Critical Parameters of the Pumping Scheme of Ar +8 Lasers Excited by Z Pinches in Long Capilaries

The present study is focused on the demonstration of the most critical parameters of the pumping scheme of a table‐top Ar +8 ‐laser excited by discharges with relatively low current and voltage ( I ≤ 20 kA, U ≤ 200 kV) in long ( L ∼ 0.5 m) capillaries. The most critical parameters of the pumping scheme were analyzed and then adjusted experimentally. The table‐top size is attributed to the use of a low‐inductance co‐axial discharge configuration that decreases the voltage and current necessary for laser excitation. Low inductance is achieved by using a capillary, water‐capacitor and water spark‐gap placed into a chamber filled with deionized water. The capillary z‐pinch is produced by the water capacitor, which is pulse‐charged by a six‐stage Marx generator, optimized for the low‐inductance discharge configuration. Optimization is performed by adjusting the value of the charging inductance and the peak charging voltage with a water spark‐gap. At the optimal conditions laser pulses with a Gaussian‐like intensity distribution and divergence angle ∼ 1 mrad and energy ∼ 10 μJ are generated. The physical method for generation of a laser beam with such parameters is based on the use of a long ( L = 0.45 m) capillary plasma (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)