CN113281361A

CN113281361A - Quick scanning XAFS system

Info

Publication number: CN113281361A
Application number: CN202110515629.XA
Authority: CN
Inventors: 储胜启; 张静; 章红宇; 常劲帆; 陈�光
Original assignee: Institute of High Energy Physics of CAS
Current assignee: Institute of High Energy Physics of CAS
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2021-08-20
Anticipated expiration: 2041-05-12
Also published as: CN113281361B

Abstract

The invention relates to a fast scan XAFS system, which is characterized by comprising: a monochromator adjusting device, an information processing device and a computer component; incident X-rays are processed into monochromatic light through a monochromator adjusting device; monochromatic light sequentially passes through the front ionization chamber and the rear ionization chamber, and the information processing device collects current signals generated by the front ionization chamber and the rear ionization chamber; the information processing device processes the current signal into a digital signal and stores the digital signal; the computer component issues a spectrum acquisition command to the information processing device, and the information processing device generates a motor control signal according to the spectrum acquisition command, wherein the signal is used for controlling the monochromator adjusting device; the information processing device transmits the digital signal and the count value of the sent motor control signal to the computer component at the same time so as to be stored by the computer component. Measurement of XAFS spectra on the order of seconds to minutes can be achieved by this system.

Description

Quick scanning XAFS system

Technical Field

The invention relates to a modern material structure analysis method-synchrotron radiation experiment method, in particular to a fast scanning XAFS system.

Background

The XAFS (X-ray Absorption File Structure) experimental method is a powerful tool for detecting local structures of substances, has the characteristics of element selectivity, independence on long-range order, sensitivity to trace elements and the like, and is one of the experimental methods which are most widely applied to synchronous radiation devices, most used by users and most abundant in result output.

Conventional XAFS data acquisition employs a step-by-step (step-by-step) stepping mode, as shown in fig. 1. The incident X-ray is changed into monochromatic light with adjustable energy after passing through the bicrystal monochromator; ionization chamber detectors are placed in front of, behind, and to the side of the sample, and some subsequent electronics, including weak current amplifiers, VF converters (VF convertors), and digital pulse counters (counters), are used primarily to collect and record the intensity of the received X-rays. During the experiment, the angle of the monochromator is changed point by point to obtain monochromatic light with corresponding energy, and then the reading of each detector is recorded. Due to the consideration of mechanical stability and communication delay between different devices, in practical program control, appropriate waiting time needs to be set, resulting in about 15 minutes for acquiring a complete XAFS spectrum.

In recent years, due to the development of in-situ experiment technology, especially in the fields of catalysis, energy, materials and the like, the demand for dynamic experiment characterization technology is more and more urgent. The step mode obviously does not meet the needs of practical research, and therefore, a time-resolved XAFS experimental system based on fast scanning (quick scanning) is developed, XAFS data acquisition can be continuously carried out in a periodic reciprocating bidirectional scanning mode, and the acquisition time of each spectrum is shortened to the second order. The system provides an indispensable experimental means for representing the dynamic evolution process of the material structure under the in-situ condition.

Meanwhile, the shortening of the acquisition time inevitably leads to the reduction of the signal-to-noise ratio of the data. In some cases we need to make a trade-off between the two. In addition, the time scale of the in-situ experiment is not uniform, and the experiment can be completed within seconds quickly and hours slowly. We have designed two different experimental models for this purpose: continuous scanning and multi-trapezoid scanning, the time resolution can be from several seconds to minute order, so as to adapt to different experimental requirements.

The reason for the long acquisition time of the conventional step mode is mainly the following:

(1) continuous stop and go, the requirement on mechanical stability is high, data acquisition can be carried out only after a certain time of waiting after the motor stops moving every time, otherwise, the X-ray intensity fluctuation caused by mechanical vibration is large;

(2) setting corresponding waiting time in a program according to communication delay among different devices;

(3) generally, unidirectional scanning from low energy to high energy is adopted, and data acquisition is not carried out when the motor returns.

Patent application No. 201310125282.3 provides an intelligent electronics device, a QXAFS system, and a data acquisition and motor control method. Although the fast scan function can also be implemented, there are the following disadvantages:

(1) the acceleration section, the deceleration section and the uniform speed section of the scanning process need to be configured in advance and stored in a designated register, and the number of scanning points is limited due to the limitation of the storage capacity of the register, so that the complete periodic reciprocating bidirectional scanning process cannot be realized.

(2) The collected data are also pre-stored in the FIFO register, the stored data points are limited, the data can be merged only in an addition and average mode, some details in the experimental process can be lost, and the time of reading the data once is required to be several seconds after the data are accumulated.

(3) During output, the pulse number sent to the motor and the acquired data are not synchronously output, so that the difficulty is brought to the correction of the later energy coordinate (obtained by calculating the pulse number), and the spectrum shape is possibly moved or deformed due to the inconsistency with the actual coordinate.

Disclosure of Invention

The invention aims to solve the problem that due to the limitation of the capacity of a register, the function of periodically and continuously changing the energy of incident X-rays can only be realized by adopting a sectional mode and scanning back and forth in a certain angle range at a proper and quick speed.

To solve the above technical problem, an embodiment of the present invention provides a fast scan XAFS system, including: a monochromator adjusting device, an information processing device and a computer component;

incident X-rays are processed into monochromatic light through a monochromator adjusting device;

the monochromatic light sequentially passes through the front ionization chamber and the rear ionization chamber, and the information processing device collects current signals generated by the front ionization chamber and the rear ionization chamber;

the information processing device processes the current signal into a digital signal and stores the digital signal; the computer component issues a spectrum acquisition command to the information processing device, and the information processing device generates a motor control signal according to the spectrum acquisition command and is used for controlling the monochromator adjusting device; and the information processing device transmits the digital signal and the count value of the sent motor control signal to a computer component for storage by the computer component.

Optionally, the monochromator adjustment device comprises a motor driver;

the motor driver is used for controlling the monochromator to rotate, and when the monochromator is positioned at different angles, the incident X-rays are processed into different monochromatic light.

Optionally, the motor driver receives a motor control signal sent by the information processing device, and controls the motor driver to rotate according to the motor control signal, so as to change the angle of the monochromator.

Optionally, the monochromator adjusting device further comprises an encoder;

the encoder is used for collecting the angle of the monochromator to generate angle information; the encoder sends the angle information to the computer component.

Optionally, a sample stage is further disposed between the front ionization chamber and the rear ionization chamber, and a sample to be tested is placed on the sample stage; the fluorescence detector is used for collecting current signals of X-ray fluorescence intensity generated when monochromatic light passes through a sample to be tested, and transmitting the current signals to the information processing device.

Optionally, the information processing apparatus and the computer component communicate with each other by using a standard TCP/IP protocol, so as to transmit the first pulse signal and the digital signal to the computer component.

Optionally, the information processing apparatus includes an FPGA, and different spectrum acquisition schemes are implemented by performing programming control on the FPGA.

Optionally, the FPGA receives and executes a spectrum sampling command of the computer component, so as to implement the spectrum sampling scheme.

Optionally, the system further comprises a high-precision clock synchronization module.

Optionally, the information processing apparatus is reserved with an expansion interface.

The embodiment of the invention provides a quick scanning XAFS system, which can realize measurement of an XAFS spectrum in the order of seconds to minutes through information interaction among a monochromator adjusting device, an information processing device and a computer assembly, and obtains a very good experimental result after experimental verification. The system aims to provide powerful experimental support for representing the dynamic change process of the in-situ experiment on one hand; and on the other hand, a flexible programmable experimental mode is provided to adapt to the research requirements of different time scales.

Drawings

FIG. 1 is a block diagram of a conventional XAFS data acquisition in a step-by-step (step-by-step) step mode in the background of the invention;

fig. 2 is a block diagram of a fast scan XAFS system provided by an embodiment of the present invention;

fig. 3 is a detailed block diagram of a fast scan XAFS system according to an embodiment of the present invention;

fig. 4 is a diagram illustrating actual test results of a fast scan XAFS system according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 2 is a block diagram of a fast scan XAFS system according to an embodiment of the present invention. Referring to fig. 2, a fast scan XAFS system, comprising: the monochromator 13 regulates the device 1, the information processing device 2 and the computer component 3.

The incident X-rays are processed into monochromatic light by the monochromator 13 conditioning device 1.

The monochromatic light sequentially passes through the front ionization chamber 4 and the rear ionization chamber 5, and the information processing device 2 collects current signals generated by the front ionization chamber 4 and the rear ionization chamber 5.

The information processing apparatus 2 processes the current signal into a digital signal and stores the digital signal; the computer component 3 issues a spectrum acquisition command to the information processing device 2, and the information processing device 2 generates a motor control signal according to the spectrum acquisition command, wherein the motor control signal is used for controlling the adjustment device 1 of the monochromator 13; the information processing device 2 transmits the digital signal and the count value of the motor control signal to the computer component 3, so that the computer component 3 can store the count value.

The embodiment of the invention provides a quick scanning XAFS system, which can realize measurement of an XAFS spectrum in the order of seconds to minutes through information interaction among a monochromator 13 adjusting device 1, an information processing device 2 and a computer assembly 3, and obtains a very good experimental result after experimental verification. The system aims to provide powerful experimental support for representing the dynamic change process of the in-situ experiment on one hand; and on the other hand, a flexible programmable experimental mode is provided to adapt to the research requirements of different time scales.

Fig. 3 is a detailed block diagram of a fast scan XAFS system according to an embodiment of the present invention. With reference to fig. 3, on the basis of the above embodiment, the monochromator 13 adjustment device 1 comprises a motor driver 11;

the motor driver 11 is used for controlling the monochromator 13 to rotate, and when the monochromator 13 is positioned at different angles, the incident X-rays are processed into different monochromatic light. The motor driver 11 receives the motor control signal sent by the information processing device 2, and controls the motor driver 11 to rotate according to the motor control signal.

The monochromator 13 adjustment device 1 further comprises an encoder 12; the encoder 12 is configured to acquire an angle of the monochromator 13 to generate angle information; the encoder 12 sends the angle information to the computer component 3.

On the basis of the above embodiment, a sample stage 6 is further arranged between the front ionization chamber 4 and the rear ionization chamber 5, and a sample to be tested is placed on the sample stage 6; the fluorescence detector is used for collecting current signals of X-ray fluorescence intensity generated when monochromatic light passes through a sample to be tested, and transmitting the current signals to the information processing device 2.

On the basis of the above embodiment, the information processing apparatus 2 and the computer component 3 communicate using a standard TCP/IP protocol to transmit the count value of the motor control signal and the digital signal to the computer component 3.

And a TCP protocol stack completely designed based on a hardware description language (Verilog) is adopted, so that the resource occupancy rate of the FPGA is reduced, the manufacturing cost of electronic equipment is reduced, and the data transmission bandwidth and the data transmission distance are improved. The design solves the problems that a large amount of experimental data can be generated in the rapid scanning process, and how to transmit and store the large data in real time.

The measurement data of the fast scanning XAFS system adopts a complete reading mode, each pulse sent to the driving motor is numbered, the pulse numbers and the sampling values of the ADC are packaged and cached strictly according to the time sequence, and all the data are transmitted to the computer component 3. All test data are completely reserved in the whole spectrum acquisition process, so that very high flexibility is provided for analysis of the spectrum acquisition data at the later stage.

The data communication of the fast scanning XAFS system adopts a full-duplex working mode, and during data acquisition, the data can be transmitted to the computer component 3, and meanwhile, a new spectrum acquisition command issued by the computer component 3 can be received and put into a command buffer for waiting execution. Through the mode of executing the command and receiving the new command at the same time, the number of the executable commands of the equipment can be greatly increased, and the capability of continuously acquiring the spectrum for a long time of the equipment is greatly expanded.

Specifically, the fast scan XAFS system uses a stepping motor to drive the monochromator 13 to rotate, and when a pulse signal is input, the rotor of the stepping motor rotates by an angle, the output angular displacement is proportional to the input pulse number, and the motor speed is proportional to the pulse frequency. The QXAFS (Quick X-ray Absorption File Structure) spectrum acquisition process adopts a fully parameterized and ordered design, each pulse for driving the motor to rotate is used as a basic command unit, and the parameter of each pulse can be configured through a command. By using each pulse as a basic command unit, the whole motor rotation process can be completely programmable, and the motor rotation can be controlled randomly, so that a random spectrum collection mode can be realized, and the adaptability and flexibility of the device are greatly expanded. The common electronic instructions are as shown in table one:

instruction 1	Motor waiting time
		Instruction
2	Segment instruction repetition
		Instruction
3	Segment instruction repeat completion
		Instruction
4	Single instruction repeat
		Instruction
5	Executable instruction end
		Instruction
6	Global reset
		Instruction 7	Channel enable
Instruction 8	End of initialization
		Instruction 9	Start measurement

Watch 1

Through commands such as single instruction repetition and segment instruction repetition, the number of instructions can be greatly compressed, and excessive same instructions are prevented from being issued.

All instruction reception, storage, and execution are implemented within the FPGA. A double-port RAM is designed in the FPGA to be used as a storage space of the instruction, and a register is arranged to mark whether the instruction is completely issued. All the commands to be issued are generated on the PC and then issued to the electronic equipment through a TCP protocol. If the spectrum collecting mode is simple, the required instruction quantity is less than the instruction storage space in the FPGA, the PC issues all the instructions at one time, the register marks that the instructions are issued and finishes, and after the electronics receives the measurement starting instruction, the instructions in the instruction memory are executed one by one until all the instructions are executed. If the spectrum collecting mode is complex and all the instructions cannot be issued at one time, the PC issues the instructions of the FPGA instruction storage space quantity firstly, does not mark the register for finishing instruction issuing, and directly sends the instruction for starting measurement. And the electronic equipment starts to execute the instructions one by one after receiving the measurement starting instruction, and simultaneously checks the instruction sending completion register. If the register is not marked, starting to calculate the number of the executed instructions, if the number of the executed instructions reaches half of the instruction storage space, sending a request for continuously issuing the instructions and the number of the instructions which can be sent to the PC, after receiving the request, the PC issues subsequent instructions according to the number of the requested instructions, and judging whether the instruction sending completion register needs to be marked according to whether all the instructions are sent completely. The FPGA continues to execute the remaining instructions in the instruction memory while sending requests and receiving new instructions. If the electronic equipment detects that the instruction sending completion register is marked, the electronic equipment does not send a request for continuing sending to the PC. Because the execution time of the instruction is far longer than the instruction issuing time, the continuity of the instruction execution in the FPGA can be ensured. Through the full duplex mode of executing the instruction and receiving the instruction, the number of executable instructions of the equipment can be greatly increased, and the capability of continuously acquiring the spectrum for a long time by the equipment is expanded.

Specifically, in a Beijing synchrotron radiation device 1W1B experiment station, a Cu standard sample with the thickness of 5 microns is adopted for testing, a continuous scanning mode is used, the motor scanning speed is 5000pps, and the reciprocating two-way acquisition is carried out. Two cycles of continuous operation, as shown in FIG. 4, for a total of four spectra (CuRun1-4), each spectra was acquired at approximately 8.1 seconds. This was compared to the step-scan XAFS spectrum (about 12 minutes), and the curves of the two were observed as shown in fig. 4, and were found to be almost perfectly coincident, sufficiently accounting for the practical effects of the fast-scan XAFS system. And compared to the intelligent electronics terminal test results (Cu foil-Qscan, about 17 seconds), the data are completely coincident, but the time resolution of the fast scan XAFS system is doubled.

The information processing device 2 has very strong adaptability and flexibility, ADC acquisition and stepping motor driving functions are controlled by FPGA chip programming, the spectrum acquisition process is completely parameterized and ordered, and experimental modes such as continuous scanning, multi-trapezoid scanning and the like can be realized by configuring different parameters according to the research requirement

On the basis of the above embodiment, the information processing apparatus 2 includes an FPGA, and different spectrum sampling schemes are implemented by performing programming control on the FPGA. And the FPGA receives and executes a spectrum acquisition command of the computer component 3 to realize the spectrum acquisition scheme.

The FPGA device belongs to a semi-custom circuit in an application-specific integrated circuit, is a programmable logic array, and can effectively solve the problem of less gate circuits of the original device. The basic structure of the FPGA comprises a programmable input/output unit, a configurable logic block, a digital clock management module, an embedded block RAM, wiring resources, an embedded special hard core and a bottom layer embedded functional unit. The FPGA has the characteristics of abundant wiring resources, high repeatable programming and integration level and low investment, and is widely applied to the field of digital circuit design. The design process of the FPGA comprises algorithm design, code simulation, design and board machine debugging, wherein an algorithm framework is established by a designer and actual requirements, an EDA (electronic design automation) is used for establishing a design scheme or an HD (high definition) for compiling design codes, the code simulation is used for ensuring that the design scheme meets the actual requirements, finally, board level debugging is carried out, related files are downloaded into an FPGA chip by a configuration circuit, and the actual operation effect is verified.

The information processing device 2 adopts an integrated design, integrates the functions of a plurality of devices together according to modularization, and greatly saves space and cost. Meanwhile, a unified high-precision clock is adopted, so that the time synchronism and reliability are improved, the problem of communication delay among a plurality of devices is solved, and the experiment efficiency is improved.

A data acquisition module, a data cache module, a logic control module, a motor control module and a data transmission module are integrated on a Field Programmable Gate Array (FPGA). The measuring circuit collects and processes current signals of X-ray intensity generated by an X-ray detector in a QXAFS experiment, and the current signals are processed into digital signals and then sent to the data acquisition module.

The data acquisition module stores the digital signal to the data cache module; the data cache module is connected with the logic control module, and the logic control module is connected with the data transmission module.

And the motor control module generates a motor control signal according to the spectrum acquisition command, sends the motor control signal to the motor driver 11 and controls the motor driver 11 to rotate.

The channel through which the motor control module sends out the motor control signal according to the spectrum acquisition command can be understood as a stepping motor control output channel of the FPGA. And the motor control output channel is mainly used for controlling the motor driver 11 to rotate.

The design can improve the time resolution of the XAFS experiment, and realize the accurate control of the scanning direction and speed of the monochromator 13, so that the monochromator can scan back and forth in a certain angle range at a proper and fast speed, and the energy of the incident X-ray can be changed periodically and continuously. The prior art intelligent electronic device can only realize the function in a sectional mode due to the limitation of the capacity of the register, and if the parameters of each scanning are inconsistent, a new configuration file needs to be rewritten after each scanning is finished, so that the next scanning process can be started.

The data transmission module acquires the digital signal from the data cache module through the logic control module and transmits the digital signal to the computer component 3.

The measurement circuit comprises a first channel and a second channel; the first channel is used for acquiring a first current signal of a front ionization chamber 4 in a QXAFS experiment, and the current signal of the front ionization chamber 4 represents the ray intensity before X-rays pass through a sample; the second channel is used for acquiring a second current signal of the rear ionization chamber 5 in the QXAFS experiment, and the current signal of the rear ionization chamber 5 represents the ray intensity of X-rays after the X-rays pass through a sample.

The measurement circuit includes a third channel; the third channel is used for collecting a third current signal of a fluorescence ionization chamber in a QXAFS experiment, and the current signal of the fluorescence ionization chamber represents the X-ray fluorescence intensity generated after the interaction between the sample and the X-ray.

The measurement circuit further comprises a fourth channel; the fourth channel is used for collecting the transmission signal of the standard sample.

The measuring circuit comprises a digital-to-analog conversion module, and the digital-to-analog conversion module is used for converting the current signal into a digital signal.

The measurement circuit includes 4 ADC signal input channels. The sampling precision of each ADC is 16 bits, the highest sampling rate is 10MHz, and the high enough measurement precision and the high enough acquisition speed are ensured. An ADC is an Analog-to-digital converter, which is referred to as an Analog-to-digital converter, and an Analog-to-digital converter, which is a device for converting a continuous signal in an Analog form into a discrete signal in a digital form. An analog to digital converter may provide the signal for measurement. A typical analog-to-digital converter converts an analog signal into a digital signal representing a proportional voltage value. However, some electronic devices in which the analog-to-digital converter is not pure, such as the rotary encoder 12, may also be considered an analog-to-digital converter.

Such a design may require rapid acquisition of detector data while scanning rapidly. The data acquisition provided by the prior art uses an integration circuit scheme, namely VF converter + pulse counter, to effectively suppress electronic noise by integrating for a long time (greater than 0.1 second), but this scheme is not suitable for fast data acquisition (sampling time of a single data point is less than 1 millisecond).

And 4 ADC signal input channels and 1 stepping motor control output channel are controlled by the FPGA chip. The high real-time performance and the timing precision of the FPGA ensure the strict consistency of the motor state data and the measured data. The following problems are solved: to obtain the XAFS experimental spectra, the incident X-ray energy (i.e., monochromator 13 angle) and absorption coefficient values (scaled from detector data) for each data point need to be determined simultaneously. In the step mode, the motion control and data acquisition of the monochromator 13 are separated, i.e. the motor of the monochromator 13 is at rest at the time of data acquisition. However, during the fast scan, the movement of the monochromator 13 and the data acquisition are synchronized. The time synchronism between the two needs a uniform clock for control, and the output needs to synchronously output the pulse number and the collected data, otherwise, the spectrum is distorted.

The embodiment of the invention provides a rapid scanning XAFS system, which can realize measurement of an XAFS spectrum in the order of seconds to minutes by constructing information interaction among a measurement circuit, a data acquisition module, a data cache module, a logic control module, a motor control module and a data transmission module, and obtains a very good experimental result after experimental verification. The system aims to provide powerful experimental support for representing the dynamic change process of the in-situ experiment on one hand; and on the other hand, a flexible programmable experimental mode is provided to adapt to the research requirements of different time scales.

On the basis of the above embodiment, a first current amplifier is arranged between the front ionization chamber 4 and the first channel to amplify the first current signal; a second current amplifier is arranged between the rear ionization chamber 5 and the second channel to amplify the second current signal.

On the basis of the above embodiment, the FPGA may further include a command cache module, and the command cache module is connected to the logic control module; the computer component 3 issues a spectrum acquisition command to the command cache module through the data transmission module and the logic control module; the command takes one step of motor rotation as a basic command, and programmable fast scan XAFS spectrum acquisition can be realized by matching with other commands.

The fast scanning XAFS system integrates the functions of signal measurement and stepping motor driving, and the spectrum collection process is completely parameterized and ordered. By setting different parameters and different commands, the whole spectrum acquisition process can be programmed on line, and is not limited to a certain spectrum acquisition mode, and users can write different commands according to different requirements, so that spectrum acquisition in any mode is realized, and the adaptability and flexibility of the equipment are greatly improved.

On the basis of the above embodiment, the system further comprises a high-precision clock synchronization module. IEEE1588-2019 is a protocol for realizing high-precision clock synchronization in a network system, and mainly comprises a high-precision clock reference source (GPS, rubidium clock and the like), a synchronous switch and board card nodes, wherein each node board card in the clock synchronization network can provide a synchronous clock with the synchronization precision better than 1 ns. Because the requirements of synchronous radiation experiments on synchronous measurement mainly are synchronous requirements of synchronous starting measurement and the like among a plurality of devices under relative time, absolute time synchronization under UTC time is not required (for example, different devices are required to start measurement at a certain minute and a certain second at a certain time in a certain day in a certain month in a certain year), the electronic device simplifies an IEEE1588-2019 protocol during synchronous design, removes a high-precision clock reference source part with high price, and integrates the design of a clock synchronization node with the electronic design, so that the electronic device realizes a clock synchronization function under the condition of not additionally using a node board card. When the electronic device is designed, the functions of node design, measurement, control and the like are designed on one PCB, the same chip is multiplexed, for example, the FPGA for measurement and the FPGA for synchronous nodes are multiplexed, only one FPGA chip is used, and the node FPGA design is used as an IP and is integrated into the design of the FPGA for measurement. By adopting the fusion design, each electronic device can be regarded as a synchronous node with the functions of measurement and control. After a plurality of electronic devices are connected to the synchronous switch, the synchronization among the electronic devices can be realized. Because the synchronous switch is compatible with a standard Ethernet switch, and the electronic equipment adopts a standard TCP protocol for data transmission, the clock synchronization network can be borrowed for data transmission, and the clock synchronization and the data transmission of a plurality of pieces of equipment can be realized only by using the synchronous switch.

On the basis of the above embodiment, the information processing apparatus 2 is reserved with an expansion interface. The fast scanning XAFS system is based on a traditional double-crystal monochromator 13 and a detector, the traditional equipment is conventional equipment of an XAFS experimental station, other equipment does not need to be additionally arranged, an interface adopts standard BNC, serial ports and network ports, the universality is strong, and the fast scanning XAFS system can be applied to a plurality of XAFS experimental stations.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A fast scan XAFS system, comprising: a monochromator adjusting device, an information processing device and a computer component;

the information processing device processes the current signal into a digital signal and stores the digital signal; the computer component issues a spectrum acquisition command to the information processing device, and the information processing device generates a motor control signal according to the spectrum acquisition command, wherein the motor control signal is used for controlling the monochromator adjusting device; and the information processing device simultaneously transmits the digital signal and the count value of the sent motor control signal to a computer component for storage by the computer component.

2. A fast-scan XAFS system according to claim 1, wherein the monochromator adjustment means comprises a motor drive;

the motor driver is used for controlling the monochromator to rotate, and when the monochromator is positioned at different angles, the incident X-rays are processed into monochromatic light with different energies.

3. A fast scan XAFS system according to claim 2, wherein the motor driver receives a motor control signal from the information processing device and controls the motor driver to rotate to change the angle of the monochromator in response to the signal.

4. A fast-scanning XAFS system according to claim 2, wherein the monochromator adjustment means further comprises an encoder;

5. The fast-scanning XAFS system according to claim 1, wherein a sample stage is further disposed between the front and rear ionization chambers, the sample stage having a sample to be tested placed thereon; the fluorescence detector is used for collecting current signals of X-ray fluorescence intensity generated when monochromatic light passes through a sample to be tested, and transmitting the current signals to the information processing device.

6. A fast-scanning XAFS system according to claim 1, wherein the information processing apparatus communicates with the computer assembly using standard TCP/IP protocols to transmit the count of motor control signals and the digital signals to the computer assembly.

7. A fast-scanning XAFS system according to claim 1, wherein the information processing means comprises an FPGA, and wherein the different sampling schemes are implemented by programming the FPGA.

8. The fast-scanning XAFS system according to claim 7, wherein the FPGA receives and executes a sampling spectrum command of a computer component implementing the sampling spectrum scheme.

9. A fast-scanning XAFS system according to claim 1, further comprising a high precision clock synchronization module.

10. A fast-scanning XAFS system according to claim 9, wherein the information processing apparatus is reserved with an extended interface.