Nuctech Company Limited

Tsinghua University

Other

Xinshui Yan

Yaohong Liu

Jinsheng Liu

Chuanxiang Tang

Huaping Tang

Wei Jia

Wei Yin

Huaibi Chen

Yuanjing Li

Jianjun Gao

Zhiqiang Chen

Ziran Zhao

Yumei Chen

Wei Li

Feng Gao

Shangmin Sun

Dan Zhang

Zhanfeng Qin

Chong Gu

Xiying Liu

Weiqiang Guan

Hao Shi

Qinghui Zhang

Xiaotian Liang

De Wei

Ping Wang

Kejun Kang

Quanwei Song

Wenhui Huang

Dongsheng Zhang

Jiaru Shi

The disclosed technology relates to a gate protection circuit for an Insulated Gate Bipolar Transistor (IGBT), the IGBT being used as a switch device in a solid state pulse modulator based on the MARX generator principle, the gate protection circuit including: a voltage regulator configured to supply a stable voltage to an emitter of the IGBT with respect to the ground for a gate of the IGBT.

Protection circuit, oscillation compensation circuit and power supply circuit in solid state pulse modulator

The present disclosure provides a ray calibration device and a working method thereof, and a radiation imaging system and a working method thereof, and belongs to the field of radiation imaging technology. The present disclosure can solve the problems that the existing calibration devices have low calibration efficiency and require relatively large spaces. The ray calibration device of the present disclosure includes a driving part, a cam part and a calibration part, wherein the calibration part is located below the cam part; the driving part is adapted to drive the cam part to rotate; and the cam part is adapted to exert a force on the calibration part to enable the calibration part to move into a ray area downwards.

Ray calibration device and operating method thereof, and radiation imaging system and operating method thereof

The present disclosure provides a filament power supply for an electron accelerator and an electron accelerator. The filament power supply includes: a rectifier circuit configured to convert a power frequency AC voltage signal into a DC voltage signal; an inverter circuit configured to convert the DC voltage signal into an AC voltage signal; a sampling circuit configured to sample the AC voltage signal to obtain a current sampling signal or a voltage sampling signal; a pulse width modulation control chip configured to adjust a pulse width modulation signal until a voltage of the current sampling signal is equal to that of a reference current signal, or a voltage of the voltage sampling signal is equal to that of a reference voltage signal; a modulation circuit configured to modulate the power frequency AC voltage signal to obtain a modulation signal and output the pulse width modulation signal and the modulation signal.

Filament power supply for electron accelerator and electron accelerator

The disclosed technology relates to a ray energy calibration device and method, and a ray imaging system. In one aspect, the ray energy calibration device includes a plurality of wheels arranged to be rotatable about a common shaft and each provided with one or more protruding blocks at respective specific positions of an outer circumference thereof. The ray energy calibration device further includes a plurality of calibration members, with each of the calibration members being configured such that through rotation of a corresponding one of the wheels, the calibration member can be moved to a calibration position by the protruding block at a specific position on the outer circumference of the wheel.

Ray energy calibration device, ray energy calibration method and ray imaging system

The present invention provides a pulse modulating power source, which comprises: a plurality of discharging modules connected in series during discharging; a plurality of triggers corresponding to said plurality of discharging modules, wherein each trigger provides a trigger signal to the corresponding discharging module to turn it on; a control logic module for controlling the trigger signals so as to turn on said plurality of discharging modules successively with a time delay; an output terminal for outputting a voltage.

Apparatus and method for controlling pulse output

The present invention may perform fluoroscopic imaging simultaneously on the subjects in at least two channels using only one electron accelerator, at least two sets of X-ray beams and at least two sets of detector systems, through the design of the electron accelerator, the shielding and collimating device, the at least two detector arrays and various mechanical composite structures. The X-ray fluoroscopic imaging system according to the present invention may be designed in specific forms of a stationary type, an assembled type, a track mobile type or vehicular mobile type, etc., and has advantages such as simple structure, low cost, strong function, good image quality and the like.

X-ray fluoroscopic imaging system

An apparatus and method to generate distributed x-rays. A hot cathode of an electron gun is used in vacuum to generate electron beams having certain initial movement energy and speed. Periodic scanning is performed with the initial low-energy electron beams, which are thus caused to be reciprocally deflected. A current-limiting device is provided in the travel path of the electron beams along the direction of the reciprocal deflection. Through holes arranged in an array on the current-limiting device, only part of the electron beams targeting specific positions can pass to form sequential electron beam currents distributed in an array. These electron beam currents are accelerated by a high-voltage electric field to obtain high energy, bombard an anode target, and thus sequentially generate corresponding focus spots and x-rays distributed in an array at the anode target.

Apparatuses and methods for generating distributed x-rays in a scanning manner

The X-ray fluoroscopic imaging system of the present invention comprises: an inspection passage; an electron accelerator; a shielding collimator apparatus comprising a shielding structure, and a first collimator for extracting a low energy planar sector X-ray beam and a second collimator for extracting a high energy planar sector X-ray beam which are disposed within the shielding structure; a low energy detector array for receiving the X-ray beam from the first collimator; and a high energy detector array for receiving the X-ray beam from the second collimator. The first collimator, the low energy detector array and the target point bombarded by the electron beam are located in a first plane; and the second collimator, the high energy detector array and the target point bombarded by the electron beam are located in a second plane.

The present invention provides a high voltage pulse modulating power source based on alternate group triggering, which comprises: a DC stabilized voltage source for supplying power to the high voltage pulse modulating power source; a plurality of solid-state switches; a plurality of triggers corresponding to said plurality of solid-state switches, wherein each trigger provides a trigger signal to its corresponding solid-state switch to turn on said corresponding solid-state switch, wherein said plurality of triggers are divided into at least two groups of triggers; a time sequence control module, which, at time t, controls said plurality of triggers to generate trigger signals so as to turn on said plurality of solid-state switches simultaneously, and at time t, controls one group of said at least two groups of triggers to generate trigger signals to turn on solid-state switches corresponding to this group of triggers, wherein time tand time tappear alternately.

Apparatus and method for voltage alternating pulse output

Apparatuses and methods for generating distributed x-rays

The present disclosure relates to a phase shifter, an accelerator, and an operating method therefor. The phase shifter comprises a rotating part having a first hollow structure, the first hollow structure having a first cavity, a distance between a circumference of the cross section of the first cavity and a rotation center of the rotating part changing periodically and continuously in a peripheral direction, such that when the rotatory part rotates, a phase shift occurs between two adjacent microwave pulses at an outlet of the phase shifter. The operating method comprises transmitting a microwave pulse within the accelerator at a repetitive frequency v Hertz; the driving devices drives the rotating part to rotate at a rotation speed of n RPM, wherein n=15v*m, m is an odd number, 1, 3, 5 . . . , such that when transmitting a microwave pulse each time, the long axis of the oval cross section of the first cavity of the rotatory part is rotated to a horizontal or vertical state.

Phase shifter, accelerator and method of operating the same

An irradiating device and a method for controlling it are provided. The device comprises an electron accelerator and a scanning box connected to the electron accelerator, wherein the scanning box is provided with a target, an electron beam exit window positioned at left or right side of the target and a scanning magnet. The device integrates the functions of both the existing irradiating device outputting electron beams and those outputting X-rays. When the scanning magnet is in operation, the irradiating device outputs electron beams; and when the scanning magnet is not in operation, the irradiating device outputs X-rays. Therefore, the device is capable of outputting two radiation sources so as to meet requirements for radiation-processing articles with different sizes.

Irradiating device and method for controlling the same

A high-voltage automatic changeover switch, includes a support and a control circuit board mounted on the support. In one embodiment, the support includes an insulating frame, four high-voltage contacts mounted on each of two opposite plates of the insulating frame, four high-voltage contacts on the same plate being pair-to-pair arranged, the high-voltage contacts at the corresponding positions on the two plates being pair-to-pair arranged. A motor is provided on the support, and when switching the high voltages, the control circuit board controls the rotation of the motor to automatically switch the connection relation between the high-voltage contact pairs. Embodiments of the switch have a voltage-resistance of above 50 KV, allowing a pulse current of not less than 500 A to pass through, and good contact performance and a high stability. In one aspect, the high-voltage automatic changeover switch performs automatic switching of power source high voltages in an accelerator system, so that the accelerator obtains electron beams with different energies, thus allowing an expanded scope of application of the accelerator, including updating and upgrading of non-destructive testing systems, custom container inspection systems, and high-energy CT systems.

Growing community of inventors

Beijing, China

Xinshui Yan