In synchrotron light source applications, the photon beam interaction with various materials can produce electric charge which can be measured as current and be used to diagnose particle trajectories, beam intensity, beam profile, position, and stability. Sirius, a 4th-generation Brazilian synchrotron light source, will make use of hundreds of low-intensity measurement instruments. This work aims to show and discuss the design details, challenges, and test results of an Ethernet four-channel high-performance digital ammeter, applied for general-purpose beam diagnostics. The device is based on low-noise and extremely low input bias bipolar transimpedance amplifiers with eight selectable ranges (full scales from pA to mA). Characterization results show that the achieved gain, accuracy, and noise performance are on the same order of magnitude as those of expensive commercial benchtop equipment. In low bandwidth applications, the device was able to measure amplitudes of hundreds of picoampere with intrinsic noise of units of femtoampere (RMS). The designed device is a cost-effective solution.

中文翻译：

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开发用于光束诊断的四通道高分辨率数字皮安表

在同步加速器光源应用中，光子束与各种材料的相互作用可以产生电荷，该电荷可以作为电流进行测量，并用于诊断粒子轨迹、光束强度、光束轮廓、位置和稳定性。天狼星是第四代巴西同步加速器光源，将使用数百个低强度测量仪器。这项工作旨在展示和讨论用于通用光束诊断的以太网四通道高性能数字电流表的设计细节、挑战和测试结果。该器件基于低噪声和极低输入偏置双极互阻抗放大器，具有八个可选范围（从 pA 到 mA 的满量程）。表征结果表明，所实现的增益、精度和噪声性能与昂贵的商用台式设备处于同一数量级。在低带宽应用中，该器件能够测量数百皮安的幅度以及飞安 (RMS) 单位的固有噪声。所设计的设备是一种具有成本效益的解决方案。