Abstract:
The results of the experiments on the formation of a plasma emitter with small spatial dimensions for pulsed radiography in the soft X-ray spectral range are presented. Emitting hot plasma was formed as a result of compression of the plasma jet by a current pulse with amplitude $I_m$ = 215 kA and rise time $T_{\mathrm{fr}}$ = 200 ns. For the jet formation, we used a plasma gun based on the arc discharge ($I_m$ = 8.5 kA and $T_{\mathrm{fr}}$ = 6 $\mu$s) initiated by breakdown over the surface of a dielectric in vacuum. The experiments were carried out with aluminum, tin, copper, and iron plasma jets. A single emitter, i.e., point Z-pinch (PZ-pinch), was formed when an interelectrode gap of a high current generator of 1.3–1.5 mm was used. The smallest spatial dimensions of the emitting region were obtained with the use of aluminum and tin. For a tin jet, the diameter of the emitting region was 7 $\pm$ 2 $\mu$m and its height was 17 $\pm$ 2 $\mu$m. The emission pulse duration at half-height was 2–3 ns. The total emission yield per pulse in the spectral range 1.56–1.90 keV was 30–50 mJ for the aluminum pinch and 10–30 mJ for the tin pinch. The developed method makes it possible to carry out radiographic examination of microobjects (including biological ones) 1–1000 $\mu$m in thickness, with spatial (10–20 $\mu$m) and time (2–3 ns) resolution.
Fulltext:
PDF file (1801 kB)
