A 22-pole radiofrequency ion trap setup for laboratory astrophysical studies

The formation of large interstellar molecules starting from small reactants constitutes the bottom-up approach in astrochemistry. An experimental setup wherein the ionic reactant is prepared and allowed to react with neutral reactants within a confined interaction space is most desirable for this approach. Here, we present our efforts in constructing a 22-pole radio-frequency ion trap experimental setup that could act as a reaction chamber for the neutral reactant and trapped ions. A compact piezo-based pulsed supersonic expansion discharge source was developed to achieve efficient production of anions, particularly metal-bearing ions. In addition, two other ion sources, namely, the electron impact ion source and the plasma supersonic discharge ion source, were developed to cater to the production of specific ions. The geometry of this experimental setup facilitates photo excitation of trapped ions. The trapping efficiency was studied by trapping SF5+ and SF6- for a few seconds. The control exhibited by various parameters on the efficiency of the trapping is discussed in detail. Potential studies that could be performed with this new experimental setup are also discussed.