PRECISE MEASUREMENT OF ASTRO-NUCLEAR RECTION USING RECOIL MASS ANALYZER

The astro-nuclear reaction ofイD14エD1He+イD112エD1C->イD116エD1O+イD2 cmエD2 = 300 keV plays a very important role in the supernovae and in the primordial nuclear synthesis。在30年多的时间里，世界上的实验性问题一直没有得到精确的实验性数据，尽管如此，还是被发现到了极其小的交叉部分。在目前的研究中，我们开发了新的仪器和方法，以精确地测量反应交叉部分的范围从E-D2厘米-D2 = 3 MeV到700 keV，我们采用了反向动力学方法。在这种方法中，对反应产品的检测-D116-D1 O的有效性超过了100次，在许多实验中被采用的γ射线检测更有效。为了分离D116 D1 O在前向角度和D112 D1C-beam，我们开发了一个回收质量分离器，它由一个电衰减器、两个磁衰减器、四个四极磁和四个辅助多磁共振器组成。我们还开发了一个新的blow-in类型的窗口气体目标，找到了足够的气体-信任能力，并生产理想的气体分配。满意度目标thickness被气体冷却系统中的brow-in gas target together所吸引。我们通过新的accel-decel方法使用Kyushu大学串联加速器在强焦点光束加速器中成功。在这一成功中，我们展示了一个大的串联加速器可以用一个小的修改来改造一个小串联。我们也在一个大光圈气体过滤器的发展中成功了。通过两项成功，一种低能量光束是必要的，用于在强度超过100次的累积中进行星形核实验。Moreover we have succeeded in the production of the pulse beam to be used for the background reduction.After the above developments， we have started the preliminary experiment for the measurement of theイイD14イD1He+イイD112イエD1C->イD116イエD1+γ reaction cross section。

The astro-nuclear reaction of ィイD14ィエD1He+ィイD112ィエD1C->ィイD116ィエD1O+γ at EィイD2cmィエD2 = 300 keV plays a very important role in the supernovae and in the primordial nuclear synthesis. In spite of experimental efforts in the world over 30 years, no precise experimental data have been obtained yet due to the extremely small cross section. In the present study, we have developed new instruments and methods in order to precisely measure the reaction cross section in the range from EィイD2cmィエD2 = 3 MeV to 700 keV.We adopted the inverse kinematics method. The detection of the reaction product ィイD116ィエD1O in this method is more than 100 times more efficient than the γ-ray detection so far adopted in many experiments. To separate ィイD116ィエD1O coming out in forward angle and the ィイD112ィエD1C-beam, we developed a recoil mass separator that is composed of one electric deflector, two magnetic deflectors, four quadrupole magnets, and four auxiliary multipole magnets.We also developed a new blow-in type windowless gas target which was found to have enough gas-confining power and to produce ideal gas distribution. Satisfactory target thickness is obtained by the blow-in gas target together with the gas cooling system.We succeeded in strong-focus beam acceleration by the new accel-decel method using Kyushu University tandem accelerator. In this success, we showed that the large tandem accelerator can be transformed to a small tandem with a little modification. we also succeeded in the development of a large aperture gas stripper. By the two successes, a low-energy beam necessary for the astro-nuclear experiment in creased more than 100 times in intensity. Moreover we have succeeded in the production of the pulse beam to be used for the background reduction.After the above developments, we have started the preliminary experiment for the measurement of the ィイD14ィエD1He+ィイD112ィエD1C->ィイD116ィエD1+γ reaction cross section.