Stopping Powers of Metallic Elements for Median- and High-Velocity Protons

金属元素对中速和高速质子的阻止本领

• 批准号: 10640386
• 负责人: SAKAMOTO Naoki
• 金额: $ 2.18万
• 依托单位: Nara Women's University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640386/
• 关键词: Stopping Power; Mean Excitation Energy; Bethe-Bloch Formula; Multiple Scattering; Actual Path Length Correction; 多重散乱; 行路長の補正

Stopping powers of Ti, Fe, Ni, Cu and Zn were measured for median- and high-velocity protons. The uncertainty of the present results were ±0.4%. In high-velocity regime stopping powers were theoretically described by the Bethe-Bloch formula which could reproduce experimental values very well (within 1% accuracy). It is necessary to use rather thick foils in order to know their accurate thickness, which are essential to obtain accurate stopping power data. For a thick target incident protons may lose more than 50% of their initial energy within a target foil. Under such a condition the actual path length of protons becomes slightly longer than the target thickness. When we wish to measure very accurate stopping powers of elements, we can not neglect such an effect.To estimate actual path length corrections we need the knowledge on the angular distributions due to multiple scattering. Therefore, we measured angular distributions due to multiple scattering for 26 kinds of target thickness … More and incident energy combinations. Comparing measured results with theoretical predictions, we found that an excellent agreement was obtained for both Moliere theory and the theory of Sigmund and Winterbon. With these theories we can obtain a reliable estimation of the correction.The present stopping powers were compared with compilation values of ICRU Report 49 and of Andersen and Ziegler. In general, the present results were found to be slightly smaller than compilation values. In case of Fe, however, the present results were smaller by 〜10% than those ICRU Report 49 at around 0.2 MeV. Mean excitation energies of Ti, Fe, Ni, Cu and Zn were extracted from the present stopping powers. The I-values are 236.7 eV, 287.9 eV, 313.6 eV, 319.8 eV and 326.8 eV for Ti, Fe, Ni, Cu and Zn, respectively. These I-values are compared with those obtained by other authors.The Bethe-Bloch formula is generally used for description of stopping powers for protons above 1.0 MeV. In the present study it is found that the formula can be used for protons above 〜0.7 MeV or possibly above 0.5 MeV. Less

测量了Ti、Fe、Ni、Cu和Zn对中高速质子的阻挡力。测定结果的不确定度为±0.4%。在高速状态下，停车功率在理论上由贝特-布洛赫公式描述，该公式可以很好地再现实验值（精度在1%以内）。为了获得准确的停止功率数据，有必要使用较厚的箔片，以了解其准确的厚度。对于厚靶，入射质子在靶箔内可能损失其初始能量的50%以上。在这种条件下，质子的实际路径长度略长于目标厚度。当我们希望非常精确地测量元素的停止力时，我们不能忽视这种效应。为了估计实际的路径长度修正，我们需要了解由于多重散射引起的角分布。因此，我们测量了26种不同目标厚度和入射能量组合下的多重散射角分布。将实测结果与理论预测相比较，我们发现莫里哀理论与西格蒙德和温特本的理论非常吻合。利用这些理论，我们可以得到一个可靠的校正估计。将目前的停止力与ICRU Report 49和Andersen and Ziegler的汇编值进行比较。一般来说，发现当前的结果略小于编译值。然而，在Fe的情况下，目前的结果比ICRU报告49的结果小约10%，约为0.2 MeV。从目前的停止功率中提取了Ti、Fe、Ni、Cu和Zn的平均激发能。Ti、Fe、Ni、Cu和Zn的i值分别为236.7 eV、287.9 eV、313.6 eV、319.8 eV和326.8 eV。这些i值与其他作者得到的值进行了比较。贝特-布洛赫公式通常用于描述质子在1.0兆电子伏以上的停止功率。在本研究中发现，该公式可用于~ 0.7 MeV以上的质子，也可能用于0.5 MeV以上的质子。少

项目成果

N. Sakamoto et al.: "Stopping of Ti for Protons from 0.2 to 13.5 MeV : Correction for the Actual Path Length due to Multiple Scattering"Nucl. Instr. and Meth. B. (印刷中). (2000)

N. Sakamoto 等人：“质子从 0.2 到 13.5 MeV 的停止：由于多重散射而校正实际路径长度”Nucl. and Meth. (2000)。

N.Sakamoto, H.Ogawa and H.Tsuchida: "Stopping Powers of Ti for Protons from 0.2 to 13.5 MeV : Correction for the Actual Path Length due to Multiple Scattering"Nucl. Instr. Meth. B. (in press). (2000)

N.Sakamoto、H.Okawa 和 H.Tsuchida：“Ti 对质子从 0.2 到 13.5 MeV 的阻止本领：由于多次散射而校正实际路径长度”

N.Sakamoto et al.: "Stopping Powers of Ti for Protons from 0.2 to 13.5 MeV:Correction for the Actual Path Length due to Multiple Scattering"Nucl.Instr.and Meth.B. (in press). (2000)

N.Sakamoto 等人：“Ti 对 0.2 至 13.5 MeV 质子的阻止本领：由于多重散射而对实际路径长度的校正”Nucl.Instr.and Meth.B。