Ion kinetic energy modulation device and method

Abstract

The invention discloses an ion kinetic energy modulation device, which comprises a vacuum cavity, a drift tube, a time sequence device, a voltage signal source, an ion beam, an ion source and an ion detector, constant potential is loaded on the vacuum cavity, an ion source, a drift tube and an ion detector are sequentially arranged in the vacuum cavity, and an ion beam emitted by the ion source enters from one end of the drift tube, penetrates through the drift tube and finally reaches the ion detector; the time sequence device controls the voltage signal source to load potential for the drift tube; the invention further discloses an ion kinetic energy modulation method, the relative position of the ion beam relative to the drift tube is obtained, when the ion beam is in the drift tube, constant potential is loaded on the drift tube to adjust the overall speed of the ion beam, and when the ion beam enters the drift tube or is ready to leave the drift tube, the drift tube loads changing potential to adjust the speed of the ion beam. And carrying out ion velocity distribution adjustment on the ion beam. According to the invention, only one drift tube is needed, and the change of ion kinetic energy and ion kinetic energy broadening can be realized by adjusting the potential of the drift tube.

Description

Technical Field

[0001] This invention belongs to the field of ion beam technology, and relates to an ion kinetic energy modulation device and an ion kinetic energy modulation method, which are applicable to the kinetic energy modulation of ion beams. Background Technology

[0002] Ions, as one of the most important elements in nature, are widely used not only in laboratories but also in people's daily lives. Especially in applications and research related to ion beams, adjusting ion kinetic energy, particularly adjusting the broadening of ion kinetic energy, often requires the use of relatively complex electrode combinations, which brings great inconvenience to the design and construction of application devices. At the same time, the complex structure also limits its application scenarios and scope. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in the prior art by providing an ion kinetic energy modulation device and an ion kinetic energy modulation method.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: An ion kinetic energy modulation device includes a vacuum cavity, a drift tube, a timing device, a voltage signal source, an ion beam, an ion source, and an ion detector; a constant potential is applied to the vacuum cavity. An ion source, a drift tube, and an ion detector are sequentially arranged inside the vacuum chamber. The ion beam emitted by the ion source enters from one end of the drift tube, passes through the drift tube, and finally reaches the ion detector. The timing device controls the voltage signal source to apply a potential to the drift tube.

[0005] The ion beam consists of ion clusters emitted multiple times at equal time intervals from an ion source, with each emitted ion cluster having an initial velocity... The charge-to-mass ratio is consistent; the drift tube 1 is a tubular metal electrode.

[0006] An ion kinetic energy modulation method, utilizing the aforementioned ion kinetic energy adjustment device, includes the following steps: Step 1: Scan the time interval between the time when the drift tube is applied to the potential and the time when the ion cluster is emitted by the ion source. Based on the time-of-flight spectrum pulse signal of the ion beam, obtain the position of the ion beam relative to the drift tube at different time intervals. Step 2: Based on the different positions of the ion beam relative to the drift tube, the timing device controls the voltage signal source to apply a potential to the drift tube, thereby modulating the ion kinetic energy of the ion beam.

[0007] The process of obtaining the position of ion beam 4 relative to drift tube 1 at different time intervals includes the following steps: The ion beam is positively charged, and a constant potential is applied to the vacuum cavity. A timing device triggers a voltage signal source to apply a constant potential to the drift transistor. and make ; The time interval between the moment the drift tube is applied to the potential and the moment the ion clusters emitted by the ion source are scanned. If the following occur in sequence: the pulse signal of the ion beam's time-of-flight spectrum does not change, the pulse signal of the ion beam's time-of-flight spectrum is distorted at the front end, the pulse signal of the ion beam's time-of-flight spectrum shifts forward as a whole, the pulse signal of the ion beam's time-of-flight spectrum is distorted at the end, and the pulse signal of the ion beam's time-of-flight spectrum does not change, then the relative positions of the ion beam and the drift tube are as follows: the ion beam has not reached the drift tube inlet, the ion beam has reached the drift tube inlet and some ions have entered the drift tube, the ion beam is entirely located inside the drift tube, the ion beam is entirely located at the drift tube outlet and some ions have flown away from the drift tube, and the ion beam leaves the drift tube outlet.

[0008] When the time-of-flight spectrum pulse signal of the ion beam just begins to distort, the position of the ion beam relative to the drift tube is as follows: the ion beam reaches the drift tube inlet; after the ion beam reaches the drift tube inlet, time elapses... The ion beam's position relative to the drift tube during flight is such that the ion beam is ready to leave the drift tube outlet; where... The length of drift tube 1, The initial velocity of the ion beam originating from the ion source is given.

[0009] The modulation of the ion beam's kinetic energy includes: The ion beam carries a positive charge. When the ion beam reaches the entrance of the drift tube, a timing device triggers a voltage signal source to load the drift tube with a potential that decreases over time. This reduces the velocity distribution of the ion beam. The ion beam carries a negative charge. When the ion beam reaches the inlet of the drift tube, a timing device triggers a voltage signal source to apply a time-increasing potential to the drift tube. This reduces the velocity distribution of the ion beam. The ion beam carries a positive charge. When the ion beam reaches the entrance of the drift tube, a timing device triggers a voltage signal source to apply a time-increasing potential to the drift tube. Increase the velocity distribution of the ion beam; The ion beam carries a negative charge. When the ion beam reaches the inlet of the drift tube, a timing device triggers a voltage signal source to load the drift tube with a potential that decreases over time. This increases the velocity distribution of the ion beam.

[0010] The potential As time increases, Based on the following formula: ; The potential As time goes by, Based on the following formula: ; in, For time variables, This represents the initial energy width distribution of the ion beam. Let be the charge of each ion in the ion beam. The voltage signal source is the change in voltage applied to the drift transistor. Time spent.

[0011] The modulation of the ion beam's kinetic energy includes: When the ion beam carries a positive charge and is entirely located inside the drift tube, a timing device triggers a voltage signal source to apply a constant potential to the drift tube. ,and The overall velocity of the ion beam is reduced and adjusted. When the ion beam carries a positive charge and is entirely located inside the drift tube, a timing device triggers a voltage signal source to apply a constant potential to the drift tube. ,and The overall speed of the ion beam is increased and adjusted. When the ion beam carries a negative charge and is entirely located inside the drift tube, a timing device triggers a voltage signal source to apply a constant potential to the drift tube. ,and The overall speed of the ion beam is increased and adjusted. When the ion beam carries a negative charge and is entirely located inside the drift tube, a timing device triggers a voltage signal source to apply a constant potential to the drift tube. ,and The speed of the ion beam is adjusted to decrease overall.

[0012] The modulation of the ion beam's kinetic energy includes: The ion beam carries a positive charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam is adjusted to reduce the ion velocity distribution and increase the overall velocity. The ion beam carries a positive charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam is adjusted to reduce the ion velocity distribution and the overall velocity. The ion beam carries a positive charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam is adjusted to increase the ion velocity distribution and the overall velocity. The ion beam carries a positive charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam is adjusted to increase the ion velocity distribution while decreasing the overall velocity. The ion beam carries a negative charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam is adjusted to reduce the ion velocity distribution and the overall velocity. The ion beam carries a negative charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam is adjusted to reduce the ion velocity distribution and increase the overall velocity. The ion beam carries a negative charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam is adjusted to increase the ion velocity distribution while decreasing the overall velocity. The ion beam carries a negative charge. As the ion beam prepares to leave the drift tube outlet, a timing device triggers a voltage signal source to apply a potential to the drift tube. electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam is adjusted to increase the ion velocity distribution and the overall velocity.

[0013] The potential As time increases, Based on the following formula: ; The potential As time goes by, Based on the following formula: ; in, This is a DC potential bias. For time variables, Let represent the initial energy width distribution of the ion beam, and q represent the charge of each ion in the ion beam. The voltage signal source is the change in voltage applied to the drift transistor. Time spent.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention does not require complex electrodes for adjusting ion kinetic energy. It only requires a drift tube. By adjusting the potential of the drift tube, the ion kinetic energy or the ion kinetic energy broadening can be changed, and the ion kinetic energy and the ion kinetic energy broadening can be changed simultaneously.

[0015] 2. This invention greatly simplifies the instrument structure and reduces the complexity of the system design. At the same time, the simple structure is easy to extend to other applications and has good scalability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 The potential simulation diagram shows the vacuum cavity and drift tube under one state, where the drift tube potential is 100V and the vacuum cavity potential is 0V. Figure 3 The potential simulation diagram is shown for the vacuum cavity and drift tube under another state, where the potential of the drift tube is -50V and the potential of the vacuum cavity is 0. Figure 4 This is a schematic diagram of the structure when ions have completely entered the drift tube. Figure 5 This is a schematic diagram of the structure when ions fly away from the drift tube; In the diagram, 1-drift tube; 2-timing device; 3-voltage signal source; 4-ion beam; 5-vacuum chamber; 6-ion source; 7-ion detector. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] Example 1: like Figure 1 As shown, an ion kinetic energy modulation device includes a drift tube 1, a timing device 2, a voltage signal source 3, an ion beam 4, a vacuum chamber 5, an ion source 6, and an ion detector 7; a constant potential is applied to the vacuum chamber 5. An ion source 6, a drift tube 1, and an ion detector 7 are sequentially arranged inside the vacuum chamber 5. The ion beam 4 emitted by the ion source 6 enters from one end of the drift tube 1, passes through the drift tube 1, and finally reaches the ion detector 7. The ion beam 4 is a cluster of ions continuously and stably emitted from the ion source 6 (each emitted ion cluster has the same initial velocity, the same charge-to-mass ratio, and the same time interval). The drift tube 1 is a tubular metal electrode, with one end being the inlet and the other end being the outlet. A voltage signal source 3 is connected to the drift tube 1, and the potential applied to the drift tube 1 is the output potential of the voltage signal source 3. A timing device 2 is connected to the voltage signal source 3 and controls the potential output of the voltage signal source 3. The ion beam 4 passing through the drift tube 1 is detected by the ion detector 7, which can be an ion detection instrument such as a Faraday cup, a microchannel plate, or a deceleration field analyzer.

[0020] Figure 2 and Figure 3 This involves simulation calculations of the potential of drift tube 1 and vacuum cavity 5, such as... Figure 2 As shown in the figure, when a ground potential is applied to vacuum cavity 5 and a 100V potential is applied to drift tube 1, it can be seen from the figure that the potential inside drift tube 1 is the same as the potential on drift tube 1, both being 100V. A potential gradient appears at the inlet and outlet of drift tube 1 due to the difference in potential; as shown in the figure... Figure 3 As shown, a ground potential is applied to the vacuum cavity 5, and a -50V potential is applied to the drift tube 1. The potential inside the drift tube 1 changes synchronously with the potential on the drift tube 1 to -50V. Due to the difference in potential, a potential gradient appears at the inlet and outlet of the drift tube 1.

[0021] In summary, when a constant potential is applied to the vacuum cavity 5, the potential inside the drift tube 1 is the output potential of the voltage signal source 3, and the area outside the drift tube 1 inside the vacuum cavity 5 is the constant potential applied to the vacuum cavity 5.

[0022] Example 2: When ions fly freely in space, their kinetic energy broadens, meaning their velocity is not uniform but rather distributed. Therefore, ions disperse in space due to differences in velocity. Generally, in an ion beam, faster ions are in front and slower ions are behind. Furthermore, in many applications, it is necessary to modulate the kinetic energy of the ion beam, including reducing or increasing the velocity distribution, or increasing or decreasing the overall velocity of the ion beam. This can be achieved using the ion kinetic energy modulation device described in Example 1.

[0023] An ion kinetic energy modulation method, utilizing the ion kinetic energy modulation device described in Example 1, includes the following steps: Step 1: Scan the time interval between the time when the potential is applied to the drift tube 1 and the time when the ion clusters emitted by the ion source 6 are emitted. Based on the time-of-flight spectrum pulse signal of the ion beam 4, obtain the position of the ion beam 4 relative to the drift tube 1 at different time intervals.

[0024] In the case of a positively charged ion beam 4 emitted from ion source 6: the positively charged ion beam 4 arrives at ion detector 7 after a period of flight, where it detects the ion signal and generates a time-of-flight spectrum. In this time-of-flight spectrum, the ion signal is presented as a pulse envelope. A constant potential is applied to vacuum cavity 5. Then the potential around drift tube 1 (the region inside vacuum cavity 5 excluding drift tube 1) is: The timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1. and make The timing device 2 is used to scan the timing device 2. The timing device 2 controls the voltage signal source 3 to apply voltage pulses to the drift tube 1. The scanning time is the time when the drift tube 1 is loaded with potential. The time-of-flight spectrum signal of the ion beam 4 is observed to obtain the position of the ion beam 4 relative to the drift tube 1.

[0025] The position of ion beam 4 can be determined through the following phenomena: a) When the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1, When ion beam 4 has not yet reached the inlet of drift tube 1, as it passes through drift tube 1, it encounters a rising potential gradient upon entering drift tube 1, causing its kinetic energy to decrease. Upon leaving drift tube 1, it encounters a falling potential gradient, causing its kinetic energy to increase. The magnitude of the decrease or increase in kinetic energy for each ion in ion beam 4 is [missing value]. ,in, The charge of each ion in ion beam 4 is given. Therefore, the kinetic energy of ion beam 4 remains unchanged before and after passing through drift tube 1, meaning that the time-of-flight spectrum pulse signal of ion beam 4 does not change significantly.

[0026] b. When the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1, When ion beam 4 reaches the inlet of drift tube 1 and some ions enter drift tube 1, the overall kinetic energy of ion beam 4 remains unchanged, but the potential energy of some ions at the tip of ion beam 4 increases. When these ions exit drift tube 1, they will be within a decreasing potential gradient. The ion beam accelerates downwards, but the remaining ions in ion beam 4 undergo the same process as in ion beam a, with no significant change in velocity. This indicates a significant distortion at the front end of the time-of-flight spectrum pulse signal of ion beam 4. When scanning the interval between the moment the potential is applied to drift tube 1 and the moment the ion cluster is emitted by ion source 6, if the time-of-flight spectrum of the ion beam remains unchanged one moment and the front end of the time-of-flight spectrum pulse signal just begins to distort the next moment, it indicates that this time point is the moment the ions enter drift tube 1. Since the distortion of the time-of-flight spectrum signal occurs at the front end, by continuously changing the trigger time and observing the proportion of the distortion range of the time-of-flight spectrum to the entire time-of-flight spectrum signal, when the distortion range at the front end is not significant in the overall signal, it can be determined that ion beam 4 has just begun to enter drift tube 1. Figure 1 As shown.

[0027] c. When the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1, When the ion beam 4 is entirely within the drift tube 1, its overall kinetic energy remains unchanged, but its potential energy increases. As it exits the drift tube 1, it experiences a decreasing potential gradient. The overall acceleration is characterized by a shift in the overall time-of-flight spectrum pulse signal of ion beam 4, such as... Figure 4 As shown.

[0028] d. When the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1. When the ion beam 4 is located entirely at the outlet of drift tube 1 and some ions are exiting drift tube 1, the overall kinetic energy of the ion beam 4 remains unchanged, but the potential energy of the ions at the end of the ion beam 4 increases. As they exit drift tube 1, they will be within a decreasing potential gradient. The ion beam accelerates downwards, but the remaining ions of ion beam 4 have already exited drift tube 1 without a significant change in velocity. This indicates a significant distortion at the end of the pulse signal in the flight time spectrum of ion beam 4. Since the distortion in the flight time spectrum occurs at the end, by continuously changing the trigger time and observing the proportion of the distortion range in the entire flight time spectrum signal, when the distortion range at the signal tail is not significant in the overall signal, it can be determined that ion beam 4 has just begun to exit the drift tube 1 outlet. Figure 5 As shown.

[0029] e. When the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1, When the ion beam 4 has already flown away from the outlet of the drift tube 1, the change in the potential of the drift tube 1 does not affect the ion beam 4, that is, the time-of-flight spectrum pulse signal of the ion beam 4 does not change significantly.

[0030] Since both phenomena a and e involve no significant change in the time-of-flight spectrum pulse signal of ion beam 4, the potential on drift tube 1 will be reloaded during the scanning timing device 2. If the initial loading of the drift tube 1 does not result in a significant change in the time-of-flight spectrum pulse signal of ion beam 4, but a significant change occurs during the scanning timing device 2 (corresponding to any one of phenomena b, c, or e), then the initial loading of the drift tube 1 corresponds to phenomenon a. If the initial loading of the drift tube 1 does not result in a significant change in the time-of-flight spectrum pulse signal of ion beam 4 during the scanning timing device 2, then the initial loading of the drift tube 1 corresponds to phenomenon e.

[0031] In summary, if the following occur sequentially: the time-of-flight spectrum pulse signal of ion beam 4 remains unchanged; the leading edge of the time-of-flight spectrum pulse signal of ion beam 4 is distorted; the overall time-of-flight spectrum pulse signal of ion beam 4 shifts forward; the trailing edge of the pulse signal in the time-of-flight spectrum of ion beam 4 is distorted; and the time-of-flight spectrum pulse signal of ion beam 4 remains unchanged, then the relative positions of ion beam 4 and drift tube 1 are as follows: ion beam 4 does not reach the inlet of drift tube 1; ion beam 4 reaches the inlet of drift tube 1 and some ions enter drift tube 1; ion beam 4 is entirely located inside drift tube 1; ion beam 4 is entirely located at the outlet of drift tube 1 and some ions fly away from drift tube 1; and ion beam 4 leaves the outlet of drift tube 1.

[0032] Furthermore, when the time-of-flight spectrum pulse signal of ion beam 4 just begins to distort (for example, when the distortion range accounts for a proportion of the entire time-of-flight spectrum signal greater than 0 and less than a set threshold), the position of ion beam 4 relative to drift tube 1 is: ion beam 4 reaches the inlet of drift tube 1. Due to the length of drift tube 1... It is fixed; the ion beam 4 enters the drift tube 1 with an initial velocity originating from the ion source 6. If the ion beam 4 flies at a constant speed, then the flight time of the ion beam 4 in the drift tube 1 is... It is fixed, consisting of the time it takes for the ion beam 4 to reach the inlet of drift tube 1 plus the flight time of the ion beam 4 within the drift tube. This allows us to obtain the time when ion beam 4 is ready to leave the outlet of drift tube 1.

[0033] The ion beam 4 emitted from ion source 6 carries a negative charge: The ion beam 4 emitted from ion source 6 carries a negative charge, and a constant potential is applied to vacuum cavity 5. A constant potential greater than that applied to drift tube 1 At that time, that is The negatively charged ion beam 4 accelerates when it encounters a decreasing potential gradient and when it encounters a rising potential gradient. By selecting the same trigger time as the positively charged ion beam 4 emitted from ion source 6, the flight time spectrum of the negatively charged ion beam 4 will be completely consistent with that described in the description of the positively charged ion beam 4 emitted from ion source 6.

[0034] By scanning the timing device 2 to trigger the drift tube 1 to apply a constant potential at different times after the ion cluster emitted by the ion source 6, the position of the ion beam 4 relative to the drift tube 1 at different times can be obtained. Since the ion beam 4 continuously and stably generates ion clusters, determining the relative position of one ion cluster 4 with respect to the drift tube 1 allows the determination of the position of subsequent ion beams 4 with respect to the drift tube 1.

[0035] Step 2: Based on the different positions of the ion beam 4 relative to the drift tube 1, the timing device 2 is triggered to control the voltage signal source 3 to apply a potential to the drift tube 1, thereby modulating the ion kinetic energy of the ion beam 4.

[0036] In ion beam 4, ions with higher kinetic energy travel at higher speeds and reach drift tube 1 more quickly, where they are held at a constant potential by a constant potential. Encountering changes Electric potential.

[0037] The ion beam 4 may exhibit the following behaviors as soon as it reaches the inlet of drift tube 1: Scenario 1: Ion beam 4 carries a positive charge. When ion beam 4 reaches the inlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to load a potential that decreases over time onto drift tube 1. The velocity distribution of ion beam 4 is adjusted at the inlet of drift tube 1.

[0038] Case 1.1, if the electric potential Above the potential Maximum value: When ion beam 4 reaches the inlet of drift tube 1, due to... Then ion beam 4 will encounter a decreased potential gradient, and at this time, ion beam 4 will be in a state of decreased potential gradient. Accelerated under the electric field. The kinetic energy of ion beam 4 increases, and increased kinetic energy means increased velocity. Since the potential of drift tube 1 decreases over time, ions arriving at the entrance of drift tube 1 later will encounter an even lower potential. The larger the value, the greater the acceleration of ions that arrive at the inlet of drift tube 1 later.

[0039] The derivative of the electric potential is the electric field. Electric potential and electric field exist simultaneously. A potential gradient exists at the drift tube opening, and the magnitude of this potential gradient is... When ions move in a gradient potential field, they undergo a conversion between kinetic and potential energy, meaning their kinetic energy changes accordingly. The above analysis shows that ions arriving at the inlet of drift tube 1 earlier have a faster velocity but receive less acceleration at the inlet, while ions arriving later have a slower velocity but receive greater acceleration at the inlet. Therefore, the velocity difference between slower and faster ions in ion beam 4 will significantly decrease, resulting in a correspondingly smaller velocity distribution in ion beam 4.

[0040] Case 1.2, if the electric potential Below the potential The maximum value, but higher than the electric potential. Minimum value: At the initial moment, when ion beam 4 reaches the inlet of drift tube 1, due to... Then ion beam 4 will encounter an increased potential gradient, and at this time, ion beam 4 will be in the increased potential gradient. Under the generated electric field, the ion beam 4 decelerates, and its kinetic energy decreases, which in turn reduces its velocity. Since the potential of drift tube 1 decreases over time, when a section of the ion beam 4 reaches the entrance of drift tube 1, the potential of drift tube 1 becomes the same as the surrounding potential. At this point, the ions encounter a uniform potential at the inlet of drift tube 1, and their kinetic energy remains unchanged, meaning their velocity remains constant. However, as the potential of drift tube 1 continues to decrease over time, at this point... At this point, the ions that reach the inlet of drift tube 1 will encounter a decreasing potential gradient, under which the ions accelerate, that is, the ion velocity increases.

[0041] From the above analysis, we can see that the ions initially reaching the inlet of drift tube 1 are slowed down, and with the change in potential... The reduction, As the ions get smaller, the rate of deceleration decreases until a certain point... Reduce to Similarly, at this time, the ions maintain a constant velocity when passing through the inlet of drift tube 1, and then... At this point, the ions arriving at the inlet of drift tube 1 have increased velocity under the influence of the decreasing potential. That is, ions arriving earlier at the inlet of drift tube 1 have a faster velocity, but the velocity reduction is greater; ions arriving later at the inlet of drift tube 1 have a slower velocity, but are accelerated. This significantly reduces the velocity difference between slower and faster ions in ion beam 4, meaning the velocity distribution of ion beam 4 is correspondingly reduced. In this situation, the overall ion velocity distribution is that ions at the beginning are faster, and ions at the end are slower. Since the overall potential is decreasing, faster ions are decelerated, and slower ions are accelerated; that is, ions at the beginning are decelerated, and ions at the end are accelerated. The overall decreasing potential ensures that faster ions decelerate more and slower ions accelerate more.

[0042] To ensure that the velocity difference of the ion beam 4 after the potential change is smaller than the velocity difference before entering the tube opening, the potential drop rate needs to be determined based on the ion velocity distribution.

[0043] Case 1.3, Electric Potential Below the potential Minimum value: When ion beam 4 reaches the inlet of drift tube 1, due to... Then ion beam 4 will encounter an increasing potential gradient, and at this time, ion beam 4 will be in the increasing potential gradient. Under the generated electric field, the ion beam 4 decelerates, and its kinetic energy decreases, which in turn reduces its velocity. Since the potential of drift tube 1 decreases over time, ions arriving later at the entrance of drift tube 1 will encounter an even lower potential. The smaller the velocity, the less the ions decelerate as they arrive later in drift tube 1. From the above analysis, we can see that ions arriving earlier at the inlet of drift tube 1 have a faster velocity but experience greater deceleration at the inlet; conversely, ions arriving later at the inlet of drift tube 1 have a slower velocity but experience less deceleration at the inlet. Therefore, the velocity difference between slower and faster ions in ion beam 4 will be significantly reduced, meaning the velocity distribution of ion beam 4 will decrease accordingly.

[0044] Scenario 2: Ion beam 4 carries a negative charge. When ion beam 4 reaches the inlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential to drift tube 1 that increases over time. The velocity distribution of ion beam 4 is adjusted at the inlet of drift tube 1.

[0045] For negatively charged ions, their behavior in an electric potential field is exactly the opposite of that of positively charged ions; that is, the acceleration behavior of positively charged ions in an electric field becomes deceleration behavior, and vice versa. As explained in Analysis 1 above, it is only necessary to... The velocity distribution of ion beam 4 can be reduced by changing the potential to one that increases with time. That is: If constant potential Above the potential Maximum value: The velocity distribution of ion beam 4 was reduced accordingly.

[0046] If constant potential Below the potential The maximum value, but higher than the electric potential. Minimum value: The velocity distribution of ion beam 4 was reduced accordingly.

[0047] If constant potential Below the potential Minimum value: The velocity distribution of ion beam 4 was reduced accordingly.

[0048] Case 3: Ion beam 4 carries a positive charge. When ion beam 4 reaches the inlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential that increases over time to drift tube 1. The velocity distribution of ion beam 4 is adjusted at the inlet of drift tube 1.

[0049] This adjustment process has the opposite effect on the velocity distribution of ion beam 4 as in case 1, showing that the velocity distribution of ion beam 4 is increased accordingly.

[0050] Case 4: Ion beam 4 carries a negative charge. When ion beam 4 reaches the inlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to load a potential that decreases over time onto drift tube 1. The velocity distribution of ion beam 4 is adjusted at the inlet of drift tube 1.

[0051] This adjustment process has the opposite effect on the velocity distribution of ion beam 4 as in case 2, showing that the velocity distribution of ion beam 4 is increased accordingly.

[0052] During the velocity distribution adjustment process of the ion beam 4 described above, the voltage signal source 3 applies a potential to the drift tube 1. The rate of decrease or increase is ,in, This is the charge of each ion in ion beam 4. This represents the initial energy width distribution of ion beam 4. Voltage signal source 3 generates a potential applied to drift transistor 1. Range (potential rise and fall) The time taken for the change, i.e. Over time The change is .but As time increases, , As time decreases, ; It is a time variable.

[0053] Energy distribution of ions Regarding the velocity distribution of ion beam 4, it is first necessary to obtain its initial velocity distribution. Several mature experimental methods exist for obtaining this distribution, including using collinear laser spectroscopy to measure the Doppler broadening of the laser spectrum, or directly obtaining the initial velocity distribution using a deceleration field analyzer. Without applying a time-varying electric field to drift tube 1 (i.e., without triggering a potential change in voltage signal source 3), obtaining the initial velocity distribution of ion beam 4 using the above methods yields the initial energy width distribution of ion beam 4. The voltage signal source 3 mentioned above is the voltage applied to the drift tube 1. The rate of descent is Due to the initial energy width distribution of ion beam 4 The ion charge of ion beam 4 is constant; only the potential needs to be changed from... Time to drop to 0 That is, changing the rate of potential decrease, scanning at different The rate of descent (i.e., changing the value of T) until a suitable value is found. The descent rate enables the energy width distribution of ion beam 4. To achieve the desired value, thus obtaining an ion beam with the required velocity width distribution.

[0054] After ion beam 4 fully enters drift tube 1, the following situations may occur: After the ion beam 4 has fully entered the drift tube 1, a constant potential is applied to the drift tube 1 by the timing device 2 triggering the voltage signal source 3. The overall velocity of ion beam 4 is adjusted.

[0055] After the ion beam 4 has completely entered the drift tube 1, the potential around the drift tube 1 is: The timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1. When the ions completely enter the drift tube 1, applying a potential to the drift tube 1 will change the overall potential of the ion beam 4. At this time, the kinetic energy of the ion beam 4 inside the drift tube 1 does not change, but its potential energy changes. When it flies out of the drift tube 1, due to the potential gradient at the opening of the drift tube 1, a change will occur between the kinetic and potential energies of the ions, resulting in a change in the overall velocity of the ion beam 4. This is used to reduce or increase the overall velocity of the ion beam 4.

[0056] The following operations can be performed on ions with different polarities: If the ion beam 4 is positively charged, after the ion beam 4 has completely entered the drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1. ,Require At this point, when ion beam 4 exits from drift tube 1, it encounters a rising potential gradient, causing its potential energy to increase. According to the law of conservation of energy, the increase in potential energy of ion beam 4 is equivalent to the decrease in kinetic energy. Simultaneously, due to the potential... and Since all ions in ion beam 4 are at a constant potential, they experience the same degree of deceleration when exiting drift tube 1. This means the overall velocity of ion beam 4 decreases, and the reduction in kinetic energy within ion beam 4 is... , Let be the charge of each ion in ion beam 4, and let ion beam 4 decrease at a rate of . ,in, The mass of each ion in ion beam 4. This represents the charge of each ion in ion beam 4.

[0057] when When ions exit drift tube 1, they encounter a decreasing potential gradient, and simultaneously, due to the potential... and Since both are at a constant potential, all ions in ion beam 4 experience the same degree of acceleration upon exiting drift tube 1, meaning the overall velocity of ion beam 4 increases. The rate of increase in ion beam 4 is... ,in, The mass of each ion in ion beam 4. Here is the charge of each ion in ion beam 4. The initial velocity of ion beam 4 upon reaching the inlet of drift tube 1 is given.

[0058] If the ion beam 4 is negatively charged, its behavior in the potential is opposite to that of positively charged ions. The timing device 2 triggers the voltage signal source 3 to apply a constant potential to the drift tube 1. ,when This can achieve an overall reduction in the velocity of the ion beam 4, when This will enable an overall increase in the velocity of the ion beam.

[0059] In practical applications, many experiments or applications require low-energy, low-kinetic-energy broadened ions. This device, combined with this method, can reduce the velocity distribution of ions and decelerate them. Furthermore, these methods can be combined to simultaneously reduce both the velocity distribution and the velocity. Depending on the specific needs, this device can also be used for ion acceleration and ion kinetic energy broadening. Its flexible combination allows for convenient modulation of ion kinetic energy without the need for complex structures and devices; complex kinetic energy modulation can be achieved through time-varying potentials and simple electrode structures.

[0060] Example 3: Referring to Example 2, the potential can also be changed when the ion beam 4 leaves the drift tube 1, so as to directly and synchronously realize the reduction of the velocity distribution of the ion beam 4 and the overall speed regulation.

[0061] Ion beam 4 carries a positive charge. When ion beam 4 is about to fly away from the outlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential to drift tube 1. electric potential With constant potential It is DC biased and changes over time, when ,at this time, It increases over time. While decreasing the ion velocity distribution of ion beam 4, if... If the overall ion velocity increases, This reduces the overall ion velocity. Ion beam 4 carries a positive charge. When ion beam 4 is about to fly away from the outlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential to drift tube 1. electric potential With constant potential It is DC biased and changes over time, when ,at this time, It decreases over time. While increasing the ion velocity distribution of ion beam 4, if... If the overall ion velocity increases, This reduces the overall ion velocity. Ion beam 4 carries a negative charge. When ion beam 4 is about to fly away from the outlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential to drift tube 1. electric potential With constant potential It is DC biased and changes over time, when ,at this time, It decreases over time. While reducing the ion velocity distribution of ion beam 4, if... If the overall ion velocity is reduced, This increases the overall ion velocity. Ion beam 4 carries a negative charge. When ion beam 4 is about to fly away from the outlet of drift tube 1, the timing device 2 triggers the voltage signal source 3 to apply a potential to drift tube 1. electric potential With constant potential It is DC biased and changes over time, when ,at this time, It increases over time. While increasing the ion velocity distribution of ion beam 4, if... If the overall ion velocity is reduced, This increases the overall ion velocity.

[0062] The following example uses positively charged ions. The same effect can be achieved by simply changing the potential of negatively charged ions in the opposite direction to that of positively charged ions.

[0063] The operating conditions are as described in Example 1, and the external potential of drift tube 1 is... When the ion beam 4 fully enters the drift tube 1 and begins to exit the drift tube 1 (i.e., when the ion beam 4 leaves the outlet of the drift tube 1), the timing device 2 triggers the voltage signal source 3 to apply a potential to the drift tube 1. In the above formula, This is a DC potential bias. Represented as the potential loaded by drift tube 1 This is a DC biased potential that changes over time. This is the initial energy width distribution of ion beam 4. Here is the charge of each ion in ion beam 4. Voltage signal source 3 applies a change in voltage potential to drift tube 1. Time spent, It is a time variable.

[0064] With electric potential For example, by From the expression, it can be seen that as the potential of drift tube 1 increases with time, the potential gradient... As time increases, this operation reduces the velocity distribution of ions, with the faster ion beams encountering smaller potential gradients. This means that the ion speed is low, and the slower-moving ions in ion beam 4 encounter a larger potential gradient later. That is, the ion speed is high. At the same time, since the kinetic energy of ion beam 4 remains constant in drift tube 1, it will have a potential gradient when it leaves the outlet of drift tube 1. Overall growth rate under the influence of ( ) or slow down ( This simultaneously reduces the ion velocity distribution of ion beam 4. The amount of reduction in the ion velocity distribution of ion beam 4 can be adjusted by continuously changing the time T.

[0065] Similarly, it only requires properly allocating the voltage signal source 3 after the timing device 2 is triggered to apply the potential to the drift tube 1. If electric potential gradient As time decreases, this operation is used to increase the velocity distribution of ions, with the faster ion beams (4) encountering a large potential gradient. This means that the ions accelerate rapidly, while the slower-moving ions in ion beam 4 encounter a smaller potential gradient later on. That is, a small ion growth rate can make ion beam 4 have a smaller overall growth rate ( ) or slow down ( This simultaneously increases the ion velocity distribution of ion beam 4. It only requires continuously changing the time... This allows for adjustment of the amount of increase in the ion velocity distribution of ion beam 4.

[0066] When ion beam 4 is negatively charged, the principle is the same as above, and will not be repeated here.

[0067] It should be noted that in Example 2, when the ion beam 4 is inside the drift tube 1, a constant potential is applied to the drift tube 1. Therefore, when the ion beam 4 accelerates or decelerates as a whole, each ion in the ion beam 4 encounters the same potential gradient, and the amount of acceleration or deceleration of each ion in the ion beam 4 is the same. However, in Example 3, when the ion beam 4 is preparing to leave the drift tube 1, a changing potential is applied to the drift tube 1. The potential gradient encountered by the ions in the ion beam 4 that arrive at the exit of the drift tube 1 at different times is different. Therefore, the amount of acceleration or deceleration of the ions in the ion beam 4 that arrive at the exit of the drift tube 1 at different times is different. However, they all undergo acceleration or deceleration motion, and due to the DC potential bias... In the presence of ion beam 4, each ion will have the same energy change. Therefore, when the ion beam 4 leaves the outlet of the drift tube 1, its speed distribution changes while its overall speed increases or decreases.

[0068] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0069] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An ion kinetic energy modulation device, comprising a vacuum chamber (5), characterized in that, It also includes a drift tube (1), a timing device (2), a voltage signal source (3), an ion beam (4), an ion source (6), and an ion detector (7); a constant potential is applied to the vacuum chamber (5). An ion source (6), a drift tube (1) and an ion detector (7) are arranged sequentially inside the vacuum chamber (5). The ion beam (4) emitted by the ion source (6) enters from one end of the drift tube (1), passes through the drift tube (1) and finally reaches the ion detector (7). The timing device (2) controls the voltage signal source (3) to apply a potential to the drift tube (1).

2. The ion kinetic energy modulation device according to claim 1, characterized in that, The ion beam (4) consists of ion clusters emitted multiple times at equal time intervals from the ion source (6), with each emitted ion cluster having an initial velocity... The charge-to-mass ratio is consistent; the drift tube (1) is a tubular metal electrode.

3. An ion kinetic energy modulation method, utilizing the ion kinetic energy modulation device according to claim 2, characterized in that, Includes the following steps: Step 1: Scan the time interval between the time when the potential is applied to the drift tube (1) and the time when the ion cluster is emitted by the ion source (6). Based on the time-of-flight spectrum pulse signal of the ion beam (4), obtain the position of the ion beam (4) relative to the drift tube (1) at different time intervals. Step 2: Based on the different positions of the ion beam (4) relative to the drift tube (1), the timing device (2) is triggered to control the voltage signal source (3) to apply a potential to the drift tube (1) and modulate the ion kinetic energy of the ion beam (4).

4. The ion kinetic energy modulation method according to claim 3, characterized in that, Obtaining the position of the ion beam (4) relative to the drift tube (1) at different intervals includes the following steps: The ion beam (4) is positively charged, and a constant potential is applied to the vacuum cavity (5). The timing device (2) triggers the voltage signal source (3) to apply a constant potential to the drift tube (1). and make ; The time interval between the time when the potential is applied to the drift tube (1) and the time when the ion clusters emitted by the ion source (6) are scanned. If the following occur in sequence: the time-of-flight spectrum pulse signal of the ion beam (4) does not change, the front end of the time-of-flight spectrum pulse signal of the ion beam (4) is distorted, the time-of-flight spectrum pulse signal of the ion beam (4) moves forward as a whole, the end of the pulse signal in the time-of-flight spectrum of the ion beam (4) is distorted, and the time-of-flight spectrum pulse signal of the ion beam (4) does not change, then the relative positions of the ion beam (4) and the drift tube (1) are as follows: the ion beam (4) does not reach the inlet of the drift tube (1), the ion beam (4) reaches the inlet of the drift tube (1) and some ions enter the drift tube (1), the ion beam (4) is located inside the drift tube (1), the ion beam (4) is located at the outlet of the drift tube (1) and some ions fly away from the drift tube (1), and the ion beam (4) leaves the outlet of the drift tube (1).

5. The ion kinetic energy modulation method according to claim 4, characterized in that, When the time-of-flight spectrum pulse signal of the ion beam (4) just begins to distort, the position of the ion beam (4) relative to the drift tube (1) is as follows: the ion beam (4) reaches the entrance of the drift tube (1); after the ion beam (4) reaches the entrance of the drift tube (1), time elapses... During flight, the position of the ion beam (4) relative to the drift tube (1) is as follows: the ion beam (4) is ready to fly away from the outlet of the drift tube (1); where, The length of the drift tube (1) Let be the initial velocity of the ion beam (4) starting from the ion source (6).

6. The ion kinetic energy modulation method according to claim 5, characterized in that, The modulation of the ion kinetic energy of the ion beam (4) includes: The ion beam (4) carries a positive charge. When the ion beam (4) reaches the inlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to load the drift tube (1) with a potential that decreases over time. This reduces the velocity distribution of the ion beam (4); The ion beam (4) carries a negative charge. When the ion beam (4) reaches the inlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential that increases with time to the drift tube (1). This reduces the velocity distribution of the ion beam (4); The ion beam (4) carries a positive charge. When the ion beam (4) reaches the inlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential that increases with time to the drift tube (1). This increases the velocity distribution of the ion beam (4); The ion beam (4) carries a negative charge. When the ion beam (4) reaches the inlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to load the drift tube (1) with a potential that decreases over time. Increase the velocity distribution of the ion beam (4).

7. The ion kinetic energy modulation method according to claim 6, characterized in that, The potential As time increases, Based on the following formula: ； The potential As time goes by, Based on the following formula: ； in, For time variables, The initial energy width distribution of the ion beam (4) is given. The charge of each ion in the ion beam (4) is... The voltage signal source (3) is used to apply the potential change to the drift tube (1). Time spent.

8. The ion kinetic energy modulation method according to claim 5, characterized in that, The modulation of the ion kinetic energy of the ion beam (4) includes: When the ion beam (4) is positively charged and is located inside the drift tube (1), a constant potential is applied to the drift tube (1) by the timing device (2) triggering the voltage signal source (3). ,and The overall velocity of the ion beam (4) is reduced and adjusted. When the ion beam (4) is positively charged and is located inside the drift tube (1), a constant potential is applied to the drift tube (1) by the timing device (2) triggering the voltage signal source (3). ,and The speed of the ion beam (4) was adjusted to increase overall; When the ion beam (4) is negatively charged and is located inside the drift tube (1), a constant potential is applied to the drift tube (1) by the timing device (2) triggering the voltage signal source (3). ,and The speed of the ion beam (4) was adjusted to increase overall; When the ion beam (4) is negatively charged and is located inside the drift tube (1), a constant potential is applied to the drift tube (1) by the timing device (2) triggering the voltage signal source (3). ,and The velocity of the ion beam (4) is reduced as a whole.

9. The ion kinetic energy modulation method according to claim 5, characterized in that, The modulation of the ion kinetic energy of the ion beam (4) includes: The ion beam (4) carries a positive charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam (4) is adjusted to reduce the ion velocity distribution and increase the overall velocity. The ion beam (4) carries a positive charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam (4) is adjusted to reduce the ion velocity distribution and the overall velocity. The ion beam (4) carries a positive charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam (4) is adjusted to increase the ion velocity distribution and the overall velocity. The ion beam (4) carries a positive charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam (4) is adjusted to increase the ion velocity distribution and decrease the overall velocity. The ion beam (4) carries a negative charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam (4) is adjusted to reduce the ion velocity distribution and the overall velocity. The ion beam (4) carries a negative charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It decreases over time, and The ion beam (4) is adjusted to reduce the ion velocity distribution and increase the overall velocity. The ion beam (4) carries a negative charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam (4) is adjusted to increase the ion velocity distribution and decrease the overall velocity. The ion beam (4) carries a negative charge. When the ion beam (4) is about to fly away from the outlet of the drift tube (1), the timing device (2) triggers the voltage signal source (3) to apply a potential to the drift tube (1). electric potential With constant potential It is DC biased and changes over time, when It grows larger over time, and The ion beam (4) is adjusted to increase the ion velocity distribution and the overall velocity.

10. The ion kinetic energy modulation method according to claim 9, characterized in that, The potential As time increases, Based on the following formula: ； The potential As time goes by, Based on the following formula: ； in, This is a DC potential bias. For time variables, The initial energy width distribution of the ion beam (4) is given. The charge of each ion in the ion beam (4) is... The voltage signal source (3) is used to apply the potential change to the drift tube (1). Time spent.

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