摘要:
The present invention provides an enhanced THz electromagnetic source structure achieving a very high aspect ratio of 500 to 1 of electron beam width to electron beam thickness of the electron beam moving in the direction across the grating structure while maintaining its cross-section. The structure comprises a magnetic circuit providing a unique low magnetic field slot placed in a steel core for the placement of an electron gun, thus allowing the electron beam to be focused without the interaction of a magnetic field while still supporting a high magnetic field in the grating region. Additionally, the structure comprises an electrostatic shield preventing potential difference between the anode voltage and the grounded steel core from affecting the focusing of the electron beam.
摘要:
An apparatus for airborne particle sorting is provided comprising a charging system adapted for applying an electrostatic charge to the particles, such that particles of at least a first group are deflected to a greater extent than particles of a second group are deflected. A focusing system is adapted for electrostatically focusing substantially at least the particles of the first group into a focused stream that is narrower than the input air stream. A deposition system is adapted for substantially depositing the particles of the first group from the focused stream upon a target surface, where the target surface may be transported to an analysis system capable of analyzing the particles deposited thereon.
摘要:
The invention is a method and apparatus for the detection of terahertz radiation. In one embodiment, frequency modulated spectroscopy is performed on a swept source of coherent far infrared electromagnetic radiation that is focused on a target. A beam of radiation passes through a cell in which the target is housed, losing energy as certain frequencies are absorbed by contaminants in the target. A detector is positioned to determine how much energy is lost by the radiation (e.g., which frequencies fail to transmit through the cell), thereby indicating the presence of contaminants in the target.