This paper presents the Forward Time Projection Chamber (FTPC) system of the NA61/SHINE experiment at the CERN SPS accelerator. This TPC system applies a novel tandem-TPC design to reduce the background originating from particle tracks not synchronous with the event trigger. The FTPC system is composed of three chambers with alternating drift field directions. The chambers were installed directly along the beamline region of the NA61/SHINE detector in a medium- to high-intensity (10-100 kHz) hadron or ion beam. The tandem TPC system has proved to be capable of rejecting out-of-time background tracks not associated with a primary interaction. In addition, the system performs tracking and inclusive dE/dx particle identification for particles at and near the beam momentum. This shows that a tandem-TPC-based chamber design may be used also in other experimental applications with a demand for low material budget, tracking capability, and the need for dE/dx particle identification, all while in the presence of a relatively high particle flux.

中文翻译：

---

CERN NA61/SHINE 实验的前向 TPC 系统：串联 TPC 概念

本文介绍了 CERN SPS 加速器上 NA61/SHINE 实验的前向时间投影室 (FTPC) 系统。该 TPC 系统采用新颖的串联 TPC 设计，以减少源自与事件触发不同步的粒子轨迹的背景。FTPC 系统由三个具有交替漂移场方向的腔室组成。在中高强度 (10-100 kHz) 强子或离子束中，这些腔室直接沿着 NA61/SHINE 探测器的束线区域安装。串联 TPC 系统已被证明能够拒绝与主要交互无关的超时背景轨迹。此外，该系统对束动量处和附近的粒子执行跟踪和包容性 dE/dx 粒子识别。