Generation of electromagnetic fields of extremely high intensity by coherent summation of Cherenkov superradiance pulses

We demonstrate both theoretically and experimentally the possibility of correlating the phase of a Cherenkov superradiance (SR) pulse to the sharp edge of a current pulse, when spontaneous emission of the electron bunch edge serves as the seed for SR processes. By division of the driving voltage pulse across several parallel channels equipped with independent cathodes we can synchronize several SR sources to arrange a two-dimensional array. In the experiments carried out, coherent summation of radiation from four independent 8-mm wavelength band SR generators with peak power 600 MW results in the interference maximum of the directional diagram with an intensity that is equivalent to radiation from a single source with a power of 10 GW

Coherent summation of emission from relativistic Cherenkov sources as a way of production of extremely high-intensity microwave pulses

For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to the sharp edge of an e-beam current pulse. Our theoretical consideration is referred to quasi-stationary and superradiative (SR) generation regimes when spontaneous emission of the e-beam edge serves as the seed for the development of further coherent oscillations. Phase correlation of the excited microwave pulses with the characteristics of the current pulse front and/or an initial external electromagnetic pulse has been additionally confirmed by particle-in-cell simulations. Pulse-to-pulse stability of the radiation phase within several percents of the oscillation period makes it possible to arrange multichannel schemes producing mutually coherent microwave pulses. In the experiments that have been carried out, the cathodes of independent generators were powered by identical accelerating pulses from strictly synchronized voltage modulators, or by splitting the pulse from a single powerful modulator. For the 2-ns regime with the power of each Ka-band backward-wave oscillator about 100 MW, we demonstrate quadratic growth of the power density in the interference maximum of the directional diagram. In a short pulse SR regime, with the peak power of 600 MW in a single channel, for a four-channel 2-D array, we attained a 16-fold radiation intensity gain

Quantum properties of parametric four-wave mixing in a Raman-type atomic system

We present a study of the quantum properties of two light fields used in parametric four-wave mixing in a Raman-type atomic system. The system realizes an effective Hamiltonian of beam-splitter-type coupling between the light fields, which allows one to control squeezing and amplitude distribution of the light fields, as well as realizing their entanglement. The scheme can be feasibly applied to engineer the quantum properties of two single-mode light fields in properly chosen input states

Quantum properties of a parametric four-wave mixing in a Raman-type atomic system

We present a study of the quantum properties of two light elds used to parametric four-wave mixing in a Raman type atomic system. The system realizes an e ective Hamiltonian of beamsplitter type coupling between the light elds, which allows to control squeezing and amplitude distribution of the light elds, as well as realizing their entanglement. The scheme can be feasibly applied to engineer the quantum properties of two single-mode light elds in properly chosen input states

Study of humoral immunity in animals immunized with emulsion FMD vaccines

The paper demonstrates results obtained during the study of humoral immunity in cattle after single immunization with inactivated emulsion FMD vaccines based on Montanide ISA 70 and ISA 206 adjuvants. The humoral immunity was assessed using virus neutralization test and ELISA. The vaccines were demonstrated to induce high level of antibodies maintained for 70 days post vaccination (observation period)