We discuss a recently demonstrated type of microwave spectroscopy of trapped ultra-cold atoms known as " echo spectroscopy " [M.F. Andersen et. al., Phys. Rev. Lett., in press (2002)]. Echo spectroscopy can serve as an extremely sensitive experimental tool for investigating quantum dynamics of trapped atoms even when a large number of states are thermally populated. We show numerical results fo...

We report measurements of the positronium (Ps) $2^{3}S_{1}\ensuremath{\rightarrow}2^{3}P_{2}$ interval in which atoms traveling free space were irradiated with microwave radiation generated using a horn antenna. Previous this transition, performed waveguides, exhibited asymmetric and shifted line shapes. In free-space we here, much smaller line-shape asymmetry was observed, but large frequency ...

We report room-temperature ferromagnetism of graphitic petal arrays grown on Si substrates by microwave plasma chemical vapor deposition without catalyst. The samples have been characterized by Raman and X-ray photoelectron spectroscopy to confirm the absence of possible ferromagnetic impurities. The petals exhibit ferromagnetic hysteresis with saturation magnetization of ∼4.67 emu cm(-3) and c...

Frequency multipliers based on superlattice (SL) devices as nonlinear elements have been developed as radiation sources for a terahertz (THz) laboratory spectrometer. Input frequencies of 100 and 250 GHz from backward wave oscillators have been multiplied up to the 11th harmonic, producing usable frequencies up to 2.7 THz. Even at these high frequencies the output power is sufficient for labora...

Microwave-assisted reactions are an environmentally friendly approach for synthesizing organic compounds. In this study, oximation of acetylferrocene and acetophenone was conducted under both microwave irradiation conventional heating conditions. Acetylferrocene were subjected to the two conditions in various solvent mixtures, extent conversion determined by 1H nuclear magnetic resonance spectr...