高电荷态电子回旋共振(Electron Cyclotron Resonance,ECR)离子源产生金属离子束的方法有炉子加热法、溅射法、MIVOC(Metallic Ion from Volatile Compounds)等,其中炉子加热法具有产生的束流强度高、稳定性好的特点。炉子加热法的技术...高电荷态电子回旋共振(Electron Cyclotron Resonance,ECR)离子源产生金属离子束的方法有炉子加热法、溅射法、MIVOC(Metallic Ion from Volatile Compounds)等,其中炉子加热法具有产生的束流强度高、稳定性好的特点。炉子加热法的技术核心是加热炉,按其工作温区主要分为低温炉、高温炉两大类。高温炉主要针对熔点1 500°C以上的金属钴、钛、钒、铂、铀等。通过ANSYS仿真模拟分析了高温炉钽坩埚的温度分布、高温下因膨胀所受热应力及其在ECR离子源工作环境的强磁场中所受的安培力作用。根据模拟分析结果研制了电阻式加热高温炉,并对其进行了离线测试,实验中钽坩埚在1 800°C以上发生的形变与ANSYS模拟结果相符,并根据模拟分析给出了改进方案。改进后的电阻式加热高温炉离线测试能在1 500°C稳定维持48 h以上,而在1 846°C时可稳定维持达6 h以上,结果表明:研制的电阻式加热高温炉可应用于ECR离子源产生强流高电荷态难熔金属离子束。展开更多
In the paper,daily near-surface wind speed data from 462 stations are used to study the spatiotemporal characteristics of the annual and seasonal mean wind speed(MWS)and effective wind energy density(EWED)from 1960 to...In the paper,daily near-surface wind speed data from 462 stations are used to study the spatiotemporal characteristics of the annual and seasonal mean wind speed(MWS)and effective wind energy density(EWED)from 1960 to 2016,through the methods of kriging interpolation,leastsquares,correlation coefficient testing,and empirical orthogonal function(EOF)analysis.The results show that the annual MWS is larger than 3 m s-1 and the EWED is larger than 75 W m-2 in northern China and parts of coastal areas.However,the MWS and EWED values in southern China are all smaller than in northern China.Over the past 50 years,the annual and seasonal MWS in China has shown a significant decreasing trend,with the largest rate of decline in spring for northern China and winter for coastal areas.The annual MWS in some areas of Guangdong has an increasing trend,but it shows little change in southwestern China,South China,and west of Central China.Where the MWS is high,the rate of decline is also high.The main spatial distributions of the annual MWS and the annual EWED show high consistency,with a decreasing trend year by year.The decreasing trend of wind speed and wind energy resources in China is mainly related to global warming and land use/cover change.展开更多
Ion source as one very unique and critical part of ion accelerator needs consistent research and development work to improve the performance and to meet the future accelerator needs as well. The ion source group at IM...Ion source as one very unique and critical part of ion accelerator needs consistent research and development work to improve the performance and to meet the future accelerator needs as well. The ion source group at IMP is taking the responsibility of high performance intense beam ion source development, operation and exploration.展开更多
In 2015, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3, is 3 335.5 and 3 168.5 h, respectively, amouting to 6 504 h. Except 26Mg7+, which was required by the accel...In 2015, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3, is 3 335.5 and 3 168.5 h, respectively, amouting to 6 504 h. Except 26Mg7+, which was required by the accelerator but failed to be produced due the oxidation of the material, 20 kinds of ion beams have been delivered successfull.The failure time is 49 h this year, mainly attributed to the breakdown of the cryostat system.展开更多
In 2014, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3is 3 594 and 3 457.2 h, respectively, amouting to 7051.2 h. 17 kinds of ion beams have been delivered success...In 2014, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3is 3 594 and 3 457.2 h, respectively, amouting to 7051.2 h. 17 kinds of ion beams have been delivered successfull.The failure time is shrinked down to 8 h in this year, which is the lowest among these years. Table 1 summarizesthe main information about the ion beams delievered by the two ion sources. Fig. 1 shows the comparison of theion beam delivering time for HIRFL-CSR accelerator facitily from the three ion sources, LECR3, SECRAL andLAPECR1 since 2007.展开更多
SECRAL (Superconducting ECR Ion Source with Advanced design in Lanzhou) is a next generation ECR ion source, and aims at developing a very compact superconducting ECR ion source with an innovative magnet design, which...SECRAL (Superconducting ECR Ion Source with Advanced design in Lanzhou) is a next generation ECR ion source, and aims at developing a very compact superconducting ECR ion source with an innovative magnet design, which realizes a minimum-B trap by means of six sextupole coils external to the three axial solenoidal coils, i. e. contrary to what is usually done in any ECR ion sources. In this way, the展开更多
基金This work was supported by the National Key R&D Program of China[grant numbers 2016YFA0600403 and 2016YFA0602501]the General Project of the National Natural Science Foundation of China[grant number 41875134].
文摘In the paper,daily near-surface wind speed data from 462 stations are used to study the spatiotemporal characteristics of the annual and seasonal mean wind speed(MWS)and effective wind energy density(EWED)from 1960 to 2016,through the methods of kriging interpolation,leastsquares,correlation coefficient testing,and empirical orthogonal function(EOF)analysis.The results show that the annual MWS is larger than 3 m s-1 and the EWED is larger than 75 W m-2 in northern China and parts of coastal areas.However,the MWS and EWED values in southern China are all smaller than in northern China.Over the past 50 years,the annual and seasonal MWS in China has shown a significant decreasing trend,with the largest rate of decline in spring for northern China and winter for coastal areas.The annual MWS in some areas of Guangdong has an increasing trend,but it shows little change in southwestern China,South China,and west of Central China.Where the MWS is high,the rate of decline is also high.The main spatial distributions of the annual MWS and the annual EWED show high consistency,with a decreasing trend year by year.The decreasing trend of wind speed and wind energy resources in China is mainly related to global warming and land use/cover change.
文摘Ion source as one very unique and critical part of ion accelerator needs consistent research and development work to improve the performance and to meet the future accelerator needs as well. The ion source group at IMP is taking the responsibility of high performance intense beam ion source development, operation and exploration.
文摘In 2015, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3, is 3 335.5 and 3 168.5 h, respectively, amouting to 6 504 h. Except 26Mg7+, which was required by the accelerator but failed to be produced due the oxidation of the material, 20 kinds of ion beams have been delivered successfull.The failure time is 49 h this year, mainly attributed to the breakdown of the cryostat system.
文摘In 2014, the service time of the two on-line ion sources of HIRFL-CSR accelerator facility, SECRAL and LECR3is 3 594 and 3 457.2 h, respectively, amouting to 7051.2 h. 17 kinds of ion beams have been delivered successfull.The failure time is shrinked down to 8 h in this year, which is the lowest among these years. Table 1 summarizesthe main information about the ion beams delievered by the two ion sources. Fig. 1 shows the comparison of theion beam delivering time for HIRFL-CSR accelerator facitily from the three ion sources, LECR3, SECRAL andLAPECR1 since 2007.
文摘SECRAL (Superconducting ECR Ion Source with Advanced design in Lanzhou) is a next generation ECR ion source, and aims at developing a very compact superconducting ECR ion source with an innovative magnet design, which realizes a minimum-B trap by means of six sextupole coils external to the three axial solenoidal coils, i. e. contrary to what is usually done in any ECR ion sources. In this way, the
