A photoelectron velocity map imaging spectrometer for experiments combining synchrotron and laser radiations

Abstract

A velocity map imaging/ion time-of-flight spectrometer designed specifically for pump-probe experiments combining synchrotron and laser radiations is described. The in-house built delay line detector can be used in two modes: the high spatial resolution mode and the coincidence mode. In the high spatial resolution mode a kinetic energy resolution of 6% has been achieved. The coincidence mode can be used to improve signal-to-noise ratio for the pump-probe experiments either by using a gate to count electrons only when the laser is present or by recording coincidences with the ion formed in the ionization process.

Extreme ultraviolet ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization, and electron energy-loss spectra

“…29 The experimental setup is described in more detail in a previous publication. 16 In short, a continuous beam of He nanodroplets with a mean size ranging from 200 to 17 000 He atoms per droplet is generated by varying the temperature T 0 of a cryogenic nozzle.…”

Photoelectron angular distributions: developments in applications to isolated molecular systems

“…O'Keefe et al have developed a velocity map imaging/ ion time-of-flight spectrometer designed specifically for pump-probe experiments combining synchrotron and laser radiations and which allows either high spatial resolution or coincidence detection [95]. In work undertaken on the prototype X-ray FEL in Japan, Suzuki and co-workers measured time-resolved photoelectron images using a femtosecond UV laser for the pump step and a VUV free-electron laser to perform the ionization step as a means of monitoring ultrafast internal conversion and intersystem crossing in pyrazine [96].…”

Experimental investigation of the interatomic Coulombic decay in NeAr dimers

“…As the experimental apparatus employed (shown in Fig. 1) has been described previously [23], only a brief outline of the salient points is presented here. A supersonic beam was formed by expanding a 12:1 mixture of Ne and Ar through a liquid-nitrogen-cooled nozzle with an internal orifice diameter of 50 μm.…”