184 results about "Cyclotron" patented technology

The invention relates to the technical field of axial focusing enhancement of a cyclotron, and provides an axial focusing enhancement method and system for a medical cyclotron, and the method comprises the steps: collecting vibration data, a beam intensity value, temperature data, the positions of all particles in a particle beam, the average magnetic field intensity, the magnetic field intensity difference, and the current; the divergence angle and energy of the particle beam are measured; determining an axial focusing effect evaluation value at the current sampling moment; determining the particle beam stability at the current sampling moment, and determining the magnetic field uniformity at the current sampling moment by combining the average magnetic field intensity and the magnetic field intensity difference at the current sampling moment; and the axial focusing effect evaluation value, the average magnetic field intensity and the current at the current sampling moment are combined to realize the axial focusing enhancement of the medical cyclotron. According to the invention, the focusing precision of axial focusing enhancement of the medical cyclotron and the stability of the focusing effect can be improved.

The invention relates to a low-energy type cyclotron and a solid target device used for the low-energy type cyclotron, and the solid target device comprises a target material installation part which is used for installing a target material and comprises a first end and a second end which are oppositely arranged in the first direction; the first cooling piece is arranged at the first end of the target material mounting piece, a first cooling cavity is formed in the first cooling piece, and a gas cooling medium circulates in the first cooling cavity; and the second cooling piece is arranged at the second end of the target material mounting piece, a second cooling cavity is formed in the first cooling piece, and the second cooling cavity is used for circulating a liquid cooling medium. The cyclotron is simple in structure and low in refitting cost, can be additionally arranged on the basis of an original accelerator system, does not need to be reformed, and greatly reduces the use cost; by arranging the first cooling piece and the second cooling piece which are separated, air cooling and water cooling are physically isolated, no mixed loop exists, starting is conducted as needed through an independent control system, the cooling efficiency is greatly improved, and the cooling device is more suitable for the low-energy cyclotron.

A particle acceleration and extraction system includes a cyclotron having a stripping assembly and a target. The cyclotron includes an acceleration chamber and is operable to generate a magnetic field and an electric field in the acceleration chamber such that charged particles in the acceleration chamber are accelerated along a spiral path extending outward and at increasing energies from an initial energy E1 to a final energy E2, E2 being greater than E1. The target defines a target location outside of the acceleration chamber. The stripping assembly is positioned in the acceleration chamber and is operable to extract a charge from the charged particles at an intermediate location of the outward spiral path whereby the post-stripping assembly particles are directed towards the target location. The charged particles have an intermediate energy E3 at the intermediate location that is between E1 and E2.

The utility model discloses a kind of variable beam binding devices for cyclotron, install in beam pipeline, realize the size and shape of remote online hard constraint beam envelope by the variable adjustment of inner hole, involve variable beam binding technical field, including vacuum connection flange, fixed support, transmission gear, rotary disc, gear disc, blade combination, the blade combination, vacuum connection flange are connected with vacuum pipeline;Fixed support, the fixed support is set to vacuum connection flange side edge, and the fixed support is used to fix beam binding blade, motor, transmission gear, rotary disc;Gear disc is connected with the fixed support, and one side of the beam binding blade combination is connected;Rotary disc.The utility model can adjust multiple beam binding aperture, without disassembling when adjusting, save vacuum extraction and replacement time.Structure is simple, and cost is low, and implementability is high.Dismounting is reduced simultaneously, and the time of maximum degree operation personnel contact dose can be operated.

The invention provides a core column and magnetic pole structure of an endogenous cyclotron, the core column is symmetrically arranged in central areas at two sides of a central plane of the accelerator, the core column is a big-end-down circular truncated cone-shaped core column, a pair of core column concave platforms is arranged on the circular truncated cone, and the core column concave platforms are used for arranging ion sources; according to the magnetic pole structure, a main magnetic pole and a core column are integrally manufactured, and the core column in the middle of the integrated magnetic pole structure is of a big-end-down circular-truncated-cone-shaped structure; chamfers are arranged at the junctions of the two side faces and the upper surface of each magnetic pole of the integrated magnetic pole structure, and four slopes inclining towards the central point of the central area are designed in the head area of the fan-shaped magnetic pole, so that transition from a circular truncated cone in the central area to a peripheral magnetic field is smoother; on the basis that the radial size of the upper surface of the core column is not increased, the head magnetic field is still improved by increasing the volume, close to the lower surface, of the core column; the two symmetrical concave platforms are designed on the circular truncated cone type core column, so that the symmetry of a magnetic field is reserved, and meanwhile, a sufficient installation space is reserved for an ion source.

The invention relates to the technical field of magnetic field measuring devices, and discloses a cyclotron magnetic field measuring device which comprises a lower Dewar, a lower magnet, an upper Dewar, an upper magnet, and an adjusting and detecting part and a supporting and rotating part which penetrate through central holes of the lower Dewar, the lower magnet, the upper Dewar and the upper magnet. The probe adjusting part comprises an adjusting driving part, a screw rod driven by a bevel gear set and a sliding table in threaded connection with the screw rod; and the detection piece comprises two feeler levers which are symmetrically arranged on the sliding table and have different lengths, and the feeler levers are respectively connected with the first Hall probe and the second Hall probe. The supporting and rotating part comprises a supporting and driving piece connected with the lower motor and arranged below the bevel gear set; and the driving piece is connected with the motor and arranged above the bevel gear set and the driving piece, so that rotary adjustment is achieved, and contact with the magnet is avoided. The device further comprises a measuring frame, a linear guide rail, a measuring protection part and an auxiliary measuring part. Axial translation of the probe is realized through the driving and adjusting part, radial rotation is realized through the supporting and rotating part, and the magnetic field intensity of different areas between the upper magnet and the lower magnet can be comprehensively and accurately measured in combination with the probe rods with different lengths.

The present invention relates to a cyclotron comprising first and second internal ion sources configured to form first and second beams of identical charged particles wherein the cyclotron is further configured to generate a local asymmetry of an accelerating electric and / or magnetic field, the first beam and the second beam are combined to form a combined beam and the combined beam passes through a single extraction outlet. The invention also relates to an acceleration system comprising N cyclotrons, where M cyclotrons are the cyclotrons according to the invention, Mgt; 0. The invention also relates to a device for treating a patient by BNCT, comprising: an acceleration system according to the invention; a target configured to emit an epithermal neutron beam when bombarded with the proton or deuteron multi-combination beam; and a treatment region configured to hold a patient to be treated within the treatment region.

The present disclosure relates to a cyclotron, a radiation therapy apparatus, an adjustment unit, an adjustment device of a superconducting coil, and an adjustment method thereof. The adjustment unit includes a rotating shaft, a drive assembly, a transmission assembly, and a detection element. The rotating shaft is capable of rotating driven by an external drive unit; the drive assembly includes an actuator and a tension assembly, the actuator being configured to drive the tension assembly to move linearly through rotation, and one end of the tension assembly being connected to a superconducting coil and capable of driving the superconducting coil to move; the transmission assembly is connected to the rotating shaft and the actuator, respectively, and configured to transmit power to the actuator; and the detection element is connected to the actuator and configured to monitor a displacement of the tension assembly and a displacement of the superconducting coil.

The invention provides a cyclotron electrostatic deflection plate beam loss heat source reconstruction method, and relates to the technical field of particle accelerator thermal analysis and multi-physics field coupling calculation, and the method comprises the steps: 1, configuring beam dynamics simulation parameters, multi-particle tracking is carried out under a three-dimensional field graph containing a central area electromagnetic field, a harmonic coil magnetic field and an electrostatic deflection electric field, and a particle loss list is generated; step 2, transferring the particle loss list into a beam source file of a Monte Carlo radiation transport program, configuring Monte Carlo parameters including a deflection plate material, a boundary, a particle type and an energy spectrum, executing particle transport simulation, and obtaining a three-dimensional energy deposition matrix on an electrostatic deflection plate element; according to the method, high-resolution heat source reconstruction is realized, the peak temperature rise calculation error of the deflection plate can be reduced, a temperature field solving result can be fed back to optimize the particle source, and a reliable basis is provided for thermal structure design and cooling optimization of the electrostatic deflection plate.

1. The name of the design product: ring magnetic support. 2. The use of the design product: the design product is used for supporting electronic equipment. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: design 1 perspective view 1. 5. Design 1 is designated as the basic design.

The invention discloses a particle beam leading-out device, a stripping film adjusting method and a cyclotron, and relates to the field of cyclotrons, the particle beam leading-out device comprises a driving motor, a magnetic fluid sealing device, a flange and a right-angle transmission mechanism which are connected in sequence; the driving motor is fixed at the front end of the flange through a motor mounting bracket; the input end of the magnetic fluid sealing device is connected with an output shaft of the driving motor, and the output end of the magnetic fluid sealing device penetrates through the flange and the support to be connected to the right-angle transmission mechanism. The right-angle transmission mechanism is connected to the driving motor and the two film stripping structures, so that the two film stripping structures can be subjected to angle adjustment or position switching, and the right-angle transmission mechanism is composed of the base, the first main shaft and the second main shaft and realizes movement direction switching through a structural mode of a hinge and a connecting rod; vibration and noise generated by gear meshing can be effectively avoided, abrasion loss is greatly reduced through the structure, and therefore the maintenance frequency of equipment is greatly reduced.

This application relates to an ion cyclotron antenna device, including a controller; a detection component electrically connected to the controller, the detection component being used to detect the direction of the magnetic field in real time; a rotating device electrically connected to the controller; and an ion cyclotron antenna connected to the rotating device. When the direction of the magnetic field changes, causing the magnetic field direction to no longer be perpendicular to the ion cyclotron antenna, the detection component immediately feeds back a signal to the controller. The controller compares the relative positional relationship between the antenna and the magnetic field, and then outputs a command to the rotating device, enabling the rotating device to drive the ion cyclotron antenna to rotate and adjust, so that the ion cyclotron antenna is once again perpendicular to the direction of the magnetic field. Through the coordinated work of the detection component, the rotating device, and the controller, the relative perpendicularity between the ion cyclotron antenna and the direction of the magnetic field can always be guaranteed, thereby effectively suppressing the generation of parallel electric fields, reducing the generation of sheath potential, reducing the impact of high-energy particles on the antenna, and extending the steady-state operation time of the antenna and the nuclear fusion device.

The invention discloses a first and third harmonic shared cavity type impedance matching mechanism for a high-frequency buncher, which is characterized in that the first and third harmonic shared cavity type impedance matching mechanism is connected with a bunching electrode to jointly form the first and third harmonic shared buncher; the shared buncher is arranged between an external ion source of the cyclotron and the cyclotron; the cavity type impedance matching mechanism shared by the first harmonic and the third harmonic comprises a cavity type matching circuit shared by the first harmonic and the third harmonic and a coupler shared by the first harmonic and the third harmonic. According to the invention, the groove which is folded for multiple times is innovatively processed in the lower cavity of the cavity, so that the integrated structure of the lower cavity and the outer conductor is ingeniously realized, and the risk of folding cracking is fundamentally eliminated. Through the first harmonic and third harmonic shared cavity design, the function of originally needing two independent bunchers is integrated into one shared cavity, the system cost is effectively reduced, meanwhile, the occupied space is remarkably reduced, and the requirement of a compact accelerator is perfectly met.

The present application relates to the technical field of accelerator beam measurement, and particularly discloses a water gravity type inner target beam measurement device, which comprises a beam measurement assembly, a gravity adjustable cooling assembly, a lever balance assembly and a limiting piece, the beam measurement assembly is connected to one end of the lever balance assembly through the gravity adjustable cooling assembly, and the limiting piece is arranged on the side surface of the lever balance assembly. The device adopts a seesaw type structure, fully utilizes the installation space in the cyclotron shell, utilizes the gravity of the cooling liquid as the power of the seesaw type structure, can omit the arrangement of a complex power driving piece, is small in size, simple in structure, low in cost, good in cooling effect, and stable in the beam size of the inner target measurement piece during measurement.

The invention relates to a cyclotron which enables the production of α- or β-emitting radionuclides. The cyclotron, with a magnetic periodicity of 3, comprises three accelerating cavities connected to the centre, thus not requiring phase control between the cavities, forming a single high-frequency resonator. The six accelerating gaps per turn enable rapid acceleration (the angle ϕ between the accelerating gaps of each cavity being approximately 30°) which is essential for acceleration at the third and sixth harmonics. This cyclotron preferably has an injection system (31) supplied by different types of ion sources, making it possible to efficiently accelerate charged particles having Z / A ratios equal to 1 / 2 and to 1 / 4. The cyclotron may also have stripping extraction means positioned in the cyclotron so as to extract the charged particles and double their state of charge. These particles enable a set of nuclear reactions for producing α-emitting radionuclides.

The invention provides controllable nitrogen-hydrogen nuclear fusion equipment. The controllable nitrogen-hydrogen nuclear fusion equipment comprises a hydrogen nuclear particle generation device, a nitrogen nuclear generation device, a convolution migration particle accelerator and a focusing reaction field, the hydrogen nuclear particle generation device is provided with a hydrogen nuclear particle outlet, and the hydrogen nuclear particle outlet conveys hydrogen nuclear particles into the rotary migration particle accelerator; the rotary migration particle accelerator comprises a straight line section and an arc section, the hydrogen nuclear particles sequentially penetrate through the straight line section and the arc section to increase the speed, and the hydrogen nuclear particles with the increased speed are conveyed to the focusing reaction field; the nitrogen nuclear particle outlet conveys low-speed nitrogen nuclear particles into the focusing reaction field; the hydrogen nuclear particle beam with the increased speed and the low-speed nitrogen nuclear particle beam are converged towards the center of the focusing reaction field to generate nuclear reaction. According to the cyclotron migration particle accelerator, through the synergistic effect of the linear section and the arc section, hydrogen nucleus particles are accelerated through an electric field, meanwhile, the particles are deflected in the arc section, and repeated acceleration is achieved.

The present application relates to the technical field of cyclotron, and discloses a cyclotron ion source replacement device and a replacement method. The device is separated from the upper part of the cyclotron, and a lifting channel is constructed through the cavity of the lower central shaft, a sealing flange and a plug valve. A lifting member is arranged in the vacuum tube to transfer the ion source to a second vacuum chamber. The replacement is completed by opening the window after the gas valve releases the vacuum. After the gas is closed and vacuumed to the same vacuum degree as the main cavity, the plug valve is opened and the lifting member is reversely driven to push the ion source back to the working position, so that the ion source is quickly and reliably replaced under controlled vacuum conditions.

The invention relates to a radio frequency resonant cavity based on a short-circuit sliding block. The radio frequency resonant cavity comprises an input coaxial transmission line; the connector is connected with the input coaxial transmission line; the first output coaxial transmission line and the second output coaxial transmission line are connected with the connector. The first shifting mechanism is arranged on the first output coaxial transmission line, and the second shifting mechanism is arranged on the second output coaxial transmission line; each of the first output coaxial transmission line and the second output coaxial transmission line comprises an inner conductor, a short-circuit sliding block and an outer conductor, the outer conductor coaxially sleeves the inner conductor, a coaxial cavity is formed between the outer conductor and the inner conductor in a matching manner, and the short-circuit sliding block is connected with the first displacement mechanism and the second displacement mechanism; the short-circuit sliding block is movably arranged in the coaxial cavity. According to the ion cyclotron wave power transmission system, the effect of obtaining large voltage by means of small power is achieved, possible sparking points can be detected under the working condition of large voltage, then measures are taken in advance to prevent the sparking phenomenon, and stable operation of the ion cyclotron wave power transmission system is guaranteed.

The invention provides a calculation compensation method for an isochronous magnetic field of a cyclotron, and relates to the technical field of data processing, and the method comprises the steps: carrying out the particle tracking through a numerical integration method, and adjusting the initial parameters of particles through iterative search, when the deviation between the position and the momentum of the particle after the particle moves for one circle and the initial value is within a preset error range, obtaining a closed orbit of the charged particle; on the basis of a closed orbit, radial and axial tiny disturbance is applied to the initial state of the particles, multi-circle movement of the particles is tracked, oscillation data is recorded, fast Fourier transform analysis is conducted on the oscillation data, and radial oscillation frequency and axial oscillation frequency of the particles are extracted; and calculating the cyclotron frequency of the particles according to the closed orbit, and generating parameters for evaluating and compensating the isochronous magnetic field of the cyclotron in combination with the radial oscillation frequency and the axial oscillation frequency. The operation stability and the particle acceleration efficiency of the accelerator can be effectively improved.

The application relates to the technical field of plasma, in particular to a medical cyclotron beam centering adjustment method and system. The method comprises the following steps: acquiring a magnetic field sequence, a beam sequence and a current sequence; obtaining a beam fluctuation factor according to the difference in lag number corresponding to the maximum autocorrelation coefficient of the magnetic field sequence and the beam sequence, the correlation of the magnetic field sequence and the beam sequence, and the difference in the maximum autocorrelation coefficient; forming a beam fluctuation sequence by using the beam fluctuation factor; dividing the beam fluctuation sequence, and also dividing the current sequence; fitting a straight line based on the current fluctuation sequence and the current sequence; obtaining the current influence intensity at the current moment according to the difference between the excitation current in all sub-sequences and the overall excitation current of the current sequence and the mean square error; improving the proportional term according to the current influence intensity, controlling the excitation current based on the proportional term, and adjusting the proportional term in real time to optimize the magnetic field control effect. The application realizes higher and more stable nuclide production efficiency.

A process for producing technetium-99m from a molybdenum-100 metal powder, comprising the steps of:(i) irradiating in a substantially oxygen-free environment, a hardened sintered target plate coated with a Mo-100 metal, with protons produced by a cyclotron;(ii) dissolving molybdenum ions and technetium ions from the irradiated target plate with an H2O2 solution to form an oxide solution;(iv) raising the pH of the oxide solution to about 14;(v) flowing the pH-adjusted oxide solution through a resin column to immobilize K[TcO4] ions thereon and to elute K2[MoO4] ions therefrom;(vi) eluting the bound K[TcO4] ions from the resin column;(vii) flowing the eluted K[TcO4] ions through an alumina column to immobilize K[TcO4] ions thereon;(viii) washing the immobilized K[TcO4] ions with water;(ix) eluting the immobilized K[TcO4] ions with a saline solution; and(x) recovering the eluted Na[TcO4] ions.

The present invention relates to the field of particle accelerators, and discloses a cyclotron cavity acceleration voltage measurement system and measurement method. The system includes: a radio frequency front-end module, which completes the filtering and attenuation of the AD module input signal and the filtering and amplification of the DA module output signal; an AD module, which completes the digitization of the input signal after the radio frequency front-end processing; a DA module, which completes the simulation of the output signal after the feedback processing; a signal processing module, which completes the control of the AD module and the DA module, amplitude and phase detection, tuning motor control and cavity voltage measurement, and completes data interaction with the display and control unit through Ethernet; a display and control unit. The present invention can measure the cavity voltage online by designing a cyclotron cavity voltage measurement system. Q The value is calculated, the high-frequency cavity parallel shunt impedance is calculated, and the current cavity voltage value is calculated by measuring the power consumption inside the cavity.

The invention provides a composite target material for producing astatine-211 through a cyclotron and an active cooling system of the composite target material, and relates to the technical field of radionuclide preparation. The composite target material comprises a working part and a connecting part which are integrally formed, the upper surface of the working part is provided with an inclined surface or a concave curved surface used for depositing a bismuth layer, and a plurality of liquid cooling runners communicated with one another are integrated in the connecting part; the active cooling system further comprises a supporting cooling base detachably connected with the composite target material, and the supporting cooling base and the composite target material jointly form a closed circulating cooling loop. The thermal load distribution can be optimized by changing the geometric configuration of the working surface, and the integrated liquid cooling and modular assembly and disassembly design is combined, so that efficient heat dissipation is realized, and meanwhile, rapid replacement of the target material is supported. According to the system, the anti-meltdown capability and the operation stability of the target material are remarkably improved, and the system is suitable for large-scale high-yield preparation of astatine-211.

This application discloses an ion source position adjustment mechanism and method thereof. The ion source position adjustment mechanism includes an installation component and an adjustment component. The installation component is disposed in the magnet valley region of a cyclotron and is used to install the ion source. The adjustment component is arranged radially along the cyclotron, with one end connected to the installation component and the other end extending through the vacuum cavity wall of the cyclotron to the outside of the vacuum cavity. The adjustment component can drive the installation component to move along a first direction and a second direction to adjust the position of the ion source, wherein the first direction and the second direction are perpendicular. This application can ensure that the ion source position adjustment accuracy meets the usage requirements while allowing the ion source position adjustment operation to be completed without personnel entering the accelerator, ensuring the personal safety of personnel and improving debugging efficiency.

The invention relates to the technical field of inductive coupling devices, and discloses an inductive coupling device for a cyclotron, and the inductive coupling device comprises an inner conductor and an outer conductor, the outer conductor sleeves the inner conductor, and a power feed-in end is formed at one end of the inner conductor; the coupling structure is connected with the inner conductor and the outer conductor; the separation structure sleeves the inner conductor and is connected between the inner conductor and the outer conductor; a shielding structure is formed on the end portion, deviating from the power feed-in end, of the inner conductor, and at least part of the separation structure is opposite to the shielding structure. Therefore, by arranging the shielding structure, the shielding structure can block electrons emitted by the high-voltage electrode of the cyclotron and reduce the risk that the electrons impact the separation structure, so that the risk that metallized coating is generated on the surface of the separation structure is reduced, the insulation performance of the separation structure is kept, and power feed-in of the cyclotron is kept; and the cracking risk of the separation structure due to overheating is reduced, so that the service life of the separation structure is prolonged.

This invention discloses a method for protecting beam measurement signals in a cyclotron accelerator, comprising: suppression of coupled high-frequency signals in the accelerator under normal conditions: measuring and adjusting the parameters of the first set of series resonant circuits S21 using a network analyzer, so that the frequency corresponding to the lowest point of S21 is equal to the accelerator's high-frequency frequency f0, and satisfying S21 < -30dB; calibration of the capacitor rotation angle scale range before abnormal condition monitoring; transmission line oscillation monitoring under abnormal conditions: setting the speeds of the first set of motors and the second set of motors, so that the first set of motors and the second set of motors drive the capacitor to move within the calibrated rotation angle scale range; transmission line oscillation control under abnormal conditions: when the signal interlocking device detects a high level input, the interlocking signal prohibits the output of the high-frequency system signal source and the operation of the power source, and the accelerator high-frequency system stops operating; this invention solves the problems of the beam measurement device being greatly interfered with by the accelerator's high-frequency signals and being greatly interfered with by unexpected transmission line oscillations.

The present application relates to the technical field of cyclotron voltage control, and specifically to a method and device for controlling the accelerating voltage of a medical cyclotron. The method comprises: dividing the alternating voltage signal into three stages according to the sudden change of the alternating voltage signal within a conversion cycle; analyzing the periodic fluctuations of the high-level stage and the low-level stage, the rate of change of the transition edge stage, and the degree of disorder of the change, to obtain the control intervention degree of the conversion cycle; obtaining an adjustment coefficient according to the stage to which the voltage amplitude at the same moment in the alternating voltage signal at the current moment in the previous conversion cycle belongs; and obtaining a control proportional coefficient at the current moment by combining the change in magnetic field intensity at the current moment, the adjustment coefficient, and the control intervention degree of the previous conversion cycle at the current moment, and performing feedback control on the alternating voltage signal. The present application can improve the control accuracy of the accelerating voltage of a medical cyclotron.

The application relates to the technical field of inductive coupling devices, and discloses an inductive coupling device for a cyclotron, which comprises an inner conductor and an outer conductor, the outer conductor is sleeved on the inner conductor, one end of the inner conductor is provided with a power feeding end, a coupling structure is connected with the inner conductor and the outer conductor, a separation structure is sleeved on the inner conductor and connected between the inner conductor and the outer conductor, and the end of the inner conductor, which is away from the power feeding end, is provided with a shielding structure, and at least part of the separation structure is opposite to the shielding structure. Thus, by arranging the shielding structure, the shielding structure can block the electrons emitted by the high-voltage electrode of the cyclotron, the risk of the electrons hitting the separation structure is reduced, the risk of the surface of the separation structure being plated with a metal film is reduced, the insulation performance of the separation structure is beneficially maintained, the power feeding of the cyclotron is beneficially maintained, the risk of the separation structure being broken due to overheating is reduced, and the service life of the separation structure is beneficially prolonged.

A method of manufacturing a cyclotron (10) for producing a beam (18) of accelerated particles comprises the following steps: A cyclotron set-up is defined, the cyclotron set-up including a number of sectors (12) having an RF cavity (14, 16) of the cyclotron (10), an arrangement of the sectors (12) relative to each other and a cavity type for each of the sectors (12) selected from the group comprising acceleration cavities and flattop cavities. Then, a beam path in the cyclotron (10) is determined for a default operation mode and at least one beam path in the cyclotron (10) is determined for a cavity failure mode in which the radio-frequency cavity (14, 16) of one or more of the sectors (12) is not operational. A position of an extraction device (20) of the cyclotron (10) within the sectors (12) is calculated based on the determined beam paths, and the extraction device (20) is placed at the calculated position. Further, a cyclotron (10) and a method for operating a cyclotron (10) is described.