Picosecond pulsed beams of light and heavy keV ions at the Time-of-Flight Medium energy ion scattering system at Uppsala University

A 16 MHz electrostatic beam chopper is implemented at the Uppsala University ToF-MEIS system to complement the 4 MHz sinusoidal scanning, refining the resolution without drift-tube bunching. The system is benchmarked with H2+, He+, and Ne+ ions in transmission and backscattering geometries. The estimated true pulse duration for 60 keV He+ is 34 ps while the direct beam impinging on the detector resulted in measured pulse widths of 295 ps for He ions and 481 ps for Ne ions. In backscattering geometries, ions impinging on the target yield measured pulse durations of 459 ns for H ions, 550 ps for He ions and 810 ps for Ne ions and lead to energy resolution measurements of 2.4 keV (100 keV H), 0.9 keV (60 keV He), and 2.4 keV (160 keV Ne). Discussions cover straggling effects on achievable energy resolution and how to obtain estimates of the true duration of the ion pulse.