Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples

Summary, in English

In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

• Author: Dmitry Baranov; Robert J. Hill; Jisu Ryu; Samuel D. Park; Adriana Huerta-Viga; Alexa R. Carollo; David M. Jonas
• Publishing year: 2017-01-01
• Language: English
• Publication/Series: Review of Scientific Instruments
• Volume: 88
• Issue: 1
• Links: http://dx.doi.org/10.1063/1.4973666
• Document type: Journal article
• Publisher: American Institute of Physics (AIP)
• Status: Published
• ISBN/ISSN/Other: ISSN: 0034-6748