CN212111821U - X-ray time evolution process measuring device - Google Patents

Abstract

An X-ray time evolution process measurement device relates to the field of quantitative measurement of X-ray radiation flow, the X-ray time evolution process measurement device comprises: a pulse stretching system and a signal processing system, the pulse stretching system includes an acceleration zone, a drift zone and a collection area, the acceleration area is used to accelerate the electrons, and the speed of the electrons entering the acceleration area in different time periods is different, the drift area is used to make the electrons move at a uniform speed, and the collection area is used to collect the electrons; The signal processing system is connected to the collection area, and is used for obtaining signal measurement results through a spread-back calculation. The X-ray time evolution process measuring device can expand the signal, and then obtain the measurement result of the short pulse signal through the stretching back calculation, so as to realize the measurement with high time resolution.

Description

X-ray time evolution measuring device

technical field

The utility model relates to the field of quantitative measurement of X-ray radiation flow, in particular to an X-ray time evolution process measurement device.

Background technique

In inertial confinement laser fusion research, X-ray radiation flow diagnostics are currently measured using two complementary techniques.

One technique is to use a soft X-ray spectrometer composed of an X-ray diode (XRD) array to measure the X-ray radiation flux and radiation energy spectrum. At present, the time-resolved energy spectrum with a resolution of the order of 100ps can be obtained through the energy channel response.

Another technique is to use a flat-response detector composed of a flat-response film and gold cathode XRD. The detector is also measured based on an XRD detector, and its time resolution is consistent with that of a soft X-ray energy spectrometer composed of an XRD array. Although this technology and device can realize quantitative measurement in X-ray time evolution measurement, which can meet the research needs, there are still the following shortcomings: the time resolution is not high enough to meet the measurement of X-ray time evolution process of faster signals.

Utility model content

The purpose of the present invention is to provide an X-ray time evolution process measurement device, which can broaden the signal, and then obtain the measurement result of the short pulse signal through the stretching back calculation, thereby realizing the measurement with high time resolution.

The utility model is realized in this way:

An X-ray time evolution process measurement device, comprising: a pulse stretching system and a signal processing system, wherein:

The pulse stretching system includes an acceleration zone, a drift zone and a collection zone, the acceleration zone is used to accelerate electrons, and the speed of electrons entering the acceleration zone in different time periods is different, and the drift zone is used to make the electrons Moving at a uniform speed, the collection area is used to collect electrons.

The signal processing system is connected to the collection area, and is used for obtaining signal measurement results through spread-back calculation.

In a feasible embodiment, the pulse stretching system includes a magnetic focusing tube, and a magnetic focusing flight zone is formed in the magnetic focusing tube, and the acceleration zone, the drift zone and the collection zone are all located in the magnetic focusing flight zone Area.

In a feasible embodiment, a cathode plate and an anode grid are arranged in the magnetic focusing tube, and the cathode plate and the anode grid generate a time-varying electric field excited by radio frequency under the action of a ramp bias, so as to form the the acceleration zone.

In one possible embodiment, the cathode plate is a flat response transmissive cathode plate.

In a feasible embodiment, a rear-end grid is arranged in the magnetic focusing tube, the anode grid and the rear-end grid are both grounded, and a gap is formed between the anode grid and the rear-end grid. the drift region.

In a feasible implementation, an electron collector is arranged in the magnetic focusing tube, and the electron collector is connected to an oscilloscope.

In a possible embodiment, the electron collector is a reflective X-ray diode.

In a feasible implementation, the X-ray time evolution process measurement device further includes a biased T-type isolator, and the electron collector and the oscilloscope are connected through the biased T-type isolator.

In one possible implementation, the biased T-type isolator includes an RC blocking circuit.

In a feasible embodiment, the X-ray time evolution process measurement device further comprises a signal generator, the signal generator is respectively connected with the cathode plate and the anode grid, so as to connect the cathode plate with the anode grid. The anode grid applies a ramp bias.

The beneficial effects of the present utility model at least include:

During use, X-rays enter the acceleration zone after forming photoelectrons. In the acceleration zone, the photoelectrons entering the acceleration zone at different time periods have different speeds, and enter the collection zone after the photoelectrons drift for a period of time, so the collected signal waveform is relatively incident. The signal waveform is broadened in the time domain width, so that the time of the electronic pulse is amplified. The signal waveform after time domain expansion is transmitted to the signal processing system, and the signal processing system obtains the signal measurement result through the stretching back calculation.

The X-ray time evolution process measurement device provided by the present application broadens the short pulse signal, and then the measurement result of the short pulse signal can be obtained through the stretching back calculation, thereby realizing the measurement with high time resolution.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention. Therefore, it should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram one of a pulse stretching system in an X-ray time evolution process measurement device provided by an embodiment of the present invention;

2 is a second structural schematic diagram of a pulse stretching system in an X-ray time evolution process measurement device provided by an embodiment of the present invention;

3 is a schematic structural diagram of an X-ray time evolution process measurement device provided by an embodiment of the present utility model;

FIG. 4 is a waveform diagram of a ramp bias applied to an acceleration region in an X-ray time evolution process measurement device provided by an embodiment of the present invention.

In the picture:

110 - acceleration zone;

120 - drift zone;

130 - Collection area;

140 - Magnetic focus flight zone;

150 - Magnetic focusing tube;

151 - cathode plate;

152 - Anode grid;

153 - rear grid;

154 - Electron collector;

160-biased T-type isolator;

170 - oscilloscope;

200 - Signal generator.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. The embodiments described above are a part of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that is usually placed when the utility model product is used, only for the convenience of describing the present utility model and simplifying the description, not Indicating or implying that the X-ray time evolution process measuring device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhanging" etc. do not imply that a component is required to be absolutely horizontal or overhang, but rather may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal than "vertical", it does not mean that the structure must be completely horizontal, but can be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arrangement", "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Some embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. The embodiments described below and features in the embodiments may be combined with each other without conflict.

first embodiment

Referring to FIG. 1 to FIG. 3 , this embodiment provides an X-ray time evolution process measurement device, including: a pulse stretching system and a signal processing system, wherein:

The pulse stretching system includes an acceleration zone 110, a drift zone 120 and a collection zone 130. The acceleration zone 110 is used to accelerate the electrons, and the speed of the electrons entering the acceleration zone 110 in different time periods is different, and the drift zone 120 is used to make the electrons move at a uniform speed , the collection area 130 is used to collect electrons.

The signal processing system is connected to the collection area 130 for obtaining signal measurement results through a spread-back calculation.

The device uses pulse broadening technology to broaden the short pulse signal, and combined with the existing XRD diagnosis technology, the measurement result of the short pulse signal can be obtained through the stretching back calculation, thereby realizing the measurement with high time resolution.

Assuming that the pulse width of the measured signal is 20 ps and the pulse width is 10 times, the pulse width of the extended signal is 200 ps, then the existing 100 ps time-resolved diagnostic equipment has sufficient capability to measure the extended signal.

As shown in FIG. 1 , the pulse stretching system includes a magnetic focusing tube 150 , and a magnetic focusing flight zone 140 is formed in the magnetic focusing tube 150 .

As shown in FIG. 2 , the magnetic focusing tube 150 is provided with a cathode plate 151 and an anode grid 152 , and the cathode plate 151 and the anode grid 152 generate a time-varying electric field of radio frequency excitation under the action of a ramp bias to form the acceleration zone 110 .

The X-ray radiation signal interacts with the cathode plate 151 to emit photoelectrons, and the photoelectrons enter the acceleration region 110 between the cathode plate 151 and the anode grid 152, and are generated by the cathode plate 151 and the anode grid 152 under the action of the ramp bias. The time-varying electric field is excited by radio frequency, and the intensity of the electric field decreases with time, so the photoelectrons generated at different times obtain different speeds.

For short-pulse input signals, optimizing the time-varying voltage of the acceleration zone 110 and controlling the relative time relationship between the optical pulse and the excitation electrical pulse of the cathode plate 151 can reduce the difference in broadening magnification caused by the difference in entry time and achieve quasi-linear broadening. Specifically, the X-rays are synchronized on the rising edge of the ramp bias pulse signal, so that the photoelectrons emitted first obtain more energy than the photoelectrons that follow, so that the speed of the front photoelectrons is faster.

Further, a rear-end grid 153 is arranged in the magnetic focusing tube 150. In order to avoid induced current in the collection area 130, the anode grid 152 and the rear-end grid 153 are both grounded, that is, the anode grid 152 and the rear-end grid 153 are grounded. At the same potential, a drift region 120 is formed between the anode grid 152 and the rear-end grid 153 . The photoelectrons accelerated by the acceleration zone 110 enter the drift zone 120 with different axial initial velocities, and the photoelectrons drift uniformly in the drift zone 120. Since the photoelectrons have different axial initial velocities, their drift times are different.

In one possible embodiment, the back end grid 153 is an XRD grid.

In a possible embodiment, an electron collector 154 is provided in the magnetic focusing tube 150 , and the electron collector 154 is connected to the oscilloscope 170 . The electron collector 154 collects the electrons and outputs them to the oscilloscope 170 to output a signal waveform through the oscilloscope 170 .

During specific implementation, preferably, the cathode plate 151 is a flat-response transmissive cathode plate. Since the cathode plate 151 used is a flat corresponding projection cathode plate, the corresponding relationship between the signal intensity recorded by the oscilloscope 170 and the total amount of reagents in the X-ray radiation flow can be easily obtained through calibration, so that the signal recorded by the oscilloscope 170 can be reflected. The magnitude of the X-ray radiation stream at the push.

In this embodiment, the electron collector 154 uses electron collecting electrodes.

Preferably, the electron collector 154 employs reflective XRD.

As shown in FIG. 3 , further, the X-ray time evolution process measurement device further includes a biased T-type isolator 160 , and the electron collector 154 and the oscilloscope 170 are connected through the biased T-type isolator 160 . Biased T-isolator 160 applies a bias to reflective XRD.

Preferably, the bias T-type isolator 160 includes an RC blocking circuit to ensure that the positive bias voltage is applied to the output head without affecting the output of the pulse signal.

In a feasible embodiment, the X-ray time evolution process measurement device further includes a signal generator 200, which is connected to the cathode plate 151 and the anode grid 152, respectively, so as to apply a ramp bias to the cathode plate 151 and the anode grid 152. pressure.

As shown in FIG. 3 and FIG. 4 , this embodiment provides a set of experiments, and the experiments are carried out on a short-pulse laser device, using pulsed light with a wavelength of 266 nm as a detection signal. In this experiment, the short-pulse laser is generated by the signal generator 200 , and the signal generator 200 is used to provide ramp bias pulses for the cathode plate 151 and the anode grid 152 . The anode grid 152 and the rear grid 153 are both grounded, and an electron collector 154 is arranged on the side of the rear grid 153 away from the anode grid 152. The electron collector 154 adopts a reflective XRD. In order to ensure the time of the reflective XRD To resolve, a bias voltage of 1500V needs to be applied. The bias voltage application method of the reflective XRD needs to use the bias voltage T-type isolator 160 . The bias T-type isolator 160 is an RC blocking circuit, which ensures that the positive bias voltage is applied to the output head without affecting the output of the pulse signal. The signal of the reflection XRD is output to the oscilloscope 170 .

Specifically, the signal generating device in FIG. 3 provides a short-pulse laser with a wavelength of 266 nm, and the short-pulse laser is irradiated to the flat response projection cathode plate, and photoelectrons are generated at the cathode plate 151, and the photoelectrons are in the acceleration region 110 (ie, the ramp bias electric field) Therefore, the photoelectrons entering the acceleration region 110 in different periods generate different initial velocities. After the photoelectrons with different initial velocities move at a constant speed for a certain distance in the drift zone 120 of the magnetic focusing flight zone 140 , they are finally received by the electron collector 154 and output to the oscilloscope 170 . The electron collector 154 can ensure time resolution by using reflection XRD.

The time resolution of the X-ray time evolution process measurement device reaches 100ps. For a signal with a pulse width of 8ps, the preset stretching magnification M=10. According to the pulse stretching formula:

Among them, t ₁ is the time when the first electron enters the acceleration zone, t ₂ is the time when the last electron enters the acceleration zone, t' ₁ is the time when the first electron is ejected from the acceleration zone, and t ₂ ' is the time when the last electron is emitted by the acceleration zone. The ejection time of the acceleration zone, e is the electron quantity, m is the electron mass, k is the ramp-up slope of the pulse bias source, U ₀ is the initial voltage, and s is the electron drift distance.

As shown in FIG. 4 , the existing k=40V/ps, U0 ₌ -4000V. Assuming that the electron enters the time t ₁ =25ps, then s=42mm can meet the need of widening. In order to ensure the measurement effect, increase the preset magnification to 100, other conditions remain unchanged, and the electronic drift distance can be increased to 420mm.

For the above short pulse input signal, the time-varying voltage of the acceleration zone 110 can be optimized to control the relative time relationship between the optical pulse and the excitation electrical pulse applied to the cathode plate 151, thereby reducing the difference in broadening magnification caused by the difference in entry time, and achieving accurate Linear stretch.

Specifically, the X-ray synchronization is made on the rising edge of the ramp bias pulse signal. For example, in FIG. 4, the electron entry time can be controlled to be between 0-100ps, 100ps-200ps, or 200ps-300ps and other rising intervals. , during these time periods, the photoelectrons that are emitted first gain more energy than the photoelectrons that are later, making the photoelectrons emitted first to travel faster.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. an X-ray time evolution process measuring device, is characterized in that, comprises: pulse stretching system and signal processing system, The pulse stretching system includes an acceleration zone, a drift zone and a collection zone, the acceleration zone is used to accelerate electrons, and the speed of electrons entering the acceleration zone in different time periods is different, and the drift zone is used to make the electrons Uniform motion, the collection area is used to collect electrons; The signal processing system is connected to the collection area, and is used for obtaining signal measurement results through spread-back calculation. 2 . The X-ray time evolution process measurement device according to claim 1 , wherein the pulse stretching system comprises a magnetic focusing tube, and a magnetic focusing flight zone is formed in the magnetic focusing tube, and the acceleration zone, the drift zone and the drift zone are formed in the magnetic focusing tube. 3 . Both the area and the collection area are located in the magnetic focusing flight area. 3 . The X-ray time evolution process measuring device according to claim 2 , wherein a cathode plate and an anode grid are arranged in the magnetic focusing tube, and the cathode plate and the anode grid are in a slope biased relationship. 4 . Under the action, a time-varying electric field excited by radio frequency is generated to form the acceleration zone. 4 . The X-ray time evolution process measurement device according to claim 3 , wherein the cathode plate is a flat response transmission cathode plate. 5 . 5 . The X-ray time evolution process measurement device according to claim 3 , wherein a rear-end grid is arranged in the magnetic focusing tube, the anode grid and the rear-end grid are both grounded, and the anode grid is grounded. 6 . The drift region is formed between the grid and the back-end grid. 6 . The X-ray time evolution process measurement device according to claim 5 , wherein an electron collector is arranged in the magnetic focusing tube, and the electron collector is connected to an oscilloscope. 7 . 7 . The X-ray time evolution process measurement device according to claim 6 , wherein the electron collector is a reflective X-ray diode. 8 . 8 . The X-ray time evolution process measurement device according to claim 6 , further comprising a biased T-shaped isolator, and the biased T-shaped isolator is passed between the electron collector and the oscilloscope. 9 . connect. 9 . The X-ray time evolution process measurement device according to claim 8 , wherein the bias T-type isolator comprises an RC blocking circuit. 10 . 10 . The X-ray time evolution process measuring device according to claim 3 , further comprising a signal generator, and the signal generator is respectively connected to the cathode plate and the anode grid, so as to be the cathode for the cathode. 11 . A ramp bias is applied to the plate and the anode grid.

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