Investigation of dense argon plasmas in a simple capillary discharge

In a simple capillary discharge with charging voltages as high as 35 kV den se argon plasmas were produced and studied displaying reproduceable emissio n of the 3p - 3s lines of the Ar Ix ion. The obtained electron densities di d not exceed 2 x 10(18) cm(-3), and no clear lasing was observed. Pinhole s pectra and time resolved measurements of the electron density indicate that the compression of the plasma was too weak because of the slow current ris e. Comparison with a faster discharge indicates that a minimum current rise of 0.6 x 10(12) A/s is needed to obtain sufficient compression and thus me asurable gain on Ar IX 3p - 3s lines.