37results about How to "Reduce beam loss" patented technology

The invention discloses a system and a method for improving beam current intensity distribution after leading an ion beam out. A positive bias current-conducting plate is added between the top part and the bottom part of a beam current path between a beam current leading-out system and a mass analysis magnet, wherein the positive bias current-conducting plate can generate an electric field so that part beam current is pressed to the middle part; a bias voltage can modulate beam current intensity to increase the beam current intensity, so that the beam current loss caused by the mass analysis magnet is compensated; and simultaneously, some nonlinear angle changes caused by the positive bias current-conducting plate is independently corrected by utilizing an angle controller. By using the system and the method, the beam current loss caused by an analysis magnet inlet can be reduced; high beam current transmission efficiency is achieved by greatly improving the beam current of an analysis magnet; and the density distribution of the beam current can be optimized more conveniently when the beam current uniformity distribution is adjusted.

The invention relates to an accelerator, aims at solving the problem that an existing electronic accelerator is low in average beam current power and cannot meet the using demand of the fields of material irradiation and the like, meanwhile gives consideration to using economical efficiency and provides an electronic helical accelerator. The electronic helical accelerator comprises a radio-frequency resonance cavity, a pair of ridge-shaped electrodes, a four-pole magnet, a deflection magnet, a beam current motion pore passage, a pore passage inlet, a pore passage outlet and a grid-control electronic gun, wherein the beam current motion pore passage comprises a beam current deflection pore passage and ridge-shaped electrode beam current pore passages, the four-pole magnet and the deflection magnet are arranged outside the beam current deflection pore passage, electronic beams led from the pore passage inlet is subjected to acceleration, focusing and deflection in the beam current motion pore passage and finally jet out of the pore passage outlet, and the whole acceleration process is finished. The electronic helical accelerator is high in radio-frequency utilization efficiency and good in using economical efficiency, effectively improves the average beam current power and can well meet the using demand of the fields of material irradiation and the like.

The invention discloses a proton beam flow intensity modulation method and system. In a proton therapy device based on a cyclotron, an energy selection module makes the transmission efficiency of the proton beam with different energies very different, but a treatment end requires the proton beam to maintain a stable flow intensity range. The method of the invention firstly obtains the beam loss and the transmission efficiency of the proton beam with different energies in an energy reduction process after the energy modulation of the proton beam, and obtains a flow intensity ratio from low energy to high energy. According to the clinical requirements of the proton beam flow intensity dynamic ratio, after different energy points which have been subjected to energy modulation undergo expansion and collimation, the flow intensity modulation within a design proportional region is completed and the flow ratio can be controlled within a certain value. The method and the system of the invention are based on the Monte Carlo calculation method and the beam optics. The design method is reliable, and the realization scheme has a small space requirement, which is important for maintaining the beam stability in the proton therapy process.

The invention discloses a plasma window windowless seal-based liquid-state metal spallation neutron target device. The liquid-state metal spallation neutron target device comprises a plasma window and a liquid-state metal target, wherein the plasma window is arranged at the front end of the liquid-state metal target; the liquid-state metal target further comprises a liquid container; a liquid-state metal target material is held in the liquid container; a high-pressure cavity, a heat exchanger and a liquid-state metal circulating pipeline are arranged in the liquid container; the high-pressure cavity is arranged on the top of the liquid container; an opening is formed in the center of the bottom of the high-pressure cavity; a particle beam is in contact with a part bombarded by the beam through the opening; the heat exchanger is arranged on the inner wall of the liquid container to discharge heat to the exterior; and the metal liquid circulates in the liquid container through the liquid-state metal circulating pipeline. According to the plasma window windowless seal-based liquid-state metal spallation neutron target device, windowless seal of the liquid-state metal target is realized; the beam loss of the particle beam in a passage of the plasma window is reduced; the gasification of the liquid-state metal is reduced; and the steam of the metal entering a vacuum pipeline is reduced.

A hologram recorder (A2) includes: a light source (10) for emitting a coherent beam; a spatial light modulator (20) provided with unit areas having a plurality of beam reflection elements (21) to reflect the beam from the light source (10) in a main direction as a signal beam or a cut-off direction; and a signal beam optical system (30, 31) for directing the signal beam to the hologram recording medium B. The recorder (A2) further includes: a wavefront reshaper (40, 41, 42) for condensing the beams thinned out in the cut-off direction by the beam reflection element (21) of the modulator (20), and reshaping the wavefront of the condensed beams; and a reference beam optical system (50, 51) for directing the beam from the reshaper (40, 41, 42) to the recording medium (B) as a reference beam to be shone in an overlapping manner with the signal beam.

The invention discloses a high-frequency ultra-short electron gun grid regulation and control pulse power supply system, which mainly comprises the following four schemes: a high-frequency ultra-shortelectron gun grid regulation and control pulse power supply system for generating voltage-multiplying pulses, a high-frequency ultra-short electron gun grid regulation and control pulse power supplysystem for directly generating high-frequency ultra-short pulses, a high-frequency ultra-short electron gun grid regulation and control pulse power supply system for generating frequency-multiplying and phase-adjustable pulses, and a high-frequency ultra-short electron gun grid regulation and control pulse power supply system for directly generating polarity and phase-adjustable pulses. Output ofvoltage-multiplying pulses, high-frequency ultra-short pulses, frequency-multiplying and phase-adjustable pulses and polarity and phase-adjustable pulses is realized respectively.

A manufacturing method of a waveguide structure includes forming a metal layer of a predetermined size on a substrate to form a structure, forming a lower clad layer on the structure in order to completely cover the metal layer, forming a core layer of a predetermined size on the lower clad layer at the location corresponding to the metal layer, and forming an upper clad layer thereon in order to completely cover the core layer.

The invention provides a moving target for neutron generation. The moving target comprises a vacuum cavity, a moving device and a target body, wherein the moving device and the target body are installed in the vacuum cavity; the moving device is installed on the inner wall of the top of the vacuum cavity; the target body is detachably installed on the moving device through a hook assembly, and the moving device can control the reciprocating motion of the target body. The moving device is adopted to control the target body to move left and right in a reciprocating mode, so that the problem of high local heat caused by flow beam concentration of an existing static target is solved, heat deposition of the target body in unit volume is effectively reduced, the heat concentration peak value of the target body is also reduced, and the requirement for proton beam beams is reduced.

The invention discloses a high-energy hydrogen ion implantation method and device. The device is characterized in that a negative hydrogen ion source is located at the left side of a main accelerator,and is in sealed connection with an inlet of the main accelerator through a rubber ring; a first magnetic lens is arranged between the outlet of the negative hydrogen ion source and the inlet of themain accelerator; a cryogenic pump and a molecular pump are respectively positioned on an upper cover plate and a lower cover plate of the main accelerator; electrodes of the main accelerator comprisean intermediate electrode and a high-voltage electrode, and the intermediate electrode and the high-voltage electrode are electrified by a high-voltage power supply to form an electric field to accelerate ions; a stripping film is located on the high-voltage electrode, negative hydrogen ions are converted into protons, and a second magnetic lens is arranged between an outlet of the main accelerator and a scanning deflection device. The device is compact in structure, the same group of electrodes are used for carrying out two-stage acceleration on ions, the number of the electrodes is reduced,the size of the whole accelerator is smaller, and the manufacturing cost is lower. In addition, energy control and linkage can be accurately realized, and stable and high-energy ions can be obtained.

An overmoded distributed interaction network is provided that generates high peak and average RF power amplification at high frequencies. A series of overmoded cavities are bounded by parallel or concentric grids that may be separated by metallic spacers adapted to function as a photonic bandgap circuit to suppress competing electromagnetic modes. The selected electromagnetic modes have wavelengths much shorter than the lateral dimension of the grids, allowing the beam-wave interaction to be distributed transversely for improved interaction efficiency. The grids may optionally be slotted and arranged to provide a serpentine traveling wave tube configuration.

The invention relates to a vacuum exhaust system of a superconducting cyclotron. The vacuum exhaust system comprises a first exhaust passage, a second exhaust passage and a third exhaust passage, wherein the first exhaust passage is arranged in a high-frequency inner rod (7) of a high-frequency system of the superconducting cyclotron; the second exhaust passage is arranged between the high-frequency inner rod (7) of the high-frequency system and a high-frequency outer conductor (4); the third exhaust passage is arranged between the high-frequency outer conductor (4) of the superconducting cyclotron and a main magnet cover plate (2); and the first exhaust passage, the second exhaust passage and the third exhaust passage all carry out exhausting through a D plate (5) arranged at the end part of the high-frequency inner rod (7). By the vacuum exhaust system of the superconducting cyclotron, a plurality of vacuum exhaust passages are arranged according to the structural design characteristic of the high-frequency system, so that conductance of vacuum exhausting of the superconducting cyclotron is improved; the vacuum pumping rate of the superconducting cyclotron is improved; the beam loss is reduced; and the beam quality is improved.

The invention discloses a method for improving the cutting precision of a screw tap and prolonging the service life of the screw tap. The method comprises the following steps that firstly, grease is brushed off from a cutter seam of the screw tap, and then the screw tap is put into an ultrasonic cleaning tank for deoiling cleaning, then is dehydrated and air-dried, and then is put into a vacuum chamber; a gas ion source of a cold cathode is started, argon ions are adopted to bombard the surface of the screw tap, then an arc ion source is started, arc discharge is formed, arc discharge is generated on a graphite cathode target, and then carbon plasma is generated in an anode cylinder; the carbon plasma is led out of a discharge chamber through an electrode and filtered through a magnetic field, neutral and polymolecular graphite particles are filtered out, and a single carbon ion flow is formed; and the single carbon ion flow is focused through a magnetic lens to form an ion beam, and the ion beam is scanned through a deflection magnetic field and matched with a rotary table to form a deposition surface to be deposited on the screw tap, so that an amorphous tetrahedron carbon coating is formed.