Curry-Jet SETUP

The "curry-jet" is a jet spectrometer setup combining spontaneous Raman scattering with a supersonic jet expansion. <br><br>The carrier gas (typically helium) is enriched by the desired substance in either a cryostatically cooled (S1) or a heated (S2) saturator system, depending on the vapor pressure and the desired concentration.The mixture is supersonically expanded through a heatabe slit nozzle (N) from 0.1-1.3 bar stagnation pressure into the vacuum chamber at ca 1 mbar background pressure. A continuous operation is ensured by roots and rotary vane backing pumps in series with a maximum pumping speed of ca. 500 m³/h.The expansion is probed 1-3 mm downstream the nozzle by a focussed (L1) 532 nm cw laser (Spectra Physics Millennia eV) with a maximum output of 25 W.The scattered light is collected in a 90° angle with a standard 50 mm photo objective (O) as a collimator and focussed outside the chamber onto a 1000 mm monochromator with a 1340x400 px L-N₂ cooled CCD detector (Princeton Pylon 400 B) attached to it.This Raman spectrometer is used under non-resonant conditions and the good signal-to-noise ratio is accomplished by long integration times up to 10 minutes and averaging of multiple spectra.Calibration is done with krypton and neon calibration lamps through the pinhole (PH).<br>Cosmic ray removal is achived by a script-based pixel-to-pixel comparison of multiple spectra.<br>The setup is under constant improvement, thus the presented scheme applies to group research from 2015 to 2018. Selected publications are mentioned below, for a more complete record, see: https://hbond.uni-goettingen.de/publicat.html<br>(abbreviations used in the english version: BP - bypass, BS - beam stop, CV - check valve, EF - edge filter, L - focus lens, M - laser mirror, N - nozzle, O - objective, P - pressure gauge, PH - pinhole, S - saturator, SV - solenoid valve, W - window)<br>