A device for studying photodissociation at low temperature

Abstract

The invention relates to the field of optoelectronics and molecular reaction kinetics, and provides a device used for studying photoinduced separation at low temperature. An ion source adopts a cesium sputtering ion source with low repetition rate. A focusing electrode group and a mass selection electrode group are circular electrodes. Only the hole of the center of the electrode I in the focusing electrode group is provided with a metal mesh, while the holes of the center of five electrodes in the mass selection electrode group are all provided with metal meshes. An accelerator comprises an electrode, an ion reflector, an extractor, a grounding electrode and the like, and is adhered to a metal mesh. Separate low temperature cold screens are arranged outside the focusing electrode group and the mass selection electrode group. A voltage is applied to the mass selection electrode group. An energy focusing condition can be realized by adjusting the ratio of the voltage applied to the focusing electrode group and the mass selection electrode group, and the mass spectrum resolution is improved. Laser incident and ion motion directions are orthogonal. Ion oscillation realizes beam concentration through a particle mass selector, and is phase-locked in a mode-locked laser. Instantaneous coincidence overlap of an ion beam and a laser pulse is ensured.

Description

technical field [0001] The invention relates to the field of optoelectronic imaging technology and molecular reaction dynamics, in particular to a device for studying photo-induced separation at low temperature, which can simultaneously perform imaging of electrons and ion fragments, and can produce ions with low internal energy and improved energy precision. . Background technique [0002] Particle velocity imaging technology is an important method for the study of molecular reaction dynamics. Its most important feature is that it can obtain the full three-dimensional velocity and direction distribution of scattering particles in one image at the same time, that is, it can simultaneously obtain the energy spectrum of particles. information and angular distribution information. Particle velocity imaging techniques can be applied in simultaneous measurements of photodissociation, where photodissociation of electrons in steady-state molecular anions produces dissociated neutr...

AI Technical Summary

Problems solved by technology

Since the internal energy of the molecular beam will be reintroduced during the ionization process, resulting in an increase in its vibrational freedom, the spectrum obtained by the detector will cause broadening and affect the accuracy of the experiment. Therefore, it is necessary to cool the ion beam as much as possible in the experiment.

[0003] In the existing cooling technology, the purpose of reducing the internal energy of ions is achieved by embedding molecules into atomic clusters such as helium clusters or using radio frequency ion traps in a cooled buffer gas atmosphere to store ions. However, the above cooling technologies are not suitable for Photo-induced separation simultaneous measurement experiment

In addition, photo-separation synchronous measurement experiments generally require high duty cycle and low event rate to avoid data confusion. In this way, some low repetition rate techniques require longer data acquisition time or increase the difficulty of separating pseudo-events. Can not make photo-induced separation synchronous measurement experiment be implemented under the situation of ion cooling, or the cooling process does not improve experimental results, the device for studying photo-induced separation at a low temperature can solve the problem

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