分别采用单、双透镜系统研制短磁聚焦变像管,并利用Lorentz 3D-EM软件模拟电子运动成像,研究其成像畸变。当成像比例为1∶1、阴极电压为-3 kV时,模拟得到单、双透镜系统的空间分辨率分别为17.07 lp/mm和24.49 lp/mm;在离轴6 mm处,单、双透镜系统的成像畸变率分别为1.43%和0.98%;在离轴为12 mm处,单、双透镜系统的成像畸变率分别为7.5%和2.5%。实验结果表明:在离轴6 mm处,单、双透镜系统的成像畸变率分别为2.4%和0.9%;在离轴12 mm处,单、双透镜系统的成像畸变率分别为8.5%和3.2%。研究表明,采用双磁透镜成像系统有助于改善成像畸变,提高空间分辨率。

We use single- and double-lens systems to develop the short magnetic focusing image converter tubes respectively, and simulate the electronic motion imaging to study the imaging distortion by the Lorentz 3D-EM software. When the imaging ratio is 1∶1 and the cathode voltage is -3 kV, the spatial resolutions of the single- and double-lens systems are 17.07 lp/mm and 24.49 lp/mm respectively; the imaging distortion rates of single- and double-lens systems are 1.43% and 0.98% at 6 mm off axis respectively; the imaging distortion rates of single- and double-lens systems are 7.5% and 2.5% at 12 mm off axis respectively. Experimental results show that the imaging distortion rates of single- and double-lens systems are 2.4% and 0.9% at 6 mm off axis respectively; the imaging distortion rates of single- and double-lens systems are 8.5% and 3.2% at 12 mm off axis respectively. It is concluded that the double-magnetic-lens imaging system can reduce the imaging distortion and improve the spatial resolution.