To devise an activation technique for characterizing mixed radiation fields, secondary particles from a copper target irradiated by 24 GeV/c protons were measured at the CERN High-energy AcceleRator Mixed field facility (CHARM). Activation detector sets consisting of aluminum, niobium, indium, and bismuth, were placed at 30 cm from the target at angles of 15° to 160° with respect to the beam axis. The nuclides generated in these detectors due to irradiation by secondary particles were analyzed by $\gamma$-ray spectrometry, and the angular distributions of the production rates were obtained. The results of Monte Carlo calculations using FLUKA code was compared with the experimental results. The calculated results well agreed with the measured data at all angles. The influence of competitive reactions on the measured data were also evaluated by FLUKA. The following nuclear reactions, with low affectivity by competitive reactions, were identified as promising tools for characterizing mixed radiation fields: the ¹¹⁵In($n$, $n^{\prime }$)${}^{115\mathrm{m}}$In reaction for detecting neutrons emitted by the evaporation process, the ⁹³Nb($\gamma$, $n$)${}^{92\mathrm{m}}$Nb reaction for verifying the photon distribution generated by neutral-pion decay (${\pi }^0\to 2\gamma$), and the ²⁰⁹Bi($p$, 4$n$)²⁰⁶Po reaction, which detects secondary protons.

为了设计一种激活技术来表征混合辐射场，在CERN高能加速器混合场设施（CHARM）中测量了被24 GeV / c质子辐照的铜靶材产生的次级粒子。将由铝，铌，铟和铋组成的激活检测器组放置在距目标30 cm处，相对于射线轴成15°至160°的角度。这些检测器中由于二次粒子的照射而产生的核素通过$\gamma$射线光谱法，获得生产率的角分布。将使用FLUKA代码的蒙特卡罗计算结果与实验结果进行了比较。计算结果与各个角度的测量数据都非常吻合。FLUKA还评估了竞争反应对实测数据的影响。下列核反应具有较低的竞争性反应，被认为是表征混合辐射场的有前途的工具：¹¹⁵ In（$ñ$， ${ñ}^{\prime }$）${}^{115\mathrm{米}}$在检测蒸发过程中发射的中子的反应中，⁹³ Nb（$\gamma$， $ñ$）${}^{92\mathrm{米}}$Nb反应，用于验证由中性小子衰变产生的光子分布（${\pi }^0\to 2\gamma$）和²⁰⁹ Bi（$p$，4$ñ$）²⁰⁶ Po反应，可检测次级质子。