The Curry-jet

Curry - Classical unrestricted Raman spectroscopy

The curry-jet is a versatile custom spectrometer that combines Raman scattering with supersonic jet-cooling to investigate molecular interactions and conformational preferences. Substances are evaporated and picked up by a carrier gas using several saturators, enabling us to mix substances and investigate mixed complexes. A heatable stainless steel saturator and heatable nozzle allow us to measure low volatile substances.

The vacuum chamber of the setup is pumped by two Roots vacuum pumps (250 and 500 m3/h) and a rotary vane pump (100 m3/h), leading to a sufficiently low background pressure of about 1 mbar during continuous expansions. The resulting jet is probed by a 532 nm continuous wave laser with an output power of 25 W. Light is collected at a 90° angle using a fast camera lens and focused on the slit of a Czerny-Turner monochromator. The signal is detected by a liquid nitrogen cooled, sensitive CCD camera with 1340×400 pixels resolution.

Besides the variable temperature of the nozzle, an important adjustable parameter is the distance of the laser beam to the nozzle, which allows to carry out Raman measurements in different regions of the jet expansion. Collision induced relaxation processes can therefore be closely investigated [147].