Abstract: Methods and apparatus for synthesizing radiochemical compounds are provided. The methods include generating a quasi-neutral plasma jet, and directing the plasma jet onto a radionuclide precursor to provide one or more radionuclides. The radionuclides can be used to prepare radiolabeled compounds, such as radiolabeled biomarkers.

Abstract: Methods and apparatus for synthesizing radiochemical compounds are provided. The methods include generating a quasi-neutral plasma jet, and directing the plasma jet onto a radionuclide precursor to provide one or more radionuclides. The radionuclides can be used to prepare radiolabeled compounds, such as radiolabeled biomarkers.

Abstract: A high efficiency system generates a VED virtual antenna by taking advantage of the vertical electric field created by natural effects in the lower ionosphere at latitudes in the vicinity of the dip equator. An ionospheric heater is employed to direct a heating radiation beam into a region of the ionosphere located at an altitude of 75-105 Km. The heating effect of the beam drives vertical oscillator currents that radiate ELF/VLF signals in the ionosphere.

Abstract: A method and apparatus for causing interruptions in the ionospheric electrojet to produce ULF/ELF/VLF signals enhances low frequency communications capabilities. A high power transmitter heats ionospheric electrons to enhance the electron-neutron collision rate with an antenna beam that can be modulated in the ELF and VLF frequency ranges. In order to increase efficiency of HF to ELF power conversion by more than two orders of magnitude, a heater is swept over a 35 degree cone on timescales faster than the plasma cooling rate at the heating altitude. Thus, the antenna beam is swept over an area of earth atmosphere to cause heating of ionospheric electrons in regions proximate to each other. The antenna is swept at a rate faster than the cooling rate of the atmosphere and is used to heat regions at an altitude of about 90 km. In addition, an electric field generated by the antenna beam is monitored and the heating region is shaped to optimize a vertical component of the electric field.