阅读说明：本技术 一种单个离子实时监测装置及方法 (Single ion real-time monitoring device and method ) 是由 刘俊亮 于得洋 于 2019-09-29 设计创作，主要内容包括：本发明涉及一种单个离子实时监测装置及方法,该装置包括：屏蔽外壳,其上形成有入射口和出射口；电子发射膜,沿径向设置在屏蔽外壳内,用于在入射离子轰击下产生出射电子；两电场均压环阵列,对称设置在电子发射膜的两侧,用于提供大面积的均匀电场；两位置灵敏探测器,对称在两电场均压环阵列的外侧,用于探测电子发射膜产生的出射电子,以获得出射电子的落点位置和到达时刻；两永磁体,对称在两位置灵敏探测器的外侧,用于提供轴向磁场。本发明可实现高精度、高灵敏度的单离子在线监测,为单粒子效应地面模拟实验提供精确的离子事件信息,解决目前单粒子效应研究实验中离子注量测量误差较大的问题,提高实验的准确性和可靠性。(The invention relates to a single ion real-time monitoring device and a method, wherein the device comprises: a shield case on which an incident port and an exit port are formed; the electron emission film is arranged in the shielding shell along the radial direction and is used for generating emergent electrons under the bombardment of incident ions; the two electric field grading ring arrays are symmetrically arranged on two sides of the electron emission film and are used for providing a large-area uniform electric field; the two position sensitive detectors are symmetrically arranged at the outer sides of the two electric field grading ring arrays and used for detecting emergent electrons generated by the electron emission film so as to obtain the falling point positions and the arrival moments of the emergent electrons; and the two permanent magnets are symmetrically arranged at the outer sides of the two position sensitive detectors and are used for providing axial magnetic fields. The invention can realize the single-ion on-line monitoring with high precision and high sensitivity, provides accurate ion event information for single-particle effect ground simulation experiments, solves the problem of larger ion injection measurement error in the current single-particle effect research experiments, and improves the accuracy and the reliability of the experiments.)

1. A real-time single ion monitoring device, comprising:

the shielding shell (6), wherein an incident port and an exit port are formed on the shielding shell (6);

the electron emission film (2) is arranged in the shielding shell (6) along the radial direction and used for generating emergent electrons under the bombardment of incident ions, and a connecting line of an incident port and an emergent port of the shielding shell (6) penetrates through the electron emission film (2);

the two electric field grading ring arrays (3) are symmetrically arranged on two sides of the electron emission film (2) and are used for providing a large-area uniform electric field;

the two position sensitive detectors (4) are symmetrically arranged on the outer sides of the two electric field grading ring arrays (3) and are used for detecting the emergent electrons generated by the electron emission film (2) so as to obtain the falling point positions and the arrival moments of the emergent electrons;

the two permanent magnets (5) are symmetrically arranged on the outer sides of the two position sensitive detectors (4) and used for providing an axial magnetic field so as to restrain emergent electrons from spirally advancing along the direction of the magnetic field.

2. The real-time single ion monitoring device according to claim 1, wherein the direction of the electric field provided by the electric field grading ring array (3) and the direction of the magnetic field provided by the permanent magnet (5) are both perpendicular to the electron emission film (2).

3. The single ion real-time monitoring device according to claim 1, wherein the electron emission film (2) is selected from a pure carbon film, a pure aluminum film, a NaI-plated aluminum film or a CsI-plated aluminum film.

4. The single ion real-time monitoring device according to claim 1, wherein the electric field grading ring array (3) is composed of a plurality of laminated grading rings, and adjacent grading rings are connected through high-precision resistors.

5. The real-time single ion monitoring device according to claim 1, wherein the position-sensitive detector (4) is a two-dimensional position-sensitive detector based on a microchannel plate.

6. The real-time single ion monitoring device according to claim 1, wherein the shielding housing (6) is a soft iron housing for providing a magnetic line loop for the magnetic field of the permanent magnet (5).

7. A real-time single-ion monitoring method using the real-time single-ion monitoring device of any one of claims 1 to 6, the method comprising the steps of:

1) connecting the electron emission film (2) with negative high voltage, grounding the anodes of the two position-sensitive detectors (4) at the same time, and placing a sample (7) to be detected near an emergent port of the shielding shell (6);

2) the method comprises the steps that incident heavy ions (1) are injected into a single-ion real-time monitoring device from an incident port of a shielding shell (6) along a certain angle, the incident heavy ions (1) penetrate through an electron emission membrane (2) and then continuously penetrate out of the single-ion real-time monitoring device from an emergent port of the shielding shell (6) along a straight line, and finally are prevented from being in a sample (7) to be detected;

3) when the incident heavy ions (1) pass through the electron emission film (2), energy is deposited in the electron emission film (2) at the falling point position (11) of the incident heavy ions, so that backward emergent electrons and forward emergent electrons are generated on the incident surface and the emergent surface of the electron emission film (2) respectively;

4) the forward emergent electrons and the backward emergent electrons respectively fly to the position sensitive detectors 4 at two sides of the electron emission film (2) under the common guidance of an electric field and a magnetic field in the shielding shell (6) and are detected, and then the positions are respectively recorded as a falling point position (12) and a falling point position (13);

5) and finally, reversely deducing a falling point position (11) and an arrival time of the incident heavy ions (1) on the electron emission membrane (2) through the falling point position (12) or the falling point position (13), further deducing the falling point position (14) of the incident heavy ions (1) on the sample (7) to be detected along the incident direction of the incident heavy ions (1) and through the straight line of the falling point position (11), and simultaneously deducing the arrival time of the incident heavy ions (1) to the sample (7) to be detected through the speed of the incident heavy ions (1) and the position of the sample (7) to be detected relative to a single ion real-time monitoring device.

Technical Field

The invention relates to a device and a method for monitoring weak ion beams in real time, in particular to a device and a method for monitoring single ions in real time in a single-particle effect ground heavy ion accelerator simulation experiment.

Background

The single event effect experiment by using the heavy ion accelerator is a process for reproducing a space radiation environment on the ground, and whether the result is really effective depends on the adopted experimental device and experimental method. The ion fluence being necessary to obtain a single event cross-sectionAnd the measurement accuracy of the parameters directly influences the calculation accuracy of the single event section. The beam intensity adopted by the single particle experiment is generally very weak (10 to 10)³-10⁶ions/cm²S) and requires on-line monitoring, which presents certain difficulties in measuring ion fluence.

At present, ion fluence detectors commonly used in single-particle effect ground heavy ion accelerator simulation experiments include a scintillator detector, a solid track detector, a gas detector and the like. The basic principle of the scintillator detector is that incident particles emit light when passing through a scintillator film, the light is collected to a photocathode of a photomultiplier by means of an ellipsoidal reflector, a current pulse is obtained at an anode after photoelectron multiplication, the amplitude of the pulse is proportional to the energy deposited by the particles in the film, and the number of the pulses is equivalent to the number of the incident particles. The solid track detector uses a Polycarbonate (PC) film, the film is opened according to the size of a chip, then is attached to the front of a device, is irradiated with the device, and is subjected to off-line treatment after the experiment is finished. In off-line treatment, firstly, the particle tracks are etched to a proper size through chemical etching, and then the ion number of a unit area is obtained through observation by a scanning electron microscope. The basic principle of the gas detector is that an incident ion beam passes through the gas detector to ionize gas on a path, electrons generated by ionization form avalanche type ionization proliferation in an electric field of a certain nearby metal wire, and a special electronic system is used for detecting pulse signals generated by discharge, so that information such as the position, time and the like of ions can be obtained.

Although weak beam current can be monitored by using the scintillator detector, and online beam current monitoring is realized, the method has large errors which mainly come from noise of the detector, miscounting and interference of a target chamber environment. The theoretical detection efficiency of the solid track detector can reach 100%, but the off-line processing mode of the solid track detector cannot meet the requirement of on-line monitoring required by experiments. Furthermore, the scintillator detector cannot give the position of the particles, whereas the solid track detector, although giving the overall position distribution of the particles, cannot give position information of each ion. Although the gas detector can simultaneously obtain the position and time information of incident ions, the gas detector needs to block beam current during measurement, and belongs to an off-line monitoring method.

Disclosure of Invention

In view of the above problems, the present invention provides a single ion real-time monitoring device and method for single event effect ground heavy ion accelerator simulation experiment, which is developed by using a detector technology conforming to measurement and position sensitivity, and can simultaneously monitor ion fluence, and position and time information of a single incident ion.

In order to achieve the purpose, the invention adopts the following technical scheme: a single ion real-time monitoring device, comprising: the shielding shell is provided with an incident port and an emergent port; the electron emission film is arranged in the shielding shell along the radial direction and used for generating emergent electrons under the bombardment of incident ions, and a connecting line of an incident port and an emergent port of the shielding shell penetrates through the electron emission film; the two electric field grading ring arrays are symmetrically arranged on two sides of the electron emission film and are used for providing a large-area uniform electric field; the two position sensitive detectors are symmetrically arranged at the outer sides of the two electric field grading ring arrays and are used for detecting the emergent electrons generated by the electron emission film so as to obtain the falling point positions and the arrival moments of the emergent electrons; and the two permanent magnets are symmetrically arranged at the outer sides of the two position sensitive detectors and are used for providing an axial magnetic field so as to restrain emergent electrons from spirally advancing along the direction of the magnetic field.

Preferably, the electric field direction provided by the electric field grading ring array and the magnetic field direction provided by the permanent magnet are both perpendicular to the electron emission film.

Preferably, the electron emission film is selected from a pure carbon film, a pure aluminum film, a NaI-plated aluminum film or a CsI-plated aluminum film.

The single ion real-time monitoring device is preferably characterized in that the electric field grading ring array is composed of a plurality of laminated grading rings, and adjacent grading rings are connected through a high-precision resistor.

Preferably, the position sensitive detector is a two-dimensional position sensitive detector based on a microchannel plate.

Preferably, the shielding shell is a soft iron shell and is used for providing a magnetic line loop for the magnetic field of the permanent magnet.

A single ion real-time monitoring method adopts the single ion real-time monitoring device, and comprises the following steps:

1) connecting the electron emission film with negative high voltage, grounding the anodes of the two position sensitive detectors, and placing a sample to be detected near an emergent port of the shielding shell;

2) the method comprises the steps that incident heavy ions are injected into a single-ion real-time monitoring device from an incident port of a shielding shell along a certain angle, the incident heavy ions penetrate through an electron emission film and then continuously penetrate out of the single-ion real-time monitoring device from an emergent port of the shielding shell along a straight line, and finally the heavy ions are prevented from being in a sample to be detected;

3) when the incident heavy ions pass through the electron emission film, energy is deposited in the electron emission film at the falling point position of the incident heavy ions, so that backward emergent electrons and forward emergent electrons are generated on the incident surface and the emergent surface of the electron emission film respectively;

4) the forward emergent electrons and the backward emergent electrons respectively fly to the position sensitive detectors 4 at two sides of the electron emission film under the common guidance of an electric field and a magnetic field in the shielding shell and are detected, and then the positions are respectively recorded as a falling point position and a falling point position;

5) and finally, reversely deducing the falling point position and the arrival time of the incident heavy ions on the electron emission membrane through the falling point position or the falling point position, further deducing the falling point position of the incident heavy ions on the sample to be detected along the incident direction of the incident heavy ions and through the straight line of the falling point position, and simultaneously deducing the arrival time of the incident heavy ions to the sample to be detected through the speed of the incident heavy ions and the position of the sample to be detected relative to a single ion real-time monitoring device.

Due to the adoption of the technical scheme, the invention has the following advantages: 1. the invention can realize the single-ion on-line monitoring with high precision and high sensitivity, provides accurate ion event information (including total fluence information, arrival time and arrival position of each ion) for single-particle effect ground simulation experiments, solves the problem of larger ion fluence measurement error in the current single-particle effect research experiments, and improves the accuracy and reliability of the experiments. 2. The two position sensitive detectors of the invention work independently, and only two position sensitive detectors have signals at the same time to be regarded as effective counting (coincidence measurement), which can greatly reduce the error counting rate and greatly improve the anti-interference capability compared with the method only adopting a single detector. Moreover, because the flight time of the emergent electrons in the device is very short, generally in the order of nanoseconds, the device can accurately know the arrival time of ions; in addition, the constraint action of the electromagnetic field in the device is added, the drop point dispersion of the emergent electrons on the position sensitive detector is very small, and therefore the device can accurately know the arrival position of the ions.

Drawings

FIG. 1 is a schematic diagram of the structure of a single-ion real-time monitoring device according to the present invention;

FIG. 2 is a schematic diagram illustrating the principle of the single-ion real-time monitoring method of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the invention can be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

As shown in fig. 1, the single-ion real-time monitoring device provided by the present invention comprises: a shielding shell 6, wherein an incident port and an emergent port are formed on the shielding shell 6; the electron emission film 2 is arranged in the shielding shell 6 along the radial direction and used for generating emergent electrons under the bombardment of incident ions, and a connecting line of an incident port and an emergent port of the shielding shell 6 penetrates through the electron emission film 2; the two electric field grading ring arrays 3 are symmetrically arranged on two sides of the electron emission film 2 and are used for providing a large-area uniform electric field; the two position sensitive detectors 4 are symmetrically arranged at the outer sides of the two electric field grading ring arrays 3 and are used for detecting the emergent electrons generated by the electron emission film 2 so as to obtain the falling point positions and the arrival moments of the emergent electrons; the permanent magnets 5 are symmetrically arranged on the outer sides of the two position sensitive detectors 4 and used for providing an axial magnetic field so as to restrain emergent electrons from spirally advancing along the direction of the magnetic field and improve position resolution.

In the above embodiment, it is preferable that the direction of the electric field provided by the electric field grading ring array 3 and the direction of the magnetic field provided by the permanent magnet 5 are both perpendicular to the electron emission film 2 to simplify the estimation process of the incident ion position.

In the above embodiment, preferably, the electron emission film 2 may be selected from a pure carbon film, a pure aluminum film, a NaI-plated aluminum film, a CsI-plated aluminum film, or the like.

In the above embodiment, preferably, the electric field grading ring array 3 is composed of a plurality of laminated grading rings, and adjacent grading rings are connected through a high-precision resistor.

In the above embodiment, it is preferable that the position-sensitive detector 4 is a two-dimensional position-sensitive detector based on a microchannel plate (MCP).

In the above embodiment, it is preferable that the shielding case 6 is a soft iron case for providing a magnetic line loop for the magnetic field of the permanent magnet 5, reducing leakage of the magnetic field, and preventing the magnetic field from affecting other devices attached to the apparatus.

Based on the single-ion real-time monitoring device provided in the above embodiment, the invention also provides a single-ion real-time monitoring method, which comprises the following steps:

1) connecting the electron emission film 2 with negative high voltage, grounding the anodes of the two position sensitive detectors 4, and placing the sample 7 to be detected near the exit port of the shielding shell 6;

2) the incident heavy ions 1 are injected into the single-ion real-time monitoring device from an incident port of the shielding shell 6 along a certain angle, the incident heavy ions 1 penetrate through the electron emission membrane 2 and then continuously penetrate out of the single-ion real-time monitoring device from an exit port of the shielding shell 6 along a straight line (the deflection of an electric field and a magnetic field in the shielding shell 6 to the incident heavy ions 1 can be ignored), and finally are prevented in a sample 7 to be detected;

3) when the incident heavy ions 1 pass through the electron emission film 2, energy is deposited in the electron emission film 2 at the falling point position 11 of the incident heavy ions, so that backward outgoing electrons and forward outgoing electrons are generated on the incident surface and the outgoing surface of the electron emission film 2 respectively;

4) the forward emergent electrons and the backward emergent electrons respectively fly to the position sensitive detectors 4 at two sides of the electron emission film 2 under the common guidance of an electric field and a magnetic field in the shielding shell 6 and are detected, and then the positions are respectively recorded as a falling point position 12 and a falling point position 13;

5) and finally, the falling point position 11 and the arrival time of the incident heavy ions 1 on the electron emission membrane 2 can be reversely deduced through the falling point position 12 or 13, the falling point position 14 of the incident heavy ions 1 on the sample 7 to be detected is deduced through the straight line of the falling point position 11 along the incident direction of the incident heavy ions 1, and the arrival time of the incident heavy ions 1 to the sample 7 to be detected is deduced through the speed of the incident heavy ions 1 and the position of the sample 7 to be detected relative to the single-ion real-time monitoring device.

The above embodiments are only used for illustrating the present invention, and the structure, size, arrangement position and shape of each component can be changed, for example, the appearance size of each component, the providing mode of the magnetic field, the kind of the detector, the geometrical structure after assembly, etc., on the basis of the technical solution of the present invention, the improvement and equivalent transformation of the individual components according to the principle of the present invention should not be excluded from the protection scope of the present invention.