Neonlike Ar and Cl 3p-3semission from aθ-pinch plasma

Time-resolved extreme-ultraviolet emission from sixteen 3p-3s transitions, some of the type in which lasing has been demonstrated in heavire elements, is measured for neonlike Ar⁸⁺ and Cl⁷⁺. These observations are made on a hydrogen {θ}-pinch plasma with a 5% admixture of argon or freon (for Cl). Fourteen 3d-3p spectral lines are also detected. The measured intensities are compared to theoretical predictions. All major lines agree within ±{}30%. Hence, there is no evidence of anomalously intense lines originating on 2p⁵3p J=2 upper levels compared to J=0, as observed in gain experiments.