main menu from here

Time of Flight Low Energy Atom Scattering Spectroscopy



Atom scattering spectroscopy for surface structure and elemental analysis

The low energy ion scattering spectroscopy (LEIS) is a powerful method for surface crystal structure and elemental composition analysis of then topmost several layers of the crystal surface. However, analyses of insulator surfaces have been very difficult because of the electric charge-up caused by ions. To overcome the difficulties of charge up effects on insulator surfaces, we have developed a new type of surface instrument, TOFLAS-3000 (Time Of Flight Low energy Atom Scattering spectroscopy).

Basic Principle

TOFLAS-3000 is composed of ionization source, neutralization room (converting ions to atoms), micro-channel plate (MCP) detector and main analysis vacuum chamber.
The ions generated in the ionization source are accelerated and chopped into a pulsed beam. The pulsed beam is neutralized in the neutralization room and transformed into neutral (atom) beam.
The atom beam hitting the sample surface is scattered all the directions. Only backward-scattered atoms are detected by MCP detector, the energy and frequency of detected atoms are measured by time of flight (TOF) analysis.

Outline DiagramPrinciple Diagram

Elemental and structural analysis of a crystal surface can be made by the time of flight techniques, because an energy and density of a scattered atom depends on the mass and the density of the target atom in/on the crystal surface.
When the atom in the second and the third atomic layer is covered by the shadow corn due to the first atomic layer, shown in the left (A), the atoms only in the first atomic layer can be detected. In case of (B), the first and the second layerfs atoms are detected. Thus, the crystal structure of the surface can be analyzed by examining the incident angle dependence of the scattered intensity at desired flight time.


November, 2012
Pascal Co., Ltd. builds the Ibaraki Factory at Naka-city Ibaraki Japan.
September, 2010
Pascal Co., Ltd. introduces TOFLAS-3000; the New Surface Analysis Solution using Atom Scattering Spectroscopy.
April, 2008
Pascal Co., Ltd. starts to produce Cryo Cooler Series for optical, electrical or hall effect measurements.
Febrary, 2008
Pascal Co., Ltd. builds the New Head Office and moves there
  • Back to top