X-ray-Generated Impulses in Cylindrical Samples at the National Ignition Facility*

Experiments that study x-ray-generated impulses provide important insights into how materials respond in extreme environments. In such an experiment, high fluence x-rays deposit energy into a sample, causing rapid heating and subsequent expansion of vaporized material on the sample surface. The rapid material expansion generates a shock wave into the remaining cold material, which propagates through and can cause material damage upon transit or upon reflection from the sample rear surface. As the development of high-intensity x-ray line-emission sources advances[1], experiments on such x-ray-induced impulses in centimeter-scale coupon samples have been underway on the National Ignition Facility (NIF)[2]. In this talk, we present results from a novel extension to the x-ray effects platform that measures for the first time the effects of NIF x-rays on large-scale 10 cm cylindrical samples. We identify how the prompt impulse varies as a function of x-ray angle of incidence in the NIF target geometry. The development of this platform and results from initial experiments pave the way for future analysis on x-ray delivered impulses to more complex geometry samples. 

 

[1] M. J. May et al., Phys. Plasmas 26, 063105 (2019).

[2] D. Goto and S. J. Moon, LLNL-TR-817143 (2020).