Single-shot measurement of transverse second moments using the projection method

• Main Authors: Gwanghui Ha, John G. Power, Eric E. Wisniewski, Wanming Liu, Manoel Conde
• Format: Article
• Language: English
• Published: American Physical Society 2021-01-01
• Series: Physical Review Accelerators and Beams
• Online Access: http://doi.org/10.1103/PhysRevAccelBeams.24.012802

We introduce a diagnostic for measuring the transverse phase space (TPS) and transverse second moments of a particle beam in a single shot. The diagnostic consists of a slit followed by a simple projection beam line to project the TPS onto an imaging screen. The beam line is composed of a skew quadrupole magnet followed by a normal quadrupole magnet with an imaging screen at the end. The skew quadrupole generates a coupling between the initial x and the final y, while the normal quadrupole removes the correlation between the initial x and the initial x^{′}. Thus, the initial (x,x^{′}) is mapped onto the final (x,y). The slit is needed before the projection beam line to remove the initial (y,y^{′}) contribution from the final (x,y) image on the screen. We present simulation studies and a demonstration of the diagnostic with an experiment performed at Argonne Wakefield Accelerator facility. We also discuss the method’s limitations.