Pulsed supersonic source of vdW complexes for high-temperature applications: Spectroscopy and beam characteristics

Application of a modified version of high-temperature high-pressure all-metal pulsed source of supersonic molecular beam is demonstrated in a production of van der Waals (vdW) complexes. The vdW complexes are produced possessing controllable rotational temperature (T _rot ) in the range from 3 K to 19 K. An effective control over T _rot is illustrated employing excitation spectrum recorded using the B ³1(5³ P ₁) ← X ¹0⁺(5¹ S ₀) transition in CdAr. First-time resolved rotational structure in the profile of the υ′ = 2←υ′′ = 0 vibrational component is reported. The control over T _rot is crucial in a dissociation of the (¹¹¹Cd)₂ isotopologue in the supersonic beam. For the process, excitation at well defined J′← J′′ rotational transition within the (υ′,υ′′) = (40,0) vibrational band of the A ¹0 _u ⁺(5¹ P ₁) ← X ¹0 _g ⁺(5¹ S ₀) transition is employed. It is followed by the dissociation using A ¹0 _u ⁺(υ′ = 40,J′′) → X ¹0 _g ⁺ bound → free transition. An analysis and simulation of the (40,0) vibrational band rotational structure are presented. Parameters describing conditions in the supersonic beam, degree of rotational cooling, Doppler broadening and spectral bandwidth of the laser beam are used.