bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibrational excitation cross sections for non-equilibrium nitric oxide-containing plasma
Authors: Laporta V , Vialetto L , Guerra V
Published: April 2022

A full set of vibrationally-resolved cross sections for electron impact excitation of NO(X2Π, v) molecules is calculated from ab initio molecular dynamics, in the framework of the local-complex-potential approach. Electron–vibration energy exchanges in non-equilibrium thermodynamic conditions are studied from a state-to-state model accounting for all electron impact excitation and de-excitation processes of the nitric oxide vibration manifold, and it is shown that the calculated vibration relaxation times are in good agreement with the experimental data. The new vibrational excitation cross sections are used in a complete electron impact cross section set in order to obtain non-equilibrium electron energy distributions functions and to calculate electron transport parameters in NO. It is verified that the new cross sections bring a significant improvement between simulations and experimental swarm data, providing an additional validation of the calculations, when used within the complete set of cross sections investigated in this work.
Bistable sound insulator with an abrupt stiffness shift using magnetic-coupled dielectric elastomer actuator
Authors: Zhang Yu , Li Bo , Chang Longfei , Ma Fuyin , Zhou Xiaoling , Chen Guimin
Published: April 2022

Aiming at noise isolation in low frequency range, this paper presents a novel kind of membrane sound insulator featuring a bistable actuation, by combining magnets and multilayer dielectric elastomer actuator (DEA). With a critical applied voltage on DEA, it deforms and the magnets attract in terms of a bistable snapping, which leads to an abrupt stiffness shift, and consequently regulates the sound transmission loss peak frequency. An electromechanical model is established to reveal the bistable characteristics and to study the effect of voltage and structure parameters for design optimization. The sound-insulation measurement experiment verifies the tunable acoustic performance. The sound-insulation peak frequency has a maximum shift of 142, 130, and 141 Hz under voltages of 2000, 2500, and 3000 V, respectively, showing an advancing figure of merit compared with the existed acoustic metamaterial based on dielectric elastomer.
Superconducting detectors for rare event searches in experimental astroparticle physics
Authors: Kim Yong-Hamb , Lee Sang-Jun , Yang Byeongsu
Published: April 2022

Superconducting detectors have become an important tool in experimental astroparticle physics, which seeks to provide a fundamental understanding of the Universe. In particular, such detectors have demonstrated excellent potential in two challenging research areas involving rare event search experiments, namely, the direct detection of dark matter (DM) and the search for neutrinoless double beta decay. Here, we review the superconducting detectors that have been and are planned to be used in these two categories of experiments. We first provide brief histories of the two research areas and outline their significance and challenges in astroparticle physics. Then, we present an extensive overview of various types of superconducting detectors with a focus on sensor technologies and detector physics, which are based on calorimetric measurements and heat flow in the detector components. Finally, we introduce leading experiments and discuss their future prospects for the detection of DM and the search for neutrinoless double beta decay employing superconducting detectors.
Vibrational description of the LiAr molecule in its X
2Σ+ and A
2Π electronic states in the framework of an algebraic model
Authors: Sboui Insaf , Slama Marwa , Ghazouani Sami , Mounir Ben El Hadj Rhouma
Published: April 2022

In this work, the vibrational energy levels, the kinetic energy and the potential energy of the LiAr molecule in its X
2Σ+ and A
2Π electronic states are studied using the Morse potential and so(2, 1) spectrum generating algebra approach. An algorithm for the recursive evaluation of the expectation value of

Z

q

=

e

−
α
(
r
−

r

e

)

q

for a given state of Li (X
2Σ+) Ar and Li (A
2Π) Ar are proposed. As an application closed-form estimations for the value

r

n

of Li (X
2Σ+) Ar and Li (A
2Π) Ar were derived using Jensen’s inequality. This allows us to obtain several inequalities relating the radial expectation value

r

n

of Li (X
2Σ+) Ar and Li (A
2Π) Ar at the logarithme of the expectation value of

Z

q

=

e

−
α
(
r
−

r

e

)

q

. These obtained outcomes are compared to the published results, both theoretical and experimental, and show a good agreement.
Analysis of reproducibility by using inclusive and exclusive statistics in the framework of a bilateral comparison
Authors: Álvarez Liliana , Colin Castellanos Carlos , Giarmana Gastón , López Celis Armando , Beer Ethel
Published: April 2022

A comparison of 11 steel gauge blocks (8 short and 3 long) calibrated by absolute interferometry is presented. Thus, the results of the individual measurements of five designated signatories (three from INTI and two from CENAM) were analyzed in order to evaluate the impact of possible correlations and systematic effects in the reproducibility of the measurements. All measurements were carried out in the framework of a bilateral key comparison between CENAM and INTI and following their own calibration procedures. The measurement analysis was performed by using inclusive and exclusive statistics. The agreement between all measurements is satisfactory and no detectable systematic effects were observed. Average offsets were also calculated for each operator, verifying that systematic effects did not affect the measurements of the present exercise. Even though the approaches deployed to analyze the results are well-established, this work provides a detailed example of analysis in the field of gauge block metrology. This exercise has also allowed to validate the internal criteria considered by each institute for selecting final results.
Mechanical properties of metal–matrix composites reinforced with carbide structures
Authors: Morozov N F , Semenov B N , Smirnov V M , Zemtsova E G
Published: April 2022

Metal–matrix composites based on an aluminum matrix reinforced with ceramic particles are widely used as structural materials in the aerospace and automotive industries. The main problems in the manufacture are the uniformity of the distribution of particles over the volume, poor adhesion of ceramic particles to the matrix metal, and the formation of aluminum carbide at the interfaces, leading to undesirable embrittlement. We propose a new technique for the manufacture of metal–matrix composites, which consists in creating a composite material, when carbide nanostructures form a framework in the volume of an aluminum matrix, and which allows solving the above problems. A finite element model of deformation of a metal–matrix composite reinforced with carbide structures is constructed.
Reinforcement of polymer composite materials by titanium dioxide nanoparticles synthesized in plasma discharge under ultrasonic cavitation
Authors: Kolesnik S A , Bulychev N A
Published: April 2022

In this work, the synthesis of titanium dioxide nanoparticles in plasma discharge was carried out under ultrasonic cavitation. It was found that applied acoustoplasma method allows to synthesize nanosized particles of titanium dioxide with the controlled shape and narrow size distribution. Polymer composite materials based on synthesized nanoparticles of titanium dioxide and epoxy polymer have been obtained by the in situ method by curing with preliminary ultrasonic dispersing. The composition and structure of the obtained TiO2 polymer composite materials have been studied by scanning electron microscopy. The mechanical properties of the obtained film polymer composite materials were investigated to determine the tensile strength, elastic modulus and relative deformation. It was found that nanoparticles in optimal concentration (3%) lead to the reinforcement of obtained composite materials.
On a pseudo-periodicity in the elastodynamics
Authors: Kurdina S P , Gevorgyan H A
Published: April 2022

The periodic laws of motion of a real mechanism imply the periodicity of all dynamic characteristics of the mechanism during such a movement, including the elastic displacements of its constituent links. This statement covers the most difficult problem of the dynamics of an elastically deformable body. However the existing publications devoted to the study of flexible mechanisms do not mention the periodicity of elastic displacements of the links when the mechanisms move according to periodic laws. This article discusses the periodicity and pseudo-periodicity of the elastic displacements of the links using examples of calculations of the motion of a double pendulum and a slider–crank mechanism without taking into account dissipative forces.
Quadrature formulas for Cauchy-type integrals with the Cauchy kernel to a integer power and a Jacobi weight function with complex exponents
Authors: Amirjanyan H A , Sahakyan A V , Kukudzhanov A K
Published: April 2022

The paper presents quadrature formulas for hypersingular integrals of various orders. It is assumed that the density of these integrals is represented as a product of a function that satisfies the Hölder condition and a weight function of Jacobi orthogonal polynomials. In this case, the exponents of the weight function can be complex numbers, the real part of which is greater than -1. Numerical analysis of the dependence of the root-mean-square deviation of the quadrature formula of order 8 on the value of the hypersingular integral calculated using standard software packages is carried out for various complex values of the weight function exponents. For hypersingular integrals up to the fourth order inclusive, a numerical analysis of the convergence of quadrature formulas is carried out for certain complex values of the exponents of the weight function.
Modeling of self-healing of microcracks in the process of longitudinal electroplastic rolling
Authors: Kukudzhanov K V
Published: April 2022

Multiscale model to describe the process of self-healing of microcracks in thin metal sheets during longitudinal electroplastic rolling is developed. The simultaneous treatment of a mechanical load and a pulsed high-energy electromagnetic field on the sheet is assumed. Finite element modeling has shown that under certain conditions microcracks and micropores can self-heal partially in the working zone. Impact of external pulsed high-energy electromagnetic field leads to welding of the shores of microcracks by molten metal in their tops, while the length and volume of cracks decrease.
Contact problem for a piecewise-homogeneous plane with an interfacial crack under dry friction
Authors: Hakobyan V N , Hakobyan L V , Dashtoyan L L
Published: April 2022

The article considers the contact problem of indentation of an absolutely rigid stamp with dry friction into one of the edges of an interfacial finite crack located in a piecewise homogeneous elastic plane. The governing system of equations for the problem is derived in the form of a system of three singular integral equations with respect to the normal contact pressure under the stamp and dislocation components of the displacements of the crack edge points. The exact solution is constructed. The behavior of contact stresses near the end points of a crack is studied depending on the ratio of the elastic characteristics of heterogeneous materials of half-planes that formed a piecewise-homogeneous plane.
Formation of a hybrid of electroacoustic waves in piezoelectric layered composites
Authors: Avetisyan A S , Khachatryan V M , Mkrtchyan M H
Published: April 2022

Investigating the reflection and refraction of electroelastic waves at a plane interface without acoustic contact between two piezoelectric half-spaces of different textures, it was found that: (i)As a result of the incidence of a two-component electroelastic shear wave on the interface between the media, the same wave is reflected into the first half-space, and a three-component electroelastic plane strain wave is refracted into the second half-space. In the utmost cases, in layered inhomogeneous waveguide, a wave hybrid of electroacoustic waves is formed. This makes it possible to transmit along the boundary of non-acoustic contact of media a hybrid of electroacoustic surface waves of the Gulyaev-Bluestein type and Rayleigh type localized near this boundary. (ii)As a result of the incidence of a two-component electroelastic plane strain wave on the interface between the media, the same wave is reflected into the first half-space, and a three-component electroelastic shear wave is refracted into the second half-space. This also makes it possible to organize a hybrid of electroacoustic waves of elastic shear and plane deformation of the type of periodic electroelastic Floquet waves in a periodically transversely inhomogeneous piezoelectric composite. The conditions for the possible formation of the hybrid and the characteristics of their propagation in the layered composites of piezoelectrics of the hexagonal symmetry class 6mm and

6

¯

m2 are discussed.
Supersonic divergence of a panel with a free edge initially loaded in two directions tensile and compressive forces
Authors: Martirosyan S R
Published: April 2022

In the article, in a linear formulation, the problem of the static stability of a rectangular plate in a supersonic gas is investigated, initially loaded in two directions, respectively, stretched along the gas flow and compressed in the direction perpendicular to the gas flow velocity, under the assumption that the gas flow runs on its free edge. An analytical solution to the problem is obtained. The space of parameters of the “plate-flow” system was partitioned into areas of stability and static instability in the form of panel divergence and in the form of localized divergence. The corresponding critical velocities are found. The ratio of the stress coefficients characterizing the tensile and compressive forces, leading to the dominance of the stabilization effect, has been established. It is shown that compressive forces have an insignificant effect on the stability of sufficiently elongated plates, in comparison with tensile forces. The boundary value of the tensile stress coefficient is found, starting from which the elongated plates are stable at the beginning of the interval of supersonic velocities.
Fuel ignition delay in hydrogen diesel
Authors: Bunev V A , Korzhavin A A , Senachin A P , Senachin P K
Published: April 2022

A new mathematical model is considered for modeling the induction period of fuel self-ignition in a hydrogen diesel engine with high-pressure injection equipment. Reconstruction of the macrokinetic equation and numerical modeling of the process of self-ignition of fuel in a hydrogen diesel engine are carried out.
Formation features of benz(a)pyrene and nitrogen oxides when burning brown coal in boilers with liquid slag removal system
Authors: Elsukov V K , Latushkina S V
Published: April 2022

In the article, the authors examine the experience of burning Kansk-Achinsk coal (KAC) in the boilers of the BKZ-320-140PT type at the CHPP-6 in Bratsk. The article considers the results of the experiments carried out at two boilers (b.u.No.5 and No.7), where the organization of aerodynamic processes is significantly different. These results are presented as the dependences of the concentrations of nitrogen oxides (NOx) and benz(a)pyrene (BaP), as well as the content of combustibles in fly-ash (Cf) on several parameters simultaneously, namely, the boiler load, the number of working dust collecting systems, and excess air. The following conclusions have been drawn: 1) two parameters have the most significant effect on the amount of BaP emissions – the scheme of entering drying gases into the combustion chamber and the excess air in the combustion chamber; 2) there is a certain relationship between BaP emissions and the content of combustibles in fly-ash: a lower Cf value corresponds to the mode with a lower concentration of BaP. It follows that BaP emissions can be reduced by measures reducing chemical and mechanical underburning (q3 and q4), primarily the turbulization of flue gases. The formula is proposed that clarifies the values of BaP emissions during vortex combustion. It is shown that the formation of NOx is also significantly affected by the same parameters as the formation of BaP, as well as the load of the boiler. The effect of these parameters is explained. Various technological measures are proposed to reduce pollutant emissions comprehensively by providing vortex combustion in the boilers with both liquid and solid slag removal systems.
Cutoff limitation of left-hand polarization wave and candidates for further enhanced producing multicharged ions on ECRIS
Authors: Kato Y , Kubo W , Harisaki S , Anan M , Tsuda K , Sato K , Owada I , Maenaka T
Published: April 2022

Based on experimentally obtained plasma parameters in an electron cyclotron resonance (ECR) ion source (ECRIS) and theoretical considerations, it is turned out the essential factor that is currently presumed to define the increase in multicharged ion current in ECRIS is not simply the density limit of ordinary wave and right-hand cutoffs, but is also higher density one of left-hand cutoff. There are two response guidelines that can be considered to make it possible to overcome limitations, except for the conventional simply increasing the frequency and the magnetic field strength. One is advanced high-frequency resonance, i.e., upper-hybrid resonance (UHR), which is conversion from electromagnetic to electrostatic wave essentially without cutoff. The others are due to the introduction of lower frequency waves than ECR’s one, which has no density limit in a more essential sense. The latter is the introduction of lower-hybrid resonance (LHR) or ion cyclotron resonance (ICR). We will describe experimentally obtained plasma parameters, and will discuss these candidate applications.
Redefining plasma chambers for ECR Ion Sources: the IRIS structure
Authors: Mascali D. , Galatà A. , Gallo S. , Leonardi O. , Mauro G. S. , Naselli E. , Pidatella A. , Russo F. , Sorbello G. , Torrisi G.
Published: April 2022

One possible way to optimize microwave coupling and plasma confinement in Electron Cyclotron Resonance (ECR) Ion Sources is a revolutionary design strategy of plasma chambers, breaking the cylindrical symmetry. This contribution reports about the design and numerical validation of an innovative resonant cavity playing as plasma chamber of ECR ion sources. The new chamber, named IRIS (Innovative Resonators for Ion Sources), was argued starting from the 3D structure of the plasma and, therefore, fashioned to the twisting magnetic structure. The microwave launching scheme was radically changed as well, consisting of side-coupled slotted-waveguides with diffractive apertures smoothly matching the overall structure of the camera. This approach also enables a profound optimization of cooling systems and overall spaces in general (for gas feedings, oven systems, sputtering, etc.). Here we report on the conceptual study, electromagnetic design and PIC simulations of the electron heating in the novel resonant cavity, comparing results with those for standard (cylindrical) chamber, and also considering the impact of microwave feeding led by single aperture rectangular waveguides vs. waveguide-slotted antennas. Manufacture strategy, based on additive manufacturing techniques, will also be discussed.
Two-rod-antenna microwave injection system for production of circularly polarized microwaves in cylindrical ECRIS cavities
Authors: Philipp Alexandra , Molodtsova Maria , Ritter Erik
Published: April 2022

In the design of Electron Cyclotron Resonance Ion Sources (ECRIS) three topics generally need to be addressed: (i) The feed of a microwave to generate a plasma, (ii) the creation of a magnetic field guiding the charged particles, and (iii) the design of an ion extraction system. In this report, we concentrate on improvements of aspect (i), a new microwave injection system introduced to the Dresden ECRIS 2.45M, a permanent-magnet 2.45 GHz ECRIS, applied, e.g., for the production of proton currents in medical particle therapy. The improvements include the replacement of its one-rod antenna system by two rod antennas on one cross-sectional circle of the cylindrical ECRIS cavity positioned under an angle of 90° towards each other. Feeding two microwave signals with a relative phase shift of 90°, a right-hand circularly polarized wave can be created inside the cavity to efficiently heat the electrons. Basic considerations, simulations, and results from first experiments are presented.
New Commissioning Results of the MIST-1 Multicusp Ion Source
Authors: Winklehner Daniel , Conrad Janet , Smolsky Joseph , Waites Loyd , Weigel Philip
Published: April 2022

For the sterile neutrino experiment IsoDAR (Isotope Decay-At-Rest), we have developed a compact particle accelerator system delivering a 10 mA, continuous wave (cw) proton beam at 60 MeV to a neutrino production target. The accelerator comprises a compact isochronous cyclotron, an RFQ embedded in the cyclotron yoke, and an ion source. To reduce space charge effects during injection and acceleration, we are accelerating H+
2 instead of protons. To produce the needed cw H+
2 beam current of 10 mA (nominal) at the required purity and quality, we have built a new filament driven, multicusp ion source (MIST-1). Here we report commissioning results for long-time running at reduced power, demonstrating the feasibility of the design. Highlights include an H+
2 beam current density of ≈ 10 mA/cm2, ≈ 80% H+
2 fraction, and extrapolated emittances of 0.05 π-mm-mrad (RMS, normalized) after extraction. We also present high fidelity simulations that are in good qualitative and quantitative agreement with emittance measurements in our test beam line.
The AISHa ion source at INFN-LNS
Authors: Castro G. , Celona L. , Chines F. , Costanzo G. , Gammino S. , Leonardi O. , Malferrari L. , Massara A. , Maugeri C. , Neri L. , Odorici F. , Passarello S. , Reitano R. , Russo F. , Siliato D.
Published: April 2022

The Advanced Ion Source for Hadrontherapy (AISHa) is an ECR ion source operating at 18 GHz, developed with the aim of producing high intensity and low emittance highly charged ion beams for hadrontherapy purposes. Due to its unique peculiarities, AISHa is a suitable choice for industrial and scientific applications. In the framework of the INSpIRIT and IRPT projects, in collaboration with Centro Nazionale di Adroterapia Oncologica (CNAO), new candidates for cancer treatment (including metal ion beams) are being developed. Moreover, within the IONS experiment, AISHa will be the test-bench for the development of an innovative active plasma chamber designed to increase plasma confinement by changing plasma fluxes. OES technique will be also used to refine techniques of non-invasive plasma diagnostics. Finally, a dedicated setup is under realization to provide impinging beams and detection systems for target production in nuclear physics experiments.
Impurities Reduction Conditionings to Recover Best Beam Quality of J-PARC Cesiated RF-Driven H- Ion Source with New Parts Exposed to Plasma
Authors: Ueno Akira , Ohkoshi Kiyonori , Ikegami Kiyoshi , Oguri Hidetomo
Published: April 2022

For the J-PARC operations, only three plasma chambers (PCHs) of #7, #8 and #9PCHs among ten PCHs have been used since the transverse emittances of the beam produced with them are more superior than those with others for unknown reasons. However, the #7PCH beam emittances were enlarged by 16 % with a brand-new plasma electrode temperature control plate (PETCP) to solve the air leak at the VCR vacuum fitting. The impurities from the new parts exposed to the plasma seemed to cause the degradation. The beam with almost the best emittances was reproduced by #4PCH with a new PETCP after a new impurities reduction conditionings for 48 hours, in which the impurities produced by the plasma were reduced as small as possible by scanning both of 2-MHz-RF power and axial magnetic field in #4PCH.
RF power transfer efficiency of H ion sources: fluid modeling of accelerator source geometries
Authors: Briefi S , Zielke D , Fantz U
Published: April 2022

The plasma in RF driven negative hydrogen ion sources is sustained via inductive coupling with large power levels of up to 100 kW and low frequencies around 1 MHz. This leads to currents of around 100 A flowing over the RF coil and corresponding voltages in the kV range. The associated risk of arcing limits the reliability of the whole ion source. The required power level can be reduced via optimizing the RF power transfer efficiency η, which is typically only in the range of 50 to 60% for H- sources used for neutral beam injection systems. In order to study the optimization of η systematically, a self-consistent fluid model has been set up and successfully validated with experimental measurements at the BATMAN Upgrade test bed. For H- sources applied at particle accelerators, no experimental measurements of η are available so far. In order to gain a first insight into the RF power transfer efficiency of these sources, exemplary simulations were carried out with the fluid code. The simulated plasma parameters are in good agreement with results from OES measurements. η shows an increasing trend with larger source radius and a virtually constant value with increasing RF power. For benchmarking these first results, dedicated measurements at an accelerator source setup are inevitable.
Beam instability in the vicinity of beam extraction region of negative ion source
Authors: Nagaoka K. , Nakamoto R. , Sasaki T. , Hamajima T. , Nakano H. , Ikeda K. , Fujiwara Y. , Osakabe M. , Takeiri Y. , Tsumori K.
Published: April 2022

Beam instability in the presheath region of negative ion beam extraction is investigated in theoretically and experimentally. The linear stability analysis shows that the beam instability is unstable due to coupling between positive ion flow and negative ion flow. On the other hand, no clear activity can be seen in the experiment in the frequency range predicted by the theory. The beam instability in the presheath region of negative ion beam extraction may not cause the degradation of the beam focusing because of collisional damping and/or Landau damping.
Towards the optimization of the Cs evaporation configuration for long pulse operation of negative ion sources
Authors: Mimo A. , Wimmer C. , Wünderlich D. , Fröschle M. , Fantz U.
Published: April 2022

Negative ion sources for neutral beam injection rely on surface production of negative ions on a caesiated low work-function surface (plasma grid). To maintain the low work function in long pulses (one hour) and the desired source performance (extracted H-/D- ions and limited co-extracted electrons), Cs needs to be constantly delivered onto the plasma grid. The CsFlow3D code was applied to the RF driven negative ion source ELISE to simulate the evaporation and the plasma-assisted redistribution of Cs. The Cs flux stability is investigated for consecutive one hour plasma pulses and compared with experiments. The effect of different positions of the Cs oven for the case of ELISE equipped with two racetrack shaped RF drivers was investigated: a considerable increase of the Cs flux occurs when evaporating where the plasma is in contact with surfaces, as confirmed also by the back-tracking of the Cs particles reaching the PG. Additionally, an alternative evaporation method close to the plasma grid was designed with the help of CsFlow3D and tested in BATMAN Upgrade, with the aim of increasing the Cs flux onto the PG and achieve a better control of caesiation in long pulses.
Radioactive and Stable Ion Beam production at GANIL
Authors: Dubois M. , Bajeat O. , Barué C. , Bosquet V. , Chauveau P. , Damoy S. , Frigot R. , Hormigos S. , Jardin P. , Lechartier N. , Lemagnen F. , Maunoury L. , Métayer V. , Osmond B.
Published: April 2022

GANIL Facilities deliver ion beams from Proton to Uranium up to 95MeV/A. The Cyclotron facility combined with the SPIRAL1 facility provides Stable Ion Beams (SIB) since 1983 and Radioactive Ion Beams (RIB) since 2001 for Physics experiments. R&D of new stable and radioactive beams are continuously under progress matching physicist requirements. During the last ten years, the SPIRAL1 facility was upgraded to extend its capabilities to deliver RIBs of condensable elements. After a new one delivered in 2019, off-line R&D’s have been done on the Target Ions Source System and also on the Charge Breeder to improve efficiencies and achieve an operational and reliable facility.

In parallel, the commissioning of the LINAC-SPIRAL2 facility started in 2019 with a proton beam production. In 2020, a 16 kW proton beam was delivered for the first time on the Neutron For Science physics area, and a 4 mA beam of 4He2+ was produced with the PhoenixV3 ECR ion source to mimic a deuteron beam. In this article, an overview of GANIL ion sources, beam properties and future developments are described.
Empirical study of multidimensional Child-Langmuir law with plasma ion source extraction using round apertures
Authors: Kosonen S T , Kalvas T , Tarvainen O , Toivanen V
Published: April 2022

One dimensional Child-Langmuir (CL) law is commonly used in ion source physics to describe space charge limited ion extraction from the plasma. Recently 2D and 3D CL laws have been derived, but plasma ion extraction does not strictly meet the assumptions in these CL laws. Investigations on the applicability of the CL laws to ion source extraction were conducted using filament-driven ion source, measuring the beam currents as a function of extraction voltage. The experiments are complemented with simulations where IBSimu is used for studying the behaviour of plasma meniscus. Three different voltage regions were identified with low, moderate and high voltage. With moderate voltages the extracted beam current density shows signs of 3D CL law. The results indicate that for the total beam current CL laws are not valid but instead require collimation for the CL effects emerge.
Double-sided detector for electron beam alignment and measurement of back-streaming electrons in ExtendedEBIS at BNL
Authors: Ikeda Shunsuke , Beebe Edward , Kanesue Takeshi , Kondrashev Sergey , Okamura Masahiro
Published: April 2022

We developed an electron beam detector installed between the superconducting solenoids in ExtentedEBIS. The detector is two-sided. Each side has 4 quadrant plates with an aperture slightly larger than the electron beam radius. The gun-side is for alignment of primary electron beam. The collector side detector is to measure the electrons back-streaming from the collector or the downstream electrodes to the cathode. It is important to understand how the back-streaming electrons behave and how to control it. The detector was designed with considerations of heat load. The influence on the electric potential distribution was investigated. A detector test showed that the back-streaming electrons were affected by the external electromagnetic fields and the space charge of the primary electron beam. It was proved that the behaviour of the electrons can be observed by this detector.
Generation of proton and carbon ion beam from laser ion source using hydrocarbon oil target
Authors: Takahashi K , Katane H , Miyazaki K , Harukawa N , Ishikuro K , Sasaki T , Kikuchi T
Published: April 2022

The supply of high-flux proton and carbon ions are required for applications such as accelerator-driven neutron sources and heavy ion radiotherapy. So far, it is shown that a laser ion sources using the target of plastics made of hydrocarbons can provide protons and carbon ions. On the other hand, due to the damage of the target by laser irradiation, it is necessary to change the laser irradiation position every time, and the number of ion supply is limited to the area of the laser target. To solve the problem of target damage, we suggest a laser target in which the surface is continuously renewed by flowing hydrocarbon oil instead of solid hydrocarbon. In this study, we demonstrated the generation of protons and carbon ions using the target made of a hydrocarbon oil for a diffusion pump.
Space Charge Compensation Study of High Intensity Ion Beams
Authors: Shen Z , Sun L T , Jia Z H , Fang X , Qian C , Zhao H W
Published: April 2022

The space charge effect is one of the key factors affecting ion beam transport and ion beam quality, especially for low-energy high-intensity ion beams. It can be partially compensated by the secondary electrons produced from the ionization of residual gas molecules in the beam pipe, and we are interested in the accurate value of this compensation degree. In this paper, we use a Three-grid Energy Analyzer (TEA) to measure the secondary ion energy distribution of the beam, which corresponds to the compensated beam potential distribution. To have accurate evaluation of the compensation degree, it is essential to adopt a proper transverse distribution of the ion beam, other than using the Gaussian theorem for uniform beams. The results of a space charge compensation degree study for singly charged ion beams with a 2.45GHz microwave ion source and for multiply charged ion beams with a high charge state ECR ion source are presented.
High Power Density Beam Measurement of a Single Beamlet Multi-Grid Prototype H- Negative Ion Accelerator
Authors: Saquilayan G Q , Kisaki M , Kojima A , Shimabukuro Y , Murayama M , Hiratsuka J , Ichikawa M , Watanabe K , Tobari H , Kashiwagi M
Published: April 2022

Beam optics of the ITER prototype accelerator with 88 mm acceleration gap length has been examined through H- beam acceleration tests at the ITER target beam perveance. The beam optics has been examined for beam energies up to 790 keV under the ITER target perveance. The total grid heat load was successfully reduced to 10 %, which was lower than the allowable value of 15 %. The beam emittance of the ITER perveance has been measured for the first time by using newly developed emittance measurement system consisting of carbon-fiber-composite (CFC) plate with pin-holes. The emittance of 790 keV H- beam shows the divergence angle of the beam core is satisfied with the ITER requirement of <7 mrad. Measurement at the beam periphery was made possible by modifying the pin-hole size of pepper-pot apertures, and the observed divergent components were 20 mrad. The ratio of the diverged beam became lower with the increase of the beam energy. This result contributes the design of the ITER accelerator and the beam line components.
Production of Radioactive Molecular Ions in Radiofrequency Quadrupole Gas-Reaction Cells
Authors: Charles Chris R.J. , Ames Friedhelm , Kester Oliver , Malbrunot-Ettenauer S. , Babcock Carla , Schultz Brad E. , Peters Cameron , Flannigan Erin L. , Alary Jean-Francois , Laxdal Aurelia , Kunz Peter , Lassen Jens , Teigelhoefer Andrea , McCausland Phil J.A. , Flemming Roberta
Published: April 2022

Limited types of radioactive molecules (RM) can be made inside hot-cavity targets at ISOL facilities like TRIUMF. However, extreme conditions in these targets present formidable unsolved challenges to efficient production and delivery of RM’s. Here we propose using RFQ gas-reaction cells to produce RM from radioactive ion beams (RIB) by room temperature RIB-gas chemical reactions at eV energies. Two options are possible: (1) using an ion reaction cell (IRC) that is a linear RFQ ion guide and reaction cell used as an ‘on-line ion source’, and (2) using the ARIEL RFQ cooler-buncher (ARQB). RFQ gas-cells are a controllable and efficient method to produce RM from chemical reactants that cannot be used in ISOL targets. This ‘online chemistry’ offers a way to enable groundbreaking Beyond Standard Model (BSM) physics research, using a wide diversity of new rare and exotic RM beams that would be difficult or impossible to produce in hot-cavity targets.
Operation experience of LION and RHIC-EBIS for RHIC and NSRL
Authors: Kanesue T. , Beebe E. , Coe B. , Ikeda S. , Kondrashev S. , Lopez-Reyes A. , Okamura M. , Schoepfer R. , Rodowicz T.
Published: April 2022

LION is a laser ablation ion source to provide singly charged heavy ions of various species for RHIC-EBIS. High charge state heavy ion beams from RHIC-EBIS are used for RHIC physics experiments and NASA Space Radiation Laboratory (NSRL) quasi-simultaneously. The demands for heavy ion beams are growing and more ion species are available and more NSRL beam time is used because of unique capability and flexibility of the sources. With the combination of LION and RHIC-EBIS, ion species can be switched on a pulse-by-pulse basis without the effect of previously used species. The present performance and operation experiences of LION and RHIC-EBIS are shown.
Magnet system design for the new 18 GHz ECR ion source at GSI
Authors: Andreev A , Maimone F , Mäder J , Lang R , Patchakui P T , Tinschert K , Hollinger R
Published: April 2022

In order to increase intensities and charge states of available ion species, a new room-temperature ECR Ion Source (ECRIS) operating at 18 GHz is currently under development at GSI. The new ECRIS is based on a Heavy Ion Ion Source Injector (HIISI), developed at the Department of Physics, University of Jyvüskyla (JYFL), and features three normal conducting coils and a permanent magnet hexapole for plasma confinement. The latter has to be installed inside a refrigerated hexapole chamber, allowing to achieve the required radial confining field and avoiding demagnetization of permanent magnets. Computer simulations are carried out with Opera software package for two Halbach hexapole arrangements and the resulting three-dimensional magnetic fields are compared. The demagnetization of permanent magnets due to the superposition of fields generated by the coils and the hexapole is also simulated for both arrangements.
Trapping secondary electrons in ExB drift for an alpha generating penning ion source
Authors: Savard N , Groutso A , Melanson S , Potkins D , Dehnel M
Published: April 2022

A Penning ion source test stand has been developed by D-Pace to characterize alpha ion extraction from a helium discharge with variations in: extraction potential up to 15 kV, gas flow rate up to 30 sccm, and magnetic field confinement up to 1.1 Tesla. A brief summary of the Penning ion source design is described. Attempts at extraction of ions leads to severe sparking events on the high voltage insulator due to ExB drifts of secondary electrons. This paper shows the design of two sets of electrodes which together trap most electrons moving towards this insulator due to ExB drifts. This eliminates the severe high voltage breakdown on the insulator and allows for a more robust operation of the ion source.
Developments of control system for ion source using machine learning
Authors: Morita Y , Fukuda M , Yorita T , Kanda H , Hatanaka K , Saitou T , Tamura H , Yasuda Y , Washio T , Nakashima Y , Iwasaki M , Koay H W , Takeda K , Hara T , Chong T H , Zhao H
Published: April 2022

Various factors influence each other in an ion source. Therefore, when operating an ion source, it is necessary to optimize and adjust various parameters. This time, we performed an experiment to automize adjustment that maximizes the brightness of the beam using machine learning. By automatically adjusting 4 parameters, we succeeded in finding a point with a beam brightness of 4.32 × 10-6 mA/(imm mrad)2 in 25 steps. This shows that automatic adjustment using Bayesian optimization is feasible.
The Synthesis of Low Pt loading Agcore- Pt atoms-exposedshell Structure by Ligand Exchange Method with High Electrocatalytic Performance for Hydrogen Evolution Reaction
Authors: Di Qian , Zhu Wenjing , Luan Yiliang , Gu Yufeng , Chi Chunlei , Zhang Jun
Published: April 2022

Platinum-based nanomaterials are well-known to show excellent hydrogen evolution reaction (HER) catalytic performance. The sophisticated structural design facilitates the development of related disciplines such as water splitting devices. Here, a kind of Agcore- Pt atoms-exposedshell structure could be synthesized through ligand exchange between Ag nanoparticles and Pt polysulfide precursor at room temperature (RT). The Ag core maintains its face-centered cubic phase (FCC) crystal phase after the formation of Agcore- Pt atoms-exposedshell structure. While Pt atoms account for only 0.4617 percent of the catalyst mass. With a further electrochemical reduction of Pt (IV) atoms into metallic state Pt (0) atoms from -1.2 V vs. RHE to 0.4 V vs. RHE, the HER catalytic performance of Agcore- Pt atoms-exposedshell would exceed that of commercial 20% Pt/C at low potentials (<-0.487 V vs. RHE). Furthermore, we found the HER performance is stable, which verifies that the Pt polysulfide is tightly bound to the surface of Ag. Specifically, the present approach shows great potential for the construction of nanostructure with high atomic utilization.
Synthesis of cube-shaped PtFeNiCuCo alloy catalyst towards high performance alkaline hydrogen evolution
Authors: Liu Shi , Gan Tuanjie , Wu Jianping , Yang Xi , Liu Haiyuan , Chen Zhaoqian
Published: April 2022

The commercialization of hydrogen fuel cell technologies requires high-performance and low-cost catalysts for production of highly pure hydrogen from electrochemical water splitting. In this work, cube-shaped multicomponent alloy catalysts PtFeNiCu and PtFeNiCuCo supported on carbon nanotubes were synthesized by one-step wet chemical reduction method. Powder X-ray diffraction analysis and transmission electron microscope imply the successful synthesis of alloy catalysts. The particle size of PtFeNiCu and PtFeNiCuCo is determined to be around 12.6 nm. The impact of the Co-doping into the PtFeNiCu alloy on the structural defects and catalytic performance towards alkaline hydrogen evolution (HER) was explored. It is observed the Co-doping into PtFeNiCu alloy induces sufficient decrease of the crystalline size and enhancement of the microstrain and stacking defects, as revealed by the Williamson-Hall method. It was observed that the overpotential for PtFeNiCuCo at the current density of 10 mA/cm2 in 1 M KOH is only 27 mV and Tafel slope is 34.7 mVdec1, superior to that of PtFeNiCu and commercial Pt/C. Such enhanced electrocatalytic performance was ascribed to the extensile strain and surface defects induced by the Co-doping and the synergistic effect of Co and other metal elements.
Study on the Operation Optimization Dispatching Strategy of Small and Medium-sized Pumped Storage Power Station
Authors: Gu Zhenghan , Zhang Yi , Wu Yifeng , Zhang Feng , Tang Lv , Mo Jianguo
Published: April 2022

This paper uses equivalent substitution method and random production simulation method to calculate the static efficiency of daily operation of small and medium-sized pumped storage power stations, maximize the static efficiency under energy storage constraints, and obtain the daily output operation scheduling plan of pumped storage power station. Their utility and effectiveness are demonstrated by using multiple load curves including summer peak load and holiday load and applying the calculation results to practical scheduling operations. This method for the same type of pumped storage power station, has a general practical and guiding value.
Utilizing Metal-Organic Frameworks to Achieve High-Efficiency CO2 Electroreduction
Authors: Guo Gengzhan , Wang Tianyang , Wang Yuzhe
Published: April 2022

Electrochemical CO2 reduction reaction (CO2RR) is the key part of clean energy generation and utilization, which has great potential to help the world to reach the carbon-neutral energy cycle in the future. In line with the development of metal-organic frameworks (MOFs) with the large specific area and considerable porosity in the past two decades, some of the MOF-based electrocatalysts have shown superior ability to accelerate CO2RR. However, regarding such a significant CO2RR process, some critical disadvantages, including inferior robustness, low yield and selectivity, and idealistic working environment, are still required to be concentrated on. Herein, a comprehensive outline of the reaction mechanism of CO2 conversion and rational synthesis of the state-of-the-art pristine MOFs is given. Further, recent progress of pristine MOF-based electrocatalysts in CO2RR is systematically summarized. Lastly, the major limitations and future opportunities in MOF electrocatalysis for CO2RR are presented.
Research on the mechanism and application of rigid and flexible metal-organic frameworks in selective adsorption
Authors: Zhou Wenjing
Published: April 2022

Metal-organic frameworks (MOFs) are materials with porousness that metal ions and organic bridging ligands make up the composition to join. They are commonly employed in gas separation applications because of their extraordinarily high sorption capacities and complicated sorption behaviour. This article mainly introduces the mechanism and application of rigid and flexible MOFs used in selectively separating various gases. Rigid MOFs are just standard MOFs with rigid backbones and porous frameworks that are comparably stable and strong. Based on molecular sieving effect, interactions between adsorbates and surfaces, and the cooperative effects of size/shape exclusion and adsorbate-surface interactions, rigid MOFs used in selective adsorption of H2, O2, CH4 were highlighted. For flexible MOFs, the crystalline order of the underlying coordination network is combined with cooperative structural transformability in them. Based on size/shape exclusion, adsorbate-surface interactions and gate-opening or structural rearrangement caused by adsorbate-surface interactions, gate-opening forces that are particular to each gate, flexible MOFs used in selective adsorption of C2H2, CO2 and CH4 were discussed.
Study on protection measures of lightning electromagnetic pulse in automatic weather station
Authors: Liu Qiangjun , Chang Mingyang , Wang Lizhi
Published: April 2022

Due to automatic meteorological station, the distribution of the unique geographical location and environment, the equipment has a large number of sensors and electronic components, and a highly integrated, combined with the electronic components of low dielectric strength, compression ability and the ability to resist electromagnetic interference and weak ability to resist shock current and lightning electromagnetic pulse is easy to damage to electronic equipment. Therefore, this paper analyzes the existing problems and harms in lightning protection design of automatic weather station system in Shanxi Province, and puts forward improvement and protection measures.
Analysis of Slip rate Control Technology of Electric Vehicle Based on Sliding Mode Algorithm
Authors: Zou Xiang
Published: April 2022

With the increasingly prominent environmental and energy problems, it is very important to strengthen the research of new energy vehicles. In the research process of new energy vehicles, the safety of electric vehicles during driving is extremely important. In the braking process of electric vehicles, wheel slip control is an important factor to ensure the safety of electric vehicles. In the process of slip rate control, it is necessary to identify the wheel slip rate under different road surfaces, so as to complete the design of the slip rate controller on the basis of mastering the wheel friction characteristics. In this research, we mainly consider the maximum braking torque limit of motor output, scientifically distribute regenerative braking and hydraulic braking torque, complete the design of slip rate controller based on sliding mode algorithm, and introduce saturation function to solve the buffeting problem in road friction adaptive slip rate control method. Put forward the core of slip rate control strategy of electric vehicle. Through research, it is determined that the reasonable division of regenerative braking and mechanical braking based on slip rate can improve the safety of vehicle braking and ensure the efficiency of energy recovery. Therefore, in the process of electric vehicle slip rate control, the regenerative braking control method based on slip rate closed-loop control has application value.