8438 results about "Nuclear physics" patented technology

A system for administering transcranial magnetic stimulation in which two or more coils are applied to the patient's body. The coils each may emit a magnetic field which when positioned in one or more configurations result in field overlapping. Magnetic field overlap achieves therapeutic effects otherwise difficult, or impossible, to achieve from traditional single coil TMS devices.

MRI interference with a co-existing ultrasound system may be reduced or avoided by carrying out RF-sensitive operations of the treatment system only when gradient field activity of the MRI system is suppressed.

The invention discloses a method and tool for manufacturing a cold shield of a nuclear fusion device, and relates to the technical field of metal plate machining. The manufacturing method of the cold shield of the nuclear fusion device comprises the following steps: providing a sub-panel, a flange and a pipe fitting; the multiple sub-panels are welded, and a first middleware is obtained; welding the edge of the first middleware and the turnup to obtain a second middleware; after the pipe fitting is welded to the surface of the second middleware, a third middleware is obtained; and the third middleware is shaped. According to the method, the third middleware is shaped, that is, the third middleware is shaped after all welding procedures are completed, so that the third middleware has relatively small profile tolerance, the profile tolerance of the cold shield meets the design requirement, the assembly difficulty of the cold shield is reduced, and the risk of failure of the cold shield is reduced.

The invention discloses a compressed sensing MRI (Magnetic Resonance Imaging) reconstruction method and system based on a double-domain fusion expansion model. The method comprises the following steps: acquiring an MRI image, preprocessing the MRI image to obtain a preprocessed image and a corresponding compressed sensing measurement value, and constructing a data set; training, testing and verifying the double-domain fusion expansion model by using the data set; and outputting a reconstructed image from the MRI image after mask sampling by using a double-domain fusion expansion model. According to the double-domain fusion expansion model, a complex convolutional neural network and a K-space attention mechanism are introduced for complex value data processing and double-domain information fusion in compressed sensing MRI reconstruction. The complex value data is processed through the complex network, the amplitude and phase information of the complex field is fully utilized, the detail recovery capability and the noise suppression effect of the model are enhanced, and particularly, excellent robustness is shown at a low sampling rate. The method is excellent in performance in complex MRI data reconstruction, and has high reconstruction precision and generalization ability.

The invention relates to the field of nuclear fusion, and discloses a fixing device for a nuclear fusion preassembled assembly, and the fixing device comprises a magnet connecting assembly which comprises a first beam body and a magnet connecting part, the first beam body extends in a first direction, and the magnet connecting part is arranged on the first beam body; the vacuum chamber connecting assembly and the magnet connecting assembly are spaced in the second direction, the vacuum chamber connecting assembly comprises a second beam body and a vacuum chamber connecting part, the second beam body extends in the first direction, and the vacuum chamber connecting part is arranged on the second beam body; the beam body connecting assembly is arranged at the two ends of the second beam body in the first direction, is connected with the first beam body and comprises a first connecting piece, a second connecting piece and an elastic energy storage piece, the first connecting piece is movably connected with the second connecting piece and is detachably connected with the first beam body, and the second connecting piece is detachably connected with the second beam body; one end of the elastic energy storage piece is movably connected with the first connecting piece, and the other end is movably connected with the second connecting piece. The gap between the magnet and the vacuum chamber can be restrained, and the position precision between the magnet and the vacuum chamber is guaranteed.

A magnetic resonance image reconstruction device according to an embodiment is a magnetic resonance image reconstruction device that reconstructs magnetic resonance image data in which an artifact due to undersampling is removed or reduced based on undersampled k-space data, and includes a reconstruction unit reconstructing the magnetic resonance image data using a reconstruction network having a correction module. The correction module includes a regularization block generating second image data by performing a regularization process on first image data using a first neural network, and a data consistency block generating third image data by performing a data consistency process so that k-space data corresponding to the second image data approaches the undersampled k-space data. The correction module further includes at least one of a data consistency adjustment block adjusting the data consistency process and a regularization adjustment block adjusting the regularization process.

According to the displacement modulation and optical assistance-based SERF atom magnetometer magnetic imaging method, an SERF atom magnetometer integrated with a magnetic flux guider is used as a magnetic sensor, and low-frequency magnetic field modulation is introduced to the magnetic sensor by controlling a to-be-tested sample to perform periodic infinitesimal displacement in the sensitive direction of the magnetic sensor; the modulation signal is demodulated by combining a phase-locked amplification technology, and a magnetic response signal subjected to phase-locked demodulation at each spatial position is extracted; constructing a magnetic response matrix through two-dimensional track scanning of micron-order step pitch; an image acquisition module and a reflection optical assembly are introduced for spatial registration so as to monitor the relative position in real time, and the visibility and controllability of the magnetic imaging process are guaranteed; the point-by-point detection of fT-level weak magnetic signals can be realized on the premise that an array structure is not needed; the low-frequency noise interference can be effectively inhibited, the stability and definition of direct-current and low-frequency magnetic field imaging are improved, and the method is suitable for high-resolution space imaging application of weak magnetic sources such as magnetic domain structures, nervous tissue slices and ancient rock samples.

The invention discloses a cosmic ray muon scattering imaging method, system and device, and relates to the field of ray imaging, and the method comprises the steps: obtaining the direction information of muons in a to-be-imaged region; calculating the most probable three-dimensional scattering track of the muons in the to-be-imaged region based on Bayesian inference and a particle multiple coulomb scattering distribution function according to the direction information of the muons in the to-be-imaged region; and reconstructing a scattering density image in the to-be-imaged region according to the direction information of the muon in the to-be-imaged region and the most probable three-dimensional scattering track. By calculating the most probable three-dimensional scattering track, the scattering points can be effectively reconstructed, the utilization efficiency of muon events is improved, the scattering points are prevented from being separated from the to-be-imaged area, the most probable three-dimensional scattering track better fits the real scattering track, and then the quality of the scattering density image is improved.

The invention belongs to the technical field of magnetic particle imaging, relates to a magnetic particle imaging reconstruction method based on a calibration magnetic field generation system matrix, and aims to solve the problems that a traditional magnetic particle imaging reconstruction method is poor in applicability in asymmetric bilateral structure magnetic particle imaging equipment (A-MPI) and cannot perform imaging in any region. The method comprises the following steps: performing grid division on an imaging area, calibrating magnetic field intensity, and obtaining magnetic field gradient distribution of each point; obtaining a theoretical system matrix according to a mathematical calculation mode; randomly moving the positions of the non-magnetic field points for scanning to obtain actually measured magnetic field gradient distribution and a system matrix, and constructing a data set; expanding the data set based on the simulation system; constructing a deep learning model, and inputting the extended data set and the measured data into the training deep learning model; and inputting a theoretical system matrix at any position, and obtaining an accurate system matrix by using the trained model. According to the invention, the system matrix at any position can be obtained under the A-MPI equipment, so that imaging at any position is realized.

The invention relates to the technical field of magnetic resonance imaging, in particular to an intelligent sparse low-rank non-Cartesian magnetic resonance dynamic imaging method, which comprises the following steps of: acquiring magnetic resonance k-space data which is subjected to non-Cartesian continuous sampling by adopting multiple coils, continuously sampling data, rearranging the continuously sampled data along a time dimension by using a framing operator to obtain under-sampled k-space data, and then inputting the framed non-Cartesian under-sampled k-space data to be reconstructed into a trained network for image reconstruction. And reconstructing a final dynamic image through depth space-time sparsity, time low-rank learning, data consistency verification and loss function constraint. Compared with the prior art, the non-Cartesian magnetic resonance dynamic image reconstruction method has the advantages that the image is reconstructed through multiple times of network feedback iteration, the reconstruction speed of the non-Cartesian magnetic resonance dynamic image is greatly increased, and the temporal-spatial resolution is improved.

The invention provides a magnetic particle imaging resolution improving method and system based on frequency domain information filtering, and relates to the technical field of magnetic particle imaging. Comprising the following steps: inputting original magnetic particle imaging data into a Transform model, and selectively filtering frequency domain information in the magnetic particle imaging data through a fusion frequency domain discrimination feedforward network module in an encoder to obtain the output of the encoder; inputting the output of the encoder into a bottleneck layer, aggregating global and local information through a multi-scale attention mechanism module, and then selectively filtering frequency domain information in the magnetic particle imaging data again to obtain the output of the bottleneck layer; inputting the output of the bottleneck layer into a decoder with the same structure as the bottleneck layer to obtain deep features; inputting the deep features into a convolutional layer to obtain a residual image; and calculating the sum of the original magnetic particle imaging data and the residual image to obtain a reconstructed image. According to the invention, the overall imaging resolution of the MPI image under the low-gradient field acquisition condition is improved.

The invention relates to a multi-contrast magnetic resonance image super-resolution reconstruction method and system. The method comprises the following steps: collecting an image data set, preprocessing the image data set, and dividing the image data set into a training set and a test data set; combining a Hilbert curve, a state space model and a frequency domain enhancement mechanism to construct a multi-contrast magnetic resonance super-resolution reconstruction model based on Hilbert double-domain fusion Mamba; and training a multi-contrast magnetic resonance super-resolution reconstruction model based on Hilbert double-domain fusion Mamba by using the training data set, and then completing the test of the test data set to obtain a super-resolution reconstruction image of the target contrast magnetic resonance image. Frequency domain features are scanned through a Hilbert curve, a cross-modal global frequency dependency relationship is captured, and high-frequency texture details are effectively recovered. And multi-modal local texture information is dynamically fused through a channel attention mechanism, so that neglect of local details by linear scanning is avoided, and the texture reconstruction precision is improved.

The invention relates to the technical field of image processing, in particular to a clinical focus auxiliary segmentation system based on a nuclear magnetic resonance image. The system comprises an MRI image processing module, a lesion auxiliary segmentation module, a probability segmentation correction module and a lesion boundary smoothing module, a corresponding clinical nuclear magnetic resonance image set of a patient can be obtained, image position alignment and gray level adjustment processing can be carried out, and meanwhile a corresponding clinical image lesion segmentation model is constructed to carry out multi-scale fusion auxiliary segmentation. Generating a clinical focus region segmentation fusion image; obtaining a focus confidence probability corresponding to each pixel point in the segmentation image through the clinical focus region segmentation fusion image, and carrying out probability segmentation boundary correction on the clinical focus region segmentation fusion image to obtain a clinical focus region segmentation correction result image; and performing focus edge shape smoothing processing on the clinical focus region segmentation correction result map to generate a clinical focus edge shape segmentation optimization result. According to the invention, high-precision segmentation of the focus in the MRI image can be realized.

The invention belongs to the field of magnetic particle imaging, particularly relates to a magnetic particle high-resolution reconstruction method based on fast feature fusion, and aims to solve the problems that an existing magnetic particle reconstruction method is slow in system matrix calibration, low in reconstructed magnetic particle image resolution, limited in signal-to-noise ratio and the like. The method comprises the following steps: collecting a system matrix generated by using a standard particle sample as a low-resolution system matrix; acquiring a voltage signal of the to-be-imaged phantom; inputting the low-resolution system matrix into the trained fast feature fusion Transform model to obtain a high-resolution system matrix; and based on the voltage signal, reconstructing the high-resolution system matrix to obtain a high-resolution MPI image. According to the method, the resolution of the MPI image is improved by carrying out rapid super-division on the system matrix, tedious and time-consuming calibration in system matrix reconstruction is avoided, in addition, resolution and signal-to-noise ratio improvement can be carried out on any system matrix, and a scanning mode related to the system matrix is not needed.

The invention discloses a nuclear magnetic T2 spectrum correction method for a shale reservoir, and relates to the field of object detection, and the nuclear magnetic T2 spectrum correction method for the shale reservoir comprises the following steps: 1, determining the gas logging porosity, saturated water porosity and main mineral components of the shale reservoir; compared with the prior art, the method disclosed by the invention has the beneficial effects that a drying-saturated water-centrifugal two-dimensional nuclear magnetic resonance experiment is carried out, and signals of crystal water, clay bound water and hydroxyl in a sample are preliminarily identified; through inversion of organic matter signals in the dry sample, signals of movable water are further determined; the relation between the difference value among the gas logging porosity, the saturated water porosity and the nuclear magnetic porosity and different mineral contents is discussed, and particularly the remarkable influence of iron-containing minerals on the porosity difference value is discussed; by eliminating the influence of diffusion relaxation caused by the magnetic susceptibility difference, the T2 spectrum correction method based on the mineral magnetic susceptibility is established, and the T2 spectrum accuracy obtained through nuclear magnetic resonance measurement is improved.

The invention relates to a double-color magnetic nanoparticle imaging method based on a single-harmonic system matrix, which comprises the following steps: respectively moving two different types of magnetic nanoparticle samples to a central zero magnetic field point, applying a scanning magnetic field to enable the zero magnetic field point to scan the whole imaging field of view, applying an excitation magnetic field to magnetize magnetic nanoparticles, and applying an excitation magnetic field to magnetize the magnetic nanoparticles; acquiring magnetization frequency spectrum signals of the two magnetic nanoparticle samples; the method comprises the following steps: constructing single harmonic system matrixes A1 and A2 based on single harmonic of magnetization spectrum signals of two kinds of magnetic nanoparticle samples; measuring a to-be-measured object formed by the two kinds of magnetic nanoparticles to obtain a measurement magnetization signal U; transversely splicing the single harmonic system matrixes A1 and A2 of the two different types of magnetic nanoparticles to obtain a new single harmonic system matrix A; the concentration distributions c1 and c2 of two different types of magnetic nanoparticles are obtained by combining a new single-harmonic system matrix A with a measurement magnetization signal U, and the concentration distributions of the two different types of magnetic nanoparticles are respectively sent into different color channels to be displayed in different colors. The method has important significance in promoting the application of the magnetic nanoparticle imaging technology in clinical medicine.

The invention discloses a method for one-step electrifying extraction and separation of uranium elements from sandstone uranium ores, which comprises the following steps: adjusting the pH value of an activation environment to be less than or equal to 3 by using an activation leaching agent, and converting the uranium elements in the sandstone uranium ores into uranyl with positive charges and complexes thereof; and a direct-current electric field with the voltage gradient of 0.1-2 V / cm is applied between the cathode and the anode, so that the uranium element moves towards the cathode chamber under the action of the electric field and is selectively reduced on the cathode, and the uranium element is reduced into a low-valence insoluble uranium-containing substance through electrons to be precipitated on the surface of the cathode. According to the method, uranium ions only forming positive charges and complexes of the uranium ions are activated and leached, and the uranium element directionally moves towards the cathode under the electrophysical actions of electromigration, electroosmosis and the like, so that the extraction of the uranium element in the sandstone uranium ore is realized; and meanwhile, soluble uranium is reduced and fixed on the surface of the cathode conductive plastic electrode through electrochemical actions such as reduction generated by electrons on the surface of the cathode conductive plastic electrode, so that one-step separation and purification of the uranium element are realized.

The invention discloses an SERF atom magnetometer double-axis magnetic field detection method and device based on pulsed magnetic field modulation, relates to the technical field of magnetic field precision measurement, and compresses the action time of a modulation magnetic field additionally applied in the same unit period on a hot atom ensemble by replacing conventional continuous sinusoidal magnetic field modulation with pulsed magnetic field modulation. The pulse magnetic field with the duty ratio of d can reduce the spin exchange relaxation rate to 2d times of that of a conventional method under the same modulation amplitude and frequency, due to the fact that the spin exchange relaxation rate is effectively restrained, the collected polarizability response signal is obviously improved, and the polarizability response signal can be obtained through the pulse magnetic field with the duty ratio of d and the pulse magnetic field with the duty ratio of d. Low-relaxation-rate sensitivity-enhanced double-axis magnetic field measurement under a pulse modulation scheme is realized, the double-axis measurement sensitivity of a miniaturized SERF atom magnetometer is further improved, and the method has great significance in supporting leap-type development of a future array type extremely-weak magnetic imaging system and medical application thereof.

The invention discloses a BNCT dose calculation method, which comprises the following steps: S1, constructing a voxel model, initializing one or more particles in a simulation system, and respectively acquiring the initial position, energy and movement direction of each particle; s2, adaptively selecting a Monte Carlo particle tracking algorithm and a flux counting mode based on the region where the particles are located and the energy of the particles; s3, repeating the step S2 until the particles leave the simulation system or are killed when meeting a truncation condition; and S4, cumulatively calculating dose distribution. Through the BNCT dose calculation method, the Monte Carlo particle transport simulation time is greatly shortened, the BNCT dose calculation efficiency is optimized, and the method is suitable for rapid and high-precision radiation dose simulation under a BNCT complex tissue structure.

The invention relates to the technical field of Tokamak nuclear fusion, and discloses an assembling method of a pre-assembled assembly of a nuclear fusion device and an installing method of the nuclear fusion device. The pre-assembled assembly comprises a vacuum chamber, a window neck tube in the vacuum chamber, a vacuum chamber cold shield and a TF magnet; the assembling method of the nuclear fusion device preassembled assembly comprises the following steps: supporting between a cold shield inner sector and a vacuum chamber through a first tool; a first tool is supported between the cold shield outer sector and the vacuum chamber; the TF magnet is connected with the middle window position of the vacuum chamber through a second tool, the upper arc-shaped section of the outer fan section of the cold shield is connected with the hoisting tool of the TF magnet through a third tool, and the lower window section of the outer fan section of the cold shield is connected with the second tool; and the middle window section and the annular field magnet supporting seat are connected through a fourth tool. According to the assembling method of the nuclear fusion device pre-assembled assembly, interference among installation of the vacuum chamber, the window neck tube in the vacuum chamber, the vacuum chamber cold shield and the TF magnet can be avoided, and the stability and functionality of the pre-assembled assembly structure are guaranteed.

An example MR headset is provided. The example MR headset comprises (i) a set of imaging sensors and (ii) a set of floodlight-emitting diodes (flood LEDs), the sets of imaging sensors and flood LEDs disposed along a front-facing portion of the MR headset. The MR headset includes one or more processors configured to, while the MR headset is being caused to present MR content, and in accordance with a determination that imaging data obtained from the set of imaging sensors has an insufficient level of detail to identify hand gestures, cause illumination, using one or more flood LEDs of the set of flood LEDs, of a volume of physical space that includes the hand of the user.

The invention relates to a magnetic resonance imaging method and device and a storage medium, and the method comprises the steps: scanning a target region through employing a first magnetic resonance sequence, setting a plurality of echo times, and collecting a plurality of spin echo images; recording a plurality of echo times and corresponding dispersion sensitivity coefficients according to the first magnetic resonance sequence; scanning the target area by using the second magnetic resonance sequence to obtain an apparent dispersion coefficient; and according to the plurality of spin echo images, the plurality of echo times, the dispersion sensitivity coefficient and the apparent dispersion coefficient, fitting to obtain a transverse relaxation time constant quantitative image for correcting the dispersion influence. According to the method and the device, the problem of dispersion when a magnetic resonance transverse relaxation time constant quantitative image is obtained through a variable echo time spin echo method in the prior art is solved, and the beneficial effect of effectively improving the quantitative accuracy is achieved.

The invention belongs to the technical field of magnetic particle imaging, particularly relates to a magnetic particle imaging system and method based on a flexible receiving coil array, and aims to solve the problems that an existing rigid receiving coil is poor in biological surface adaptability and low in signal-to-noise ratio for micro geometric texture imaging. According to the structure, a receiving coil array adheres to the surface of an object to be measured, the receiving coil array and a compensation coil array are distributed on the two sides of a flexible substrate, the receiving coil array is used for receiving magnetic nanoparticle signals, and the partitioned small compensation coil array is used for conducting feed-through interference and electromagnetic interference compensation on a receiving coil; the reconstruction method comprises the following steps: sequentially carrying out Fourier transform on the collected receiving signals, extracting in-phase third harmonics and superposing to obtain processed signals, interpolating to construct a sinogram for Cartesian coordinate distribution, and reconstructing the three-dimensional particle concentration distribution of a measured object by a filtering back projection method. A flexible receiving coil array strategy is adopted, an adaptive reconstruction method is provided, and the imaging signal-to-noise ratio is improved.

The invention provides a space measurement and analysis method and system for a neutron diffraction rocking curve of a single crystal material, and the method comprises the steps: S1, building a laboratory coordinate system and a sample coordinate system, and setting a test point grid; s2, collecting a two-dimensional diffraction image of each test point to obtain angle information of the test point; s3, integrating the angle information of the test points based on the test point grid, and preprocessing the two-dimensional diffraction image; s4, extracting key structure parameters of each test point based on the preprocessed two-dimensional diffraction image; s5, constructing a stress field according to the key structure parameters; and S6, constructing a distribution map of crystal internal lattice parameters in a three-dimensional space according to the stress field. The method provided by the invention effectively improves the capability of identifying the non-uniformity and local distortion of the crystal structure, can be widely applied to the fields of residual stress evaluation, defect evolution monitoring, material quality control and the like, and has a remarkable engineering application value.

An electrically inactive betavoltaic battery, an electrically active betavoltaic battery, and methods of making the same are provided. In implementations, a method of making an electrically active betavoltaic battery includes: providing an electrically inactive betavoltaic battery device having one or more diodes incorporating a semiconductor material layer having a stable non-radioactive isotope; and irradiating the electrically inactive betavoltaic battery device with thermal neutrons, thereby causing the conversion of at least a portion of the stable non-radioactive isotope to a radionuclide and creating the electrically active betavoltaic battery, wherein the semiconductor material layer acts as both an electron emitter and an electron absorber simultaneously.

Disclosed herein is a medical system (100, 400) comprising: a magnetic resonance imaging system (102) configured for providing a respiratory signal. The respiratory signal is descriptive of a respiratory position as well as of inhalation and exhalation of the subject. The execution of machine executable instructions (140) causes the computational system to repeatedly: perform (200) the individual acquisition of k-space data using the magnetic resonance imaging system; receive (202) the respiratory signal; bin (204) the individually acquired k-space data into one of a predetermined number of k-space bins (148) using the respiratory signal and perform outlier rejection. Execution of the machine executable instructions further causes the computational system to reconstruct (208) a magnetic resonance image for each of the predetermined number of k-space bins to provide a respiratory-state resolved magnetic resonance image (150).

A positron emission tomography (PET) scanner includes a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of scintillator detectors. Each scintillator detector comprises a monolithic scintillation crystal and a plurality of photodetector arrays, such as silicon photomultipliers (SiPMs). A photodetector array is positioned on at least two nonparallel faces of each scintillation crystal. In some examples, a photodetector array is positioned on each of three orthogonal faces of each scintillation crystal.

The invention provides a simulation image generation method for simulating a scanning electron microscope and related equipment, and the method comprises the steps: constructing a first imaging feature mapping table and a second imaging feature mapping table based on the scanning electron microscope image data of a real wafer; respectively making a standard imaging script and a defect imaging script based on the two imaging feature mapping tables; obtaining a wafer three-dimensional model and analyzing associated process attribute information in each structural unit; determining a corresponding standard imaging script based on the process attribute information, and performing surface characteristic adjustment on the structural unit to generate a defect-free simulation model; determining a corresponding defect imaging script according to a preset defect introduction condition, and adding a defect on a specified structural unit to generate a simulation model with a defect; and finally, generating a simulation image for simulating the scanning electron microscope. High-simulation scanning electron microscope images are manufactured in batches through a virtual simulation means, and the diversity and coverage of a simulation image data set are improved.

The invention discloses an electromagnetic interference suppression method and system for ultra-low field magnetic resonance imaging, and belongs to the technical field of nuclear magnetic resonance, and the system comprises an electromagnetic interference signal collection module which is composed of a plurality of EMI coils and corresponding signal collectors and actively detects EMI signals from the environment; the electromagnetic interference suppression module is used for performing model training by using the data, performing electromagnetic interference suppression through a model, predicting and eliminating an EMI component based on the electromagnetic interference suppression model, and outputting k space data without EMI; and the image reconstruction module is used for receiving the EMI-free k-space data and carrying out averaging and image reconstruction on the data so as to generate a high-quality MRI image. According to the invention, EMI noise is effectively suppressed, image quality is improved, and mobile and portable development of MRI equipment is promoted.

The invention discloses a pulsed neutron generator control system based on LabVIEW, and the system comprises a neutron generator industrial personal computer which operates a virtual human-computer interaction interface developed based on LabVIEW; the console core board carries a DSP main control chip and is embedded into a real-time operating system; the driving sampling board is connected with the console core board and is integrated with a signal conditioning circuit; the neutron generator industrial personal computer communicates with the console core board through a Modbus protocol, and controls and drives the sampling board to output control signals of the three independent power supply ion sources, the storage and the acceleration pole to the neutron tube; wherein the console core board generates three paths of PWM signals with the PWM frequency of 2.5 kHz and the step length of 8191, and the three paths of PWM signals are converted into analog control signals through the driving sampling board. According to the control system, the PWM control precision is greatly improved, the voltage control precision is improved to 0.012% (100% higher than that of a conventional scheme) through the combination of the 8191 step length (13-bit resolution) and the 2.5 kHz frequency, and the neutron yield fluctuation is controlled within + / -1.5%.