针对现有散射通信系统中单极化的铝制天线面不能满足新频段散射通信对双极化轻型天线的要求,提出了X频段双极化碳纤维天线的研究;天线面采用碳纤维材料,既保证了天线面的电气性能,又降低了天线的整体重量,满足了通信系统对轻型化的要求...针对现有散射通信系统中单极化的铝制天线面不能满足新频段散射通信对双极化轻型天线的要求,提出了X频段双极化碳纤维天线的研究;天线面采用碳纤维材料,既保证了天线面的电气性能,又降低了天线的整体重量,满足了通信系统对轻型化的要求;应用HFSS软件对设计的天线进行了仿真及优化,同时基于设计及仿真结果研制了天线样机,对天线样机进行了测试,测试得到天线的电气性能均可满足设计要求,其中天线极化隔离度≥40 d B,优于双极化散射通信系统中对极化隔离度的要求。展开更多
In order to realize high energy density physics and plasma physics research at HIRFL-CSR, a magnetic alloy （MA）-loaded cavity has been studied. According to the theoretical calculation and simulation for the MA-load...In order to realize high energy density physics and plasma physics research at HIRFL-CSR, a magnetic alloy （MA）-loaded cavity has been studied. According to the theoretical calculation and simulation for the MA-loaded cavity, we achieved a better result. The MA-loaded cavity had a higher μQf value, with a higher shunt impedance and a higher accelerating gradient. The accelerating gradient was about 95 kV/m at 1.8003 MHz, 130 kV/m at 0.9000 MHz. Compared with the ferrite-loaded cavities that are used at HIRFL-CSR, with about 10 kV/m accelerating gradient, the MA-loaded cavity obviously has an advantage. The results of the theoretical calculation and the simulation, which meet the design requirements are in good agreement.展开更多
Superconducting quarter-wave resonators,due to their compactness and their convenient shape for tuning and coupling,are very attractive for low-β beam acceleration.In this paper,two types of cavities with different g...Superconducting quarter-wave resonators,due to their compactness and their convenient shape for tuning and coupling,are very attractive for low-β beam acceleration.In this paper,two types of cavities with different geometry have been numerically simulated the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz,β=0.06 beams then the relative electromagnetic parameters and geometric sizes have been compared.It is found that the second type,whose structural design is optimized with the conical stem and shaping drift-tube,can support the better accelerating performance.At the end of the paper,some structural deformation effects on frequency shifts and appropriate solutions have been discussed.展开更多
The feasibility of attaining a short-pulse-duration heavy ion beam with a nanosecond pulse length is studied in the main ring of the Heavy Ion Research Facility in Lanzhou （HIRFL）. Such a heavy ion beam can be produ...The feasibility of attaining a short-pulse-duration heavy ion beam with a nanosecond pulse length is studied in the main ring of the Heavy Ion Research Facility in Lanzhou （HIRFL）. Such a heavy ion beam can be produced by non-adiabatic compression, and it is implemented by fast rotation in the longitudinal phase space. In this paper, the possible beam parameters during longitudinal bunch compression are studied by using the envelope model. The result shows that a shortest heavy ion bunch 23Su2S＋ of 29 ns with energy of 200 MeV/u can be obtained, which can satisfy high energy density physics research.展开更多
文摘针对现有散射通信系统中单极化的铝制天线面不能满足新频段散射通信对双极化轻型天线的要求,提出了X频段双极化碳纤维天线的研究;天线面采用碳纤维材料,既保证了天线面的电气性能,又降低了天线的整体重量,满足了通信系统对轻型化的要求;应用HFSS软件对设计的天线进行了仿真及优化,同时基于设计及仿真结果研制了天线样机,对天线样机进行了测试,测试得到天线的电气性能均可满足设计要求,其中天线极化隔离度≥40 d B,优于双极化散射通信系统中对极化隔离度的要求。
文摘In order to realize high energy density physics and plasma physics research at HIRFL-CSR, a magnetic alloy （MA）-loaded cavity has been studied. According to the theoretical calculation and simulation for the MA-loaded cavity, we achieved a better result. The MA-loaded cavity had a higher μQf value, with a higher shunt impedance and a higher accelerating gradient. The accelerating gradient was about 95 kV/m at 1.8003 MHz, 130 kV/m at 0.9000 MHz. Compared with the ferrite-loaded cavities that are used at HIRFL-CSR, with about 10 kV/m accelerating gradient, the MA-loaded cavity obviously has an advantage. The results of the theoretical calculation and the simulation, which meet the design requirements are in good agreement.
文摘Superconducting quarter-wave resonators,due to their compactness and their convenient shape for tuning and coupling,are very attractive for low-β beam acceleration.In this paper,two types of cavities with different geometry have been numerically simulated the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz,β=0.06 beams then the relative electromagnetic parameters and geometric sizes have been compared.It is found that the second type,whose structural design is optimized with the conical stem and shaping drift-tube,can support the better accelerating performance.At the end of the paper,some structural deformation effects on frequency shifts and appropriate solutions have been discussed.
基金Supported by National Natural Science Foundation of China (10905082)
文摘The feasibility of attaining a short-pulse-duration heavy ion beam with a nanosecond pulse length is studied in the main ring of the Heavy Ion Research Facility in Lanzhou （HIRFL）. Such a heavy ion beam can be produced by non-adiabatic compression, and it is implemented by fast rotation in the longitudinal phase space. In this paper, the possible beam parameters during longitudinal bunch compression are studied by using the envelope model. The result shows that a shortest heavy ion bunch 23Su2S＋ of 29 ns with energy of 200 MeV/u can be obtained, which can satisfy high energy density physics research.
