Nuclear Okorokov effect of heavy ions with relativistic energy

具有相对论能量的重离子核奥科罗科夫效应

• 批准号: 07404019
• 负责人: KOMAKI Ken-ichiro
• 金额: $ 13.31万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07404019/
• 关键词: channeling; heavy ion; Okorokov effect; nuclear excitation; resonant coherent excitation; relativistic energy; 電子損失断面積

Channeling ions have a possibility to be excited in the internal levels by a periodic potential of a crystal. It is called Resonant Coherent Excitation (PCE). The condition of RCE in nuclear levels is satisfied with relativistic heavy ions supplied by HIMAC.A channeling experiment in a relativistic energy region requires a beam with extremely small angular divergence. We have developed a parallel beam, and observed the reductions of the energy deposition and the angular spread of channeling ions under several channeling conditions. channeling ions under several channeling conditions.We have succeeded in observing the atomic RCE from 1s to n=2 states with 390MeV/u Ar^<17+> ions planar channeled in a Si crystal, by measuring the charge state distribution after transmission through the crystal. Under several RCE conditions, the fraction of survived Ar^<17+> ions was observed to decrease drastically. We also measured the energy deposition of channeling ions adopting a totally depleted silicon detector as a target crystal. The energy deposition of the plannar channeling ion is closely related to the trajectory in the crystal, and provides the information of the position dependent crystal field. The resonance profiles are well explained by the L・S interaction and the Stark effect originated in the crystal field.

电子离子有可能在内部能级中被晶体的周期性电势激发。它被称为共振相干激发（PCE）。HIMAC提供的相对论重离子能满足核能级的RCE条件，在相对论能区进行沟道实验需要具有极小角发散度的束流。我们已经开发了一个平行束，并观察到的能量沉积和沟道离子的角扩展的几个沟道条件下的减少。在几种沟道条件下的离子沟道效应，通过测量390 MeV/uAr ^<17+>离子在Si晶体中的电荷态分布，我们成功地观察到了Ar ^<17+>离子在Si晶体中平面沟道时，原子从1 s态到n=2态的RCE。在几种RCE条件下，观察到存活的Ar^<17+>离子的分数急剧下降。我们还测量了采用全耗尽硅探测器作为靶晶体的沟道离子的能量沉积。平面沟道离子的能量沉积与其在晶体中的运动轨迹密切相关，并提供了晶体场位置相关的信息。利用L·S相互作用和源于晶场的Stark效应很好地解释了共振分布。

项目成果

T.Ito, T.Azuma, K.Komaki, Y.Yamazaki, M.Sano, M.Torikoshi, A.Kitagawa, E.Takada, and T.Murakami: "Energy Loss of Channeled 290MeV/u C^<6+> Ions in a Si Crystal" Nucl.Instr.Meth.B135. 132 (1998)

T.Ito、T.Azuma、K.Komaki、Y.Yamazaki、M.Sano、M.Torikoshi、A.Kitakawa、E.Takada 和 T.Murakami：“通道 290MeV/u C^<6 > 的能量损失

H.Tawara: "X Rays from Radiative Electron Capture into Continuum States in Relativistic Heavy-Ion Collisions" Phys.Rev.A55. 1-4 (1997)

H.Tawara：“相对论重离子碰撞中辐射电子俘获到连续态的 X 射线”Phys.Rev.A55。

S.Ninomiya: "L X-ray Emission from Slow Multiply Charged Ar Ions Bombarding Be and Al Targets" Nucl.Instrum.& Meth.B115. 177-180 (1996)

S.Ninomiya：“慢速多带电 Ar 离子轰击 Be 和 Al 目标产生的 L X 射线发射”Nucl.Instrum。

T.Azuma: "Trajectory Dependent Charge-state Distribution ofeavys Planar Channeled Heavy Ions" Nucl.Instrum.& Meth.B115. 310-313 (1996)

T.Azuma：“eavys 平面通道重离子的轨迹相关电荷态分布”Nucl.Instrum。

T.Ito et.al.: "Channeling with 290MeV/u C^<6+> Ions in a Si Crystal" Physica Scripta. T73. 345-346 (1997)

T.Ito 等人：“Si 晶体中 290MeV/u C^<6> 离子的通道”Physica Scripta。