A beam current detection probe

Abstract

The present application relates to a kind of beam detection probe, comprising: probe shell;Electric field cage is arranged in the probe shell, and is used to make the gas molecule in the working environment of the beam detection probe produce charge;And charge collection device is arranged in the probe shell, for collecting the charge, and the charge collection device includes semiconductor pixel chip for measuring the charge amount data of the charge and outputting in it.The present application can provide a kind of probe for the real-time, accurate monitoring of beam position and profile.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of beam detection, and particularly relates to a beam detection probe applied to an accelerator. BACKGROUND

[0002] High-energy ion beams are important means for studying nuclear physics, particle physics, atomic and molecular physics, plasma physics, material science and biological science, and also play a fundamental and key role in the application fields of single-ion effects of electronic devices and tumor radiotherapy. The HIRFL-CSR (Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring) can provide various ion beams from protons to uranium elements with an energy of several hundred MeV / u, and has created fruitful results in various fields.

[0003] With the upgrading of accelerator structure and performance, the monitoring of parameters such as beam position and profile of the accelerator operation requires higher real-time performance and accuracy, and real-time and accurate monitoring of the beam state also provides necessary data for researchers to improve experimental accuracy and better understand the mechanism of beam and matter interaction. However, the present inventors found in research that the beam detection performance of the traditional probe needs to be improved. SUMMARY

[0004] In view of the above problems, the present application aims to provide a beam detection probe which can combine a time projection chamber with a semiconductor pixel chip for real-time and accurate monitoring of particle beam position and profile.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The present application provides a beam detection probe, comprising:

[0007] a probe shell;

[0008] an electric field cage arranged in the probe shell and used for generating electric charges of gas molecules in a working environment of the beam detection probe;

[0009] a charge collection device arranged in the probe shell and used for collecting the electric charges, and the charge collection device comprises a semiconductor pixel chip used for measuring charge data of the electric charges and outputting.

[0010] In an implementation manner of the present application, the probe shell comprises an incident window used for receiving a particle beam to be detected, and an exit window opposite to the incident window.

[0011] In an implementation form of the application, the electric field cage is configured to cause the particles to be detected to collide with gas molecules in the working environment of the beam detector to generate electric charges, and to generate a set electric field to form a drift region for the electric charges to drift.

[0012] In an implementation form of the application, the charge collection device comprises:

[0013] a gate electrode configured to generate a control electric field for controlling the drift velocity of the electric charges;

[0014] a mask having openings corresponding to the plurality of semiconductor chip positions;

[0015] a chip bonding plate on which the plurality of semiconductor chips are arranged to form a chip array.

[0016] In an implementation form of the application, the set electric field is a uniform electric field, and the control electric field is parallel to the set electric field.

[0017] In an implementation form of the application, the gate electrode, the mask and the chip bonding plate have parallel main planes, and the mask is arranged between the gate electrode and the chip bonding plate.

[0018] In an implementation form of the application, the gate electrode comprises a wire grid and a support structure for the wire grid.

[0019] In an implementation form of the application, the wire grid comprises at least two layers of parallel wires.

[0020] The wires in each layer of the parallel wires are parallel to the plane of the entrance window in a radial direction.

[0021] The main plane of each layer of the parallel wires is perpendicular to the plane of the entrance window.

[0022] In an implementation form of the application, the potential of each layer of the at least two layers of parallel wires is applied according to a detector working mode of the beam detector.

[0023] In an implementation form of the application, the detector working mode comprises a periodic sampling mode, a single sampling mode and a continuous sampling mode.

[0024] The present application has the following advantages: in the present application, the beam detector comprises a detector shell, an electric field cage and a charge collection device. The beam to be detected is received in the electric field cage in the detector shell, so that the beam collides with gas molecules in the working environment to generate charges, and the charges drift in the drift region in the electric field cage. The semiconductor pixel chip in the charge collection device accurately collects the charge amount at different positions and outputs the same, so as to accurately monitor the real-time detection of the beam position and profile. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a schematic diagram of the overall structure of a beam detection probe provided by the present application;

[0026] Figure 2 FIG. 3 is an exploded view of the charge collection device in the present application;

[0027] Figure 3 FIG. 6 is a schematic diagram of the potential of the gate electrode wire grid changing with time in the present application. DETAILED DESCRIPTION

[0028] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0029] In view of the demand for improving the real-time performance and accuracy of the detection of the particle beam position and profile, the present application provides a beam detection probe, which comprises: a detector shell; an electric field cage arranged in the detector shell and used for generating charges of gas molecules in the working environment of the beam detection probe; and a charge collection device arranged in the detector shell and used for collecting the charges, and the charge collection device comprises a semiconductor pixel chip used for measuring the charge amount data of the charges and outputting the same. In the present application, the detector shell, the electric field cage and the charge collection device form a time projection chamber (TPC) architecture, and the charge collection device comprises the semiconductor pixel chip, so that the charge amount at different positions can be accurately and rapidly detected in real time, and the data can be outputted for accurately detecting the beam and profile.

[0030] Reference Figure 1 In one embodiment of the present application, a structure diagram of a beam detection probe is provided.

[0031] Specifically, in the embodiments of the present application, the beam detection probe includes a probe shell 1, an electric field cage 2, and a charge collection device 3.

[0032] The probe shell 1 is used to provide a uniform and controllable probe working environment, which can be a gas environment at normal temperature and pressure or close to normal temperature and pressure, such as air, Ar-CO2 mixed gas, Ar-CH4 mixed gas, etc., determined according to particle experiments or beam detection requirements. In order to provide a uniform and controllable gas working environment, the probe shell can have a support structure made of metal material and have necessary gas inflow and outflow interfaces to meet the air tightness conditions for probe operation.

[0033] The probe shell 1 is provided with parallel beam incidence windows 11 and beam emission windows. The particle beam to be detected enters the probe from the outside of the probe through the incidence window 11 and reenters the outside of the probe from the emission window. In the embodiments of the present application, the incidence window and the emission window are relative, and the naming can be exchanged, that is, the direction of the beam relative to the probe can be reversed. The emission window and the incidence window are made of insulating materials with double-sided metal film, and the entire probe shell is at the same potential in the working environment of the probe.

[0034] The electric field cage 2 is used to make the beam to be detected collide with the probe working gas molecules to generate charges. The electric field cage 2 is also used to generate a set electric field to form a drift region for the directional drift of charges.

[0035] For example, the electric field cage 2 can be composed of a top electrode, an electrode ring parallel and coaxial to the top electrode, and a bottom electrode, and a uniform electric field is formed in the cage by a suitable power supply mode. The top electrode can be a metal plane or a metal mesh plane covering all or most of the cross section parallel to itself; the electrode ring is composed of metal wires or flat metal strips, or a mixed structure of the two, and further, necessary insulating support structures can be added to the electrode ring and connected to the top electrode and the bottom electrode in a suitable manner.

[0036] During the operation of the probe, the potential setting mode of the top electrode, the electrode ring, and the bottom electrode can have multiple implementation modes. For example, each electrode ring can be at the same potential; or adjacent electrodes are connected through a resistor, and the resistance value of the resistor is proportional to the spacing of the adjacent electrodes; or the potential difference between adjacent electrodes is proportional to their spacing during the operation of the probe. The electrode ring of the electric field cage can also be replaced by a resistive film structure, and further, all equivalent structures that can generate a uniform electric field in the cage are within the scope of the present application.

[0037] Please refer to Figure 2The charge collecting device 3 mainly comprises three parts, i.e., a gate electrode 31, a mask 32, and a chip binding plate 33, and the main planes of the three parts are parallel to each other. The gate electrode 31 is used for generating a control electric field for controlling the charge drift rate. The mask 32 has openings corresponding to the positions of the plurality of semiconductor pixel chips 331. The chip binding plate 33 is provided with the plurality of semiconductor pixel chips 331 to form a chip array.

[0038] For the semiconductor pixel chip, the mask has the function of shielding the gate electrode pulse, and the mask and the gate electrode both have the function of shielding the drift region electric field change. In order to ensure a good shielding effect, more shielding grids and auxiliary structures can be arranged on both sides of the gate electrode.

[0039] In the embodiment of the present application, the set electric field of the drift region and the control electric field of the gate electrode are parallel to each other, and the electric field strengths of the two regions can be different according to the measurement requirements.

[0040] The gate electrode comprises a metal wire grid and necessary support structures. The metal wire grid is at least two layers of parallel metal wires, the radial direction of the metal wires in each layer of the parallel metal wires is parallel to the plane of the incident window, and the main plane of each layer of the parallel metal wires is perpendicular to the plane of the incident window.

[0041] As Figure 3 is a schematic diagram of the time-varying potential applied to the two layers of metal wire grids.

[0042] Specifically, in the working process of the detector, the time-varying potential of the two layers of grids is a periodic square pulse, and the bias of the two square pulses is V and the amplitude is ΔV, and the polarities are opposite.

[0043] Alternatively, according to the beam intensity and time structure parameters and different measurement purposes, a single pulse with a bias of V+ΔV and V-ΔV and an amplitude of ΔV and opposite polarities can also be provided for the two parts of the gate electrode grid.

[0044] Alternatively, according to the working principle and mode of the pixel chip and different measurement purposes, the potential of the two parts of the grid can be V, and the pixel chip can continuously read out the charge data in the detector frame by frame.

[0045] As can be seen from the above, the working mode of the detector includes a periodic sampling mode, a single sampling mode, and a continuous sampling mode.

[0046] The gate electrode grid can be replaced by any grid or mesh at the same potential, and according to the specific circumstances, this gate electrode grid or equivalent grid or mesh can not be necessary.

[0047] Specifically as Figure 3When the potentials of the two layers are both V, the gate electrode is in an "on" state (i.e. the charges of the drift region can enter the charge collection device), and when the potentials of the two layers are V+ΔV and V-ΔV respectively, the gate electrode is in an "off" state. During the operation of the detector, the current on the two parts of the grid is the same in size and opposite in direction at the rising / falling time of the above-mentioned pulse.

[0048] According to the geometry of the detector, necessary auxiliary electrodes can be arranged around the gate electrode grid to make the electric field of the charge drift region and the charge collection region away from the gate electrode grid more uniform.

[0049] In the embodiment of the present application, the mask 32 is a perforated metal plate, which can also be replaced by a metal film with an insulating support. The perforation position is directly below the sensitive region of the semiconductor pixel chip 331. According to specific conditions, the size of the perforation is the same as or similar to that of the chip sensitive region. The metal plate or metal film at the perforation position is covered with a metal wire grid on one side or both sides. The distance between the metal wire and the metal plate is about zero, and the resistance is about zero.

[0050] In the embodiment of the present application, the semiconductor pixel chip 331 can directly collect the charges in space. The semiconductor pixel chip 331 is charge-sensitive and can measure the total amount of charges collected in a period of time Δt by integration. A plurality of semiconductor pixel chips 331 are regularly and uniformly arranged on the chip binding plate 3 to form a chip array. The distribution mode of the chip array can ensure the requirements for measuring the position, direction and profile of the beam in a specific application scenario. The chip binding plate also includes one or more necessary circuit boards to ensure the normal operation of the chip array.

[0051] Further, the detector housing is also provided with necessary electronic interfaces, which can output the charge amount data collected by the chip array for operation by an external processor device (which can be a platform composed of high-speed FPGA, SOC, etc.) to quickly and accurately detect the position and profile of the beam.

[0052] In summary, in the scheme of the present application, the beam detector includes a detector housing, an electric field cage and a charge collection device. The beam to be detected is received into the electric field cage in the detector housing, so that the beam collides with gas molecules in the working environment to generate charges, and the charges drift in the drift region in the electric field cage. The semiconductor pixel chip in the charge collection device accurately collects the amount of charges at different positions and outputs the same for accurate monitoring of the real-time detection of the position and profile of the beam.

[0053] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiments, which will not be described herein.

[0054] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0055] The above only describes preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A beam detection detector, characterized in that, include: The detector housing includes an entrance window for receiving a beam of particles to be detected, and an exit window that is parallel to and opposite to the entrance window. An electric field cage, disposed within the detector housing and used to charge gas molecules in the working environment of the beam detection detector, forms a drift region for the directional drift of the charge. And a charge collection device disposed inside the detector housing for collecting the charge, wherein the charge collection device includes a semiconductor pixel chip for measuring and outputting charge quantity data of the charge; The charge collection device includes: Gate electrodes are used to generate a control electric field that controls the charge drift rate. The mask has openings corresponding to the positions of the plurality of semiconductor pixel chips and has the function of shielding the electric field changes in the drift region; A chip bonding board on which multiple semiconductor pixel chips are disposed to form a chip array; The gate electrode includes a wire grid and a support structure for the wire grid. The wire grid includes at least two layers of parallel wires. The radial direction of the wires in each layer of parallel wires is parallel to the plane of the entrance window. The main plane of each layer of parallel wires is perpendicular to the plane of the entrance window. The potential of each of the at least two layers of parallel metal wires is applied according to the detector operating mode of the beam detection detector, which includes a periodic sampling mode, a single sampling mode, and a continuous sampling mode.

2. The beam detection detector according to claim 1, characterized in that, The electric field cage is used to cause the particle beam to be detected to collide with gas molecules in the working environment of the beam detection detector to generate charges, and to generate a set electric field to form a drift region for the directional drift of the charges.

3. The beam detection detector according to claim 2, characterized in that, The set electric field is a uniform electric field; the direction of the control electric field is parallel to the set electric field.

4. The beam detection detector according to claim 3, characterized in that, The gate electrode, the mask, and the main plane of the chip bonding plate are parallel, and the mask is located between the gate electrode and the chip bonding plate.

Images