Weakly superconducting circuits

An equivalent circuit has been developed for the time-dependent dissipating state of superconductivity which accompanies quantum phase slip. This equivalent circuit is used here to analyze the superconducting thin-film ring magnetometer and to determine its operating characteristics in terms of measurable circuit parameters

Status of the Stony Brook Superconducting Heavy-Ion Linac

The present status of the Stony Brook Superconducting Heavy-Ion Linear Accelerator is described, with emphasis on recent operational results with a prototype unit of the accelerator. The basic LINAC elements are independently-phased lead-plated copper split-loop resonators operating at 151.7 MHz and optimized for velocities of either ß=v/c= 0.055 or ß=0.10. Resonators are grouped in units of either 4 low-ß or 3 high-ß resonators in compact cryostat modules separated by room-temperature quadrupole-doublet lenses. The LINAC consisting of 4 low-ß and 7 high-ß modules injected with heavy ions of mass A≃16-100 from the Stony Brook EN tandem will produce an additional energy gain of ~18 MeV per unit charge with a total heat dissipation at 4.5K of <300 Watts. In recent tests with low-ß prototype units, individual resonators were operated continuously at accelerating gradients in excess of 3.5 MV/m, and were phase and amplitude stabilized at 3.0 MV/ m using 175 Watts of RF power. Helium-temperature dissipation at 3.0 MV/m is ~8 Watts after helium-gas conditioning. The prototype low-ß module was used to accelerate a 30 Mev ^(16)O^(5+) beam to ~35 MeV

Diffraction of thermal waves in liquid helium II

Diffraction effects in thermal radiation have been produced in liquid helium II by means of a thermal grating radiating a primary (zero-order) beam accompanied by higher order beams at appropriate "Bragg" angles. These results at once demonstrate unambiguously the true wave nature of this thermal wave propagation and its conformity to Huygens' principle in the most demanding test to which second sound has been subjected. The general nature of the angular pattern, including the fine structure, conforms to the requirements of diffraction behavior for more customary wave motions. A determination of wave velocity (V2) for second sound is obtainable from the observed Bragg angles. Results of an investigation on the propagation of second sound in rotating liquid helium are presented

Has China Crowded out Foreign Direct Investment from Its Developing East Asian Neighbors?

This paper applies a gravity model to investigate the determinants of foreign direct investment (FDI) in East Asia. Economic fundamentals, such as market size, per capita income and country risk indicators, economic and cultural ties, exchange rate volatilities and information asymmetry are found to be important determinants for FDI. Globally, the inward FDI among high-income OECD economies declined significantly on average over the period of 1990-2003, whereas the inward FDI of the high-income OECD economies in emerging market economies gained substantially. In the East Asian region, the ASEAN-4 (Indonesia, Malaysia, the Philippines and Thailand) received above-average inward FDI from the high-income OECD economies after controlling for their economic fundamentals. By contrast, China's FDI from the high-income OECD economies is below average relative to its economic fundamentals. Therefore, it is difficult to establish that China has crowded out FDI from its developing ASEAN neighbors. Copyright 2007 Institute of World Economics and Politics, Chinese Academy of Social Sciences.