Theoretical Study of the Reaction Mechanism of Low Energy Heavy Ion Collisions

低能重离子碰撞反应机理的理论研究

• 批准号: 60540166
• 负责人: TAKIGAWA Noboru
• 金额: $ 1.22万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60540166/
• 关键词: Heavy Ion Collisions; Fusion; Quantum Tunneling; Muon Catalyzed Fusion; Pre-Equilibrium Process; Coupled Channel Method; Statistical Theory; サプライザル法

1. We studied the effects of nuclear intrinsic degrees of freedom on the heavy ion fusion reactions. Our main results are: (1) Nuclear vibrational modes of excitation largely enhance the fusion cross section at sub-barrier energies. (2) This enhancement is mainly due to the large potential renormalization. (3) The extra-ordinarily large enhancement for the <^(74)Ge> and <^(74)Ge> collision suggests that a large deformation of <^(74)Ge> is induced in the unified system. (4) The dimension of the coupled-channels equations can be considerably reduced for heavy systems. (5) A geometrical interpretation holds for the fusion reaction in the limit of adiabatic tunneling.2. We derived the retarded friction functions for the energy and the angular momentum dissipation due to nuclear surface vibrational excitation in low energy heavy ion collisions. We then clarified the dependence of the dissipation mechanism on the incident energy.3. We derived a formula, which determines the lag of microscopic degrees of freedom in quantum tunneling in multi-dimensional systems. This method was then applied to the muon catalyzed d-t fusion, and showed that the mon-adiabaticity reduces the sticking probability of the muon to the fusion synthesized alpha particle by about 30 %.4. We applied Weidenmuller's new statistical theory to nuclear pre-equilibrium process. The result agreed with that of Agassi et al. in the limit of weak coupling, but differes in the strong coupling limit. Also, the level density was calculated by this method.5. We calculated the elastic scattering and the absorption cross sections using a time dependent mean field theory (TDMF).6. We showed that the <root> E constraint in the surprisal analysis of heavy ion reactions arises from a constraint to the exciton number. Also, we calculated the level density for the exciton model by taking into account the angular momentum.

1.我们研究了核固有自由度对重离子聚变反应的影响。我们的主要结果是：（1）激发的核振动模式很大程度上增强了亚势垒能量下的聚变截面。 (2) 这种增强主要是由于大势重整化。 (3) <^(74)Ge>和<^(74)Ge>碰撞的异常大的增强表明在统一系统中引起了<^(74)Ge>的大变形。 (4) 对于重型系统，耦合通道方程的维数可以大大减小。 (5) 绝热隧道极限下聚变反应的几何解释成立。2．我们推导了低能重离子碰撞中核表面振动激发引起的能量和角动量耗散的延迟摩擦函数。然后我们阐明了耗散机制对入射能量的依赖性。 3．我们推导出了一个公式，该公式确定了多维系统中量子隧道效应的微观自由度的滞后。然后将此方法应用于μ介子催化的d-t聚变，结果表明单绝热性使μ介子对聚变合成的α粒子的粘附概率降低了约30％。4．我们将魏登米勒的新统计理论应用到核预平衡过程中。这一结果与 Agassi 等人的结果一致。弱耦合极限不同，而强耦合极限不同。并用该方法计算了水平密度。 5．我们使用时间相关平均场理论 (TDMF) 计算了弹性散射和吸收截面。6。我们表明，在重离子反应的令人惊讶的分析中，<root> E 约束源于对激子数的约束。此外，我们还考虑了角动量来计算激子模型的能级密度。

项目成果

S.Adachi: Nucl.Phys.A462. 61-71 (1986)

S.Adachi：Nucl.Phys.A462。

T.Tsukamoto: Prog.Theor.Phys.76. 645-653 (1986)

T.Tsukamoto：Prog.Theor.Phys.76。

N. Takigawa: "Effects of Muon Lag on the Sticking Probability in Muon Catalyzed d-t Fusion" Journal of Muon Catalyzed Fusion (Proc. of the International Symposium <micro> CF 86, Sep. 1-3,1986, Tokyo, ed. K. Nagamine). (1987)

N. Takikawa：“Effects of Muon Lag on the Sticking Probability in Muon Catalyzed d-t Fusion” Journal of Muon Catalyzed Fusion (Proc. of the International Symposium <micro> CF 86, Sep. 1-3,1986, Tokyo, ed. K

N.Takigawa: Journal of Muon Catalyzed Fusion.

N.Takikawa：μ介子催化聚变杂志。

M.A. Nagarajan: "Geometric Interpretation of the adiabatic model for Heavy Ion Fusion" Phys. Rev.C34. 894-898 (1986)

M.A. Nagarajan：“重离子聚变绝热模型的几何解释”Phys。