| 摘要 |
PURPOSE:To enhance an S/N ratio while reducing the amt. of neutrinos irradiating a sample by cutting off beam using a metal plate and blocking the passage of neutral particles in an almost perfect state. CONSTITUTION:The ion generated from an ion source 1 passes through apertures 21 and is accelerated by an electrode 22 to form ion beam. The ion beam passes through the aperture 19 provided to the center of a detector 4 through a chopper 2 to reach a sample 5 and is reflected by the sample 5 to be detected by the detector 4. The chopping means of an ion scattering spectroscopic device is constituted of the chopper 2, a motor 3 and a motor control circuit 20 to be connected to a computer 8. The chopper 2(a perforated disc composed of an ion beam cutting-off substance such as a metal) is rotated by rotating the motor 3 to open the track of ion beam and a moment when pulse ion beam is generated is monitored by a pulse generator 10 to send a start signal to a time digital converter 11. That is, since pulse ion beam is mixed in the vicinity of the sample 5 during the irradiation of the sample with pulse ion beam, the amt. of neutral particles irradiating the sample 5 is reduced and an S/N ratio is enhanced. |
