Superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half wave resonators. Due to the rising demand on high current, the issue of beam loading and space c...Superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half wave resonators. Due to the rising demand on high current, the issue of beam loading and space charge problems has arisen. Qualities of low cost and high accelerating efficiency are required for SC cavities, which are properly fitted by using an SC quarter wave resonator （QWR）, We propose a concept of using QWRs with frequency 162.5 MHz to accelerate high current proton beams. The electromagnetic design and optimization of the prototype have been finished at Peking University. An analytical model derived by the transmission line theory is used to predict an optimal combination of the geometrical parameters, with which the calculation by Microwave Studio shows a good agreement. The thermal analysis to identify the temperature rise of the demountable bottom plate under various levels of thermal contact also has been done, and the maximum increment is less than 0.5 K even though the contact state is poor.展开更多
The superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half-wave resonators. Due to the rising demand on high current, the issue of beam loading and spa...The superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half-wave resonators. Due to the rising demand on high current, the issue of beam loading and space-charge problems has arisen. Qualities of low cost and high accelerating efficiency are required for SC cavities, which are properly fitted by using SC quarter-wave resonators （QWR）. We propose a concept of using QWRs with frequency 162.5 MHz to accelerate high current proton beams. The main factor limiting SC QWRs being applied to high current proton beams is vertical beam steering, which is dominantly caused by the magnetic field on axis. In this paper, we intend to analyze steering and eliminate it to verify the qualification of using QWRs to accelerate high intensity proton beams.展开更多
A re-buncher with spiral arms for a heavy ion linear accelerator named as SSC-LINAC at HIRFL （the heavy ion research facility of Lanzhou） has been constructed. The re-buncher, which is used for beam longitudinal mod...A re-buncher with spiral arms for a heavy ion linear accelerator named as SSC-LINAC at HIRFL （the heavy ion research facility of Lanzhou） has been constructed. The re-buncher, which is used for beam longitudinal modulation and matching between the RFQ and DTL, is designed to be operated in continuous wave （CW） mode at the Medium-Energy Beam-Transport （MEBT） line to maintain the beam intensity and quality. Because of the longitudinal space limitation, the re-buncher has to be very compact and will be built with four gaps. We determined the key parameters of the re-buncher cavity from the simulations using Microwave Studio software, such as the resonant frequency, the quality factor Q and the shunt impedance. The detailed design of a 53.667 MHz spiral cavity and measurement results of its prototype will be presented.展开更多
基金Supported by Major Research Plan of National Natural Science Foundation of China (91026001)
文摘Superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half wave resonators. Due to the rising demand on high current, the issue of beam loading and space charge problems has arisen. Qualities of low cost and high accelerating efficiency are required for SC cavities, which are properly fitted by using an SC quarter wave resonator （QWR）, We propose a concept of using QWRs with frequency 162.5 MHz to accelerate high current proton beams. The electromagnetic design and optimization of the prototype have been finished at Peking University. An analytical model derived by the transmission line theory is used to predict an optimal combination of the geometrical parameters, with which the calculation by Microwave Studio shows a good agreement. The thermal analysis to identify the temperature rise of the demountable bottom plate under various levels of thermal contact also has been done, and the maximum increment is less than 0.5 K even though the contact state is poor.
文摘The superconducting （SC） cavities currently used for the acceleration of protons at a low velocity range are based on half-wave resonators. Due to the rising demand on high current, the issue of beam loading and space-charge problems has arisen. Qualities of low cost and high accelerating efficiency are required for SC cavities, which are properly fitted by using SC quarter-wave resonators （QWR）. We propose a concept of using QWRs with frequency 162.5 MHz to accelerate high current proton beams. The main factor limiting SC QWRs being applied to high current proton beams is vertical beam steering, which is dominantly caused by the magnetic field on axis. In this paper, we intend to analyze steering and eliminate it to verify the qualification of using QWRs to accelerate high intensity proton beams.
基金Supported by Pioneering and Interdisciplinary Research of Big Sciences (Y115210YQ0)
文摘A re-buncher with spiral arms for a heavy ion linear accelerator named as SSC-LINAC at HIRFL （the heavy ion research facility of Lanzhou） has been constructed. The re-buncher, which is used for beam longitudinal modulation and matching between the RFQ and DTL, is designed to be operated in continuous wave （CW） mode at the Medium-Energy Beam-Transport （MEBT） line to maintain the beam intensity and quality. Because of the longitudinal space limitation, the re-buncher has to be very compact and will be built with four gaps. We determined the key parameters of the re-buncher cavity from the simulations using Microwave Studio software, such as the resonant frequency, the quality factor Q and the shunt impedance. The detailed design of a 53.667 MHz spiral cavity and measurement results of its prototype will be presented.
