Speaker: Andre Al-Haddad, PSI
Program Description:
The Maloja endstation, located in the soft X-ray branch, Athos, at SwissFEL is dedicated to atomic, molecular, and nonlinear x-ray physics and chemical dynamics. The Athos branch offers a wide range of novel x-ray beam modes enabling a new class of experiments in the soft x-ray regime. The Maloja endstation was built with flexibility in mind, offering a variety of sample environments and measurement techniques that allows users to take advantage of the Athos modes. In this talk, I will provide an overview of the Athos operation modes and endstation concept and capabilities. Next, I will delve into the optical laser system and laser/x-ray timing diagnostics enabling time resolved techniques. I will further present our recent results from the pilot experiment on time resolved x-ray photoelectron spectroscopy (XPS) in gas target. By monitoring the binding energy of core-level electrons in C1s and I4d, we traced the ultrafast dynamics of Methyl-iodide (CH3I) upon 266nm laser excitation on the 10s to 100s of femtoseconds. Theoretical modeling is in progress to understand the chemical shifts observed. Despite our results being preliminary, we have shown the unique capabilities of XPS spectroscopy to trace chemical dynamics with atomic site selectivity on few femtoseconds time scales.
