摘要:
A method for phase contrast imaging comprises: illuminating an object by terahertz radiation such that the terahertz radiation interacts with the object; illuminating a diffraction grating by the terahertz radiation that has interacted with the object; translating the diffraction grating along the direction of the grating wave vector, to measure, for each of different grating positions, an intensity distribution of the terahertz radiation that has interacted with the object and with the grating in a diffraction field; and retrieving a phase contrast image of the object from the intensity distributions. An apparatus for phase contrast imaging comprises: a terahertz radiation emitter for generating terahertz radiation, which illuminates an object to interact with the object; a diffraction grating, which is illuminated by the terahertz radiation that has interacted with the object; a terahertz radiation detector for measuring, for each of different grating positions, an intensity distribution of the terahertz radiation that has interacted with the object and with the grating in a diffraction field; and a data collecting and processing system for retrieving a phase contrast image of the object from the intensity distributions.
摘要:
Disclosed is a detector device, comprising: an adjustable positioning base and a detector module. The adjustable positioning base includes: a horizontal plate being able to fixedly connect onto an annular rotation table or disk; and a vertical plate extending from the horizontal plate and generally perpendicular to the horizontal plate. A horizontal through long groove is provided at one side of the vertical plate, and the detector module is able to fixedly installed in said horizontal through long groove of the adjustable positioning base. By employing the technical solution defined in the present invention, the detector device has a compact structure, and precision adjustment and positioning for the detector device can be achieved. In addition, the present invention also provides a CT inspection system having the above detector device.
摘要:
A method and an apparatus for measuring terahertz time-domain spectrum, which relate to the field of terahertz time-domain spectrum. The method comprises the steps of: generating a first pulse laser beam from a first femtosecond laser device at a preset repetition frequency to generate THz pulses; generating a second pulse laser beam from a second femtosecond laser device at the repetition frequency; measuring electric field intensities of the THz pulses at respective phase differences between the first pulse laser beam and the second pulse laser beam; and obtaining a THz time-domain spectroscopy by performing Fourier transformation of data representative of the electric field intensities. THz spectrum measured according to the method and apparatus improves spectroscopy resolution and provides a broader detection range.
摘要:
It is disclosed an imaging system comprising: radiation generating means including at least one radiation source for generating radiations; data acquiring means including an detector matrix faced the radiation source for obtaining projection data by receiving radiations penetrated through an object to be inspected; transporting means for making the object to be inspected between the radiation source and the detector matrix linearly moving relative to the radiation source and the detector matrix; and controlling and image processing means for controlling the radiation generating means, the data acquiring means and the transporting means, and for reconstructing an image of the object to be inspected from the projection data. The imaging system according to the present invention achieves a real stereoscopic radiography by using straight-line trajectory scan and reconstructing a tomographic or stereoscopic image through a straight-line filtered back-projection algorithm. The present imaging system has advantages of fast examination speed, no rotation, and out of large cone-angle problem in a circular-orbit cone-beam CT.
摘要:
The present invention discloses a dual array detector module adapted to radiation-imaging, comprising: a first detector array consisting of a plurality of first detectors and arranged on a first surface of a heavy metal plate; a second detector array consisting of a plurality of second detectors and arranged on a second surface of the heavy metal plate, the second surface is opposite to the first surface; and a mounting frame, in which the first detector array and the second detector array arranged on the first and second surfaces of the heavy metal plate respectively are mounted in the mounting frame. The dual array detector module according to the present invention is simple in structure and convenient for mounting and maintenance, so that a great economic benefit can be obtained by improving the structure simply and increasing a little of investment.
摘要:
A method and an apparatus for liquid safety-detection by backscatter with a radiation source relate to a radiation detecting technology field. The invention comprises using a radiation source, a collimator, a detector, a data collector and a computer data processor, and has the main steps of: 1) a liquid article to be detected being placed onto a rotatable platform; 2) the ray emitted from the radiation source causing Compton scattering at the surface of the liquid after passing through the package layer of the liquid article; 3) the scattering photons being received by the detector after passing the collimator; 4) the detector transmitting the received data to the data collector; and 5) the data collector transmitting the amplified and shaped data to the computer data processor, which processes the data to obtain the liquid density of the detected article, then compares the result with the densities of dangerous articles in a current database, and gives warning if finding that the density of the detected article is consistent with that of a dangerous article. Comparing to the prior art, the invention has a convenient use, a rapid and accurate detection, a strong anti-interference, a high use safety and reliability, and an easy protection.
摘要:
A boron-coated neutron detector, comprising a cathode tube with a plurality of passages formed therein along its longitudinal direction, the inner wall of each passage being coated with boron material; an electrode wire serving as an anode and arranged longitudinally in each of the passages, the electrode wire adapted to be applied with high voltage; and an insulating end plate to which each end of the cathode tube is fixed, the electrode wire being fixed to the cathode tube via the insulating end plate. Preferably, the cathode tube is formed by jointing a plurality of boron-coated substrates. The boron-coated neutron detector increases the detection efficiency of the neutron detector, which may reach or even exceed the detection efficiency of the 3He neutron detector of the same size, and the cost thereof is much cheaper than the 3He neutron detector.
摘要:
An X-ray imaging system comprising: an X-ray source, a source grating, a fixed grating module and an X-ray detector, which are successively positioned in the propagation direction of X-ray; an object to be detected is positioned between the source grating and the fixed gating module; said source grating can perform stepping movement in a direction perpendicular to the optical path and grating stripes; wherein the system further comprises a computer workstation for controlling said X-ray source, source grating and X-ray detector so as to perform the following processes: the source grating performs stepping movement in at least one period thereof; at each stepping step, the X-ray source emits X-ray to the object to be detected, and the detector receives the X-ray at the same time; wherein after at least one period of stepping and data acquisition, the light intensity of X-ray at each pixel point on the detector is represented as a light intensity curve; the light intensity curve at each pixel point on the detector is compared with a light intensity curve in the absence of the object to be detected, a pixel value of each pixel point is calculated from change in said light intensity curve; an image of the detected object is reconstructed according to the calculated pixel value.
摘要:
The present invention provides an ion collection device for an ion mobility spectrometer and an ion mobility spectrometer. The ion collection device comprises: an aperture grid for restraining influence of ion drift movement in a drift region on ion collection; and a first electrode disposed at a downstream side of the aperture grid in an ion drift direction, the first electrode is mechanically and electrically coupled with the aperture grid. With the above configuration, the aperture grid and the first electrode are at the same electric potential, and form a focusing electrical field with an ion collection part. Therefore, ions entering the collection region will not scatter into a shield cover.
摘要:
A sample feeding device for a trace detector is disclosed. The sample feeding device comprises: a sample feeding chamber disposed in the sample feeding device to desorb a sample from a sample feeding member; and a valve assembly configured to fluidly communicate the sample feeding chamber with a drift tube of the trace detector during feeding sample. With the above configuration of the present invention, for example, the sensitivity of the detector can be increased by improving the permeation ratio of the sample. In addition, interior environment of the drift tube is isolated from exterior environment to avoid a drift region of the drift tube from being polluted. The important parameters, such as sensitivity, a position of a peak of a substance, a resolution, of the detector can be kept constant. As a result, operation reliability and consistency of the detector can be achieved.