Energy Loss of Fast Oxygen Ions in Metal Foils : Emergence Angle and Change State Dependence

本研究旨在探讨快氧离子透过薄金属箔时能量损失与其出射角度及电荷状态的关系。我们还对电荷态分数与出射角之间的关系感兴趣。我们在1991年和1992年用Au箔测量了具有各种变化态的氧离子的角相关能量损失。1992年和1993年，我们用1 ~ 50 μ g/cm ^2的碳膜研究了氧离子电荷态分数与出射角的关系。出射氧离子的电荷态用磁场垂直分离，并用位置灵敏探测器（PSD）探测。通过纵向移动PSD，我们可以测量氧离子的能量损失随角度的变化。对于Au箔，发现氧离子的能量损失随着出射角度的增加而增加。增加的量与在Au箔中观察到的质子一样大。电荷态分数被发现是几乎独立的出现的角度。离子的能量损失与出射离子的电荷状态有关，这一点尚未得到证实。这些结果被认为是由于靶箔的厚度。为了研究电荷态分数对出射角的依赖性，我们测量了薄碳箔的氧离子的角度依赖性电荷分数。在碳箔的情况下，观察到的电荷状态不平衡，新兴离子的电荷分数被发现强烈依赖于出射角。此外，即使对于已经达到电荷状态平衡的厚度，我们观察到电荷分数随出现角的增加而变化。这些测量有望带来电荷变化反应微分截面的知识。

The purpose of this research project is to investigate the dependence of energy loss of fast oxygen ions which transmitted thin metal foils on their emerging angles and charge states. We are also interested in the relation between charge state fraction adn emerging angle. We measured the angle-dependent energy loss of oxygen ions which have various change states by using Au foils in the term 1991 and 1992. The dependence of charge state fractions of oxygen ions on emerging angles was investigated with 1 to 50 mug/cm^2 carbon foils in the term 1992 and 1993.The charge states of emerging oxygen ions were vertically separated with magnetic field and detected by an position sensitive detector (PSD). Moving the PSD holizontally, we coud measure the angle-dependent energy loss of oxygen ions. As for the Au foil, the energy loss of oxygen ions was found to increase with increasing emerging angles. The amount of the increase was as large as that observed for protons in an Au foil. The charge state fraction was found to be almost independent of emerging angles. It was not confirmed that the energyloss of ions depended upon the charge state of emerging ions. These results were considered to be due to the thickness of the target foil.In order to investigate the dependence of the charge state fraction on emergence angles, we measured the angle-dependent charge fraction of oxygen ions for thin carbon foils. In the case of carbon foils for which the charge state nonequilibrium was observed, the charge fraction of emerging ions was found to depend strongly on emergence angles. Moreover, even for the thickness where charge state equilibrium was already attained we observed that charge fraction varied with increasing emerging angles. These measurements are expected to bring about the knowledge on the differential cross sections of charge changing reactions.