Experimental kinetic energy releases (KER) for (a) C2H22+ → H++C2H+, (b) C2H22+ → CH++CH+, (c) C2H22+ → C++CH2+ and (d) C2H23+ → H++C2H2+ integrated over all delay times |τ| < 350 fs

Figure 2. Experimental kinetic energy releases (KER) for (a) C2H22+ → H++C2H+, (b) C2H22+ → CH++CH+, (c) C2H22+ → C++CH2+ and (d) C2H23+ → H++C2H2+ integrated over all delay times |τ| < 350 fs.

Abstract

Few-photon induced ultrafast dynamics in acetylene (C2H2) leading to several dissociation channels—deprotonation (H++C2H+ and H++C2H2+), symmetric break-up (CH++CH+) and isomerization (C++CH2+)-–were investigated employing the (XUV; extreme ultra-violet)-pump–(XUV; extreme ultra-violet)-probe scheme at the free-electron laser in Hamburg, combined with multi-hit coincidence detection. The kinetic energy releases and fragment-ion momentum distributions for various decay channels are presented. The C++CH2+ and H++C2H2+ channels reveal clear signatures of ultrafast molecular mechanisms, demonstrating potential applications of our pump-probe technique to complex systems in order to study a large variety of ultrafast phenomena in the XUV regime.