Domain implosion: Generating hard x-rays from laser-driven ion implosion on solid and hollow gold microtubes

Abstract

Using 2.5-D particle-in-cell simulations, we evaluate the microtube implosion (MTI) mechanism of laser-driven ion acceleration as hard x-ray sources. Using the same amount of material for both solid and hollow gold microtubes, the density and energies of electrons and photons produced by the interaction of ultrarelativistic (≥ 10²³ W/cm²) laser pulses with these microtubes were analyzed. The highest electron and photon mean energies were achieved for hollow microtubes, with values increasing as the target thickness approaches the relativistic skin depth of gold. The interaction of electrons with the bulk of the microtubes is more significant in producing hard x-rays compared to the accumulation of these electrons at the center of the tubes. With these bremsstrahlung-emitted photon energy values, pair production in this mechanism may be possible through the Bethe-Heitler process.