Regular Article

High-energy electron radiography of microstructures in a dense material

¹ State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences, Shanghai 201800, P.R. China
² National Key Laboratory of Shock Wave and Detonation Physics, China Academy of Engineering Physics, Mianyang 621000, P.R. China
³ Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P.R. China

^a e-mail: tianye@siom.ac.cn
^b e-mail: michaeljs_liu@siom.ac.cn

Received: 7 January 2016
Revised: 28 June 2016
Accepted: 5 July 2016
Published online: 2 August 2016

Abstract

This study presents experimental and numerical results for the high-energy electron-beam radiography of two types of microstructures in a dense material. A copper step target with 1- and 4-mm-thick steps is irradiated by an electron beam with an energy of 150 MeV. A peak and valley structure with 285 µm width was observed in 4-mm step target experiment, as indicated by the “valley to peak” feature at the 4-mm step boundary caused by multiple scattering. In a gap-target experiment, the rate of increase of the penetrant-electron counts with a gap width of 500–900 µm grows from 1.5 to 2.5 times the background counts. Consequently, the width of the gaps can be approximately deduced from the ratio of the penetrant-electron counts combined with the peak value. The features observed in the experiment are reproduced by a Monte Carlo-FLUKE code with parameters similar to those used experimentally.