The ion recombination is examined in parallel-plate ionization chambers in scanning proton beams at the Danish Centre for Particle Therapy and the Skandion Clinic. The recombination correction factor k s is investigated for clinically relevant energies between 70 MeV and 244 MeV for dose rates below 400 Gy min −1 in air. The Boutillon formalism is used to separate the initial and general recombination. The general recombination is compared to predictions from the numerical recombination code IonTracks and the initial recombination to the Jaffé theory. k s is furthermore calculated with the two-voltage method (TVM) and extrapolation approaches, in particular the recently proposed three-voltage (3VL) method. The TVM is in agreement with the Boutillon method and IonTracks for dose rates above 100 Gy min −1 . However, the TVM calculated k s is closer related to the J...

中文翻译：

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在扫描质子笔形束中绘制初始和一般重组图。

在丹麦粒子治疗中心和Skandion诊所的平行板电离室中，在扫描质子束中检查离子重组。针对空气中剂量率低于400 Gy min -1的70 MeV至244 MeV之间的临床相关能量，研究了重组校正因子ks。Boutillon形式主义用于区分初始重组和一般重组。将常规重组与数值重组代码IonTracks的预测以及对Jaffé理论的初始重组进行了比较。此外，利用两电压法（TVM）和外推法，特别是最近提出的三电压（3VL）法来计算ks。对于高于100 Gy min -1的剂量率，TVM与Boutillon方法和IonTracks一致。然而，