Project/Area Number |
12640282
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
素粒子・核・宇宙線
|
Research Institution | KYUSHU UNIVERSITY |
Principal Investigator |
MORIKAWA Tsuneyasu Faculty of Sciences,. KYUSHU UNIVERSITY Research Associate, 大学院・理学研究院, 助手 (00274423)
|
Project Period (FY) |
2000 – 2001
|
Project Status |
Completed (Fiscal Year 2001)
|
Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
Keywords | secondary beam / recoil mass separator / collective states / Coulomb excitation / isomer / nuclear structure / 反跳躍核分離装置 / 荷電粒子 / 重イオン / 位置検出 |
Research Abstract |
In order to precisely determine the astro-physical nuclear reaction rate at very low energy, which is important for the study of stellar evolutions, a high-resolution recoil mass separator (RMS) has been constructed at the Kyushu university tandem accelerator laboratory (KUTL). By using the differences in the energy and momentum, the RMS is capable of separating with high S/N ratio the reaction products from the primary beams. It is possible to produce the secondary beams of unstable nuclei by using this KUTL RMS system. In the present study, aiming the realization of the spectroscopy with secondary beam induced reactions, we developed the method for production of the secondary beams. The method employs the fusion evaporation reactions of inverse kinematics where heavy projectile from the accelerator and the light target nucleus are combined. By using the inverse kinematics, the reaction products are recoiled into a limited region of forward solid angle with a kinematic energies enough for the secondary reactions. Since the fluorine-18 secondary beam was turned out to be very difficult to produce, due to the limitations in the accelerators and the RMS, we then focused on the development of the sodium-22 secondary beam which is produced by fluorine-19 beam and helium-4 target. It was confirmed that with the present system it is possible to produce the sodium-22 secondary beam at an intensity of more than 10000 cps without any significant contamination originating from the primary beam. We also developed the charged particle detection/monitor system for the secondary beam experiments. The detectors are made of plastic scintillators coupled to position sensitive photo multiplier tubes. The system has the high endurance against irradiation and the fast timing characteristics suitable for the TOP measurements. Further development will be made to realize the spectroscopy by Coulomb excitation experiments with secondary beams.
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