التحقيق في خصائص إنتاج البلازما لموجهات التفريغ الشعرية

Abstract

This paper investigates the testing of plasma waveguides that are suitable for the guiding of high power
femtosecond laser pulses in non-linear laser-plasma interaction experiments. Plasma is created by ionising the gas
injected into the capillary using a high voltage pulse. Two waveguides were used: each is 4 cm in length but with a
different capillary diameter profile. The first waveguide was a linear (straight) waveguide with a constant diameter
of 288 μm and the second featured a taper in its diameter from 289 – 232 μm. To characterise the performance of
each capillary, high voltage testing was undertaken using a vacuum chamber. The straight capillary produced a
steady current of 320 A with a voltage input of 17kV. The tapered capillary was tested with the current flowing from
the large end to the small end to produce a reasonably stable current of 300 A with an input voltage of 16 kV. In
both straight and tapered capillaries, the temporal fluctuations of the current pulse demonstrates excellent stability of
the plasma current.