Budget Amount *help |
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1996: ¥3,800,000 (Direct Cost: ¥3,800,000)
|
Research Abstract |
The performance of the crossed-beam apparatus to measure the angular distribution of the scattered ions created by charge-transfer reactions was improved much. It consists of a small Electron-Beam-Ion-Source, a double electrostatic hemispherical energy-selector, and an ion detector. To obtain good energy- and angular-resolution, a supersonic nozzle-beam is used to prepare the target. The accuracy of the collision-energy detennination was found to be better than 0.1 eV, and that of angular -reading was about 0.5 degree. The ions were extracted from the source by the extraction potential of 2 kV, then decelerated to 250 x q eV, where q denote the charge-state of the ions, then mass-selected by a Wien-filter. The mass-selected ions were decelerated to the transmission energy of the selector, about 30 xq eV, then again decelerated to the desired collision energy using two sets of three-element lens. The angular divergence of the primary beam was about*0.5 degree , and the energy spread was estimated to be 0.3 x q eV, at FWHM.The intensity of the beam was in the order of pA at 10 eV.For the energy analysis of the product ions, a 90 degree electrostatic cylindrical deflector was used, and a position-sensitive detector system is attached to that. During the course of this study, it is noticed that the most important point is the noise redaction. Therefore, the analyzer system is located inside well shielded-box. The kinetic energy of 0^<2+> ions produced in one-electron capture process in 0^<2+> + He collisions were measured at Ecm = 10 eV, from 0 to 5 degree in the laboratory frame. Only a single peak was observed on the energy spectrum. This peak corresponds to the reaction, 0^<2+>(^3P) + He ---> 0^+(^2P) + H^e + 5.6 eV ; this agrees well with that reported previously, and proved that the performance of the apparatus is good enough to do measurement in an unexplored energy region.
|