Time-resolved EUV spectra from nitrogen Z-pinching capillary discharge

Abstract

Time-integrated spectra and time-resolved spectra (20 ns resolution) of nitrogen discharge plasma radiation were recorded and analyzed. Plasma was created by a 70 kA, 29 ns rise-time current pulse flowing through a 5 mm inner diameter, 224 mm long capillary filled with nitrogen to initial pressure ∼0.1 ÷ 1 kPa. Spectra were captured in the wavelength range 8.3 ÷ 14 nm. This spectral region contains nitrogen Balmer series lines including potentially lasing NVII 2 -3 transition 1 . Spectral lines were identified using the NIST database and the FLY kinetic code. Together with spectra the capillary current was measured. Due to the low inductance design of the driver, the pinch is observable directly from the measured current. 13.38 nm NVII 2 -3 line was observed in gated, and also in time-integrated spectra for currents >60 kA. For higher gas-filling pressure also other Balmer series lines were observed.

Plasma dynamics at the preionization stage in discharge-based EUV lasers

“…More recently ablation of solid targets with the 46.9 nm laser was considered for high-resolution mass spectrometry [14,15], manufacturing microelectromechanical systems [16,17] and generation of warm dense matter [18]. Work on extending operation of discharge-based lasers into the shorter wavelength range using recombination pumping in a nanosecond capillary discharge in nitrogen [19][20][21][22][23] is currently undergoing.…”