This paper describes the construction, rf measurement and tuning, rf conditioning, and beam commissioning of a compact 325 MHz interdigital $H$-mode (IH) drift tube linac (DTL) with modified KONUS (Kombinierte Null Grad Struktur, combined zero-degree structure) beam dynamics at Tsinghua University. This IH-DTL accelerates a proton beam from 3 MeV to 7 MeV in about 1 m. With a high rf frequency of 325 MHz, the cavity is designed to be compact while retaining a high average gradient of $4\mathrm{MV}/\mathrm{m}$. The efficient shunt impedance $Z{T}^2$ is $101\mathrm{M}\mathrm{\Omega }/\mathrm{m}$. The beam test results show good agreement with the beam dynamics design. The developed compact IH-DTL can be applied to the injectors of medical proton machines.

中文翻译：

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具有高并联阻抗的紧凑型325 MHz质子叉指型H型漂移管直线加速器的开发

本文介绍了紧凑型325 MHz叉指的结构，射频测量和调谐，射频调节和波束调试 $H$清华大学，具有改进的KONUS（康比尼尔零位Struktur，组合零度结构）光束动力学的I型（IH）漂移管直线加速器（DTL）。该IH-DTL在约1 m内将质子束从3 MeV加速到7 MeV。凭借325 MHz的高RF频率，腔体设计得紧凑，同时保留了较高的平均梯度。$4\mathrm{MV}/\mathrm{米}$。有效分流阻抗$ž{Ť}^2$ 是 $101\mathrm{中号}\mathrm{\Omega }/\mathrm{米}$。光束测试结果与光束动力学设计吻合良好。开发的紧凑型IH-DTL可应用于医疗质子机的注射器。