Soft X-ray emissions f̈rom neon gas-puff Z-pinch powered by Qiang Guang-I accelerator

The X-ray emission, especially the K-shell emission, f̈rom a neon gas-puff Z-pinch powered by the Qiang Guang-I accelerator, about 1.5 MA in amplitude and 100ns in rise time, were calculated based on the two-level model and measured with X-ray diodes and an eight-f̈rame X-ray pinhole camera. The simulation results showed that the K-shell yield is highly sensitive to the peak current. The experimental results confirmed that the matching of the Z-pinch load (mass and initial radius) to the current is crucial for getting a higher X-ray yield. Being determined by the imploding time, the pinch current plays a more important role than the current amplitude in K-shell emission. It seems that the preferable imploding time is about 110ns. The K-shell radiation power with double shells, as a whole, is higher than that using single neon shell. While an implosion of a light (32 μg/cm) and small (20mm in diameter) neon shell evolves with rather twist and asymmetries, a heavier (41 μg/cm) and bigger (25mm in diameter) neon shell implodes more symmetrically. The double neon shells, 30mm and 30 μg/cm for the outer shell, and 15-mm and 10 μg/cm for the inner shell, create almost perfect implosions evidenced by the early-time plasma shells with little perturbation and late stagnated pinch liners with a good axial uniformity. It was found that the Zippering effect leads to an earlier K-shell emission in the cathode region than that in the anode region, which extends the pulse width of K-shell emission.