Bunching System Research Articles

Ultrashort Ne+ ion pulses for use in pump–probe experiments: numerical simulations

A time resolved experiment to investigate the ultrafast dynamics following an ion impact onto a solid surface requires an ultrashort ion pump pulse in combination with a properly synchronized and time resolved probe. In order to realize such an experiment, we have investigated a strategy to use femtosecond laser photoionization of atoms entrained in a pulsed supersonic jet for the production of sufficiently short ion pulses. While the generation of Arq+ ions was targeted in previous work, it has in the meantime been demonstrated that argon is not suitable due to extensive cluster formation in the supersonic expansion. Here, we therefore present numerical simulations investigating the use of neon as a precursor gas and show the feasibility of pulses containing up to ∼1000 Ne+ ions at keV energies and picosecond duration. In the process, we demonstrate that space charge broadening can be significantly reduced by detuning the flight time focusing conditions of an ion bunching system. Moreover, the results show that a controlled variation of the buncher geometry and potentials permits the generation of picosecond pulses at variable ion energy between 1 and 5 keV.

Results of manufacturing and operation of the first accelerating structures for the linear accelerator of the SKIF injector based on a disk-loaded waveguide

The linear accelerator of the Siberian Circular Photon Source is being developed at Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences (BINP SB RAS). The test accelerator facility with the RF gun, the bunching system, the pre-accelerator and the first regular accelerating structuresoperates at Budker Institute of Nuclear Physics. The aim of work at this facility is to demonstrate the performance of the basic system of the linear accelerator, including the accelerating structures. This paper presents the first accelerating structures for the linear accelerator of the SKIF injector produced at BINP SB RAS.

Efficacy of new generation oomycete-specific fungicides on life stages of Phytophthora meadii and field evaluation through bunch spraying system

Fruit rot disease (FRD) of arecanut, caused by Phytophthora meadii, is an important fruit disease of this palm tree that resulted in huge economic losses to the growers in India. In recent years, the control of this disease has become a prime factor in the management of arecanut plantations. Though prophylactic sprayings of Bordeaux mixture (1%) along with other older fungicides are useful in reducing the disease severity. Hence, there is an urgent need for new generation molecules to combat FRD under field conditions. The present investigation was aimed at evaluating newer oomycete-specific fungicides in in-vitro on different life stages of Phytophthora and in-vivo through a Bunch Spraying System (BSS) from ground level. The pathogen was isolated, identified, and characterized from varied regions and one virulent isolate from each region was used. Out of the 11 fungicides tested, EC50 for mycelial inhibition among isolates was lowest in Famoxadone + Cymoxanil. Similarly, the lowest EC50 for sporangial production was recorded in Iprovalicarb + Propineb, Famoxadone + Cymoxanil, and Kresoxymethyl ranging from 210.70 to 517.87 mg mL_1. The most effective fungicide for inhibition of zoospore release was Dimethomorph + Mancozeb which ranged from 406.81 to 565.80 mg mL_1. Bunch spraying of fungicides such as Bordeaux mixture (1%), mandipropamid (0.5%), fosetyl-Al (0.3%), and a combination of metalaxyl-mancozeb (0.2%) from ground level had a significant (P < 0.05) effect against FRD. These fungicides were found most effective in reducing the disease up to an extent of 65–70% and which in turn increased the dry nut yield by 75–95% when applied twice compared to untreated control. However, a semi-systemic fungicide mandipropamid could be a potential alternative to the Bordeaux mixture for effective control of FRD under field conditions.

The design of fresh fruit bunch palm oil purchase system from independent smallholders to support Indonesia’s biodiesel development program

Miniplants established by the independent smallholder’s secondary cooperative is one of the efforts to get rid from monopsony market and mill. By the existence of miniplants, Fresh Fruit Bunch (FFB) sales channel will not only end at mill, but also at the miniplant in spite of in limited capacity. Each channel of FFB sales should be supported by the credible price information and the integrated purchase system. To fulfill the need of real-time & transparent price information and the integrated FFB purchase system can be realized by developing mobile application Software as a Service (SaaS) of FFB’s purchase based on a cloud platform. The method used to develop the mobile application is a system approach following the stages in SDLC (System Development Life Cycle) starting from the ideas, user requirements, system requirements, designing, deployment and maintenance. This study is restricted until the stage of designing and generating Business Process Diagram, Use Case Diagram, Data Conceptual Model and Mock up only. Both diagram and model generated in this study aids develop FFB purchase mobile application. The large number of independent smallholders has the opportunity to get a large number of mobile application users. The application will generate a large amount of data. These data can be used to develop various tools as part of the FFB e-procurement system to ensure the supply of independent smallholders’ FFB can be used for biodiesel development programs as expected by the government of Indonesia.

A Review on Data Discrepancy Factor Performance for Industrial Applications using Clustering Algorithms

DDF is the most significant measure among different bunch execution procedures to assess the immaculateness of any group component. Ordinarily, best groups are assessing by processing the quantity of information focuses inside a bunch. At the point when this tally is comparable to the quantity of required information focuses then this group is viewed as great. The greatness of the bunch system is fundamental not exclusively to discover the information check inside a group yet in addition to inspect it by totalling the information focuses these are (I) present inside a group where it ought not be and the other way around and (ii) not grouped for example anomalies (OL). The principle usefulness of DDF is that all bunch focuses can be gathered in comparative groups without exceptions, the current paper features on how contrasted with DDF more effective Clusters can be shaped through the Modern DDF. Further, we assess the exhibition of some grouping calculations, K-Means. As of late we, fostered the Modified K-Means Algorithm and Hierarchical Algorithm by utilizing the Data Discrepancy Factor (DDF).

Physics design of the HEPS LINAC

The High Energy Photon Source (HEPS) is a synchrotron radiation source with an ultrahigh brightness and under construction in China. Its accelerator system is comprised of a 6-GeV storage ring, a full energy booster, a 500-meV Linac and three transport lines. With deepening investigations on the physics designs of the storage ring and the booster, the physics scheme of the Linac has evolved through multiple versions. The final version of the Linac, including the electron gun, bunching system and main accelerator, has been determined. The Linac is an s-band normal conducting electron linear accelerator with a very high bunch charge and a large bunch charge range. Based on simulations, the Linac could provide electron bunches with charge greater than 8.5-nC, meeting the energy spread and emittance requirements. This paper first reviews the evolution and main considerations for different design versions and then describes the physics design and dynamic simulation results of the final scheme in detail.

The physics design of HEPS Linac bunching system

The High Energy Photon Source is a fourth-generation synchrotron radiation source being built in China. It is comprised of a storage ring, a full energy booster, a 500-MeV Linac and three transport lines. The pulse charge at the exit of the Linac is required to be up to 7 nC. Both single bunch and three bunches in a beam pulse might be needed according to the studies on instabilities of the booster and the beam dynamic of the main Linac. A bunching system consisting of both sub-harmonic and fundamental frequency structures is designed to meet the requirements. To obtain high transmission efficiency and control the emittance growth, multi-objective genetic algorithm is introduced to optimize the electromagnetic parameters of these structures. In this paper, detailed optimization process and the final results are presented. The total transmission efficiency of the bunching system is 97%, and the transmission efficiency of the main bunch is 95%. The normalized RMS emittance of 8.5 nC included beam charge is smaller than 60 mm mrad. The design of the bunching system is presented, and both the pulse charge and the beam emittance well meet the design requirement.

Design study of multi-charge low energy beams transport for BISOL post accelerator

Beijing Isotope-Separation-On-Line Neutron-Rich Beam Facility (BISOL) post accelerator is designed to accelerate RIBs extracted from Isotope Separation On-Line (ISOL) ion source and the beam energy will be upto 150 MeV/u for Stannum. The accelerated RIBs will be served as projectile to produce isotopes far from stable line. Multi-charge state beams transport is adopted to increase beam current, a low energy beam transport (LEBT) line is desired for selecting charge states, bunching beam from continuous wave (CW) ISOL beams and match the beam into a CW 81.25 MHz radio frequency quadrupole (RFQ). This paper mainly presents the design study of BISOL multi-charge LEBT line. The detailed optics design and beam dynamics simulation are presented. Due to lower beam energy (3 keV/u) and higher transverse emittance (0.2n,rπmmmrad), the longitudinal nonlinear effect in the bunching system cannot be ignored compared to existing LEBT bunching systems, we have investigated two novel bunching and injection modes (180∘@20.3125 MHz, 270∘@20.3125 MHz) as well as the traditional mode (180∘@40.625 MHz) to optimize the output longitudinal emittance. The beam dynamics analysis indicates that the output longitudinal rms emittance can be lowered by nearly 33% with the bunching mode of 270∘@20.3125 MHz compared to traditional mode. The detailed results are presented in this paper.

Frequency-Diverse Metasurface Antenna With Hybrid Bunching Methods for Coincidence Imaging

A frequency-diverse metasurface antenna with hybrid bunching methods for coincidence imaging is proposed in this paper. The hybrid frequency-diverse bunching metasurface antenna contains an excitation system, a frequency-diverse metasurface and a double-layer-metal-plate bunching system. Firstly, the excitation system of the metasurface antenna is divided into two parts, the bunching-excitation module and the random-excitation module. The bunching-excitation module includes a seven-element coherent antenna array that can generate bunching beams with 80 degree beamwidth from 32GHz to 36GHz; and the random-excitation module includes eight antenna elements distributed evenly to excite the frequency-diverse metasurface in the same working bandwidth. A multilayer feed system is also designed utilizing the stripline structure to feed both the bunching-excitation module and the random-excitation module. Secondly, six kinds of metamaterial elements possessing disparate transmitted phases are selected to constitute the frequency-diverse metasurface. The frequency-diverse metasurface is loaded to the excitation system to generate the frequency-diverse radiation patterns. Then, in order to achieve a narrower bunching angle, a double-layer-metal-plate bunching system is designed. Furthermore, the performances of the proposed bunching metasurface antenna, including the radiation efficiency, the reflection coefficient and the correlation coefficients of radiation patterns at different frequencies are evaluated. Finally, the coincidence imaging experiment is carried out using the proposed hybrid bunching metasurface antenna and the image of the target is reconstructed successfully. The designed is verified by both simulations and measurements.

New detection systems at U-120M cyclotron

Intensive neutron beams with energies up to 33 MeV are produced using cyclotron driven broad-spectrum and quasi-monoenergetic neutron generators at the NPI CAS. The neutron beams are well characterized with the TOF and PRT measurements. The segmented Fe-CH2 collimator is used to collimate the neutron beam and two detection systems are being developed for the studies of the reactions with neutrons. The first one is the detection system of the charged particles at different angles from the (neutron, charged particle) reactions in a vacuum chamber, the second is an array of four HPGe detectors for the detection of direct and delayed gamma photons produced in reactions of the studied material with neutrons. The advanced bunching system is also being developed at the U120M cyclotron. It will allow to direct a short (few ns long) pulse of accelerated particles to the neutron converter with the 1 µs delay between bunches. Together with 7 m long flight path this extension will open new possibilities in the cross section measurements.

Queuing Scheme with Feedback Service and Discretionary Administration

This article take a gander at a bunch area single server channel Queuing system, where the server gives two sorts of organizations viz., beginning one a central organization and the optional organization is permitted as a second organization. In case in need, the customer settle on the optional organization .We other than anticipate that after the execution of the second time of affiliation, if the structure is unfilled, the server takes a required get-away of general dissemination. Organization thwarts in the midst of principal organization at random. Additionally if the customer isn't satisfied with the primary central organization, an info advantage for the proportionate is given to make a worthy space for the customers in the system. For the above delineated covering issue, the supplementary variable technique and generating function approach are used to derive the probability generating function of the queue size and the average length of the queue.

Low-energy beam transport system for MESA

An important part of the new accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) is the low-energy beam transport system connecting the 100 keV electron source with the injector. The present setup includes the chopper and bunching system. The devices are of highest importance in order to achieve sufficient bunch compression, particularly at higher bunch charges and currents. With the circularly deflecting cavity of the chopper system it is possible to measure the longitudinal profile of the bunches upstream of the buncher, whereas downstream the longitudinal size will be measured by Smith-Purcell radiation. Based on experimental results obtained from this setup, we will discuss the beam parameters and compare them with simulations of the beamline.

Image acquisition of the test-object by the CVL-10 copper vapor amplifier and optical bunch

Images of the test object surface were obtained using a laser projection microscope and an optical bunch. Images of the surface of the test object at its different location in the experiment (the test object is located at the end of the optical bunch; the test object is located in a double focus lens; the test object is located after the optical bunch and optical system of two lenses) were obtained on the screen of a laser projection microscope.

CEPC Linac design

The Circular Electron–Positron Collider (CEPC) is a 100-km ring [Formula: see text] collider for a Higgs factory. The injector of CEPC is composed of Linac and Booster. The Linac is a normal conducting S-band Linac with a frequency of 2860 MHz; it provides electron and positron beams at an energy of up to 10 GeV with 100 Hz repetition frequency of 100 Hz. The Linac design and dynamic simulation results are discussed in detail in this paper, including electron bunching system, positron source, electron bypass transport line, damping ring and main Linacs.

Development of readout electronics for bunch arrival-time monitor system at SXFEL

A bunch arrival-time monitor (BAM) system, based on electro-optical intensity modulation scheme, is under study at Shanghai Soft X-ray Free Electron Laser. The aim of the study is to achieve high-precision time measurement for minimizing bunch fluctuations. A readout electronics is developed to fulfill the requirements of the BAM system. The readout electronics is mainly composed of a signal conditioning circuit, field-programmable gate array (FPGA), mezzanine card (FMC150), and powerful FPGA carrier board. The signal conditioning circuit converts the laser pulses into electrical pulse signals using a photodiode. Thereafter, it performs splitting and low-noise amplification to achieve the best voltage sampling performance of the dual-channel analog-to-digital converter (ADC) in FMC150. The FMC150 ADC daughter card includes a 14-bit 250 Msps dual-channel high-speed ADC, a clock configuration, and a management module. The powerful FPGA carrier board is a commercial high-performance Xilinx Kintex-7 FPGA evaluation board. To achieve clock and data alignment for ADC data capture at a high sampling rate, we used ISERDES, IDELAY, and dedicated carry-in resources in the Kintex-7 FPGA. This paper presents a detailed development of the readout electronics in the BAM system and its performance.

Studies on the S-band bunching system with the Hybrid Bunching-accelerating Structure

Generally, a standard bunching system is composed of a standing-wave (SW) pre-buncher (PB), a traveling-wave (TW) buncher (B) and a standard accelerating structure. In the industrial area, the bunching system is usually simplified by eliminating the PB and integrating the B and the standard accelerating structure together to form a β-varied accelerating structure. The beam capturing efficiency for this kind of simplified system is often worse than that for the standard one. The hybrid buncher (HB) has been proved to be a successful attempt to reduce the cost but preserve the beam quality as much as possible. Here we propose to exclusively simplify the standard bunching system by integrating the PB, the B and the standard accelerating structure together to form a Hybrid Bunching-accelerating Structure (HBaS). Compared to the standard bunching system, the one based on the HBaS is more compact, and the cost is lowered to the largest extent. With almost the same beam transportation efficiency (∼70%) from the electron gun to the linac exit, the peak-to-peak (p-to-p) beam energy spread and the 1σ emittance of the linac with the HBaS are ∼20% and ∼60% bigger than those of the linac based on the split PB/B/standard accelerating structure system. Nonetheless, the proposed HBaS can be widely applied in the industrial linacs to greatly increase the beam capturing efficiency without fairly increasing the construction cost.

Design studies on an s-band hybrid accelerating structure

In an electron linac, the standard bunching system is generally composed of a standing-wave (SW) pre-buncher (PB), a travelling-wave (TW) buncher and a standard TW accelerating structure. To keep the beam performance similar to the standard bunching system but reduce the cost as much as possible, the hybrid accelerating structure (HAS) was proposed by integrating the PB, the B and the accelerating structure together. The RF design of the HAS was conducted by 2D code SUPERFISH, which is used to determine the dimensions of the SW and TW cells, and 3D code HFSS, which is used to optimize the input and output RF coupler cells. The on-axis electric field distribution simulated by HFSS can fully meet the dynamic requirement. The phase jump in SW section is 180 $$^\circ $$ while the phase advance in TW section is 120 $$^\circ $$ . The RF design of the HAS is completed, and the engineering design of the prototype is being conducted.

Longitudinal bunch length measurement of RFQ beam using in-house developed detector system

We report here the bunch width measurement of 98keV/u ion beam accelerated through a 3.4 m long 37.8 MHz Radio Frequency Quadruple (RFQ) linac using a minimally interceptive approach. The detector system for this measurement has been indigenously developed and is based on secondary electron emission from tungsten filament on being hit by ion beam, followed by a capacitive loaded helical resonator cavity. A Channeltron Electron Multiplier (CEM) detector is used for detection of electrons. The design, development and optimization of various parameters of bunch width detector system along with its deflector cavity applicable in the low frequency regime (few tens of MHz) have been discussed. The measured bunch profile of accelerated Nitrogen beam from RFQ is in close agreement with the estimated profile obtained via simulation.

Bunch Current Measurement Using a High-Speed Photodetector at HLS II

This contribution presents a novel bunch current measurement system based on an ultra-fast photodetector and a high-speed digitizer at Hefei Light Source II (HLS II). In order to achieve bunch-by-bunch resolution, the sampling rate of the system is nearly 225 GS/s via a dedicated equivalent sampling algorithm. According to preliminary tests of daily operation mode and single-bunch mode, the root-mean-square (rms) of current relative error distribution is 1.03%, which illustrates the new system satisfies requirements for high-precision bunch current measurement. In addition, experiment results of "HLS" Morse code fill pattern mode demonstrate this system also could be a convenient and robust tool for beam top-up mode in the future.

Focusing and bunching of ion beam in axial injection channel of IPHC cyclotron TR24

The CYRCe cyclotron (CYclotron pour la ReCherche et l’Enseignement) is used at IPHC (Institut Pluridisciplinaire Hubert Curien) for the production of radio-isotopes for diagnostics, medical treatments and fundamental research in radiobiology. The TR24 cyclotron produced and commercialized by ACSI (Canada) delivers a 16-25 MeV proton beam with intensity from few nA up to 500 μA. The solenoidal focusing instead of existing quadrupole one is proposed in this report. The changing of the focusing elements will give the better beam matching with the acceptance of the spiral inflector of the cyclotron. The parameters of the focusing solenoid are found. Additionally, the main parameters of the bunching system are evaluated in the presence of the beam space charge. This system consists of the buncher installed in the axial injection beam line of the cyclotron. The using of the grid-less multi harmonic buncher may increase the accelerated beam current and will give the opportunity to new proton beam applications.