Abstract:
Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether there are drugs concealed in the inspected liquid article based on the difference between the acquired physical attributes and reference physical attributes of the inspected liquid article. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.
Abstract:
The present disclosure provides a High-Purity Germanium (HPGe) detector, comprising: a HPGe single crystal having an intrinsic region exposed surface; a first electrode and a second electrode connected to a first contact electrode and a second contact electrode of the HPGe single crystal respectively; and a conductive guard ring arranged in the intrinsic region exposed surface around the first electrode to separate the intrinsic region exposed surface into an inner region and an outer region. A leakage current derived from the intrinsic region exposed surface of the HPGe detector can be separated from the current of the HPGe detector by the conductive guard ring provided in the surface, thereby suppressing the interference of the surface leakage current.
Abstract:
The present invention discloses a corona discharge assembly, an ion mobility spectrometer, an computer program and an computer readable storage medium. The corona discharge assembly includes: an ionization discharge chamber, wherein the ionization discharge chamber includes a metal corona cylinder, and the metal corona cylinder is provided with an inlet of a gas to be analyzed and a trumpet-shaped front port which is conductive to forming a gathered electric field; multiple corona pins, in which on-off of a high voltage can be independently controlled, are installed at the center of the metal corona cylinder in an insulating manner. The present invention further discloses an ion mobility spectrometer using the above-mentioned corona discharge assembly. The present invention can be used to prolong the service life of the integral corona discharge assembly; the discharge voltage of the ion source can be reduced and the discharge stability thereof can be improved; in comparison with the suspended installation of a pin-shaped electrode, since the multiple corona pins are fixed on the PCB, during installation, the position of the electrode can be accurate and stable, thus mass manufacture is easier to achieve.
Abstract:
The present invention discloses an asymmetric field ion mobility spectrometer. It comprises an ionization source, for generating ions; an electrode plate; a plurality of electrode filaments, arranged in opposite to and spaced apart from the electrode plate by an analysis gap, wherein a high voltage of electrical field is applied between the electrode plate and the electrode filaments to form an ion migration area, the electrode filaments used to collect the ions that do not pass through the ion migration area; and a collection electrode, disposed at a rear end of the ion migration area, and collecting the ions that have passed through the ion migration area. The present asymmetric field ion mobility spectrometer is capable of improving accuracy of identifying peak positions of the ions, reducing scanning time of DC voltage and types of compensation voltage, thereby increasing ion detection efficiency.