The ambipolar electrostatic potential rising along the magnetic field line from the grounded wall to the centre in the linear gas dynamic trap, rules the available suppression of axial heat and particle losses. In this paper, the visible range optical diagnostic is described using the Doppler shift of plasma emission lines for measurements of this accelerating potential drop. We used the room temperature hydrogen jet puffed directly on the line of sight as the charge exchange target for plasma ions moving in the expanding flux from the mirror towards the wall. Both bulk plasma protons and He²⁺ ions velocity distribution functions can be spectroscopically studied; the latter population is produced via the neutral He tracer puff into the central cell plasma. This way, potential in the centre and in the mirror area can be measured simultaneously along with the ion temperature. A reasonable accuracy of 4 8% was achieved in observations with the frame rate of ≈1kHz. Active acquisitions on the gas jetalso provide the spatial resolution better than 5mm in the middle plane radial coordinate because of the strong compression of the object size when projected to the centre along the magnetic flux surface. The charge exchange radiation diagnostic operates with three emission lines: H-α 656.3nm, He-I 667.8nm and He-I 587.6nm. Recorded spectra are shown in the paper and examples for physical dependences are presented. The considered experimental technique can be scaled to the upgraded multi-point diagnostic for the next generation linear traps and other magnetic confinement systems.

双极静电势沿磁场线从接地壁上升到线性气体动态阱的中心，支配着轴向热量和颗粒损失的可用抑制。在本文中，使用等离子体发射线的多普勒频移来描述可见光范围光学诊断，以测量这种加速的电位降。我们使用直接在视线上喷出的室温氢气射流作为等离子体离子的电荷交换目标，这些离子在从镜子到壁的膨胀通量中移动。体等离子体质子和 He ²⁺可以光谱研究离子速度分布函数；后一个群体是通过中性 He 示踪剂吹入中央细胞血浆产生的。这样，可以同时测量中心和镜面区域的电位以及离子温度。在 ≈1kHz 的帧速率的观测中实现了 4 8% 的合理精度。由于沿磁通表面投影到中心时物体尺寸受到强烈压缩，因此气体射流上的主动采集还提供了在中间平面径向坐标中优于 5mm 的空间分辨率。电荷交换辐射诊断使用三个发射线：H-α 656.3nm、He-I 667.8nm 和 He-I 587.6nm。记录的光谱显示在论文中，并提供了物理依赖性的示例。