Amplified spontaneous emission in the 1035 AA doublet of O5+

Abstract

A new suggestion is made for a single-pass, high-gain, O⁵⁺ ion laboratory laser at 1035 AA. A large population inversion is shown to be generated when an X-ray pulse K shell ionises O³⁺ ions, followed by Auger ionisation to an excited state of O⁵⁺. Using a strong, pulsed X-ray source which is within present capabilities, a gain coefficient of the order of 1 cm^-1 can be produced in a pure oxygen plasma in coronal ionisation equilibrium at 10⁵K and at a density of the order of 10¹⁵ cm^-3. Constraints and requirements for the achievement of high gain are analysed. These are shown to allow a maximum number of unsaturated gain lengths ranging from several tens to several hundreds, depending upon the size and geometry of the laser configuration.