We report the measurement of electron-beam microbunching at the exit of a self-amplified spontaneous-emission free-electron laser (SASE FEL), by observation of coherent transition radiation (CTR). The CTR was found to have an angular spectrum much narrower than spontaneous transition radiation and a narrow-band frequency spectrum. The central frequency of the fundamental CTR spectrum is found t...

1. Outline of Basic NMR Principles Nuclear magnetic resonance (NMR), as all spectroscopic methods, relies upon the interaction of the sample being examined with electromagnetic radiation, here in a range of radio frequencies (11000 MHz). To absorb a photon of electromagnetic radiation, the transition energy ΔEsample due to the interaction of a nuclear spin in the sample with a magnetic field mu...

Sonoluminescence is explained in terms of quantum radiation by moving interfaces between media of di erent polarizability. It can be considered as a dynamic Casimir e ect, in the sense that it is a consequence of the imbalance of the zero-point uctuations of the electromagnetic eld during the non-inertial motion of a boundary. The transition amplitude from the vacuum into a two-photon state is ...

Based on the diffusional scattering of pseudophotons, we propose a new mechanism of x-ray radiation from a relativistic charged particle moving in a system consisting of microspheres distributed randomly in a dielectric material. The mechanism leads to a stronger dependence of radiation intensity on the particle energy, gamma = E/mc(2), than that predicted by the transition radiation, and expla...

Laser plasma accelerators have produced femtosecond electron bunches with a relative energy spread ranging from 100% to a few percent. Simulations indicate that the measured energy spread can be dominated by a correlated spread, with the slice spread significantly lower. Measurements of coherent optical transition radiation are presented for broad-energy-spread beams with laser-induced density ...

An integrated Laser Ablation Fluid RAdiation simulation Code (LAFRAC) has been developed to estimate behaviors of highly energetic ions and neutral particles from laser produced plasmas, and to estimate ionization and recombination processes. Neutral particles cannot be controlled by electric and/or magnetic forces. Therefore, estimation of the number of neutral particles and mitigation of them...

Single-cycle terahertz fields generated by coherent transition radiation from a relativistic electron beam are used to study the high field optical response of single crystal GaAs. Large amplitude changes in the sub-band-gap optical absorption are induced and probed dynamically by measuring the absorption of a broad-band optical beam generated by transition radiation from the same electron bunc...

We synthesized tunable far-infrared radiation at frequencies higher than 9 THz (300 cm (-1)) by mixing CO(2) laser, (15)NH(3) laser, and microwave radiation in a W-Co metal-insulator-metal diode. We used this farinfrared radiation to accurately measure torsion-rotation transitions of CH(3)OH in the 8-9-THz region. We also measured the frequency of the aP(7, 3) (15)NH(3) laser transition.