Quantifying spot size reduction of a 1.8 kA electron beam for flash radiography

Abstract

The spot size of Axis-I at the Dual Axis Radiographic Hydrodynamic Test facility was reduced by 15.5% by including a small diameter drift tube that acts to aperture the outer diameter of the electron beam. Comparing the measured values to both analytic calculations and results from a particle-in-cell model shows that one-third to one-half of the spot size reduction is due to a drop in beam emittance. We infer that one-half to two-thirds of the spot-size reduction is due to a reduction in beam-target interactions. Sources of emittance growth and the scaling of the final focal spot size with emittance and solenoid aberrations are also presented.

Remote sensing of high energy particle currents (HEC): towards HEC radiography

“…Ionizing radiation, such as x-rays, electrons, neutrons and protons, are used in diverse applications in science, industry, medicine, and defense, among others. In many applications, the structure of objects or their physical conditions are imaged [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Imaging of internal material properties is invariably achieved by using external scanning beams, stationary broad beams, or injected or incorporated radiation emitters, and detecting various properties of the radiation emerging from the object.…”