The ionization and dissociation of ammonia by impact of protons is investigated experimentally in a wide range of energies from 125 to 2700 keV. Coincidence measurements are used to separate single from multiple ionization. The role of the charge sign of the projectile was analyzed for the ionization by comparing the proton with previous electron data. The energy dependence of the single and multiple-ionization cross sections allowed us to evaluate the role of second-order mechanisms. For single ionization, the role of a two-step mechanism was inferred. The double-ionization cross section showed that postcollisional deexcitation takes over the two-step sequential ionization above 800 keV. Triple ionization is prompted mostly by postcollisional Auger decay.

中文翻译：

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氨中的多种碎裂机理：中速状态下质子的碰撞

在125至2700 keV的广泛能量范围内，通过实验研究了质子撞击引起的氨的电离和离解。一致性测量用于将单个电离与多个电离分开。通过比较质子与先前的电子数据，分析了弹丸的电荷符号对电离的作用。单电离和多电离横截面的能量依赖性使我们能够评估二阶机制的作用。对于单电离，推断出两步机制的作用。双电离横截面表明，碰撞后的去激励在800 keV以上接管了两步顺序电离。三次碰撞电离主要是由碰撞后俄歇衰减引起的。