Reaction cross sections (sigma(R)) for 19C, 20C and the drip-line nucleus 22C on a liquid hydrogen target have been measured at around 40A MeV by a transmission method. A large enhancement of sigma(R) for 22C compared to those for neighboring C isotopes was observed. Using a finite-range Glauber calculation under an optical-limit approximation the rms matter radius of 22C was deduced to be 5.4+/-0.9 fm. It does not follow the systematic behavior of radii in carbon isotopes with N < or = 14, suggesting a neutron halo. It was found by an analysis based on a few-body Glauber calculation that the two-valence neutrons in 22C preferentially occupy the 1s(1/2) orbital.

The single crystals of NiPc(SbF6)0.5 and NiPc(AsF6)0.5 were prepared by means of an electrochemical method. The electrical, magnetic, optical, and structural properties of these crystals were examined. These crystals are isostructural to each other, and exhibit a metallic behavior at least above 200 K. The g-values of the ESR signals remarkably depend upon temperature. By the aid of the low temperature experiments of XANES and reflectance spectrum, the temperature dependence is explained by the model based on the interaction between the small amount of local spins on the Ni atoms and the conduction electrons on the ligand chain. In addition, a sample dependence was found on the ESR properties of the crystals of NiPc(AsF6)0.5. This is attributed to the sample dependence of the concentration of the local spins on Ni atoms. From these considerations, we concluded that the ligand part is mainly oxidized in these partially oxidized salts, in other words the conduction electrons are located on the ligand chain. The bandwidth of the conduction band was estimated to be about 1 eV.

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One and two-neutron removal-reactions from 19 C and 20 C have been studied using a liquid-hydrogen target at 40 A MeV. A small cross section has been observed in the one-neutron removal reaction from 20 C. The observed inclusive removal cross sections are compared with theoretical removal cross sections calculated by using shell model spectroscopic factors and Glauber-model single-particle cross-sections. The observed momentum distributions are also compared with those calculated by using continuum-discretized coupled-channel methods. Good consistency between theory and experiment is shown in the one-neutron removal reaction from 19 C. However, our theoretical calculation fails to reproduce the neutron removal reactions from 20 C, which suggests that further improvements of the theoretical descriptions are necessary.

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