bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on a Circular Cylindrical Floating Device and Its Motion Response Characteristics
Authors: Ding Minting , Chen Zhenlei
Published: January 2023

In this paper, a circular cylindrical floating device design is proposed by combining the structural features of the cylindrical Floating Production Storage and Offloading (FPSO) and the deep-sea Spar platform. It is suitable for deep-water oil and gas field development environment in the South China Sea. This floating device adds six floats with a Spar platform hard tank role based on the cylindrical FPSO to improve the buoyant center. This paper analyzes the motion response characteristics of the circular cylindrical floating device in waves by the Eulerian multi-phase flow model of STAR-CCM+. The results show that the pitch motion characteristics of the circular cylindrical floating device are better than those of the cylindrical FPSO and ship-type FPSO in the reference [8]. In addition, the paper also investigates the motion response of the circular cylindrical floating device with different directions of the incoming flow. The analysis shows that this floating device has the lowest motion response at 30° direction incoming flow. And the Response Amplitude Operator (RAO) of pitch motion shows a negative correlation with the incoming flow direction. The research results of this paper can provide a reference for the future development of marine resources, and have a certain practical significance.
Application Research of Pulse Vibration High-Frequency Voltage Injection Method Without Speed Sensor in New Energy Vehicles
Authors: Han Yangqi , Zheng Yaqing , You Yuancheng , Chen Yajuan
Published: January 2023

The high-frequency voltage injection method of pulse vibration in the range of zero/low speed to medium-high speed has to be demonstrated for new energy vehicles., because it is very necessary and necessary to control the safety performance of the whole vehicle without speed sensor. The permanent magnet synchronous motor starts slowly to circle when the clean - energy vehicle cranked, and the correctness of the rotor’s startup position identification is significant. In order to achieve high-performance control of permanent magnet synchronous motor without speed sensor, this paper focuses mainly on how to estimate the rotor position of permanent magnet synchronous motor by amplifying the mathematical model of the motor. The high-frequency mathematical model of the permanent magnet synchronous motor’s voltage parameters are attained in the process of maintaining the motor’s preoperational position to address the problem of self-adaptability between the injected voltage and the likely phase current. The initial position identification of the rotor of a permanent magnet synchronous motor can be achieved by optimizing the adaptive method, and the pulse vibration highfrequency voltage anesthetic method also shows better efficiency and safety when the motor achieves a stable start and has sound output torque. The struggling to retain adaptive measurement device vibration high frequency voltage injection approaches is used by the light-duty low-speed new energy vehicle, which may minimize the mechanical speed sensor after becoming damaged, save the cost and improve the compactness of the electric vehicle space design, which is conducive to solving the situation of energy shortage in my country and alleviating environmental pollution. This is in line with the future development concept of society.
A TSV-Based Helical Dual-Band Antenna
Authors: Wang Fengjuan , Ren Jiashuo , Yu Ningmei , Yang Yuan
Published: January 2023

This paper come up with a novel helical dual-band antenna that can be used in terahertz (THz) band applications. The antenna is fed by a redistribution layer (RDL), and the metal patch is formed on the top and bottom surfaces of the silicon dielectric substrate, which is connected by through-silicon via (TSV) to form a helical structure. At the same time, better impedance matching can be achieved by changing the shape of the ground plate to achieve dual-band characteristics. The simulation results presentation that the return loss of the antenna in 319GHz-339GHz and 373GHz-388GHz is less than -10db, and it has good axial radiation characteristics.
Study on the Measured Signal Analysis Method Based on Sine Curve-fit Method for Ship Model Seakeeping Test
Authors: Shi Sheng-zhe , Jiang Ting , Wang Fan , Zheng Xiao-long
Published: January 2023

Ship model seakeeping test measure data included frequency ponderances of syntonic waves, mixed waves, and white noise, which affect the test result. Heave time series and pitch time series of planning hull model seakeeping test are calculated by the three-parameter sine wave curve-fit method. Amplitude, angular frequency, and phase angle are obtained. The result shows that the distortion degrees of heave and pitch decrease gradually with an increase in wavelength; when the test wavelength is 8.8m, the distortion degrees of heave and pitch are the smallest, which reach 2.79% and 4.69%; however, at a wavelength of 11m, the distortion degrees of heave and pitch increase.
Multi-beam Sonar Signal Simulation and Field Programmable Gate Array Implementation
Authors: Luo Yu , Li Shiwen , Shi Jian , Cheng Mengdi
Published: January 2023

The multi-beam bathymetric sonar system is one of the top pieces of equipment for ocean exploration. The action distance of multi-beam bathymetric sonar depends on the pulse width of the signal, and the distance resolution depends on the bandwidth of the transmitted signal. In this paper, a chirp signal generation method for shallow water multibeam sonar based on FPGA is presented to improve the performance of multibeam bathymetric sonar. A chirp signal is generated using a hardware description language with a bandwidth of B = 50 kHz and a pulse width of T = 1 ms. Compared with the traditional look-up table method, this method could release plenty of hardware resources.
Influence of Slot Combination on the Vibration of Low-Noise Asynchronous Motor
Authors: Feng Haijun , Zhang Yue , Chen Changsheng , Fu Dongliang , Li Guoping
Published: January 2023

The slot combination of stator and rotor plays a decisive role in the tangential force and radial force of the motor, to obtain the influence of slot combination on motor vibration and noise, taking a 55kW asynchronous motor with a maximum speed of 1500 r/min as an example, and four kinds of motors with different slot combination were designed. The order and frequency of electromagnetic force waves with different slot combinations were estimated by numerical method, and the influence of slot combination on the vibration of the motor was studied by test.
Research on Logic Loading Process and Signal Integrity based on Prom
Authors: Sun Pei , Ji Jin , Guo Jingtao , Fan Xinming
Published: January 2023

a certain embedded product failed to load FPGA configuration occasionally when it was powered on. In order to determine the cause of the failure, the principle of FPGA configuration circuit was studied, and the possible causes of the failure were analyzed. Through testing, theoretical analysis and comprehensive simulation, it was finally determined that the layout of CCLK matching resistance was unreasonable, which led to the wrong loading of configuration data caused by CCLK false edge acquisition. Finally, the corrective measures are proposed for the fault, and the test shows that the measures are reasonable and effective.
An Analysis of Miniaturization of 5G Massive MIMO Base Station Antenna
Authors: Gu Hanyang
Published: January 2023

This paper reviews current works and efforts on the miniaturization of the 5G Massive MIMO base station antenna design. This paper first introduces the development of the Massive MIMO, with a proper mathematical illustration. Then, some conventional parameters are introduced to measure the performance of the antenna, with a connection to the miniaturization of the antenna. Specifically, two coefficients: the gain-to-volume ratio and isolation-to-volume ratio are constructed to measure the efforts in miniaturization. Tables that collect works in the literature are presented, with detailed comparisons among working situations. Then a general conclusion and future path of miniaturization are indicated. At last, the paper introduced the challenge and future of the miniaturization of the 5G Massive MIMO base station antenna.
Density functional theory study of AlN/Hf interface
Authors: Zhang Chaoyang , Zhang Lixia , Zhuo Ziming
Published: January 2023

In this study, the performance of AlN (0001)/Hf (0001) interface, such as occupation characteristics and combined energy, were studied by using the first principles calculation package. In the AlN/Hf interface, the Al- and N-terminated interfaces have three stacking sites each (outermost top site, sub-outer top site, and hexagonal close-packed hollow site), comprising six different models. The most adhesion work occupies the N-terminal interface of the hcp-hollow site, and the interface energy was also the smallest and most stable, as well as a lower fracture work than the AlN/Ti interface. Moreover, the differential charge density were calculated, the partial density of states were plotted, and the bonding properties were discussed. Compared with other interfaces, the N-terminated interface with the hcp-hollow site exhibited more covalent characteristics; on the Al-terminated interface with the sub-outer top site, the Hf-Al metallic bond was formed. The most stable atomic occupation type in AlN/Hf interface is the hcp-hollow site of N atomic terminal.
Effect of applied stress on corrosion properties of Q235 steel with multi-layer epoxy coating
Authors: Zhang Ruixiang , Dong Yuguo , Liu Ling , Qu Xingdong , Liu Feng , Wang Yang , Peng Longgui , Du Lifei
Published: January 2023

Organic coating is one of the most effective, economical and universal methods for corrosion resistance of metal at a small, but the stability of the coating is highly dependent on the applied stress. In the study, a comprehensive experiment was conducted to investigate the corrosion progress of Q235 steel sheets in 3.5% NaCl solution and 10% H2SO4. The effect of applied stress on the corrosion as well as the corresponding adhesion characteristics of Q235 steel are examined and quantitatively analyzed. Results indicate that, compared with the NaCl solution, the H2SO4 solution has aggressive corrosion on the Q235 steel sheets, and the corrosion would be largely aggravated with increasing applied stress. Additionally, the decreased adhesion grade of the epoxy coating is a synergic result of the immersion time and the stress, and the continuous dissolution of the coating would lead to the aggravation of corrosion, which side-fact indicates that the prepared epoxy resin paint could show efficient anti-corrosive properties. Therefore, the stress has a direct influence on the adhesion ability of the prepared epoxy resin coating, which would decrease the anti-corrosion properties of the coating.
Comprehensive Analysis of Capacitance and Inductance Effect in the RLC Circuit Toward the Cut-off Frequency and Bandwidth
Authors: Qian Kun
Published: January 2023

Electronics filter design is essential for signal processing tasks in electronics, biomedical engineering, and control systems. Filter design in the frequency domain is based on the foundation laid by the theory of Fourier transform developed by Joseph Fourier in 1807, where the filter is intended to remove unwanted frequency components from the input signal. Lumped electronic filters are constructed by components of resistor (R), capacitor (C), and inductor (L). In this study, we comprehensively explored how different values of capacitors and inductors impact the cut-off or center frequency in the series LC or RLC circuit. Analytical solutions of the magnitude of the ratio between output and input voltage are provided and the results from simulations are used to compare with the derivations from the analytical solutions. The simulation result is within the range of +-0.65% of the theoretical value due to numerical precision from the simulation tool LT-Spice.
Design and Research of a hanging and releasing unmanned craft deployment and recovery
Authors: Li Xiangyu , Zhao Yapeng , Miao Hailin , Wangyong
Published: January 2023

The application potential of unmanned craft in navigation, patrol, detection, search and rescue, maritime interception, and other fields is becoming increasingly prominent, the research and development of unmanned craft in various countries have been strengthened, however, the research and development of deployment and recovery technology, which is matched with the combat mission of unmanned craft, as the core technology, is relatively lagging. In this paper, a hanging and releasing device for the unmanned craft is designed, the design scheme of the deployment and recovery device is introduced, the risk of collision between the unmanned boat and the main ship is evaluated, and structural calculations are performed using finite element analysis software. The results show that the deployment and recovery device scheme of the unmanned craft is reasonable and feasible, which provides guidance and reference for the design of relevant devices in the future.
Research on Centrifugal Blower Design and Optimization Method Based on Mean Camber Line Optimization and CFD
Authors: Fang Jiwei , Yan Peigang , Qin Jiang , Chen Huanlong
Published: January 2023

In recent years, with the development of domestic industry and the progress of production technology, the centrifugal blower, as a piece of nuclear equipment in the industry, needs to be upgraded and optimized to improve its performance. Thus, based on the mean camber line optimization and CFD, this paper carries out the design and aerodynamic optimization for a centrifugal blower, and a corresponding 3D aerodynamic optimization platform is built. Then the effects the mean camber lines have on the aerodynamic performance of the centrifugal blower are further analyzed. The results show that the stall margin and efficiency of the centrifugal blower are improved, going up to nearly 8.5% and 1.5%, respectively, after the optimization, while the total pressure ratio basically remains unchanged. The optimized mean camber lines can control the Mach number and restrain the separating flow more effectively, which contributes to improving the carrying capacity of the blower and verifies the advancement of the optimized platform. This provides a novel method for the design and optimization of centrifugal blowers.
Calibration for Installation Errors of Ultra-short Baseline Based on Direction Cosine
Authors: Luo Yu , Song Xizhao , Cheng Mengdi , Xin Mingzhen
Published: January 2023

In marine surveying and mapping, Ultra-short baseline (USBL) positioning system can provide accurate location information. So the USBL is the important guarantee of other marine jobs. However, under the influence of a complex marine environment, system errors, and acoustic curves, ultra-short baselines are subject to installation errors when installed, and the positioning accuracy can be seriously disturbed. To this end, this paper uses the direction cosine method to calibrate installation errors. To further improve positioning accuracy, this new method also consider the sound line correction. This method uses an equal gradient soundtracking algorithm to correct sound bending errors, constructs the error equation based on the transformation relationship between different coordinate systems by the direction cosine method, and linearizes the transformation parameters between the coordinate systems. The above two steps complete the calibration of installation errors of the USBL. The simulation results show that the underwater target position distribution calibrated by this method has a large convergence. The deviations from the data in all directions are concentrated around the zero point and approximately conform to a Gaussian distribution. The results indicate that the algorithm greatly improves the results of ultra-short baseline positioning and significantly increases the accuracy of underwater target positioning.
Research on Precise Flow Control and Anti-interference Performance of Load Sensitive Multi-way Valve with After-valve Compensation
Authors: Ye Yuan , Fu Ling , Junhua Zhang , Wang Wei , Yanbin Liu , Wu Bin
Published: January 2023

Regarding a load-sensitive system with after-valve compensation, in the case of a single action or composite action, theoretically, the flow of each channel neither varies with the load pressure of this channel, nor is it affected by the flow of other channels, and the anti-interference performance is good. In fact, due to the influence of factors such as the flow passage of the valve body, the matching between the pressure compensation valve and the main spool, its flow control and anti-interference performance are difficult to achieve good results, which has a great impact on the synchronization, rapid action impact and micro motion characteristics of the main engine of construction machinery. This paper studies the simplification and analysis of the system pressure drop diagram, the matching characteristics between the pressure compensation valve and the main valve, accurate modeling and simulation technology, solves the problems of flow fine control and anti-interference performance, improves the flow control accuracy of a single action and compound action, and enhances the anti-interference performance. The real vehicle test shows that the self-developed multi-way valve for compensating for load sensitivity behind the valve is installed on the 6T small excavation. The initial position of the excavator’s track is aligned along a straight line. After the test runs for 20 meters, the track offset is measured. The fast forward offset is only 20mm, and the slow forward offset is only 7mm.
The Hollow Die Design of Suspension Protective Type
Authors: Liu Yue , Cai Zhenpan , Zeng Shiqi , Chen Jiajie , Jiang Qirui
Published: January 2023

Because semi-hollow aluminum profiles are quite common in practice and have a large market demand, these profiles are characterized by a long cantilever, large tongue ratio, high complexity of mold design, and mold problems that have been bothering enterprises. These profiles are characterized by the long cantilever, large tongue ratio, high complexity of mold design, and mold problems that always have troubled enterprises. In order to solve this kind of mold strength problem, the engineering and technical personnel at home and abroad have carried out extensive research and have also obtained some successful experience. For example, mature die structures include split extrusion die and inlaid extrusion die, but these structures have certain applicable objects and conditions in practical application and have certain limitations in structure. Therefore, it is necessary to propose new and effective high-strength dies. A new type of die was present. The new die structure was named covering and protection die. With a actual product, the determination of structure parameters that it included the arrangement of portholes and the structure design of the chamber and the selection of bearings were introduced in detail. The features of the new structure were simple and easy to be processed. The practice shows that the new die can extended the life, increase of efficiency and reduce cost. The high precision dimensions and good surface quality were obtained. The new die is worth promoting. The purpose is to provide reliable data and reference for further research and development of the structure of semi hollow aluminum profiles.
Double-phase refractory medium entropy alloy NbMoTi via selective laser melting (SLM) additive manufacturing
Authors: Chen Yinan , Li Bo
Published: January 2023

Elemental metals Nb and Mo are common refractory metals, performing good properties in a high-temperature working environment. While due to their high melting points, they are hard to be manufactured. Besides, elemental metal with a single BCC phase performs onefold properties, which promotes the design of medium/high entropy refractory alloys. This paper focuses on the formability analysis of refractory metals Mo, Nb and mixed MoNbTi powder printed by SLM. It successfully demonstrated for the first time that laser metal deposition can be used to produce MoNbTi high-entropy alloy from a blend of elemental powders by in-situ alloying with the assistance of the Flow 3D app. The densities of elemental Nb, Mo and MoNbTi manufactured by the corresponding optimized printed parameters were 99.41%, 99. 13% and 97.38%, respectively. As-built MoNbTi high-entropy alloy contained FCC+BCC double phase. The FCC phase is diffusively precipitated in the BCC phase, and the boundary is moist.
Simulation of the solidification organization of X15CrNiSi20-12 alloy castings during investment casting based on the CAFE model
Authors: Xiao Zeyuan , Dong Shengquan , Nie Song , Ma Zhien , Lv Zhaozhao
Published: January 2023

In this work, the CAFE (Cellular Automata Finite Element) model was used to simulate the grain growth of X15CrNiSi20-12 austenitic stainless steel during the investment casting process, and the effects of shell thickness, shell temperature, casting temperature, and cooling rate on the solidification organization were investigated by orthogonal tests. The results show that the cooling method has an important effect on the formation of equiaxed crystals. However, the shell temperature, shell thickness, and casting temperature have a smaller effect on the formation of equiaxed crystals. A more equiaxed fine grain structure can be obtained by using a shell thickness of 7 mm, shell temperature of 1143.15 K, casting temperature of 1913.15 K, and water-cooling conditions. In addition, a decrease in the shell thickness, shell temperature, and casting temperature can lead to an increase in the grain size, while an increase in the cooling rate will lead to smaller grain size and increase the number of equiaxed fine crystals, thus improving the mechanical properties of the material.
A Method of Velocity Estimation for an Underwater Moving Source in Wave-Number Domain Based on The Warping Transform
Authors: Shiwei Xie , Ming Xu , Xiao Yuan , Mingyu Gao
Published: January 2023

When a single hydrophone is stationary and the underwater acoustic source is moving linearly at a constant velocity at the same depth, the phase of the received sound pressure signal in the frequency domain varies nonlinearly with time. Phase linearization can be achieved by warping transformation, so a method based on warping transformation is proposed to estimate the motion parameters of the source based on warping transformation. Firstly, the warping operators under different motion parameters are constructed and then used to resample the received sound pressure. Secondly, the corresponding wave-number spectrum is obtained by the Fourier transform of the resampled sound pressure. Finally, only when the search value of the motion parameter matches the real value, the energy magnitude of the wave-number spectrum concentrating in the concerned interval is maximum. Thus, the estimation of motion parameters is achieved. Simulation data verify the effectiveness of the method. Compared with the traditional Minimum Mean Square Error (MMSE) method, the proposed method has better performance in velocity estimation at low speeds and low frequencies.
Research on the Influence of Fault Arc on Polyimide Insulation Materials
Authors: Tang Muhan , Yue Pengcheng , Duan Xiongying , Ma Chang , Kong Fancong , Liao Minfu
Published: January 2023

In modern grid systems, electrical fires caused by faulty arcs occur more frequently. Arc protective clothing is the equipment that can effectively protect personal safety. Among them, polyimide insulation materials have the advantages of high-temperature resistance and high thermal resistance. Their performance in the field of arc protection is of high research value. In this paper, the effect of faulty arc on polyimide insulation material is studied by experimental and simulation control modes. The COMSOL software is used to simulate the process of electric arc affecting polyimide insulation material, and to simulate the physical field distribution of electric arc with different electrode spacing and different arc currents. An arc generation device is built, a copper calorimeter is designed to record the temperature rise of each experiment, a variety of arc parameters is changed, and the performance of polyimide insulation materials is analyzed to block the fault arc. A fault arc experimental platform was built, using a copper calorimeter to record the temperature rise of each experiment. Varying multiple arc parameters to analyze the performance of polyimide insulation materials in blocking fault arcs. The simulation and test results show that polyimide has an obvious barrier effect on the radiation temperature of the fault arc, and it can show good thermal insulation under different arc conditions, which proves that polyimide insulation materials have excellent protection performance against fault arcs in the energized operation environment.
Hydrodynamic performance in wave condition of autonomous amphibious robots
Authors: Cai Tong , Pan Dibo , Xu Xiaojun , Liu Bolong
Published: January 2023

Autonomous amphibious robot has a wide application able to move on land and sailing in water condition. In this paper, we design a new structure for autonomous amphibious robots, which can convert to water mode when coming through a water obstacle. Research on the hydrodynamic performance of amphibious robots in static water is carried out. To evaluate the impact of wave conditions on sailing characteristics, wave numerical simulation is studied. Results show that wave conditions will increase the resistance at low and medium velocities, with a maximum of 40% resistance increase at a speed of 1.5 m/s. The wave simulation model can capture wave dynamic flow well, including wave dissipation and turbulent energy loss.
Numerical Simulation of Unsteady Hydrodynamic Characteristics of Bionic Fin
Authors: Zhang Minghui , Su Yiming , Wang Chuanbao
Published: January 2023

A long uncompressed fin driven by fin rays is designed in this paper, and its kinematic model is established. The SST K-ω turbulence model is used to solve the N-S equation of three-dimensional unsteady incompressible fluid, and the hydrodynamic characteristics of the uncompressed fin are studied. The results show that when the undulating fin is started, the velocity of the surrounding fluid gradually increases with the movement of the fin surface, and the fluid moves from the leading edge of the undulating fin to the back edge along the fin surface. A relatively obvious anti-Karman vortex street is formed on both sides of the fin, and a jet is formed at the tail of the fin to generate forward thrust.
An Improved IMM-GPDA Tracking Algorithm
Authors: Xie Zhaoyang , Wang Shengli , Yu Jianguo
Published: January 2023

To improve the accuracy and efficiency of multi-maneuvering target tracking in dense clutter environments, an improved interactive multi-model generalized probabilistic data association (IMM-GPDA) algorithm is proposed in this paper. The algorithm introduces Doppler information into the measurement data. Firstly, the measurement data is pre-processed by double-threshold regional density clutter elimination, and then the pre-processed data is put into the improved IMM-GPDA algorithm with square-root cubature Kalman filter (SRCKF) and model transition probability adaptation for interaction, association, and filtering. Simulation results show that the algorithm has advanced accuracy, instantaneity, and robustness in tracking environments with multi-maneuvering targets and dense clutters.
Trajectory Tracking Control of the Wheeled Mobile Robot based on the Curve Tracking Algorithm
Authors: Peng Youhua , Zhang Peng , Fang Zheng , Zheng Shuaijie , Guo Zhijun , xing Dongxu
Published: January 2023

A controller based on the curve tracking algorithm is offered as a solution to the issue of the wheeled mobile robot’s trajectory not be precisely monitored. First, Utilizing a planar global coordinate system, the kinematics and dynamics models of the wheeled mobile robot is created. Then, the kinematic model of the actual and predicted trajectories is utilized to determine the trajectory tracking error of the wheeled mobile robot. By the trajectory tracking error system model, The curve tracking algorithm controller is employed in the outer loop control to remove the robot’s position and attitude deviation during trajectory tracking, while the PI controller is utilized in the inner loop control to precisely track the robot’s speed. The simulation results demonstrate that the suggested control technique can regulate the wheeled mobile robot’s pose error [xq yq θq]T within the ranges of 0.1m, 0.03m, and 0.03rad, which demonstrates the efficacy of the control approach.
Numerical Simulation of Flow around A Cylinder in Hyperbolic Flow Field Induced by Internal Solitary Waves
Authors: Dai Runfeng , Wang Fei , Wang Chunxiao , Li Peng , Qi Xiaoliang , Sun Rui
Published: January 2023

To study the flow field and hydrodynamic characteristics of hyperbolic flow around a cylinder caused by an internal solitary wave, the hyperbolic flow around the cylinder induced by the inner solitary wave, inlet condition is the lower deep horizontal velocity induced by the inner solitary wave and the two-dimensional Navier-Stokes equation is used as the flow field control equation according to the applicability conditions of the eKdV inner solitary wave theory. A numerical simulation method for the nonlinear action of internal solitary wave-induced hyperbolic flow on a horizontal cylinder is established. A series of calculation results show that the numerical simulation results of horizontal force on the cylinder are in good agreement with experimental results. The wakefield of hyperbolic flow around a cylinder has distinct characteristics. In the process of flow around the cylinder, the vortex does not fall off alternately and the lateral lift force is neglected. The force of internal solitary wave-induced hyperbolic flow on the cylinder is non-centrosymmetric, and with the increase of maximum Reynolds number and characteristic period, the horizontal resistance of the cylinder becomes unidirectional. Therefore, the maximum Reynolds number and the characteristic period affect the horizontal force of internal solitary wave-induced hyperbolic flow on a two-dimensional cylinder.
Research and Application of 5G Remote Control UAV with Aerial Electronic Fence
Authors: He Zhongli , Zou En , Guan Chunxi , Pang Bowei , Tang Guangfa , Ding Juan
Published: January 2023

Unmanned aerial vehicles (UAVs) are often out of control, lost, and crashed during use. The research of a 5G remote control UAV with an aerial electronic fence can solve these problems. The integrated application of 5G communication technology, Internet of Things technology, and electronic fence technology built through the GPS navigation cloud platform enables UAVs to achieve remote real-time control and electronic fence protection in the air through 5G. At the same time, UAVs can also achieve remote control, data transmission, image transmission, and other functions, so that UAVs can automatically and safely return in case of out-of-control failure, broaden the flight radius of UAVs, and improve the safety of UAVs.
Beam-based reconstruction of the shielded quench-heater fields for the LHC main dipoles
Authors: Richtmann L , Bortot L , Ravaioli E , Wiesner C , Wollmann D
Published: January 2023

Small orbit oscillations of the circulating particle beams have been observed immediately following quenches in the LHC’s superconducting main dipole magnets. Magnetic fields generated during the discharge into the quench heaters were identified as the cause. Since the resulting, shielded field inside the beam screen cannot be measured in-situ, the time evolution of the field has to be reconstructed from the measured beam excursions.

In this paper, the field-reconstruction method using rotation in normalized phase space and the optimized fitting algorithm are described. The resulting rise times and magnetic field levels are presented for quench events that occurred during regular operation as well as for dedicated beam experiments. Finally, different approaches to model the shielding behavior of the beam screen are discussed.
A design of ILC E-driven positron source
Authors: Kuriki M , Tajino H , Konno S , Liptak Z , Takahashi T , Fukuda M , Omori T , Seimiya Y , Urakawa J , Yokoya K , Kashiwagi S
Published: January 2023

ILC is an electron-positron linear collider based on Superconducting linear accelerator. Linear collider is the only solution to realize high energy electron-positron collision beyond the limit of synchrotron radiation energy loss by ring colliders. Beam current of injector of linear colliders is much larger than that of ring colliders because the beam is not reusable. Providing an enough amount of particles, especially positron is a technical issue. In this article, we present a design of electron driven positron source for ILC. After optimizations, the system design is established with an enough technical margin, e.g. avoiding potential damage on the production target.
Commissioning simulations for the DIAMOND-II upgrade
Authors: Chao H-C , Fielder R , Kallestrup J , Singh B , Martin I
Published: January 2023

The Diamond-II [1] storage ring, compared to Diamond, improves the natural emittance from 2.7 nm to 160 pm and the beam energy from 3 to 3.5 GeV. The number of straight sections is also doubled from 24 to 48 thanks to the modified hybrid six-bend-achromat lattice. To reduce the impact on the existing science program, the dark time period must be minimised. To assist in this aim, storage ring commissioning simulations have been carried out to predict and resolve possible issues. These studies include beam commissioning starting from on-axis first-turn beam threading up to beam based alignment and full linear optics correction with stored beam. The linear optics corrections with insertion devices are also included. The machine characterisations at different stages are compared. Considerations on realistic chamber limitations, error definitions and some commissioning strategies are also discussed.
A double dipole kicker for off and on-axis injection into ALBA-II
Authors: Benedetti G , Carlà M , Pont M
Published: January 2023

Injection into the ALBA-II storage ring will be performed off-axis in a 4 meters straight section with a single multipole kicker. We present a novel topology for the coils of the injection kicker, named double dipole kicker (DDK). The resulting magnetic field is the superposition of two opposite dipoles, generated by four inner and four outer conductor rods. When the eight rods are powered, the dipole term cancels and the remaining multipole field is used for off-axis injection. Alternatively, when the four inner rods are switched off, an almost pure dipole is produced, that is useful for on-axis injection during the commissioning. A prototype of DDK is presently under design to be installed and tested in the existing ALBA storage ring. The positioning of the rods is calculated in order to maximize the kick efficiency in mrad/kA and minimise the disturbance to the orbit and the emittance of the stored beam. A metallic coating with optimised thickness along the inner ceramic vacuum chamber should provide compensation for the eddy currents induced field in order to minimize the disturbance to the stored beam while ensuring sufficiently low heat dissipation by the beam image currents.
The status of the in-vacuum-APPLE II IVUE32 at HZB / BESSY II
Authors: Bahrdt J , Bakos J , Gaebel S , Gottschlich S , Grimmer S , Kuhn C , Knaack S , Laube F , Meseck A , Rethfeldt C , Rial E , Rogosch-Opolka A , Scheer M , Volz P
Published: January 2023

At BESSY II, two new beamlines for RIXS and for X-Ray-microscopy need a short period variably polarizing undulator. For this purpose, the first in-vacuum APPLE II undulator worldwide is under construction. The parameters are as follows: period length λ
0 = 32 mm, # periods = 78, minimum gap = 7mm. The design incorporates a force compensation scheme as proposed by two of the authors at the SRI 2018. All precision parts of the drive chain are located in air. New transverse slides for the transversal slit adjustment have been developed and tested. Optical Micrometers measure the gap and phase positions, similar to the system of the CPMU17 at BESSY II. They provide the signals for motor feedback loops. A new UHV-compatible soldering technique, as developed with industry, relaxes fabrication tolerances of magnets and magnet holders and simplifies the magnet assembly. A 10-period prototype has been setup for lifetime tests of the new magnetic keeper design. The paper summarizes the status of the undulator IVUE32.
Simulations of the suitability of a DC electron photogun and S-band accelerating structure as input to an X-band linac
Authors: Williams S D , Rassool R P , Sheehy S L , Taylor G N , Volpi M , Auchettl R , Dowd R T
Published: January 2023

Work has been underway for some time to design a compact electron beamline utilising X-band linear accelerating structures in the new Melbourne X-band Laboratory for Accelerators and Beams (X-LAB). The original design utilised an S-band RF photogun as an input to a pair of high gradient X-band linear accelerating structures, but we have been motivated to investigate an alternative starting section to allow for initial testing. This will utilise a DC photogun and S-band accelerating structure similar to those used at the Australian Synchrotron. Simulation results incorporating space charge of a beamline composed of a DC photogun, S-band accelerating structures, and two high gradient X-band structures will be presented. These simulation results will be optimised for minimum emittance at the end of the beamline.
Achievement of 200,000 hours of operation at KEK 7-GeV electron 4-GeV positron injector linac
Authors: Furukawa K , Akemoto M , Arakawa D , Arakida Y , Bando Y , Ego H , Enomoto Y , Higo T , Honma H , Iida N , Kakihara K , Kamitani T , Katagiri H , Kawamura M , Matsumoto S , Matsumoto T , Matsushita H , Mikawa K , Miura T , Miyahara F , Nakajima H , Natsui T , Ogawa Y , Ohsawa S , Okayasu Y , Oogoe T , Rehman M A , Satake I , Satoh M , Seimiya Y , Shidara T , Shirakawa A , Someya H , Suwada T , Tanaka M , Wang D , Yano Y , Yokoyama K , Yoshida M , Yoshimoto T , Zhang R , Zhou X
Published: January 2023

KEK electron positron injector LINAC initiated the injection operation into Photon Factory (PF) light source in 1982. Since then for 39 years, it has served for multiple projects, namely, TRISTAN, PF-AR, KEKB, and SuperKEKB. Its total operation time has accumulated 200 thousand hours on May 7, 2020. We are extremely proud of the achievement following continuous efforts by our seniors. The construction of the injector LINAC started in 1978, and it was commissioned for PF with 2.5 GeV electron in 1982. In parallel, the positron generator linac was constructed for the TRISTAN collider project. The slow positron facility was also commissioned in 1992. After the KEKB asymmetric-energy collider project was commissioned in 1998 with direct energy injections, the techniques such as two-bunch acceleration and simultaneous injection were developed. As the soft structure design of the LINAC was too weak against the great east Japan earthquake, it took three years to recover. Then the construction and commissioning for the SuperKEKB project went on, and the simultaneous top-up injection into four storage rings contributes to the both elementary particle physics and photon science.
Cooling challenges in a NEG-coated vacuum chamber of a light source
Authors: Motlagh S Talebi , Danaeifard A , Rahighi J , Saeidi F , Zamani F
Published: January 2023

In a Light Source, unused synchrotron radiation is being distributed along the walls of the chambers. Due to the small conductance of the chambers, vacuum pumping will be based on the distributed concept, and then non-evaporable getter (NEG) coating is extensively used. The vacuum chambers are made of copper alloys tube, and cooling circuits are welded to the chamber to remove the heat load from the radiation generated. Filler metal creates a brazed joint between the water-cooling pipe and the vacuum chamber body. The thermal conductivity of the fillers is less than the vacuum chamber body. On the other hand, the velocity of the water in the cooling pipe is a critical parameter in thermal calculations that must be taken into account. So, in this paper, we study and investigate the effects of the filler metal and the cooling water velocity on cooling the NEG-coated chambers.
Sensitivity of EEHG simulations to dynamic beam parameters
Authors: Samoilenko D , Hillert W , Pannek F , Ackermann S , Ferrari E , Mirian N , Niknejadi P , Paraskaki G , Schaper L , Curbis F , Pop M , Werin S
Published: January 2023

Currently, the Free electron laser user facility FLASH at DESY is undergoing a significant upgrade involving the complete transformation of one of its beamlines to allow external seeding. With the Echo-Enabled Harmonic Generation (EEHG) seeding method, we aim for the generation of fully coherent XUV and soft X-ray pulses at wavelengths down to 4 nm. The generated FEL radiation is sensitive to various electron beam properties, e.g., its energy profile imprinted either deliberately or by collective effects such as Coherent Synchrotron Radiation (CSR). In dedicated particle tracking simulations, one usually makes certain assumptions concerning the beam properties and the collective effects to simplify implementation and analysis. Here, we estimate the influence of some of the common assumptions made in EEHG simulations on the properties of the output FEL radiation, using the example of FLASH and its proposed seeding beamline. We conclude that the inherent properties of the FLASH1 beam, namely the negatively chirped energy profile, has dominant effect on the spectral intensity profile of the radiators output compare to that of the CSR induced chirp.
Emittance feedback for the Diamond-II storage ring using resonant excitation
Authors: Preston Shaun , Olsson Teresia , Singh Beni
Published: January 2023

In the Diamond Light Source storage ring, the vertical emittance is kept at 8 pm rad during operation to maintain the source brightness for the users. This is achieved by a feedback which modifies the skew quadrupole strengths, but has disadvantages such as the introduction of betatron coupling and vertical dispersion. For the proposed Diamond-II upgrade, the storage ring will have a much smaller horizontal emittance, meaning a significantly larger coupling would be required to reach the target vertical emittance, negatively affecting the off-axis injection process. To solve this problem, a feedback using the transverse multibunch feedback striplines to drive the beam at a synchrotron sideband is planned. By driving the beam resonantly in this way, the emittance can be increased without modification of the optics. This paper describes simulations of the effects of linear and non-linear optics on the excitation as well as the impact of the machine impedance for the Diamond-II storage ring.
Reconstruction and beam-transport study of the cERL dump line for high-power IR-FEL operation
Authors: Nakamura N , Tanimoto Y , Higashi N , Harada K , Shimada M , Uchiyama T , Nogami T , Ueda A , Nagahashi S , Obina T , Takai R , Sagehashi H , Nigorikawa K , Tanaka O , Kato R , Sakai H
Published: January 2023

Infrared (IR) SASE-FEL emission was successfully generated for macro pulses of about 1 μs with the maximum repetition rate of 5 Hz at the cERL. In the future, high-power FEL operation will be planned to increase electron bunches drastically with energy recovery. Therefore, the dump line was redesigned and reconstructed to increase the momentum acceptance and to improve the magnet system for avoiding serious beam loss in the high power FEL operation. Furthermore, the first beam-transport study was performed by transporting the beam directly from the injector to the beam dump through the reconstructed dump line. In this paper, we present the reconstructed dump line and the beam-transport study. The new dump line can be a model for dump lines of high-power ERL-FELs.
Photocathode performance characterisation of ultra-thin MgO films on polycrystalline copper
Authors: Benjamin C , Churn H M , Rehaag T J , Jones L B , Bell G R , Noakes T C Q
Published: January 2023

The performance expected from the next generation of electron accelerators is driving research into photocathode technology as this fundamentally limits the achievable beam quality. The performance characteristics of a photocathode are most notably: normalised emittance, brightness and energy spread. Ultra–thin oxide films on metal substrates have been shown to lower the work function (WF) of the surface, enhancing commonly utilised metal photocathodes, potentially improving lifetime and performance characteristics.

We present the characterisation of two MgO/Cu photocathodes grown at Daresbury. The surface properties such as: surface roughness, elemental composition and WF, have been studied using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). The photoemissive properties have been characterised with quantum efficiency (QE) measurements at 266 nm. Additionally, we measure the Transverse Energy Distribution Curves (TEDC) for these photocathodes under illumination at various wavelengths using ASTeC’s Transverse Energy Spread Spectrometer (TESS) and extract the Mean Transverse Energy (MTE).
Material normal energy distribution for field emission analyses from monocrystalline surfaces
Authors: Mann J I , Li Y , Nangoi J K , Arias T , Rosenzweig J B
Published: January 2023

Electron field emission is a complicated phenomenon which is sensitive not only to the particular material under illumination but also to the specific crystalline orientation of the surface. Summarizing the ability for a crystal to emit in a particular direction would be of great use when searching for good field emitters. In this paper we propose a material normal energy distribution which describes the ability of the bound electrons to tunnel under an intense electric field. This framework breaks a computationally expensive 3-D system down to a source distribution representation applicable for more efficient 1-D models. We use the Fowler-Nordheim framework to study the yield and MTE (mean transverse energy) from sources including gold, copper, and tungsten in both monocrystalline and polycrystalline forms. We find an increase in effective work function for field emission in the (111) direction for gold and copper associated with the Bragg plane intersections of the Fermi surface.
Towards high-repetition rate petawatt laser experiments with cryogenic jets using a mechanical chopper system
Authors: Rehwald M , Assenbaum S , Bernert C , Curry C B , Gauthier M , Glenzer S H , Göde S , Schoenwaelder C , Schramm U , Treffert F , Zeil K
Published: January 2023

Laser-plasma based ion accelerators require suitable high-repetition rate target systems that enable systematic studies at controlled plasma conditions and application-relevant particle flux. Self-refreshing, micrometer-sized cryogenic jets have proven to be an ideal target platform. Yet, operation of such systems in the harsh environmental conditions of high power laser induced plasma experiments have turned out to be challenging. Here we report on recent experiments deploying a cryogenic hydrogen jet as a source of pure proton beams generated with the PW-class ultrashort pulse laser DRACO. Damage to the jet target system during application of full energy laser shots was prevented by implementation of a mechanical chopper system interrupting the direct line of sight between the laser plasma interaction zone and the jet source.