A real-time beam loss monitoring system for storage ring of SSRF

In this paper we report the real-time beam loss monitoring (BLM) system at the storage ring of SSRF.The BLM-XS detectors and Ethernet data acquisition system are used in this system.Some applications and experiments of the BLM system are also presented.The BLM system provides dynamic information of beam loss for the storage ring,and is helpful to ensure the facility commissioning,investigate the problems of machine,optimize the machine parameters and further increase the beam lifetime.     

An embedded single-board computer for BPM of SSRF

An embedded single-board computer (SBC) system based on AT91RM9200 was designed for monitoring and controlling the digital beam position monitor system of Shanghai Synchrotron Radiation Facility (SSRF) through the Virtex-4 FPGA in the digital processing board.The SBC transfers the configuration commands from the remote EPICS to the FPGA,and calculates the beam position data.The interface between the FPGA and the SBC is the Static Memory Controller (SMC) with a peak transfer speed of up to 349 Mbps.The 100 Mb Ethernet is used for data transfer between the EPICS and SBC board,and a serial port serves as monitoring the status of the embedded system.Test results indicate that the SBC board functions well.     

DC active power filter based on model predictive control for DC bus overvoltage suppression of accelerator grid power supply

The China Fusion Engineering Test Reactor plans to build a 200 k V/25 A acceleration grid power supply(AGPS) for the negative-ion-based neutral beam injector prototype system. The AGPS uses a rectifier-inverter-isolated step-up structure. There is a DC bus between the rectifier and the inverter.In order to limit DC bus voltage ripple and transient fluctuations, a large number of capacitors are used, which degrades the reliability of the power supply and occupies a large amount of space. This wor...     

Development of large acceptance multi-purpose spectrometer in Korea for symmetry energy

The Rare Isotope Accelerator complex for ONline experiments(RAON) is a new radioactive ion beam accelerator facility under construction in Korea. The large acceptance multi-purpose spectrometer(LAMPS) is one of the experimental devices for nuclear physics at RAON. It focuses on the nuclear symmetry energy at supra-saturation densities. The LAMPS Collaboration has developed and constructed various detector elements, including a time projection chamber(TPC) and a forward neutron detector array. From the positron beam test, the drift velocity of the secondary electrons in the TPC is 5:3±0:2 cm/ls with P10 gas mixture, and the position resolution for pads with dimensions of 4×15 mm~2 is in the range of$ 0.6–0.8 mm, depending on the beam position. From the neutron beam test, the energy resolution of the prototype neutron detector module is determined to be 3.4%, and theposition resolution is estimated to be better than 5.28 cm.At present, the construction of the LAMPS neutron detector system is in progress.     

Technical Design of Arc-Discharge and Deceleration Power Supply for MW Level NBI System on HL-2A Tokamak

Neutral beam injection (NBI) is one of the most effective ways to heat and drive plasma in a tokamak.The mega watt level neutral beam injector on the HL-2A tokamak con-sists of four high-power ion sources.Each source is supplied by discharge,beam extraction and auxiliary power supplies.Some circuit topologies and control sequences designed for the system are presented in this paper.Some important technologies such as the notching circuit,insulated gate bipolar transistor (IGBT) series-connected switch,high-frequency switching power supply and control system based on a digital signal processor (DSP) have been used.The system can be effectively used for high current ion beam extraction,protection,ion optics and so on.The power system has been safely used in HL-2A high-parameter NBI experiments for three years.The power of NBI can be kept at higher than 0.75 MW for 1 second and the ion beam power extracted from the ion source is higher than 2 MW.The ion temperature of the plasma center is close to 2.0 keV.These results show that the design of this power system is reasonable and reliable,and it can fully meet the system requirements for NBI of the HL-2A tokamak.     

Development of 230 MeV Beam Transfer System

<正>A proton therapy system including superconducting cyclotron,beam transfer system,gantry,nozzle,treatment bed and patient positioning system is under development at Research and Design Center for Cyclotron of CIAE.The main function of the proton beam transfer system is to adjust the energy of the protons extracted from the cyclotron according to the size and position of the tumor by using the degrader and energy selection system,and control the beam size by using quadrupoles.The proton beam is transferred to the isocenter under maximizing transmission efficiently.     

Turn-by-turn system and its primary experiment at HLS

During the Phase II project of NSRL, a turn by turn BPM (Beam Position Monitor) system is proposed for storage ring diagnostics which engages log-ratio electronics circuit to measure machine properties of the HLS (Hefei Light Source) storage ring. The log-ratio processor works at 408 MHz, twice the RF frequency of HLS. Modern logarithmic amplifiers with wide dynamic range, great bandwidth, good logarithmic conformance, and low cost are attractive for beam position measurements. Injection kicker and the stripline-electrode resonant exciting methods are used to excite beam for nonlinear beam dynamics and phase space studies of stored beam. Up to 2 seconds of data acquisition is ensured. In this paper we present the performance of each component and preliminary test results of the turn-by-turn BPM system.     

RESIDUAL GAS IONIZATION BEAM PROFILE MONITOR ON 40MeV H^— BEAM TRANSPORT LINE

The monitor is composed of a pair of electrodes,a single stage of microchannel plate,a phosphor screen,a CCD camera and a PC computer,To obtain a good uniform collecting field,forming electrodes system is used instead of that with a resistive divider,The readout system is performed by the phosphor screen and the CCD camera because the spatial resolution is not limited by the mechanical structure like the anode strip type and such video display system is very useful for beam studies and operation of the 40MeV linac,Besides,the design and test results are described in detail.     

Station of Profibus Communication Board Based on STM32

<正>In the 250 MeV cyclotron,the communication between the LLRF and control system buses is required.The hardware of the control system is the PLC module,so an embedded IOC board is required as the communication module for the interaction between the control system bus and the low level.The IOC board is an embedded     

Beam Current Measurement and Adjustment System on AMS

The beam current measurement and adjustment system of HI-13 tandem accelerator massspectrometry detector system is consisted of the faraday cup, fluorescent target and a series of adjustablevertical slits(Fig.1). The system's operation is very complicated and the transmission is low for the oldsystem. A new system is instalated for improvement. We put the adjustable vertical slit, Faraday cup,     

The Power Supply System of Ion Source for NBI

The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.     

Research of High Beam H~- Production and Axial Injection

Production of high beam H and axial injection with high efficiency is one of key problems to be solved for building-up a high beam cyclotron. This project is to modify an existing test stand of axial injection system including beam dynamic calculation, key structure redesign, power supply system upgrade, cesium gas injection, et al. It is planed to increase the beam current of H- ions to more than 10 mA and improve the beam quantity clearly in about two years.     

Dose Dependence of Radiation Effect in W

The spallation neutron source system is one of the key parts of the ADS system, which provides the source neutrons for driving a sub-critical assembly. W is used for the beam window and target materials of the ADS spallation neutron source system. It is i…     

Numerical Simulation of Subcooled Boiling Inside High-Heat-Flux Component with Swirl Tube in Neutral Beam Injection System

In order to realize steady-state operation of the neutral beam injection（NBI） system with high beam energy,an accurate thermal analysis and a prediction about working conditions of heat-removal structures inside high-heat-flux（HHF） components in the system are key issues.In this paper,taking the HHF ion dump with swirl tubes in NBI system as an example,an accurate thermal dynamic simulation method based on computational fluid dynamics（CFD） and the finite volume method is presented to predict performance of the HHF component.In this simulation method,the Eulerian multiphase method together with some empirical corrections about the inter-phase transfer model and the wall heat flux partitioning model are considered to describe the subcooled boiling.The reliability of the proposed method is validated by an experimental example with subcooled boiling inside swirl tube.The proposed method provides an important tool for the refined thermal and flow dynamic analysis of HHF components,and can be extended to study the thermal design of other complex HHF engineering structures in a straightforward way.The simulation results also verify that the swirl tube is a promising heat removing structure for the HHF components of the NBI system.     

Digital RF phase detector for Linac in FEL accelerator

The digital RF (Radio Frequency) phase detector based on commercial PXI (PCI eXtensions for Instrumentation) modules for the Linac is fully described in the paper. The DBM (Double Balance Mixer) is used as the phase detector and its control and data acquisition system is based on the PXI bus. The software adopts a curve fitting algorithm. The prototype has been tested in the laboratory and the good resolution, accuracy, reproducibility and reliability are expected. The system does not present the problems of analog solution.     

Performance of a New Ion Source for KSTAR Tokamak Plasma Heating

In the experimental campaign of 2010 and 2011 on KSTAR, the NBI-1 system was equipped with one prototype ion source and operated successfully, providing a neutral beam power of 0.7-1.6 MW to the tokamak plasma. The new ion source planned for the 2012 KSTAR campaign had a much more advanced performance compared with the previous one. The target performance of the new ion source was to provide a neutral deuterium beam of 2 MW to the tokamak plasma. The ion source was newly designed, fabricated, and assembled in 2011. The new ion source was then conditioned up to 64 A/100 keV over a 2-hour beam extraction and performance tested at the NB test stand （NBTS） at the Korea Atomic Energy Research Institute （KAERI） in 2012. The measured optimum perveance at which the beam divergence is a minimum was about 2.5μP, and the minimum beam divergent angle was under 1.0° at 60 keV. These results indicate that the 2.0 MW neutral beam power at 100 keV required for the heating of plasma in KSTAR can be delivered by the installation of the new ion source in the KSTAR NBI-1 system.     

Logical and Timing Control for Diagnostic Neutral Beam Injection on HT-7

The timing and master control logic （MCL） units are the most important function units of the diagnostic neutral beam （DNB） power supply control system. The units control the operation of nine power supply subsystems of the DNB system, and provide protection for the DNB system from faults such as beam source arc down. Based on the characteristics of the DNB power supply system, the timing and MCL units have been designed, fabricated and tested. Experiments prove that the timing unit is convenient, flexible and reliable, and the MCL is functional.     

Preliminary Results of Ion Beam Extraction Tests on EAST Neutral Beam Injector

The neutral beam injection (NBI) system is one of the most important auxiliary plasma heating and current driving methods for fusion device.A high power ion beam of 3MW with 80keV beam energy in 0.5s beam duration and a long pulse ion beam of 4s with 50keV beam energy ion beam extraction were achieved on the EAST neutral beam injector on the test-stand.The preliminary results show that the EAST-NBI system was developed successfully on schedule.     

Design and Calculation of Buncher in Pulsing Beam System

1 Basic theory of the buncher The buncher system is the one of the main parts in the pulsing beam generation system for 10 MeV central region of model (CRM) compact cyclotron and it will modulate the beam in the longitudinal direction. The beam with special phase width will be compressed into very short pulse in the time with     

Development of New MOPA System for Heaven- I

At present, a new MOPA system provided with smoothing function is built. The scheme is shown in Fig.l, which includes a excellent beam profile ASE source（rebuild from LPX-150）, one three-channel discharge pumped KrF laser, two stage two-electron-pumped KrF amplifiers（pre-amplifier and main-amplifier）, the optical code system and decode system, the optical focusing system. A technique called of echelon-free induced spatial incoherence is adopted for producing smooth target beam profiles. The target is irradiated by six beams with image plane at the same time.