Tune ripple has a significant influence on beam spill ripple in RF-knockout(RF-KO)slow extraction.In this study,a model was proposed to explain how the tune ripple affects the beam spill in RF-KO slow extraction;conse...Tune ripple has a significant influence on beam spill ripple in RF-knockout(RF-KO)slow extraction.In this study,a model was proposed to explain how the tune ripple affects the beam spill in RF-KO slow extraction;consequently,a simulation was performed using the lattice of the Xi’an Proton Application Facility(XiPAF)synchrotron to verify the model.The simulation demonstrates that the tune ripple influences the beam spill in two ways.On the one hand,the tune ripple causes a direct fluctuation in the separatrix area,which induces beam spill ripple.On the other hand,the tune ripple influences the emittance growth rate in RF-knockout slow extraction.These two aspects simultaneously contribute to the beam spill ripple.展开更多
Single-phase power converters are widely used in electric distribution systems under 10 kilowatts,where the second-order power imbalance between the AC side and DC side is an inherent issue.The pulsating power is deco...Single-phase power converters are widely used in electric distribution systems under 10 kilowatts,where the second-order power imbalance between the AC side and DC side is an inherent issue.The pulsating power is decoupled from the desired constant DC power,through an auxiliary circuit using energy storage components.This paper provides a comprehensive overview of the evolution of single-phase converter topologies underlining power decoupling techniques.Passive power decoupling techniques were commonly used in single-phase power converters before active power decoupling techniques were developed.Since then,active power decoupling topologies have generally evolved based on three streams of concepts:1)current-reference active power decoupling;2)DC voltage-reference active power decoupling;and 3)AC voltage-reference active power decoupling.The benefits and drawbacks of each topology have been presented and compared with its predecessor,revealing underlying logic in the evolution of the topologies.In addition,a general comparison has also been made in terms of decoupling capacitance/inductance,additional cost,efficiency and complexity of control,providing a benchmark for future power decoupling topologies.展开更多
Particles in a storage ring oscillate in the longitudinal and transverse dimensions. Therefore, the signal that beam has generated can be analyzed in the frequency domain to extract many beam parameters, such as tune,...Particles in a storage ring oscillate in the longitudinal and transverse dimensions. Therefore, the signal that beam has generated can be analyzed in the frequency domain to extract many beam parameters, such as tune, momentum spread, emittance and their evolution with time and so on. In this paper, the transverse spectrum in HIRFL-CSR was simulated and analyzed under different conditions, including electron cooling, hollow electron beam, solenoid effect, the tune shift caused by power supply ripple and the misalignment between ion and electron beams. The result of the simulation shows that the longitudinal magnetic field of the electron cooling device should be compensated by a ＂compensation solenoid＂, and the power supply ripple must be controlled, otherwise the accumulation would be affected and the beam would be lost.展开更多
基金supported by the National Natural Science Foundation of China(No.12075131)。
文摘Tune ripple has a significant influence on beam spill ripple in RF-knockout(RF-KO)slow extraction.In this study,a model was proposed to explain how the tune ripple affects the beam spill in RF-KO slow extraction;consequently,a simulation was performed using the lattice of the Xi’an Proton Application Facility(XiPAF)synchrotron to verify the model.The simulation demonstrates that the tune ripple influences the beam spill in two ways.On the one hand,the tune ripple causes a direct fluctuation in the separatrix area,which induces beam spill ripple.On the other hand,the tune ripple influences the emittance growth rate in RF-knockout slow extraction.These two aspects simultaneously contribute to the beam spill ripple.
文摘Single-phase power converters are widely used in electric distribution systems under 10 kilowatts,where the second-order power imbalance between the AC side and DC side is an inherent issue.The pulsating power is decoupled from the desired constant DC power,through an auxiliary circuit using energy storage components.This paper provides a comprehensive overview of the evolution of single-phase converter topologies underlining power decoupling techniques.Passive power decoupling techniques were commonly used in single-phase power converters before active power decoupling techniques were developed.Since then,active power decoupling topologies have generally evolved based on three streams of concepts:1)current-reference active power decoupling;2)DC voltage-reference active power decoupling;and 3)AC voltage-reference active power decoupling.The benefits and drawbacks of each topology have been presented and compared with its predecessor,revealing underlying logic in the evolution of the topologies.In addition,a general comparison has also been made in terms of decoupling capacitance/inductance,additional cost,efficiency and complexity of control,providing a benchmark for future power decoupling topologies.
基金Supported by National Natural Science Foundation of China (10635090)
文摘Particles in a storage ring oscillate in the longitudinal and transverse dimensions. Therefore, the signal that beam has generated can be analyzed in the frequency domain to extract many beam parameters, such as tune, momentum spread, emittance and their evolution with time and so on. In this paper, the transverse spectrum in HIRFL-CSR was simulated and analyzed under different conditions, including electron cooling, hollow electron beam, solenoid effect, the tune shift caused by power supply ripple and the misalignment between ion and electron beams. The result of the simulation shows that the longitudinal magnetic field of the electron cooling device should be compensated by a ＂compensation solenoid＂, and the power supply ripple must be controlled, otherwise the accumulation would be affected and the beam would be lost.
