The CSRe internal-target is composed of a cluster-jet source, a collision chamber and a jet-catcher. The target gas which is pre-cooled to its dew-point temperatures is jetted through a Laval nozzle. During the adiabatic expansion, it is further cooled below its dew-point to reduce its transverse velocity and to grow clusters. The cluster-jet is collimated to a diameter of 3~5 mm by a four-stage collimator, bombarded by the ion-beam in the collision chamber, and finally collected by the catcher. It is able to provide nitrogen, neon, argon, krypton and xenon jet-targets of about 1E13 atoms/cm2 and the hydrogen jet-target of about 1E12 atoms/cm2, in a background vacuum of 5E-9 Pa. Several beryllium windows, as well as x-ray detectors are equipped to the collision chamber. X-ray spectroscopy studies in high-energy, highly charged ions with atoms collisions, such as the radiative electron capture and the multiple inner-shell ionization processes, are carried out based on this set-up.
