament were studied with experiment and Particle-In-Cell simulation. The energy range of the electron beam which we expected was from 1 to 20 eV. The analysis told that smaller size of filament is more useful to improve electron density in front of an extraction hole in the gun to enhance beam current. Relation between a space potential distribution in the gun and electron transport was also studied. A heater voltage to drive a filament for thermionic electron emissions has another role to form a spatial potential distribution in the gun. The potential guides electrons, which are at a distant area from the beam extraction hole, toward the hole. It can be a significant help to realize efficient electron extraction by a beam extraction electric field induced near the hole.
A Low Energy Beam Transport to Match a Multicusp Ion Source to an RFQ
Authors: Waites Loyd , Conrad Janet , Winklehner Daniel 
Published: April 2022

Abstract
The RadioFrequency Quadrupole Direct Injection Project (RFQ-DIP) uses a filament-driven multicusp ion source to produce

H
2
+

. A Low Energy Beam Transport (LEBT) injects the beam from the ion source into the RFQ. The LEBT shapes the beam to the optimum input Twiss parameters for transmission through the RFQ while minimizing the emittance. The LEBT system has been designed using the accelerator codes IBSimu and Warp. To ensure the accuracy of the simulations, a series of diagnostic tools to assess the beam quality have been integrated into the LEBT design. The LEBT also integrates a beam chopper for machine protection and duty factor control, as well as steering capability to compensate for small misalignments. Presented here are the beam dynamics simulations and the design of the LEBT and matching to the RFQ.
Concept design of new compact electron cyclotron resonance ion source with permanent magnets for multi-ion radiotherapy
Authors: Muramatsu Masayuki , Ouchi Fumihisa , Suzuki Taku , Takahashi Katsuyuki , Sasano Toshinobu , Shiraishi Tadahiro , Nomura Shinji , Takahashi Nobuaki , Kato Yushi , Katagiri Ken , Mizushima Kota , Iwata Yoshiyuki , Inaniwa Taku , Kitagawa Atsushi 
Published: April 2022

Abstract
The multi-ion radiotherapy with dose distribution and Liner Energy Transfer optimization is being studied at QST. Helium, carbon, oxygen and neon ions are considered as ion species for multi-ion therapy. A basic experiment using these ion beams has been carried out at the HIMAC. For heavy-ion radiotherapy facility, it is desirable to operate with only one ECR ion source with permanent magnets from the viewpoint of cost and maintenance. We considered the operating method with only one ion source for multi-ion radiotherapy. Ionization gases were helium, methane, oxygen, and neon to produce He2+, C4+, O6+ and Ne7+ ions. Requirement values of beam current were 940 μA correspond to He2+, 290 μA to C4+, 330 μA to O6+, and 245 μA to Ne7+, respectively. This value was obtained from the number of particles required for the cancer treatment and the transmission efficiency of the accelerator in the HIMAC. We performed some beam tests for design of a new compact ion source with the existing 18 GHz ECR ion source (NIRS-HEC). From the results of the beam tests, we estimate the mirror magnetic field of NIRS-HEC by using POISSON/SUPERFISH code. Then, the structure of the permanent magnets for new ECR ion source is determined so that they reproduce the values of the upstream mirror peak (Binj), B minimum (Bmin) and the downstream mirror peak (Bext) at the NIRS-HEC. The magnetic field of Binj, Bmin and Bext at NIRS-HEC were 1.14 T, 0.475 T and 0.9 T, respectively.
Dynamics and reactivity of thermalized ions in a radiofrequency quadrupole gas-reaction cell used for the production of radioactive molecular ions
Authors: Alary J-F , Cousins L M , Javahery R , Kieser W E , Flannigan E L , Charles C 
Published: April 2022

Abstract
Two-dimensional radiofrequency quadrupole (RFQ) ion guides are versatile tools that are used over a wide range of ion energies. Properly tuned, they can provide an ideal environment for ion-molecule chemistry to proceed by allowing thermalized ions to react on-line with gaseous reactants. We exploit this capability in the Ion Reaction Cell (IRC), an RFQ-based system designed to form radioactive molecules (RM) from radioactive ion beams (RIB). Functionally, the IRC accepts RIB produced upstream by the isotope separation on-line (ISOL) method, decelerates it to eV energies for production of the RM and then re-accelerates RM to their incident energy. This system promises to form a highly versatile source of complex inorganic or organic RM that can be used in fundamental symmetry studies or as precursors to new radiopharmaceuticals. We discuss the challenges of transferring ions from a RIB into a gas cell at room temperature while constraining ions within the RFQ energy well, and of reforming a beam from synthesized RM. Various factors influencing ion dynamics and reactivity in thermal and non-thermal zones inside the IRC are considered, using results obtained recently with the Isobar Separator for Anions, an analogous RFQ technique used in Accelerator Mass Spectrometry, to illustrate key points.
Research on collaborative planning of distributed resources and energy storage in regional integrated energy system
Authors: Ma Zhoujun , Zhang Yong 
Published: April 2022

Abstract
Aiming at the problem of high operation cost caused by low energy utilization of users in the region, a collaborative planning method of distributed resources and energy storage of regional integrated energy system is proposed. We designed the operation framework of the regional integrated energy system, and described the operation state of the equipment and the energy coupling relationship. According to the relationship between cooling, heating and power supply, the objective function is established with the lowest total operating cost, the highest reliability and the highest system emission reduction rate, and the control constraints are established for the total load in the system. We have established a collaborative ownership model for distributed resources and energy storage, and distributed energy supply and energy storage equipment in the system. It enables each energy supply and energy storage device to adjust the operating mode according to its own needs. So as to realize the reasonable supply of energy and the economical and optimal operation of all users. Taking three typical users in a park as an example, the results show that the operating costs of the three users are reduced by 15532.92 yuan, 5906.63 yuan and 24495.62 yuan respectively. The planning method can not only ensure the stable operation of the energy system, but also reduce the operation cost of users.
Numerical simulation of liquid-liquid heat pipe heat exchanger applied as sampling cooler in nuclear power
Authors: Liu Mengmeng , Tao Hanzhong 
Published: April 2022

Abstract
Monitoring and control of the temperature and pressure of water sample are critical issues in the nuclear power engineering for the efficient and safe operation. In this paper, through the thermal and fluid dynamical simulations, we demonstrated the improvement in heat transfer performance of the heat pipes used in the sampling cooler by changing the heat pipe diameters and the fin types. Heat pipes with helical fins show a 30.9% enhancement in heat transfer j factor compared to the smooth heat pipes. Additionally, the numerical results also show that the sampling cooler has an optimal helical fin pitch, which is 140mm.
Multi-objective Control Optimization of Pumped Storage Units under Successive Load Rejections
Authors: Lai Xinjie , Huang Huimin , Zheng Bo , Wu Yuechao , Luo Yuanlin 
Published: April 2022

Abstract
Pumped hydropower is one of the most important renewable energy in a power grid, which is converted into electricity through pumped storage hydropower systems (PSHS). However, the energy conversion process of a PSHS may be greatly threatened by extreme working conditions, especially successive load rejections (SLR). In order to obtain the optimal control scheme for SLR, this paper aims to study the control optimization strategies so as to achieve safe and stable operation of PSHS. Firstly, a refined nonlinear PSHS model for SLR is constructed and validated by field data. Then, a novel optimization strategy incorporating multiple objectives, multiple guide vane control law (GVCL) schemes and multiple engineering constraints are proposed. The result shows that the proposed optimization strategy is effective for solving the control problem of PSHS under SLR, the optimal GVCL for SLR can be obtained by only one optimization.
Manufacturing process optimization and quality grading method of insulating paperboard for converter transformer
Authors: Zhang Shuqi , Yu Xinru , Wu Chao , Jia Pengfei , Deng Junyu , Cheng Huanchao 
Published: April 2022

Abstract
Oil paper insulation is the main form of transformer internal insulation. Different from the conventional transformer, the insulating paperboard bears a higher electric field component in the interior of the converter transformer. Therefore, the performance of insulating paperboard plays a vital role in the reliability of converter operation. Many insulation faults have occurred in the operation of UHV converter transformer. The production process and detection standard of conventional transformer insulating paperboard can not meet the operation requirements of UHV converter transformer under high field strength. In this study, the performance of insulating paperboard for UHV converter transformer was tested and compared. Combined with the series tests of micro properties, physical and chemical properties and electrical properties in the manufacturing process of insulating paperboard, the key manufacturing process of insulating paperboard is studied, and the process measures suitable for UHV converter transformer insulating paperboard are put forward. In addition, the comparison between the current test standard of insulating paperboard and the actual operation requirements is carried out, and the key performance test indexes of insulating paperboard applicable to converter transformer that are not covered in IEC standard are analyzed. The quality classification of insulating paperboard of UHV converter transformer and conventional transformer is carried out, and the selection scheme is provided. Insulating paperboard of class A is selected to be suitable for the design and manufacture of UHV converter transformer. The research results provide support for improving the performance of insulating paperboard of UHV converter transformer and ensuring the operation reliability of transformer.
An Optimal Design of a Fire Pump with Protection Function
Authors: Peng Ziyu , Duan Yitong , He Kun 
Published: April 2022

Abstract
At present, the existing power mechanical gasoline engine fire pump is prone to large vibration during operation. Due to the lack of protection structure, long-term vibration will shorten the service life of the fire pump. Meanwhile, the upper end of the fire pump body is usually not set up with a protective structure, which is easily damaged by the extrusion and impact of objects. Therefore, a new type of protection device is designed in this paper, which plays a protective role by setting a relevant absorber at the lower end of the fire pump body, and at the same time, a buffer pad is arranged at the upper end of the cover to have the effect of buffering and shock absorption. To this end, this device has the function of reducing the damage to the fire pump body caused by the impact of heavy objects, improving the performance of the existing fire pump, and prolonging its service life.
Study of the adsorptive removal of (Fe+2) and (Ni+2) from water by synthesized magnetite/corn cobs magnetic nanocomposite
Authors: Sanad Mohamed N , El-Dek S I , Eldemerdash Usama , ElFaham Mohamed M 
Published: April 2022

Abstract
Heavy metals are principal concomitant pollutants in industrial wastewaters, posing a serious threat to public health and the environment. Herein, we develop a novel strategy to produce a new nanocomposite formed from corn cobs (CCs) and magnetite as a nanomaterial for the simultaneous removal of Fe+2 and Ni+2. The as-prepared nanocomposite was systematically characterized by x-ray diffraction, field emission scanning electron microscopy, mapping, energy-dispersive x-ray spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, zeta size, and zeta potential. Compared to the CCs and Fe3O4, the nanocomposite showed better adsorption performance. The maximum adsorption efficiency of the CC, Fe3O4, and the nanocomposite was calculated by atomic analysis to be around 91.84%, 91.28%, and 98.51%, respectively, under the same conditions. This study indicates that the nanocomposite could be a favorable biomass-derived adsorbent for the simultaneous removal of heavy metals.