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R=1.2m,90°偏转对称双聚焦高场强、高分辨率分析磁铁采用近似的Rogowski磁极边界来克服局部磁饱和现象,具有磁感应强度高于1.8 T和质量分辨率M/△M大于208的特点。在磁感应强度小于1.08 T时,磁场非均匀度小于±4×10~(-4)。该分析磁铁的边缘场分布测试结果表明:在实际使用情况下,随着磁感应强度的改变(0.4—1.5T),边缘场等效边界S_0的变化小于0.006 g_0,g_0为磁极间隙(g_0=40 mm)。聚焦修正因子I_1的变化小于0.028,I_2的变化小于0.006。对核磁铁进行一阶修正和考虑二阶的计算结果表明:离子束入射和出射角应为27.13°,若在将分析磁铁的出口曲率半径改为1443 mm的凹曲面,则有可能将二阶象差减到最小。在铅离子能量为630,530,430keV的条件下,质谱分析表明,在前、后缝各开6 mm时,可将~(204)Pb~+,~(206)Pb~+,~(207)Pb~+,~(208)Pb~+完全分开,其中~(204)Pb~+的束流强度达10 μA,可用于重元素同位素离子注入。
R = 1.2m, 90 ° deflection Symmetrical, dual-focus High-field, high-resolution analysis The magnet approximates the Rogowski pole boundary to overcome local magnetic saturation with a magnetic induction above 1.8 T and a mass resolution M / ΔM greater than 208 specialty. When the magnetic induction is less than 1.08 T, the magnetic field nonuniformity is less than ± 4 × 10 -4. The test results of the fringing field distribution of the analysis magnet show that the equivalent boundary S_0 of the fringing field changes less than 0.006 g_0 with the change of the magnetic flux density (0.4-1.5T) in practical use, and g_0 is the pole gap (g_0 = 40 mm). The change of focus correction factor I_1 is less than 0.028, and the change of I_2 is less than 0.006. The first order correction of the nuclear magnet and the second order calculation result show that the incidence and the exit angle of the ion beam should be 27.13 °. If the radius of curvature of exit of the analyzing magnet is changed to 1443 mm concave surface, Aberration minimized. In the condition of lead ion energy of 630, 530 and 430 keV, mass spectrometry analysis showed that Pb ~ (204) Pb ~ +, Pb ~ +, Pb ~ +, ~ (208) Pb ~ +. The intensity of ~ (204) Pb ~ + is 10 μA, which can be used for heavy element isotope ion implantation.