Activation Cross section measurements for 5〜7 MeV Neutrons produced with d-D reaction

为名古屋大学范德格拉夫(VDG)加速器KN-3750研制了静电三重态四极透镜和束流偏转器。用VDG加速器测量了D(d，n)3He反应产生的3-5 MeV中子的激活截面。为了聚焦比直径为5 mm的D_2气体靶的哈弗薄片(2.2μm^t)靶窗口小的d^+光束，研制了静电三重四极透镜。用石英束观察器观察到，在±3KV的电压下，可使光斑聚焦约2 mm。另一方面，为了测量产生的核的半衰期小于1 S的激活截面，还研制了用于在范德格拉夫加速器上产生脉冲中子的束流偏转器。通过在两根电极之间加20KV的电压，获得了脉冲宽度约30ms的d^+束流。通过测量^&lt；27&gt；Al(p，γ)反应，在离束条件下根本没有观察到瞬发的γ射线。利用四极透镜和束流偏转器，利用VDG加速器测量了短寿命核的中子活化截面。

An electrostatic-triplet quadrupole lens and a beam deflector have been developed for a Van de Graaf(VdG) accelerator KN-3750 at Nagoya University.Activation cross section has been measured with 3-5 MeV neutrons produced with D(d,n)^3He reactions by using a VdG accelerator. In order to focus the d^+ beam smaller than the target window made of Haver foil (2.2μm^t) of the D_2 gas target whose size is 5mm diameter, an electrostatic-triplet quadrupole lens has been developed. By applying the voltage of ± 3kV, it could focus the beam spot about 2 mm, this was observed with a quartz beam viewer. As the result, it can reduce the scattered neutron which generated in undesired area, and it considered to keep good monodiromacity of the neutron.On the other hand, in order to measure the activation cross section of which half-lives of produced nuclei is shorter than 1 s, a beam deflector has been also developed in order to generate pulsed neutrons from the Van de Graaf accelerator. By applying 20kV between two eletrodes, it makes d^+ beam whose pulse width about 30 ms. By measuring the ^<27>Al(p,γ) reaction, the prompt γ-rays were not observed at all with beam-off condition. By using the quadrupole lens and the beam deflector, neutron activation cross sections for short lived-nuclei are scheduled to measure with VdG accelerator.