Siegel der Universität

Universität zu Köln
Mathematisch-Naturwissenschaftliche Fakultät
Fachgruppe Physik

I. Physikalisches Institut

Experimental Setup

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The IR laser beam probes the carbon cluster supersonic jet roughly 10 mm downstream from the nozzle. An increase of the sensitivity is achieved by employing a multi-pass Herriott cell with 48 passes through the jet. After traversing the cell the IR laser beam is focused onto a liquid N2 cooled InSb detector. A fast ac-coupled amplifier allows time resolved detection of the weak absorption signals on a pair of gated box car integrators before collecting the data by a computer. Part of the IR laser beam is used for frequency calibration by simultaneously recording the spectrum of a reference gas and the fringe spectrum of a germanium etalon.

Experimental Setup