Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples.
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.
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Dmitry
0000000164398132
D
Baranov
Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Robert J
RJ
Hill
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Jisu
J
Ryu
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Samuel D
SD
Park
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Adriana
0000000160571268
A
Huerta-Viga
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Alexa R
AR
Carollo
Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, USA.
David M
0000000210858161
DM
Jonas