High-Areal Density (>100g/cm 2 ) Radiography using MeV X-rays Performed at the NIF-ARC Laser System

Laser-driven X-ray radiography is a potential radiographic source for static and dynamic imaging

and could soon compete with conventional sources. In particular, bremsstrahlung X-rays from

high-intensity laser-solid target interactions (>1 x 10^18 W/cm^2) can produce a broadband of

high-energy/MeV X-rays with a source size in the hundreds of microns. At the NIF-ARC laser

facility, we have conducted numerous studies on the production and scaling of MeV X-rays. We

have measured the X-ray spectrum, angular distribution, and performed radiography of high-

areal density objects [1]. The NIF-ARC laser can deliver up to 2.4 kJ in 10 ps or 4 kJ in 38 ps.

Here, we present recent experimental data obtained at the NIF-ARC from several shots at each

pulse duration to better understand the scaling of MeV X-ray production and maximize X-ray

dose. The best performance is achieved at 2.4 kJ in 10 ps, and this was used to perform

radiography on the line-of-sight of the ARC laser, providing a radiograph through >100 g/cm^2

of tungsten. Scaling of the X-ray flux and radiography performance is complemented with

analytical and simulation modeling that agrees with the experimental results.