The two-color interferometry diagnostic on the Alcator C-Mod tokamak has been upgraded to measure fluctuations in the electron density and density gradient for turbulence and transport studies. Diagnostic features and capabilities are described. In differential mode, fast phase demodulation electronics detect the relative phase change between ten adjacent, radially-separated (ΔR = 1.2 cm, adjus...

A series of long-chain methyl esters with vicinal oxo groups (1,2-diones; 1,2-diketones) were synthesized by potassium permanganate-based oxidation of methyl esters of mono-unsaturated fatty acids. The presence of two additional carbonyl groups may facilitate the synthesis of other derivatives. The starting materials were selected in such a fashion to give the 1,2-dioxo moiety in consecutive po...

It is shown that electron-phonon interaction provides a natural explanation for the unusual band dispersion of the metallic surface states at the Si(111)-(7 x 7) surface. Angle-resolved photoemission reveals a discontinuity of the adatom band at a binding energy close to the dominant surface phonon mode at h(omega0) = 70 meV. This mode has been assigned to adatom vibrations by molecular dynamic...

ALagrangian fluid model ~cold plasma, fixed ions! is developed for analyzing the coupling between electron plasma waves. This model shows that a small wave number electron plasma wave (v2 ,k2) will strongly affect a large wave number electron plasma wave (v1 ,k1), transferring its energy into daughter waves or sidebands at (v11nv2 ,k11nk2) in the lab frame. The accuracy of the model is checked ...

We propose a novel scheme of solid state realization of a quantum computer based on single spin “enhancement mode” quantum dots (QD) as building blocks. In the enhancement mode QD, just one electron can be brought into initially empty quantum dot, in contrast to the depletion mode QD based on expelling of electrons from multi-electron QDs by gates. The quantum computer architectures based on de...

Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a f...

In this paper, we report observations of reduced low-k core electron temperature and intermediate-k density fluctuations in H-mode and quiescent (QH)-mode. L-mode electron temperature fluctuation levels (0.5% ̃ T e /Te 2% for k s 0.5 as measured by correlation ECE (CECE) radiometry) are observed to decrease by at least a factor of four in H and QH-mode regimes in the DIII-D tokamak (r/a = 0.7)....

Coherent terahertz radiation from multiple electron beams excitation within a plasmonic crystal-like structure (a three-dimensional holes array) which is composed of multiple stacked layers with 3 × 3 subwavelength holes array has been proposed in this paper. It has been found that in the structure the electromagnetic fields in each hole can be coupled with one another to construct a composite ...

We derive light curves of the afterglow emission from highly collimated jets if the power-law index (p) of the electron energy distribution is above 1 but below 2. We find the following: (1) Below the characteristic synchrotron frequency, the light-curve index depends generally on p. (2) As long as the jet expansion is spherical, the light-curve index above the characteristic frequency increase...

It is shown that a two component electron distribution can emerge in a cluster under an intense laser pulse. A bulk of internal electrons adjusts adiabatically to the laser field whereas a smaller electron population at the cluster edge can undergo stochastic heating. Self-consistent equilibrium has been found and collective modes discussed for the confined electrons.