1.1 本规程描述了根据非电离能量损失（NIEL）表征材料粒子辐照的程序。NIEL在已发表的文献中用于表征带电粒子和中性粒子辐照。 1.2 尽管本规程中描述的方法适用于已知位移截面的任何粒子和目标材料（见规程 E521 )，本规程旨在用于观察到的损伤效应可能与原子位移相关的辐照。电子和光子材料中的某些辐射效应是如此，但并非所有辐射效应都是如此。 1.3 与此类似的程序用于计算带电粒子辐照中每个原子的位移（dpa）（见实践） E521 )或中子辐照（见实践 E693 ). 1.4 提供了NIEL的dpa计算指南。 1.5 与此相关的程序用于计算电子材料中的1-MeV当量中子注量（见实践） E722 )但在该实践中，包括了基于观察到的损伤效应相关性的损伤效率概念。 1.6 硅中NIEL转化为硅中单能中子注量的指南（见实践 E722 )，反之亦然。 1.7 本标准的应用需要了解颗粒的通量和能量分布，其相互作用会导致位移损伤。 1.8 辐射效应数据的相关性超出了本标准的范围。全面回顾 ( 1. ) 2. 对硅中位移损伤效应及其与NIEL的相关性的研究提供了适用于半导体材料和电子器件的适当指导。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 辐射硬度保证计划需要一种方法，将暴露于各种粒子种类的材料在大范围能量下的辐射诱导变化联系起来，包括航天器和地面环境中遇到的变化，以及粒子加速器和核裂变与聚变反应堆产生的变化。 4.2 电子和光子器件及材料中辐射损伤的一个主要来源是原子从其正常晶格位置的位移。此类损伤的适当暴露参数是通过以下方法从NIEL计算的损伤能量: 公式2 . 其他可用于表征与位移损伤相关的辐照历史的类似测量是每原子或每单位质量的损伤能量( 位移比释动能 ，当主要粒子为中性时），以及 每个原子的位移（dpa） . 参见术语 E170 这些数量的定义。 4.3 上一段中提到的每个数量应传达类似的信息，但格式不同。在每种情况下，导出的曝光参数的值取决于近似的核、原子和晶格模型，以及测量或计算的横截面。 如果要对不同粒子种类和能量引起的辐照效应进行一致的比较，则必须一致地应用这些近似值。 4.4 根据NIEL计算的损伤能量与材料特性或器件参数的特定变化之间不应存在对应关系。相反，应将损伤能量用作描述暴露的参数。即使包括不同的粒子种类和能量，它也可能是一个有用的相关变量。但是，除非在该材料或装置中证明了NIEL与特定损伤模式的相关性，否则不应将其作为损伤的衡量指标进行报告。 4.5 NIEL是一种结构，它取决于材料中粒子相互作用过程的模型，以及每种类型相互作用的横截面。 当使用NIEL作为相关参数时，必须确保使用一致的建模参数和核数据来计算每次辐照的NIEL值。 4.6 如果跟踪所有涉及原子位移的粒子，则可以使用3.2.4.7中提到的蒙特卡洛代码直接计算沉积在材料中的损伤能量，而无需使用NIEL。当某些粒子，特别是反冲重离子，不需要跟踪时，会出现尼尔概念的效用。在NIEL表示法中，这些是通过Lindhard等人提出的无限均匀介质解来处理的。 ( 10 ) .

1.1 This practice describes a procedure for characterizing particle irradiations of materials in terms of non-ionizing energy loss (NIEL). NIEL is used in published literature to characterize both charged and neutral particle irradiations. 1.2 Although the methods described in this practice apply to any particles and target materials for which displacement cross sections are known (see Practice E521 ), this practice is intended for use in irradiations in which observed damage effects may be correlated with atomic displacements. This is true of some, but not all, radiation effects in electronic and photonic materials. 1.3 Procedures analogous to this one are used for calculation of displacements per atom (dpa) in charged particle irradiations (see Practice E521 ) or neutron irradiations (see Practice E693 ). 1.4 Guidance on calculation of dpa from NIEL is provided. 1.5 Procedures related to this one are used for calculation of 1-MeV equivalent neutron fluence in electronic materials (see Practice E722 ), but in that practice the concept of damage efficiency, based on correlation of observed damage effects, is included. 1.6 Guidance on conversion of NIEL in silicon to monoenergetic neutron fluence in silicon (see Practice E722 ), and vice versa, is provided. 1.7 The application of this standard requires knowledge of the particle fluence and energy distribution of particles whose interaction leads to displacement damage. 1.8 The correlation of radiation effects data is beyond the scope of this standard. A comprehensive review ( 1 ) 2 of displacement damage effects in silicon and their correlation with NIEL provides appropriate guidance that is applicable to semiconductor materials and electronic devices. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 A radiation-hardness assurance program requires a methodology for relating radiation-induced changes in materials exposed to a variety of particle species over a wide range of energies, including those encountered in spacecraft and in terrestrial environments as well as those produced by particle accelerators and nuclear fission and fusion reactors. 4.2 A major source of radiation damage in electronic and photonic devices and materials is the displacement of atoms from their normal lattice site. An appropriate exposure parameter for such damage is the damage energy calculated from NIEL by means of Eq 2 . Other analogous measures, which may be used to characterize the irradiation history that is relevant to displacement damage, are damage energy per atom or per unit mass ( displacement kerma , when the primary particles are neutral), and displacements per atom (dpa) . See Terminology E170 for definitions of those quantities. 4.3 Each of the quantities mentioned in the previous paragraph should convey similar information, but in a different format. In each case the value of the derived exposure parameter depends on approximate nuclear, atomic, and lattice models, and on measured or calculated cross sections. If consistent comparisons are to be made of irradiation effects caused by different particle species and energies, it is essential that these approximations be consistently applied. 4.4 No correspondence should be assumed to exist between damage energy as calculated from NIEL and a particular change in a material property or device parameter. Instead, the damage energy should be used as a parameter which describes the exposure. It may be a useful correlation variate, even when different particle species and energies are included. NIEL should not be reported as a measure of damage, however, unless its correlation with a particular damage modality has been demonstrated in that material or device. 4.5 NIEL is a construct that depends on a model of the particle interaction processes in a material, as well as the cross section for each type of interaction. It is essential, when using NIEL as a correlation parameter, to ensure that consistent modeling parameters and nuclear data are used to calculate the NIEL value for each irradiation. 4.6 Damage energy deposited in materials can be calculated directly, without the use of NIEL, using the Monte Carlo codes mentioned in 3.2.4.7, if all the particles involved in atomic displacement are tracked. The utility of the NIEL concept arises in cases where some particles, especially recoiling heavy ions, do not need to be tracked. In the NIEL representation, these are treated instead by means of infinite homogeneous medium solutions of the type originated by Lindhard et al. ( 10 ) .