HANBIT is a magnetic mirror confinement device. Recent physics experimentshave been mainly focused on identifying discharge characteristics and on getting stable plasmaproduction and operation modes, by using a 500 kW...HANBIT is a magnetic mirror confinement device. Recent physics experimentshave been mainly focused on identifying discharge characteristics and on getting stable plasmaproduction and operation modes, by using a 500 kW slot antenna system at a fixed RF frequency of 3.5MHz and varying discharge conditions such as fueling rate, RF power, and B-field intensity incentral cell. Two distinct operation modes are found to be very sensitive to the RF power as well asthe ratio of the RF frequency to the ion cyclotron frequency. A MHD interchange mode of m = - 1 isclearly observed and the stabilizing mechanism can be explained by the sideband coupling theory.展开更多
For the success of PAL-XFEL, two critical systems, namely a low emittance injector and a variable gap out-vacuum undulator, are under development. In order to realize the target emittance of the PAL-XFEL injector we c...For the success of PAL-XFEL, two critical systems, namely a low emittance injector and a variable gap out-vacuum undulator, are under development. In order to realize the target emittance of the PAL-XFEL injector we carried out an optimization study of various parameters, such as the laser beam transverse profile, the laser pulse length, the laser phase,and the gun energy. The transverse emittance measured at the Injector Test Facility(ITF) is εx=0.48±0.01 mm mrad.An undulator prototype based on the EU-XFEL design and modified for PAL-XFEL was built and tested. A local-K pole tuning procedure was developed and tested. A significant reduction(90%) of the local-K fluctuation was observed. The requirement of undulator field reproducibility better than 2×10-4and the undulator gap setting accuracy below 1 μm were achieved for the prototype. The optical phase jitter after the pole height tuning at the tuning gap was calculated to be 2.6? rms, which satisfies the requirement of 5.0?.展开更多
基金The project supported by the Korea Ministry of Science and Technology
文摘HANBIT is a magnetic mirror confinement device. Recent physics experimentshave been mainly focused on identifying discharge characteristics and on getting stable plasmaproduction and operation modes, by using a 500 kW slot antenna system at a fixed RF frequency of 3.5MHz and varying discharge conditions such as fueling rate, RF power, and B-field intensity incentral cell. Two distinct operation modes are found to be very sensitive to the RF power as well asthe ratio of the RF frequency to the ion cyclotron frequency. A MHD interchange mode of m = - 1 isclearly observed and the stabilizing mechanism can be explained by the sideband coupling theory.
基金supported by the Ministry of Science,ICT and Future Planning of Korea
文摘For the success of PAL-XFEL, two critical systems, namely a low emittance injector and a variable gap out-vacuum undulator, are under development. In order to realize the target emittance of the PAL-XFEL injector we carried out an optimization study of various parameters, such as the laser beam transverse profile, the laser pulse length, the laser phase,and the gun energy. The transverse emittance measured at the Injector Test Facility(ITF) is εx=0.48±0.01 mm mrad.An undulator prototype based on the EU-XFEL design and modified for PAL-XFEL was built and tested. A local-K pole tuning procedure was developed and tested. A significant reduction(90%) of the local-K fluctuation was observed. The requirement of undulator field reproducibility better than 2×10-4and the undulator gap setting accuracy below 1 μm were achieved for the prototype. The optical phase jitter after the pole height tuning at the tuning gap was calculated to be 2.6? rms, which satisfies the requirement of 5.0?.
