Photoion yield curves of Dy@C82 in the vacuum UV region

The photoion yield curves for Dy@C82z+ (z = 1 and 2) from Dy@C82 are measured by using synchrotron radiation in the photon energy range from 24.5 to 39.5 eV. Correction has been made to compensate the effect of transient change of the density of Dy@C82 in the interaction region, with the help of the yield curve of C60z+ produced from C60 remaining as a trace impurity in the sample. The yield of Dy@C82+ exhibits a gradually descending curve with a flat region at 30-33 eV, similarly to the yield curve of C60+ from C60. The total photoabsorption cross section of Dy@C82 was evaluated to be (1.2 ± 0.4) × 10−20 m2 at the photon energy of 39.5 eV.