Dielectronic satellites of the He$_\beta$ line of the Si XIII ion in a dense laser plasma

The first precision measurements of the wavelengths and identifications were made of the satellites of the Heb line of the Si XIII ion in the emission spectrum of a laser plasma. These satellites were the result of radiation decay of the $1s3l_13l_2$ levels of the Si XII ion. The wavelengths were determined more accurately for the $1s2l_13l_2$ configurations. The experimental results obtained were compared with calculations carried out by various methods. The structure of the relative intensities of the $1s3l_13l_2$ satellites indicated that their emission occurred mainly in a thin overdense plasma region with $N_e > N_e^{cr}$.