The size of CO₂ clusters, produced in a supersonic expansion of a mixed-gas of CO₂/He or CO₂/H₂ through a three-staged conical nozzle designed based on the Boldarev's model, has been evaluated by measuring the angular distribution of light scattered from the clusters. The data are analyzed utilizing the Mie scattering theory, and the sizes of CO₂ clusters are estimated as 0.22 μm and 0.25 μm for the cases of CO₂/He and CO₂/H₂ gas mixtures, respectively. The results confirm that the Boldarev's model is reliable enough for the production of micron-sized clusters.

A detailed mathematical model is presented for a submicron-sized cluster formation in a binary gas mixture flowing through a three-staged conical nozzle. By measuring the angular distribution of light scattered from the clusters, the size of CO₂ clusters, produced in a supersonic expansion of the mixture gas of CO₂(30%)/H₂(70%) or CO₂(10%)/He(90%), has been evaluated using the Mie scattering method. The mean sizes of CO₂ clusters are estimated to be 0.28 ± 0.03 μm for CO₂/H₂ and 0.26 ± 0.04 μm for CO₂/He, respectively. In addition, total gas density profiles in radial direction of the gas jet, measuring the phase shift of the light passing through the target by utilizing an interferometer, are found to be agreed with the numerical modeling within a factor of two. The dryness (= monomer/(monomer + cluster) ratio) in the targets is found to support the numerical modeling. The apparatus developed to evaluate the cluster-gas targets proved that our mathematical model of cluster formation is reliable enough for the binary gas mixture.

The interaction of a 60-fs laser pulse with argon clusters was experimentally studied. It is shown that cluster heating by an intense femtosecond pulse preceded by a picosecond prepulse can produce pl

The Los Alamos Bright Source laser was used to create a silicon plasma by irradiation of a solid target. A very-high-resolution curved crystal spectrograph was used to detect the emitted x rays. The satellite lines due to the decay of doubly excited states that accompany the Lyman-α lines were observed. The 2p3l-1s3l radiative transitions in He-like Si were identified. In addition, all the components of the 2l2p ${}_{}{}^3{}_{}{}^{}$P–1s2l ${}_{}{}^3{}_{}{}^{}$L transitions were resolved. The spectra were compared to various collisional-radiative calculations with good results.