Recent photoelectron spectroscopy results from gas phase C 60 exhibit the same partial cross section variation with photon energy as has been observed in its solid phase. We assume that the variations originate from a fullerene specific ability to form a spherical standing wave of the final state electron by intramolecular interference or virtual reflection at the center of the photoionized molecule. The calculated photon energies of the cross section minima based on the boundary conditions of the standing wave agree fairly well with experimental data. [S0031-9007(96)00143-3]

The Keda Torus eXperiment (KTX) is a medium-sized reversed field pinch (RFP) device under construction at the University of Science and Technology of China. The KTX has a major radius of 1.4 m and a minor radius of 0.4 m with an Ohmic discharge current up to 1 MA. The expected electron density and temperature are, respectively, 2 × 10 19 m −3 and 800 eV. A combination of a stainless steel vacuum chamber and a thin copper shell (with a penetration time of 20 ms) surrounding the plasma provides an opportunity for studying resistive wall mode instabilities. The unique double-C design of the KTX vacuum vessel allows access to the interior of the KTX for easy first-wall modifications and investigations of power and particle handling, a largely unexplored territory in RFP research leading to demonstration of the fusion potential of the RFP concept. An active feedback mode control system is designed and will be implemented in the second phase of the KTX program. The recent progress of this program will be presented, including the design of the vacuum vessel, magnet systems and power supplies.

The Keda Torus eXperiment (KTX) is a new reversed field pinch (RFP) device at the University of Science and Technology of China. The construction and assembly of KTX, including the vacuum chamber, conducting shell, magnetic field windings, power supply system, active control coils, vacuum pump and data acquisition system, have been completed on August 1, 2015. Immediately following that, the first plasma was obtained on August 15, 2015. Intensive conditioning of the machine is underway to ramp up the plasma current toward its full operation. An active feedback mode control system has been built and has been implemented to control the error field around the vertical gaps of the conducting shell. The pulsed power supply systems of ohmic heating field and toroidal field (TF), using thyristor and energy storage capacitors, have been tested and commissioned. The TF power supply has flexibility in being able to operate with a reversed TF configuration and stable TF configuration. The fundamental diagnostic tools are developed for early KTX operation. Currently, the plasma current is up to 205 kA and the maximum discharge length is 21 ms, approaching to the conducting shell penetration time. Furthermore, typical RFP discharges are being produced with RFP state lasting 2 ms. These initial operation results for KTX are described in detail.

We present the optical reflectance and conductivity spectra for non-oxide antiperovskite superconductor M gCN i3 at different temperatures. The reflectance drops gradually over a large energy scale up to 33,000 cm −1 , with the presence of several wiggles. The reflectance has slight temperature dependence at low frequency but becomes temperature independent at high frequency. The optical conductivity shows a Drude response at low frequencies and four broad absorption features in the frequency range from 600 cm −1 to 33,000 cm −1 . We illustrate that those features can be well understood from the intra-and interband transitions between different components of Ni 3d bands which are hybridized with C 2p bands. There is a good agreement between our experimental data and the first-principle band structure calculations. The discovery of non-oxide superconductor M gCN i 3 has attracted much attention due to the coexistence of ferromagnetic element N i and superconductivity [1]. M gCN i 3 has the cubic antiperovskite lattice structure with space group P m3m, in which eight M g atoms occupy the cubic corners, while six Ni atoms are at the face-center positions and one C atom is inserted into the body-center position. The lattice parameter a is 3.81Å , and the specific heat measurements [5] show that M gCN i 3 is a conventional superconductor. But band calculations indicate that the N i 3d electrons dominate the density of the states (DOS) near the Fermi level E F [6,7,8,9]. Then, the N i 3d electrons are usually considered to take part in the superconducting pairing in M gCN i 3 . In such a case, an s-wave pairing is unexpected because of the existence of localized moment of Ni atom which will break the s-wave superconducting pairing.The relationship between the electronic states of N i and the superconductivity in M gCN i 3 was intensively studied. All of the known substitutions at Ni-site are found to decrease the superconducting temperature and/or bulk superconducting volume [10,11,12]. Normal state 13 C NMR measurement implies the existence of spin fluctuation above 20 K[4]. The calculated Stoner exchange parameter S = 0.43 ∼ 0.64 [7,13] and the Stoner renormalization is 5 [8]. The value is at the high edge of paramagnetic region and close to the ferromagnetic region which may lead to ferromagnetic spin fluctuation. *

We propose and demonstrate a Michelson interferometer modulator with integrated Bragg reflectors on a silicon-rich nitride–thin-film lithium niobate hybrid platform. High-reflectivity Bragg reflectors are placed at the ends of both arms, which double the electro-optic (E-O) interaction length and reduce the velocity mismatch between the microwave and optical wave. The presented Michelson interferometer modulator achieves a measured half-wave voltage length product as low as 1.06 V cm and high-speed modulation up to 70 Gbps. A 3-dB E-O bandwidth beyond 40 GHz is also achieved, which is, to the best of our knowledge, the highest modulation bandwidth of Michelson interferometer modulators.