CN111948701B - Single event effect detector - Google Patents

Abstract

The invention discloses a single-event effect detector. The detector comprises a chassis, an integrated probe and four circuit boards arranged in the chassis; the integrated probe includes: two LET spectrum sensors and two LET A large-scale integrated chip under test between spectral sensors; the chip is used to capture single event flip events; the four circuit boards include: a motherboard for signal connection between the circuit boards and a motherboard for fixing the integrated probe, a An analog board for processing LET spectral sensor signals, a computer board for data acquisition and storage, and a power board for powering the LET spectral sensor and each circuit board. The detector of the invention can directly reflect the relationship between the single event flip event and the LET spectrum of the device, on the one hand, it provides evidence for the accuracy of the LET spectrum detection, and on the other hand, it can improve the accuracy of the method for predicting the single event flip rate of the satellite.

Description

A Single Event Effect Detector

technical field

The invention relates to the field of aerospace, in particular to a single event effect detector.

Background technique

The sources of charged particles in space mainly include particles from the Earth’s radiation belt, galactic cosmic rays, and solar cosmic rays. Various high-energy particle radiations have a wide range of LET spectra, covering the range of 0.001-100MeV/(mg/cm2).

At present, the space high-energy particle radiation LET spectrum detector (detection range: 1-100MeV/(mg/cm2)) carried on the spacecraft cannot directly correspond to the single-event effect. Only the on-orbit flipping probability of the device can be obtained, but the LET value that causes the flipping of the device cannot be determined, neither of which can be directly applied to the safety design and guarantee of satellites.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned technical defects. In order to intuitively obtain the relationship between the LET value of the device and the single event turnover, the present invention enables the sensitive surface of the sensor to cover the chip by selecting a suitable sensor sensitive surface size, an integrated chip and a reasonable layout. The effective size of the single event reversal event can be traced back to the corresponding LET value (the measurable LET value is required to be as low as possible, covering all energy segments that may cause single event reversal); at the same time, the designed single event effect detection The device should solve the electromagnetic interference problem of the large-scale integrated circuit on the weak signal measurement system of the sensor, and avoid false triggering and false counting.

In order to achieve the above object, the present invention provides a single event effect detector, which includes a chassis, an integrated probe and four circuit boards arranged in the chassis;

The integrated probe includes: two LET spectrum sensors and a measured large-scale integrated chip located between the two LET spectrum sensors; the chip is used to capture single event reversal events;

The four circuit boards include: a motherboard for signal connection between each circuit board and a fixed integrated probe, an analog board for processing LET spectrum sensor signals, a computer board for data acquisition and storage, and a pair of The LET spectrum sensor and the power board that powers the various boards.

As an improvement of the above device, the integrated probe is divided into three layers, the upper layer is a piece of LET spectrum sensor fixed in the upper shielding box and its corresponding pre-amplification forming circuit, the middle is the large-scale integrated chip to be tested, The lower layer is a LET spectrum sensor fixed in the lower shielding box and its corresponding preamplifier circuit. The size of the upper shielding box and the lower shielding box are the same; the two shielding boxes are installed on the front and back sides of the motherboard, so that the two shielding boxes Corresponding to the edge; the measured large-scale integrated chip is directly welded on the motherboard, between the sensitive surfaces of the two sensors; the pre-amplification shaping circuit is used for voltage conversion and shaping of the charge pulse signal output by the LET spectrum sensor enlarge.

As an improvement of the above-mentioned device, the signal lines and power lines of the measured large-scale integrated chip are arranged on the inner layer of the motherboard; after the outputs of the two preamplifier circuits are connected to the pads of the motherboard, The layers are exported to the analog board separately.

As an improvement of the above-mentioned device, the analog board is provided with two circuits in series with the amplifier circuit, the peak protection circuit and the trigger circuit, one of which receives the signal output by the pre-amplification forming circuit in the upper shielding box; the other receives the signal output by the lower shielding box The signal output by the internal pre-amplification shaping circuit;

The amplification circuit is used to further amplify the signal output by the pre-amplification shaping circuit;

The peak protection circuit is used to maintain the peak value of the output signal of the amplifying circuit;

The trigger circuit is used to output a trigger signal when the signal amplitude exceeds the set threshold, and notify the computer board to perform A/D conversion on the signal output by the peak protection circuit.

As an improvement of the above device, the computer board is provided with two A/D conversion circuits, an FPGA control circuit, a crystal oscillator circuit, a data storage SRAM and a 1553 interface; each of the two A/D conversion circuits is connected to one peak protection circuit; 1553 The interface is the interface between the detector and the satellite platform;

The two-way A/D conversion circuits are respectively used under the control of the FPGA control circuit to perform analog-to-digital conversion on the peak value of the signal output by the peak protection circuit connected to it,

A crystal oscillator circuit is used to provide a 16MHz clock for the FPGA control circuit;

The FPGA control circuit is used to control the operation of the A/D conversion circuit after receiving the trigger signal, and is used to store the signal amplitude values output by the two A/D conversion circuits into the data storage SRAM, and is used to read the measured large-scale The data of the integrated chip is stored in the data storage SRAM, and it is also used to read the data of the data storage SRAM and send it to the satellite platform through the 1553 interface.

As an improvement of the above-mentioned device, the satellite platform packs the incident time of the incident particles, the signal amplitude output by the two A/D conversion circuits, and the address where the value of the measured large-scale integrated chip is reversed and sends it to the ground. upper computer;

The host computer calculates the loss energy ΔE according to the signal amplitude values output by the two A/D conversion circuits, and calculates the path length d of the particles passing through the sensor according to the thickness of the sensor, that is, the thickness of the sensor when the incident direction is 45°, Then the LET value of the particle in the sensor material is: LET=ΔE/d, and the location where the single event reversal event occurs is obtained through the address where the value of the measured large-scale integrated chip is reversed.

As an improvement of the above device, the power supply board is provided with a power supply interface circuit, a remote measurement interface circuit and a high voltage circuit.

The power interface circuit is used to convert the primary power provided by the satellite platform to provide working voltage for each circuit;

The telemetry interface circuit is used to detect +12V and +5V operating voltages to determine the working state of the detector;

The high-voltage circuit is used to provide a suitable bias voltage for the LET spectrum sensor.

The advantages of the present invention are:

1. The detector of the present invention can directly reflect the relationship between the single event turnover event and the LET spectrum of the device. On the one hand, it provides evidence for the accuracy of the LET spectrum detection, and on the other hand, it can improve the accuracy of the method for predicting the satellite single event turnover rate. sex;

2. The detector of the present invention integrates LET spectrum detection and single-event flip detection into one probe, which is more intuitive when analyzing single-event effects than the data obtained by independent detection in other previous schemes. At the same time, this design can save satellite resources.

3. According to the actual measurement results in orbit, the number of single event flips detected by this detector and the corresponding relationship between single event flips and LETs are in good agreement with the ground calibration, which shows that this detection mode is very effective.

Description of drawings

Fig. 1 is the schematic diagram of the integrated probe of the present invention;

Fig. 2 is the electric principle block diagram of single event effect detector of the present invention;

Fig. 3 is a three-dimensional schematic diagram of the single event effect detector of the present invention;

Fig. 4 is a three-view diagram of the structure of the single event effect detector of the present invention.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

The invention changes the structural design of the original LET spectrum detector, adds a large-scale integrated chip to be measured between two thin silicon semiconductor sensors, and directly corresponds the single particle reversal to the LET value.

1. Composition and connection relationship

The single event effect detector of the present invention comprises three parts: an integrated probe composed of a LET spectrum sensor and a large-scale integrated chip to be tested, a circuit board and a chassis structure. The chassis includes a bottom plate, a top plate and four side plates, and 4 printed circuit boards are installed inside, which are 1 motherboard (for signal connection between circuit boards and installation of probes), 1 analog board (for processing sensor signal), a computer board (used to process the collected data) and a power board (to supply power to the sensor and each circuit module). Wherein the motherboard is parallel to the installation surface, the power supply board, the computer board and the analog board are parallel to each other, perpendicular to the motherboard and inserted on the motherboard.

The probe is fixed on the motherboard and is divided into three layers. The upper layer is a LET spectrum sensor and its corresponding preamplifier circuit, which is fixed in the shielding box with screws. The middle is the large-scale integrated chip to be tested, and the lower layer is a LET spectrum sensor. The sensor and its corresponding preamplifier circuit are fixed in the shielding box with screws; the two shielding boxes have the same size.

The two shielding boxes are installed on the front and back sides of the motherboard so that the edges of the two shielding boxes correspond. The chip under test is directly welded on the motherboard at the position corresponding to the sensor, so that it is between the sensitive surfaces of the two sensors.

The signal and power lines of the large-scale integrated chip under test are all routed to the inner layer of the circuit board; the output signal of the LET spectrum sensor is connected to the pre-amplifier circuit, and the output of the pre-amplifier circuit is connected to the pad, and then leads to the analog circuit through the inner layer of the motherboard. plate for further amplification and acquisition.

2. Detection scheme and working principle

The detection scheme is shown in Figure 1. The probe consists of two silicon sensors to form a telescope system. The LSI chip under test is located between two sensors, forming a "sandwich" probe structure. The thickness of the sensor is 300 μm, and the diameter of the sensor is 26 mm. When high-energy protons or heavy ions are incident on the probe, due to the ionization of radiation, electron-hole pairs are formed inside the sensor, and the electron-hole pairs are collected to the output end of the sensor under the action of the high-voltage electric field inside the sensor to generate charge output Signal. The particle deposition energy information can be obtained through back-end circuit analysis, and the radiation LET spectrum can be calculated by combining the sensor thickness and particle incident direction information.

LET is defined as the energy loss per unit path length of a charged particle, namely:

LET = ΔE/Δx

In the formula, ΔE is the energy (MeV) lost by the charged particle, and Δx is the mass length (mg/cm2) that the charged particle passes through.

By definition, LET detection works by measuring the energy ΔE lost by a particle in the sensor. According to the direction of the particle and the thickness of the sensor, the path length d of the particle passing through the sensor is calculated, then the LET of the particle in the sensor material = ΔE/d.

The tested large-scale integrated chip is 512K*8*4SRAM produced by ATMEL company, the model is AT68166HT. Anti-total dose capability of 300krad(Si), single particle locking threshold ≥80MeV/mg/cm2. The core of the device is divided into four parts, and each part can be initialized and assigned separately (for example, each byte is set to 0x55), and it is read and judged before the end of each data packet cycle, and the position where the flip occurs , record its address. Since the number of particles with the LET value that can cause the device to flip is far less than 1/s, the period of the data packet is set to 1s, that is, the single event flip event can be corresponded to the captured particles.

3. Electronics Implementation Scheme

LET spectrum detection includes two silicon semiconductor detectors, and the signals of each sensor are output separately without signal matching. After each signal is amplified and processed with peak protection, A/D acquisition is performed. The measurable deposition energy range of each sensor is above 70keV. Since the thickness of the sensor is 300μm, that is, the mass thickness is 70mg/cm2. According to the definition of LET, the minimum measurable LET value is 0.001MeV/(mg/cm2). The output signal is amplified in multiple stages, and the upper limit of the measurable LET value can reach 100MeV/(mg/cm2).

The electronic principle block diagram is shown in Figure 2. The electronic part includes two pre-amplifier forming circuits, two main amplifiers, two peak protection circuits, two A/D conversion circuits, FPGA control circuit, 1553 communication interface, data storage SRAM, crystal oscillator, telemetry interface and power interface.

As shown in Figure 3 and Figure 4, the detector of the present invention is a cube structure with three connectors on the top: X01 is the power supply and telemetry contact, and X02 and X03 are the primary and backup for 1553B serial communication.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit them. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent replacements to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all of them should be included in the scope of the present invention. within the scope of the claims.

Claims (4)

1. A single event effect detector is characterized by comprising a case, an integrated probe and four circuit boards, wherein the integrated probe and the four circuit boards are arranged in the case;

the integrated probe includes: the large-scale integrated chip comprises two LET spectrum sensors and a large-scale integrated chip to be tested, wherein the large-scale integrated chip is positioned between the two LET spectrum sensors; the chip is used for capturing a single event upset event;

the four circuit boards include: the integrated probe comprises a motherboard for connecting signals among circuit boards and fixing the integrated probe, an analog board for processing signals of the LET spectrum sensor, a computer board for acquiring and storing data and a power supply board for supplying power to the LET spectrum sensor and the circuit boards;

the integrated probe is divided into three layers, the upper layer is a LET spectrum sensor fixed in the upper shielding box and a corresponding preamplification forming circuit thereof, the middle layer is a large-scale integrated chip to be detected, the lower layer is a LET spectrum sensor fixed in the lower shielding box and a corresponding preamplification circuit thereof, and the sizes of the upper shielding box and the lower shielding box are the same; the two shielding boxes are arranged on the front surface and the back surface of the mother board, so that the edges of the two shielding boxes correspond to each other; the large-scale integrated chip to be tested is directly welded on the motherboard and is arranged between the sensitive surfaces of the two sensors; the pre-amplification shaping circuit is used for performing voltage conversion and shaping amplification on the charge pulse signal output by the LET spectrum sensor;

the analog board is provided with two circuits formed by connecting an amplifying circuit, a peak-hold circuit and a trigger circuit in series, and one circuit receives a signal output by a pre-amplifying forming circuit in the upper shielding box; the other path receives the signal output by the preamplification forming circuit in the lower shielding box;

the amplifying circuit is used for further amplifying the signal output by the pre-amplification shaping circuit;

the peak-hold circuit is used for holding the peak value of the output signal of the amplifying circuit;

the trigger circuit is used for outputting a trigger signal according to the condition that the signal amplitude exceeds a set threshold value and informing the computer board to carry out A/D conversion on the signal output by the peak protection circuit;

the computer board is provided with two paths of A/D conversion circuits, an FPGA control circuit, a crystal oscillator circuit, a data storage SRAM and a 1553 interface; the two A/D conversion circuits are respectively connected with one peak protection circuit; the 1553 interface is an interface between the detector and the satellite platform;

the two A/D conversion circuits are respectively used for carrying out analog-to-digital conversion on the peak value of the signal output by the peak protection circuit connected with the two A/D conversion circuits under the control of the FPGA control circuit,

the crystal oscillator circuit is used for providing a 16MHz clock for the FPGA control circuit;

the FPGA control circuit is used for controlling the A/D conversion circuit to work after receiving the trigger signal and converting the two A/D circuits

The signal amplitude value output by the circuit is stored in a data storage SRAM for reading the data of the large-scale integrated chip to be tested and coexisting

And the data is stored in the data storage SRAM and is also used for reading the data of the data storage SRAM and sending the data to the satellite platform through a 1553 interface.

2. The single event effect detector of claim 1, wherein the signal line and the power line of the LSI under test are arranged in an inner layer of a motherboard; the output of the two preamplification circuits is connected to the pad of the motherboard and then respectively led out to the analog board through the inner layer of the motherboard.

3. The single event effect detector according to claim 1, wherein the satellite platform packs and downloads the incident time of the incident particles, the signal amplitudes output by the two A/D conversion circuits and the addresses of the large-scale integrated chips to be detected with the numerical value being inverted to an upper computer on the ground;

the upper computer calculates the loss energy delta E according to the signal amplitude numerical values output by the two A/D conversion circuits, calculates the length D of a path through which the particles pass in the sensor according to the thickness of the sensor, namely the thickness of the sensor when the incident direction is 45 degrees, and then the LET value of the particles in the sensor material is as follows: LET = Δ E/d, and acquiring the position of the single event upset event through the address where the numerical value of the detected lsi chip is inverted.

4. The single event effect detector of claim 1, wherein a power interface circuit, a telemetry interface circuit and a high voltage circuit are arranged on the power panel;

the power interface circuit is used for converting a primary power supply provided by the satellite platform and providing working voltage for each circuit;

the telemetering interface circuit is used for detecting the +12V and +5V working voltages so as to judge the working state of the detector;

the high-voltage circuit is used for providing proper bias voltage for the LET spectrum sensor.

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