14 results about "Electron pulse" patented technology

An embodiment of the present disclosure provides a pulse electron microscope device including: a pulse generator configured to emit a laser pulse; a first beam splitter configured to split the laser pulse into a first laser pulse and a second laser pulse; a second beam splitter configured to split the second laser pulse and to reflect a second-1 laser pulse; an interval controller configured to control a time interval between the first laser pulse and the second-1 laser pulse by controlling an optical path length of the first laser pulse; a column part including a photocathode, the photocathode configured to convert the first laser pulse into a first electron pulse and convert the second-1 laser pulse into a second electron pulse; and an inspection module configured to inspect electrical defects in the sample by detecting a change in potential occurring on a surface of the sample.

This invention belongs to the field of precision scientific instruments and vacuum technology, and discloses a liquid ultrafast electron diffraction experimental station integrating a THz diagnostic structure. The station includes a vacuum chamber, a double-sided flange arranged upstream of the liquid film location along the electron beam transmission path, a position adjustment structure, a vacuum differential pipe, and a THz diagnostic structure. The double-sided flange is fixed between the vacuum pipe flange outside the vacuum chamber and the vacuum chamber itself. The position adjustment structure is axially and adjustablely fixed coaxially within the double-sided flange. The vacuum differential pipe is coaxially fixed within the position adjustment structure and passes through the sidewall of the vacuum chamber. The THz diagnostic structure is positioned between the vacuum differential pipe and the liquid film location. This invention integrates a vacuum differential system and a THz electron beam diagnostic system in situ within a single vacuum chamber, achieving synchronous compatibility between liquid-phase ultrafast electron diffraction and electron pulse time-domain diagnostics, ensuring the accuracy of time-resolved assessment of liquid-phase structure dynamics.

The invention relates to the technical field of electron emission, and discloses a large-current pulse micro-channel plate electron emission source and an X-ray generation device. According to the electron emission source, an electron emission function layer at the head end of an MCP assembly is excited by adopting a rapidly regulated and controlled UV LED light source, and ultrafast time sequence modulation of electron beams is realized through an avalanche multiplication process of the electron beams in the MCP. By adopting a specific high-lead, low-alkali or alkali-free glass component or ceramic substrate composite functional film layer structure, the MCP assembly has long service life stability of low resistance, high current output and high power density operation. Independent bias voltage and gating voltage synchronous with electronic pulse are applied to the MCP assembly through the driving control unit, accurate thermal management is carried out in combination with a pulse-charging circulation mode, and the problems of charge compensation and thermal limitation under large current output are effectively solved. The electron emission source breaks through the bottleneck, supports peak current density exceeding 100 mA / cm under submicrosecond pulse, and realizes hundred microampere level steady-state current output under millisecond level long pulse.

The application relates to an X-ray diode signal reconstruction method, which comprises the following steps: determining an electron pulse time expansion multiple function; determining an MCP gain function; obtaining an electron pulse signal output by an X-ray diode system; performing first processing on the electron pulse signal based on the electron pulse time expansion multiple function to obtain a first processing pulse signal; performing second processing on the first processing pulse signal based on the electron pulse time expansion multiple function to obtain a second processing pulse signal; and processing the second processing pulse signal according to the MCP gain function to obtain a reconstructed signal. Through the application, the influence of the inconsistency of electron pulse time expansion multiples at different slope positions of a cathode pulse and the inconsistency of MCP gains on the measurement accuracy of the X-ray diode system can be reduced, the input signal of the X-ray diode system can be accurately reconstructed, and the measurement accuracy of the X-ray diode system can be effectively improved.

The application discloses a dose control device and method of a medical electronic linear accelerator, which comprises an electronic pulse generator, a microwave pulse generator, a control computer, a trigger pulse generator, a counting frequency divider, a dose counter, a switch, a first circuit, a second circuit and an ionization chamber; the output end of the trigger pulse generator is in communication connection with the input end of the dose counter through the counting frequency divider, the output end of the dose counter is in communication connection with the input end of the switch, and the output end of the switch is in communication connection with the input end of the electronic pulse generator through the first circuit; the output end of the trigger pulse generator is also in communication connection with the input end of the switch; and the output end of the trigger pulse generator is also in communication connection with the input end of the microwave pulse generator through the second circuit. The application has the advantages of simple structure, high reliability and the ability to realize meticulous, more accurate and more balanced dose distribution.

An electron beam source includes a vacuum chamber containing a cathode and an anode separated by a vacuum gap forming a local full-voltage capacitive structure storing electrical energy at an operating voltage. A high-voltage power supply charges the capacitive structure without an intervening Marx generator, linear transformer driver, Tesla transformer, pulse-forming network, or pulse-forming transmission line. A triggering arrangement initiates electron emission to produce electron pulses traversing the vacuum gap, with discharged electrical energy transferred predominantly to electrons crossing the gap. In some embodiments, the local capacitive structure stores a majority of total electrical energy stored at the operating voltage in capacitances directly coupled between conductors at cathode and anode potentials. Multi-beam configurations, beam steering, passive synchronization, and contamination management features may be included.

The invention provides a ray generator, which comprises a magnetron used for generating microwave energy under the action of a magnetic pulse sequence; the electron gun is used for generating electron beams under the action of the electronic pulse sequence; the accelerating tube is used for introducing microwave energy and electron beams and accelerating the electron beams according to the microwave energy; the controller is used for acquiring target accumulated dose data within target time and determining an electronic pulse sequence and a magnetic pulse sequence based on the target accumulated dose data, the magnetic pulse sequence comprises N magnetic pulses, and the N magnetic pulses are arranged at intervals in the time sequence; at least one electronic pulse in the electronic pulse sequence is synchronized with the N magnetic pulses in time sequence, and the number of the N magnetic pulses synchronized with the at least one electronic pulse in time sequence is adjustable. The invention further provides a ray generation method and radiation equipment.

The application aims at solving the technical problem that the time resolution of the system is difficult to break through the technical barrier of 100 femtoseconds due to the phase jitter between the radio frequency field and the pump laser in the prior art, and providing an ultrafast electron pulse non-jitter static magnetic time compression device and compression method; the device comprises a femtosecond laser, an ultrafast electron gun, an electron beam collimation transmission assembly, an Omega type static magnetic time compression assembly, an electron beam aberration correction and final stage focusing assembly and a sample cavity which are sequentially arranged on the light output path of the femtosecond laser; the Omega type static magnetic time compression assembly is used for introducing an energy related time delay to the ultrafast electron pulse, compensating the initial time chirp of the electron pulse, and compressing the pulse width of the ultrafast electron pulse to below 100 femtoseconds. In the process of electron pulse acceleration and pulse compression, the device does not need to consider the time jitter between the radio frequency field and the femtosecond laser, and can maximize the time resolution of the ultrafast characterization instrument.

The invention relates to a self-adaptive cleaning method suitable for a display screen and a display system. The self-adaptive cleaning method comprises the steps that S1, a starting instruction is received; s2, controlling a sensor to detect a screen; s3, receiving data detected by the sensor; s4, according to the data detected by the sensor, judging the oil stain type; s5, selecting an adaptive duty ratio to drive a vibration circuit to generate vibration with a corresponding preset hertz value according to the types of the oil stains; s6, after cleaning is completed, the steps S2-S5 are repeated; and S7, sending an ending instruction under the condition that the clean state is judged. Self-adaptive cleaning of the surface of the screen is achieved through the electronic pulse vibration and intelligent detection technology, the screen is cleaned in a liquid-free and consumable-free full-electronic control mode, and the scheme has the advantages of being low in cost, wide in application range and easy and convenient to maintain.

An electron beam pulser suitable for SEM systems directs ≤30 keV electrons through a stripline kicker. RF waves or voltage pulses deflect the beam to periodically impinge on an aperture, thereby creating electron pulses from 100 fs to 100 ns in width. In RF embodiments, the RF frequency is tuned to provide 180-degree phase slippage between the RF and the electron beam, thereby generating pulse repetition rates up to 20 GHz without divergence. The RF can be reverse propagated through the kicker to reduce kicker size and / or increase the maximum pulse repetition rate. Voltage pulse embodiments provide flexible pulse widths and timing with repetition rates up to 1 GHz. A DC bias is applied to enable electron transit only during the voltage pulses, or offset voltage pulses of opposite sign can produce narrow electron pulses only during voltage pulse overlap. The EMMP can be synchronized for pump-probe experiments.

The invention provides an adaptive control method and system for a klystron of a medical accelerator, the medical accelerator comprises an excitation source used for generating microwave pulses and an accelerating tube used for accelerating injected electronic pulses, and the method comprises the following steps: acquiring a reflected wave signal at the input end of the accelerating tube; calculating the current resonant frequency of the accelerating tube according to the reflected wave signal; and calculating the frequency deviation between the current output frequency of the excitation source and the current resonant frequency of the accelerating tube, and outputting a frequency tuning instruction to the excitation source based on the frequency deviation so as to adjust the output frequency of the excitation source and enable the output frequency of the excitation source to track the resonant frequency of the accelerating tube. The technical problem of logic failure caused by dislocation of a control object in a traditional automatic frequency control scheme is solved, the output frequency of the excitation source is dynamically adjusted through closed-loop control, efficient injection of microwave energy is ensured, and the system stability and clinical reliability of the system are improved to a great extent.

This invention relates to a high-time-resolution X-ray radiation flow diagnostic system. The system includes a microstrip cathode, a first anode grid, a vacuum drift tube, a short magnetic lens, a microchannel plate, a second anode grid, an anode, and a high-speed oscilloscope, arranged sequentially on the same axis. The microstrip cathode is subjected to a negative DC bias voltage and a curve-broadening pulse output from a high-voltage pulse generator. The microchannel plate is subjected to a gain compensation pulse, which is delayed by the broadening pulse. The delay time is the flight time required for photoelectrons generated by the microstrip cathode to travel from the microstrip cathode to the microchannel plate in the vacuum drift tube. This invention utilizes an electron pulse broadening system to broaden the time width of the photoelectron beam, achieving temporal amplification of the electron beam. Then, an electron signal sampler with an ultrafast time response is used to measure the time-amplified electron beam, thereby improving the system's time resolution.

The invention belongs to the technical field of water body radioactivity detection devices, and discloses a water body NaI (T1) detector with a temperature peak position correction function, and a NaI (T1) scintillator is used for converting gamma rays into optical signals; a crystal shell of the NaI (T1) scintillator is provided with a thermometer; the photomultiplier is used for converting the optical signal into photoelectrons and multiplying the photoelectrons; the high-voltage module is used for providing voltage for the photomultiplier; the temperature correction module is used for storing a temperature-high-voltage gain curve, adjusting high-voltage gain and stabilizing the spectrum in real time; the pre-amplifier is used for amplifying the electronic pulse; the multichannel analysis module is used for converting the pulse signal into a digital signal, carrying out statistical calculation on a pulse amplitude to obtain gamma energy spectrum data, and carrying out secondary spectrum stabilization through a characteristic peak; according to the invention, through real-time temperature monitoring and high-voltage gain dynamic adjustment, in combination with 40K characteristic peak auxiliary calibration, the problem of energy spectrum peak drift in a water body low background environment is solved, and real-time spectrum stabilization can be carried out on the detector.