Areal density and spatial resolution of high energy electron radiography

Xiao Jiahao^{1, 2}, Zhang Zimin¹, Cao Shuchun^{1, †}, Yuan Ping¹, Shen Xiaokang¹, Cheng Rui^{1, ‡}, Zhao Quantang¹, Zong Yang¹, Liu Ming¹, Zhou Xianming¹, Li Zhongping¹, Zhao Yongtao¹, Tang Chuanxiang³, Huang Wenhui³, Du Yingchao³, Gai Wei^{1, 3, 4}

Image of the aluminum step target recorded by HEER. The thickness of the target increases from the left of the picture to the right. The dark background around the target is due to the target holder frame blocking the electron beam.