5044 results about "Radiochemistry" patented technology

The present application relates to the field of nuclear reactor simulation. Disclosed are a fast simulation method and system for multi-physical field coupling and a storage medium. The method comprises: at intervals of a first preset interval time, collecting state information of each physical field of a nuclear reactor in a transient process, so as to obtain physical field snapshots of a plurality of physical fields, the transient process being simulated by a reactor simulation model corresponding to the nuclear reactor; stitching the physical field snapshots of the plurality of physical fields, so as to obtain a fully-concatenated physical field; constructing a matrix on the basis of the fully-concatenated physical field; performing order reduction processing on the matrix, so as to construct a timing model corresponding to the fully-concatenated physical field; and decomposing the timing model corresponding to the fully-concatenated physical field, so as to obtain timing models corresponding to the plurality of physical fields. The fast simulation method for multi-physical field coupling of the present application can reduce the inconsistency between different physical fields while increasing the computation speed.

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 safety monitoring of a nuclear reactor, and particularly discloses a multi-region pressure overrun leakage monitoring method for a reactor pressure vessel. The method comprises the steps of multi-region pressure data acquisition, real-time pressure field model construction, dynamic pressure field baseline modeling, pressure overrun anomaly detection, leakage source accurate positioning and evaluation based on spatial gradient analysis, topological structure mapping and multi-sensor data fusion, and graded early warning and response. By the adoption of the technical scheme, real-time and fine monitoring of pressure distribution in the reactor pressure vessel can be achieved, the rapid and accurate judgment and positioning capacity of leakage events is improved, the operation safety and reliability of nuclear power facilities are enhanced, and the reliability of the nuclear power facilities is improved. The defects of independent monitoring, local accurate positioning and complex working condition adaptability of multi-region pressure over-limit leakage in the prior art are overcome.

Main characteristic of the invention is the exploitation of the very large flux of high energy neutrons generated in a nuclear fusion tokamak with beam-driven plasma for the purpose of producing radioisotopes. It specifically relates to the deployment of precursor materials into the core of a nuclear fusion tokamak with beam-driven plasma for the purpose of exposing these materials to the neutron flux generated in the plasma by the process of nuclear fusion of Deuterium (D) and Tritium (T) to generate radioactive isotopes, so-called radioisotopes. The precursor materials contained in metallic capsules are incorporated into the blankets that surround the plasma.

The invention discloses an ion source automatic beam adjusting method, a radiotherapy system and related equipment, and relates to the technical field of radiotherapy, and the method comprises the steps: monitoring and adjusting a plurality of control parameters in real time, and obtaining an optimal control parameter combination; under the optimal control parameter combination, the variable quantity of each control parameter before and after adjustment and the performance change of the proton beam are obtained; performing a pulse width charge test according to the variation of each parameter before and after adjustment and the performance change of the proton beam; obtaining an optimal adjustment parameter and an adjustment amount through a pulse width charge test result; and through the optimal adjustment parameter and adjustment amount, automatic beam adjustment is realized, stable and efficient acceleration of the proton beam in the synchrocyclotron system is realized, and the stability and consistency of the proton beam are ensured.

In the case of forming a fine resist pattern, it is desired to further reduce the roughness of the resist pattern.SOLUTION: A substrate processing apparatus comprising: a heat treatment unit configured to bake a resist film; an exposure unit configured to irradiate the resist film having a portion irradiated with a first radioactive ray with a second radioactive ray; a development unit configured to form a resist pattern by development for removing a part of the resist film; and a control unit configured to control the exposure unit such that the second radioactive ray is collectively irradiated to an entire region of the resist film including the portion irradiated with the first radioactive ray and a portion other than the portion irradiated with the first radioactive ray. The first radiation is ionizing radiation or non-ionizing radiation, and the second radiation is non-ionizing radiation. When the first radiation is non-ionizing radiation, the second radiation is non-ionizing radiation having a wavelength longer than the wavelength of the first radiation. The resist film includes a metal oxide photoresist material.SELECTED DRAWING: Figure 1

The invention relates to the technical field of yield control, in particular to a neutron generator yield control method and system. The method comprises the following steps: establishing a polynomial model by using historical yield data to predict a target efficiency attenuation factor; dynamically determining neutron event boundaries in the pulse integral value and the pulse width two-dimensional characteristics based on the attenuation factor, and counting the neutron event boundaries; the yield deviation and the change rate are calculated, and when the deviation exceeds a threshold value, feedforward compensation is carried out on the target yield; and selecting a three-dimensional lookup table, an input deviation, a change rate and a current high voltage according to the interval to which the attenuation factor belongs, and cooperatively determining the adjustment amount of the ion source current and the accelerator high voltage. According to the scheme, the measurement and control problems caused by aging of the target piece can be solved, and the precision, the response speed and the long-term stability of yield control are improved.

The invention provides a neutron dose evaluation method and system based on mobile phone neutron activation product analysis, and the method comprises the steps: constructing an equivalent medium model for replacing a real mobile phone, and carrying out the neutron energy spectrum solving through the mobile phone activation product. The neutron energy spectrum can be reconstructed on site in daily scenes without professional equipment, such as villages, streets and shopping malls, so that the uncertainty of individual dose is reduced to a level equivalent to that of a laboratory spectrometer, the dependence on a multi-ball spectrometer, a TOF spectrometer and professionals is thoroughly eliminated, rapid and accurate measurement of the neutron energy spectrum and large-scale population dose evaluation are realized, and the accuracy of the neutron energy spectrum is improved. And a basis is provided for delimiting the influence range of the nuclear event, judging the event level of the nuclear event and formulating a hierarchical medical rescue scheme.

The utility model relates to a nuclear power high-radiation object containing device and containing and transferring equipment. The containing and transferring equipment comprises the nuclear power high-radiation object containing device. The nuclear power high-radioactivity storage device is specially designed for underwater operation, and can safely store and seal high-radioactivity waste under the condition that normal operation of a reactor is not affected. The sealing mechanism ensures that the radioactive substance storage space is completely sealed in the transferring and long-time storage process, radioactive substances are prevented from leaking, and the safety of the treatment process is greatly improved. And secondly, the torque input end allows torque to be input through an external tool to achieve rotation of the lock cylinder, so that the closing or opening action is rapidly and effectively completed, the operation process of containing and closing the radioactive substances is simplified, and the containing and closing efficiency of the radioactive wastes is improved.

The invention relates to the technical field of radiation monitoring, in particular to a radioactive foam height nuclear monitoring system and a use method. A radioactive foam height nuclear monitoring system comprises an ionization chamber detector; the collimation shielding module is provided with a containing space, the ionization chamber detector is contained in the containing space, the collimation shielding module is provided with a collimation hole, and particles generated by the self-radiation source can pass through the collimation hole. The invention provides a radioactive foam height nuclear monitoring system and a use method, and aims to solve the problem that a conventional radiation detector is difficult to bear an extremely high radiation environment and affects the detection precision.

The invention provides a tritium radiation volt isotope battery. The tritium radiation volt isotope battery comprises a shell and a stacking structure, the shell is provided with an accommodating cavity; the stacked structure is arranged in the containing cavity and comprises a positive pole piece, a semiconductor transduction layer and a negative pole piece which are arranged in a stacked mode, the semiconductor transduction layer is arranged to be an array formed by columnar nano particles, liquid tritides are distributed on the surfaces of the columnar nano particles, and the liquid tritides comprise all-tritiated N-ethyl carbazole and / or all-tritiated N-ethyl carbazole and / or all-tritiated N-ethyl carbazole and / or all-tritiated N-ethyl carbazole and / or all-tritiated N-ethyl carbazole and / or all-tritiated N-ethyl carbazole. And part of tritiated N-ethyl carbazole. The radiation volt isotope battery has improved energy conversion efficiency.

The invention discloses a gas target device for isotope production, and the gas target device comprises a seat body which is provided with a channel; the water-cooled jacket body is mounted on the seat body, and the water-cooled jacket body is provided with a water-cooled cavity for circulating a water-cooled medium; the target body is installed on the base body and comprises a target body, the target body is located in the water cooling cavity and is provided with a target cavity, and the target cavity, the channel and the accelerator beam leading-out port are sequentially arranged in the set direction. According to the gas target device for isotope production disclosed by the embodiment of the invention, the water-cooled jacket body is arranged for cooling the target body, so that the target body is prevented from being damaged due to overhigh temperature of the target gas, the target gas can receive beam irradiation with higher flow intensity, and the isotope yield is improved.

The invention provides a nuclear fuel grillwork clamping device and a vibration acceleration control method, and relates to the technical field of nuclear fuel grillwork clamping devices.The nuclear fuel grillwork clamping device comprises the steps that a plurality of clamping pieces are slidably installed in a nuclear reaction box body in the first direction and connected with the multiple clamping pieces at the same time through a transmission mechanism, and the clamping pieces are connected with the nuclear reaction box body through the structural characteristics of the transmission mechanism; and the plurality of clamping pieces are enabled to vibrate in two opposite directions of the first direction. Based on the structural design, the mode that the clamping pieces are installed in the nuclear reaction box body is changed into sliding connection from fixed connection, and the multiple clamping pieces are connected at the same time through the transmission mechanism. In the nuclear reaction process, the transmission effect of the transmission mechanism can be utilized to enable the plurality of nuclear fuel grillages to vibrate along opposite directions; therefore, the vibration amplitude of the nuclear fuel grillwork is reduced, and finally the purpose of reducing the failure rate of the nuclear fuel grillwork is achieved.

The invention discloses a particle accelerator multi-particle dynamics efficient simulation method, system and device and a medium. The method comprises the steps that a small number of macro particles are sampled from an initial macro particle beam to form a new macro particle beam; performing multi-particle beam flow dynamics simulation on the new macro particle beams by adopting a PIC algorithm, and projecting the new macro particle beams to four two-dimensional phase spaces in a distributed manner to generate low-resolution phase diagrams of the four two-dimensional phase spaces; obtaining beam physical parameters based on the new macro particle beam; and inputting the low-resolution phase diagram and the beam physical parameters into a beam halo super-resolution network, and outputting a high-resolution phase diagram of each phase space to realize multi-particle beam flow dynamics simulation. Therefore, by combining a traditional numerical calculation method and an artificial intelligence technology, the problem that an existing artificial intelligence algorithm is weak in generalization ability in the field of beam dynamics simulation is solved, rapid and high-precision simulation of the large-scale multi-particle beam flow dynamics process is achieved, and the method is applied to the field of particle accelerator beam dynamics simulation.

The invention discloses a dynamic calculation method and system for a radiation field in the cutting process of an activity non-uniform radioactive source, and belongs to the field of radiation field calculation. The method comprises the following steps: acquiring three-dimensional activity distribution data of a radioactive source; constructing a voxelization model and coupling the voxelization model with an activity grid to distribute activity; establishing an LBVH hierarchical structure of the shielding body; a point kernel is generated in a self-adaptive mode through ray tracing and average free path comparison; carrying out radiation field calculation by adopting point nuclear integration, and realizing multilayer ray tracing in the radioactive source, between the sources and a shield in the process; on-line cutting and moving operation of the voxel model is supported, and the radiation field is dynamically updated. According to the method, the cutting operation of the activity non-uniform radioactive source can be simulated, the problem that the radioactive activity of each cutting product cannot be represented after cutting by a traditional method is solved, the radiation field dynamic calculation in the activity non-uniform radioactive source cutting process can be simulated, initial modeling of the radiation environment only needs to be carried out once, and the efficiency is improved. And repeated modeling is not needed.

The invention relates to a waste liquid treatment device for automatically separating radionuclides. The waste liquid treatment device comprises a first waste liquid collection passage and a second waste liquid collection passage, an upstream liquid supply channel shared by the two channels comprises an injection pump and a multi-way valve, and the injection pump inputs liquid into the multi-way valve. The first waste liquid collecting channel directly guides cleaning liquid, replacement liquid and the like which do not need to be reserved into a waste liquid barrel through a first output port of the multi-way valve. The second waste liquid collecting channel is sequentially connected with a plurality of resin columns, a waste liquid tank, a peristaltic pump and a waste liquid barrel through a second output port of the multi-way valve, waste liquid generated by the resin columns firstly enters the waste liquid tank for temporary storage, and when the liquid level of the waste liquid tank reaches a preset threshold value, the peristaltic pump automatically pumps and discharges the waste liquid into the waste liquid barrel for centralized collection. The device can distinguish reserved liquid from waste liquid according to steps, realizes automatic flow division, temporary storage and discharge of the waste liquid, avoids manual pouring of the waste liquid halfway, ensures continuous operation of a long-time and multi-channel separation process, and reduces the risk of personnel exposure in a radioactive waste liquid treatment process.

The invention relates to the technical field of nuclear fusion, and discloses a flexible supporting device for a proliferation cladding in a nuclear fusion device. The nuclear fusion device comprises a proliferation cladding and a vacuum chamber. The flexible supporting device comprises a lower bottom plate, an adjusting plate and an upper cover plate. The elastic structure is assembled between the adjusting plate and the lower bottom plate and makes contact with the adjusting plate and the lower bottom plate. The guide rod is fixed to the lower bottom plate and penetrates through the adjusting plate and the upper cover plate, and the adjusting plate and the upper cover plate can move relative to the guide rod in the vertical direction; the driving structure is arranged between the adjusting plate and the upper cover plate and used for driving the upper cover plate to move in the vertical direction. By arranging the flexible supporting device, positioning, mounting and dismounting of the value-added cladding are facilitated, the value-added cladding can have certain flexibility, large thermal deformation generated by thermal expansion of the value-added cladding can be buffered, the risk that the value-added cladding and related parts (such as a vacuum chamber) are damaged can be reduced, and the service life of the value-added cladding can be prolonged. And the overall structure reliability of the nuclear fusion device can be improved.

Disclosed in the present invention are a scanning box device and an electron accelerator, the electron accelerator comprising an accelerating tube and a deflection coil; the scanning box device comprising a scanning chamber and a scanning box, wherein the scanning chamber is sealingly connected to the scanning box; the scanning chamber is arranged above the scanning box; the accelerating tube is arranged above the scanning chamber; the deflection coil is arranged on the outer side of the scanning chamber; and the scanning chamber is made of a non-metallic material. The present invention can prevent the generation of eddy currents in the scanning box, thus reducing the problems of energy loss and heat generation, improving the performance and stability of the apparatus.

The embodiment of the invention relates to the field of radioactive waste treatment, in particular to curing equipment. According to the curing equipment provided by the embodiment of the invention, the powdery materials are conveyed into the material containing device through the vacuum feeding device, and the material containing device is transferred to the lifting device through the clamping and transferring device, so that the material containing device is conveyed into the material processing device through the lifting device; the sealing device is used for sealing the material treatment device, so that the material reaction process is carried out in an environment with relatively good sealing performance; the pressurizing device is used for compacting the materials so as to obtain solid materials which are easier to transfer and process compared with powdery materials; the vacuum feeding device, the conveying and jacking device, the clamping and transferring device, the lifting device, the material treatment device and the pressurizing device are fixed to different positions of the body, enough space is provided for all treatment links of materials, the operation sequence of curing treatment is met, the process is simplified, and the treatment efficiency is improved.

The invention relates to the technical field of pipeline decontamination, in particular to an online pipeline ultrasonic decontamination device and method suitable for various pipe diameters, and the online pipeline ultrasonic decontamination device comprises a numerical control generator, a transducer, an amplitude-change pole, an adaptive clamp, an online monitoring device and other key components. And through the designed adaptive clamp, the device can act on pipelines with various pipe diameters and can move along the pipelines, and the decontamination requirements in different scenes are met. The online ultrasonic decontamination device is suitable for maintenance and cleaning work of pipelines with different pipe diameters in nuclear power facilities, and has important significance in improving the safety of the nuclear facilities and guaranteeing radiation protection for operators. The problem that an ultrasonic device is poor in applicability is effectively solved, meanwhile, the flexibility of the device is guaranteed, effective online decontamination of pipelines with various pipe diameters can be achieved through a single set of device, the decontamination cost of radioactive contamination of nuclear facility pipelines is effectively reduced, online efficient decontamination of radioactive contamination deposited in the pipelines is achieved, and the service life of the pipelines is prolonged. The safe and stable operation of the reactor is ensured, and the radiation risk of operators is reduced.

The invention provides a process method for improving the performance of a beta-Ga2O3 device through low-energy proton irradiation, and relates to the technical field of electronic components, and the method comprises the following steps: carrying out low-energy proton irradiation on the basis of irradiation experiment parameters at a preset environment temperature; low-energy proton irradiation with different fluence is carried out on the beta-Ga2O3 Schottky diode in a preset incidence mode to determine irradiation process data, and in combination with deep level transient spectroscopy (DLTS) analysis and device simulation, defect evolution and a hydrogen passivation mechanism caused in a beta-Ga2O3 epitaxial layer after low-energy proton incidence are revealed. According to the method, the cognitive limitation that traditional radiation must cause performance degradation of devices is broken through, and the field of low-energy proton irradiation which is not fully researched is focused.

The invention provides an anomaly diagnosis method for a nuclear power plant gamma energy spectrum continuous monitoring process, and the method comprises the following steps: S1, determining at least one target gamma characteristic peak which needs to be monitored under the current monitoring condition of a nuclear power plant, and calculating the anomaly of the target gamma characteristic peak based on the performance index of a gamma spectrometer and the expected energy of the target gamma characteristic peak; setting a parameter allowable range of each target gamma characteristic peak; the parameter permissible range at least comprises a peak center energy permissible range and a resolution permissible range; s2, acquiring a gamma energy spectrum output by the gamma spectrometer, and processing the energy spectrum to obtain actual measurement parameters of a target gamma characteristic peak; the measured parameters at least comprise a peak center energy measured value and a resolution measured value; s3, the actually measured parameters are compared with the corresponding parameter allowable ranges; and S4, if the actually measured parameter of any target gamma characteristic peak exceeds the corresponding parameter allowable range, determining that the state of the gamma spectrometer is abnormal. Automatic and real-time abnormity diagnosis of the monitoring state of the gamma spectrometer is realized.

The invention discloses a compact accelerator extremely-high vacuum system and an implementation method thereof. The compact accelerator extremely-high vacuum system comprises a dipole iron vacuum chamber, a BUMP iron vacuum chamber, a BPM cavity, a vacuum pump chamber and a quadrupole iron vacuum chamber which are sequentially connected to form a beam main line. A plurality of non-evaporable getter sheets are arranged in the dipole iron vacuum chamber and the quadrupole iron vacuum chamber in an array manner and are used for extracting active gas in a beam main line to obtain extremely high vacuum; a vacuum measuring gauge tube, a sputtering ion pump, a molecular pump and a gate valve are installed on the vacuum pump chamber, the vacuum measuring gauge tube is used for measuring the vacuum degree in the beam main line, the sputtering ion pump is used for extracting argon and methane in the beam main line and conducting baking, and the molecular pump is used for rough extraction of the beam main line and exhaust in the baking process; the gate valve is used for separating the molecular pump from the beam main line. According to the invention, hydrogen, carbon monoxide and other active gases in the system can be extracted under the condition that a titanium sublimation pump cannot be installed due to insufficient space, so that extremely high vacuum can be obtained.

The invention discloses a high-power and frequency-adjustable gyrotron loading test system for nuclear fusion, which relates to the technical field of nuclear fusion and comprises a 2-megawatt coaxial gyrotron with adjustable frequency of 170 / 240GHz and a loading test platform. The loading test platform comprises a gyrotron part loading system, a strong magnet system, a vacuumizing system, a power supply system, a load system, a cooling system, a monitoring and diagnosing system and a control system. The component loading system is used for precise assembly; the strong magnet system provides an adjustable strong magnetic field; the vacuumizing system maintains ultrahigh vacuum; the power supply system comprises a cathode power supply and a body power supply, and the body power supply is used as a high-voltage amplifier to realize 10kHz rapid power modulation; the cooling system provides independent active cooling; the load system simulates a real load; comprehensive detection of the monitoring and diagnosis system; and the control system realizes coordinated control and rapid protection. According to the invention, a complete solution is provided for development, test, operation and maintenance of the 2-megawatt-level and frequency-adjustable gyrotron.

The embodiment of the invention provides a particle source assembly and particle beam equipment, relates to the technical field of charged particle beam processing and detection equipment, and is used for improving the degree of freedom of beam state adjustment of charged particle beams. The particle source assembly comprises a particle source, an adjustable diaphragm and a collimating lens device which are arranged along a first direction. Wherein the particle source is used for generating a charged particle beam which is emitted towards the adjustable diaphragm along a first direction; the adjustable diaphragm is positioned in a transmission path of the charged particle beam, and the size of a diaphragm hole is adjustable, so that the beam size of the charged particle beam is adjusted; the collimating lens device is used for collimating the charged particle beam emitted from the adjustable diaphragm, and the position of the collimating main plane in the first direction is adjustable. The particle source assembly can be applied to particle beam equipment.

The invention discloses a rapid large-scale calculation simulation method and system for gamma radiation dose in a dynamic environment and a storage medium, and belongs to the technical field of ionizing radiation protection. The method comprises the following steps: firstly, constructing a triangular mesh scene model containing a radioactive source and a shielding body, and discretizing the radioactive source into a local point kernel; global coordinates of the point kernel and the vertex of the triangle are calculated in parallel by using a GPU, and a maximum parallelization hierarchical surrounding structure MPBVH of the scene is constructed; ray tracing is executed in parallel on the GPU, and all intersection points of MPBVH calculation rays and the shielding body are traversed to determine the thickness and the material of each shielding layer; and finally, dose values of all counting grids are calculated in parallel by adopting a point kernel method. When a radioactive source or a shielding body in a scene is subjected to dynamic changes such as movement and rotation, geometric data can be quickly updated, and calculation can be executed again. According to the method, the speed of large-scale point kernel calculation is increased, the influence of the environmental complexity on large-scale calculation time consumption is small, and the method can be suitable for rapid large-scale calculation and dynamic updating of the radiation field in the complex dynamic environment.

A Flash beam dose control method and a related device. The Flash beam dose control method comprises: obtaining a Flash beam output dose demand; controlling, by means of a Flash tuning mode, the number of pulse periods of output beam charges within a preset time; and / or controlling the pulse width of an ion source voltage by means of a pulse width mapping curve, so as to control a Flash beam output dose rate. By precisely controlling the number of pulse periods of output beam charges and the pulse width of the ion source voltage, the Flash beam output dose rate can be precisely controlled without requiring an additional shielding function for a proton therapy room, so that the dose of Flash can also be tuned in a conventional proton therapy room, thereby facilitating implementation of particle Flash radiotherapy.

The invention provides a radiation dose evaluation method and system based on radiation environment monitoring data, and relates to the technical field of radiation environment monitoring. The method comprises the following steps: recording the release source intensity of each nuclide at a release point, drawing an equally-spaced concentric arc grid, calculating the release height by combining the ground and the release point air pressure, air density and gravitational acceleration, and assigning nuclide hazard factors to the outer edge of the grid; according to the distance between the release point and the outer edge of the grid, diffusion parameters are calculated by using an empirical formula, a Gaussian atmospheric diffusion model is constructed in combination with the release height and hazard factors, and nuclide air activity concentration is output; comparing the total effective dose with a preset threshold value to calibrate a diffusion range, quantifying the radiation dose per unit area, and dividing atmospheric stability coefficient grades; constructing three types of correction factors of release height, material state and weather condition, establishing a comprehensive dose evaluation formula by combining the unit area radiation dose and the correction factors, comparing a preset threshold value, judging a risk level, and performing periodic updating.

To provide a radioactive waste discharge plan preparation support system capable of efficiently processing and managing radioactive waste.SOLUTION: A radioactive waste discharge planning support system includes a storage unit that stores information on an amount of radioactivity of radioactive waste and a measurement date of the amount of radioactivity, and a discharge planning unit that predicts a time when the amount of radioactivity becomes equal to or less than a specified value based on the information on the amount of radioactivity and the measurement date of the amount of radioactivity stored in the storage unit for the radioactive waste having the amount of radioactivity equal to or more than the specified value, and creates a discharge plan of the radioactive waste based on the predicted time.SELECTED DRAWING: Figure 1

A detector system for molecular imaging of a radionuclide comprises a 3D semiconductor detector comprising a plurality of sensor stacks of sensors made of a semiconductor material having an average atomic number Z below 40. A read-out circuitry connected to the pixels is configured to output, for each interaction induced by an incident gamma ray in the detector, a signal representative of a time, a position and an energy of the interaction in the detector. The interactions in the detector belonging to a same event induced by the incident gamma ray are predicted based on the output signals and used to estimate a direction of the incident gamma ray and reconstruct an image based on the estimated directions of incident gamma rays.