A BUILT-IN UNIT FOR LOW-ENERGY AND HYPERTHERMAL ION BACKSCATTERING AND ION-NEUTRALIZATION SPECTROSCOPY

The unit is designed to provide a surface analysis by low-energy and h yperthermal ion scattering and ion-neutralization spectroscopy. The va cuum part of the unit is mounted on a single flange and includes an io n gun that generates a beam of noble gas 2-5000-eV ions with a current of 0.1 to 1000 nA and a diameter of 0.12-1 mm. The gun is placed insi de a cylindrical analyzer and aligned with the axis. The input and out put electric fields of the analyzer are reshaped in order to transmit low-energy charged particles. The emittance of the scattered beam of i ons, whose energy distribution has a peak, is matched to the analyzer acceptance. The electronic hardware counts 1-10(6) pulse/sec from a se condary electron multiplier. The unit can operate in any vacuum chambe r with a base pressure under 10(-5) Pa. The working gas (He, Ne) press ure is equal to or higher than 10(-3) Pa.