The higher harmonics of the free electron laser(FEL)with a two-wavenumber plane wiggler magnetic field,which may induce a lot of higher harmonics,are investigated.Using a two-wavenumber wiggler comprised of two separa...The higher harmonics of the free electron laser(FEL)with a two-wavenumber plane wiggler magnetic field,which may induce a lot of higher harmonics,are investigated.Using a two-wavenumber wiggler comprised of two separate periodicities,k_(ω)and k_(ω)+Δk,numerical simulations show that the higher harmonic may be amplified and the first harmonic may be suppressed in this kind of FEL with an optimized parameterΔk.The coupling coefficient and gain coefficient in low-gain regime of the harmonic are also obtained.展开更多
In a relativistic electron cyclotron maser with an axisymmetrical quasioptical cavity of oblique rotation at arbitrary angle,the rotating angle has a great influence on beam-wave interaction.Two different physical mec...In a relativistic electron cyclotron maser with an axisymmetrical quasioptical cavity of oblique rotation at arbitrary angle,the rotating angle has a great influence on beam-wave interaction.Two different physical mechanisms are found with the rotating angle ranging from 0°to 90°.One is cyclotron auto-resonance maser regime for small angle,with small optimized external magnetic field;the other is electron cyclotron resonance maser regime for large angle,with comparatively large optimized magnetic field.展开更多
文摘The higher harmonics of the free electron laser(FEL)with a two-wavenumber plane wiggler magnetic field,which may induce a lot of higher harmonics,are investigated.Using a two-wavenumber wiggler comprised of two separate periodicities,k_(ω)and k_(ω)+Δk,numerical simulations show that the higher harmonic may be amplified and the first harmonic may be suppressed in this kind of FEL with an optimized parameterΔk.The coupling coefficient and gain coefficient in low-gain regime of the harmonic are also obtained.
基金Supported by the Doctoral Fund of the State Education Committee of China.
文摘In a relativistic electron cyclotron maser with an axisymmetrical quasioptical cavity of oblique rotation at arbitrary angle,the rotating angle has a great influence on beam-wave interaction.Two different physical mechanisms are found with the rotating angle ranging from 0°to 90°.One is cyclotron auto-resonance maser regime for small angle,with small optimized external magnetic field;the other is electron cyclotron resonance maser regime for large angle,with comparatively large optimized magnetic field.
