HOTCAP: A new software package for high-speed oscilloscope-based three-dimensional bunch charge and position measurement
Xing-Yi Xu1,2 Yong-Bin Leng1,2,3 Bo Gao3 Yi-Mei Zhou3 Shan-Shan Cao3 Jian Chen3 Fang-Zhou Chen3
1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
Vol.32, Issue 11, Article number:131 (2021)
Plain Language Summary
This study developed HOTCAP, a free, user-friendly, and interactive software, for simultaneous measurement of 3D bunch-by-bunch position and charge from the waveform of a high-speed oscilloscope. Being able to operate on Windows 10, HOTCAP could also output injection transient analysis, bunch response function reconstruction, and turn-by-turn beam analysis. Its visual interface was developed based on PyQT5. HOTCAP was coded using Python on the backend, and its architecture comprised the user interface (UI) module, the calculation module, and the input-output (IO) module. Future studies shall improve the algorithm to eliminate HOTCAP’s current need for a constant bunch length.
Bunch-by-bunch measurement includes transverse position measurements, longitudinal phase measurements, charge measurements, beam size measurements, and emittance. Among these, position measurement is the most important and common technique carried out via the random phase sampling method using a digital oscilloscope. However, since a large amount of input data and complex digital signal processing are involved, there is a high demand for comprehensive data processing algorithms or corresponding data processing software packages to be used in high-speed oscilloscope-based 3D bunch charge and position measurements. In order to fulfill the need, researchers from Shanghai Synchrotron Radiation Facility (SSRF) Beam Instrument Group have successfully developed HOTCAP (a visualization software package) to serve as an online measurement system that can simultaneously measure the bunch-by-bunch 3D position and strip the refilled charge signal. Other accelerators will benefit from this software as soon as the researchers share the source code in the near future.
The SDG Impact
SSRF strives to uphold its potential and reputation as a world-class state-of-the-art beam facility. To help achieve that, this research developed the first mature and free software package for high-speed oscilloscope-based three-dimensional (3D) bunch charge and position measurement. The output contributes to the advancement of beam diagnosis technology, which enhances the operation of synchrotron radiation facilities, realizing UNSDG 9: Industry, Innovation & Infrastructure.