Design and investigation of gas cluster ion accelerator

A gas cluster ion accelerator with energies up to 20 keV is described. Parameters of the main components of the equipment were determined. It was demonstrated that a pulse regime of the accelerator can be realized with a relatively low (500 l/sec) pumping speed of the cluster ion source. Conditions for stable cluster beam generation were found. In pulse mode ion clusters appear in the accelerated beam in the first stages of ion beam evolution. A model describing the behavior of the ion beam in the pulse regime is suggested. To analyze the beam mass composition two systems were constructed: a magnetic mass-separation system and a time-of-flight system. Cluster ions Arn+ with number of atoms/charge n ≥ 500 were detected in the beam by using deflection in a homogeneous magnetic field. Clusters up to 3000 atoms/charge were detected by using time-of-flight measurements.

► We designed three-chamber facility for gas cluster ion forming and accelerating. ► We check the facility in pulse gas feeding mode. ► We find out clusters Arn with n = 3500 in the obtained beam. ► We find out that the heavy clusters form during some part of pulse period. ► We developed a gas dynamics model describing such behavior.