A method and device for high-valence ion beam trapping cooling

Abstract

The present invention discloses a device for trapped cooling of high-valent ion beams, which includes a screening electrode, a deceleration electrode, and a linear ion trap in sequence along the ion transmission direction. A method for trapped cooling of high-valent ion beams is also disclosed, wherein corresponding timing voltages are applied to the screening electrode, the deceleration electrode, and the linear ion trap to achieve screening, deceleration, and trapping of high-valent ions; cooling lasers and back-pumping lasers are simultaneously applied to achieve cooling of the ions. By adjusting and optimizing all of the above voltages and the corresponding voltage change timings based on the different components, kinetic energies, and valence states of the high-valent ions, trapped cooling of the high-valent ion beam can ultimately be achieved. The present invention can achieve injection of high-energy high-valent ions from outside the trap and trapped cooling of high-valent ions, based on the current conventional method of only generating and achieving trapped cooling of low-valent ions within the ion trap.

Description

Technical field:

[0001] The present invention belongs to the technical field of high-valence ion trapped cooling, and in particular relates to a device for high-valence ion beam trapped cooling, and also relates to a method for high-valence ion beam trapped cooling. Technical background:

[0002] The ion clock is a new type of high-performance atomic clock that uses the inherent frequency of the transition of trapped and cooled ions as a real-time reference. It has the advantages of uncertainty and stability far exceeding that of microwave clocks. It is an optimal system for realizing the next generation of time standards, higher-precision timing and navigation, etc.

[0003] The current mainstream ion clock implementation method all uses ion traps to trap and cool monovalent ions, and monovalent ions are all produced and directly trapped in the ion trap without exception. This is because: 1. Ion traps have a limited trapping capacity for trapped ions, and can usually only trap ions with kinetic energies less than 10eV; 2. Monovalent ions have low ionization energies, only a few eV, so ions with kinetic energies below eV can be directly produced in the ion trap through laser sputtering of metal targets or laser above-threshold ionization. For high-valent ions, their ionization energies usually exceed hundreds of eV, so laser sputtering and laser above-threshold ionization are no longer applicable. Instead, high-energy bombardment is required for their production. However, the environment generated by high-energy bombardment is complex, the energy is high, and the ion composition is complex, so it cannot be directly transferred to an ion trap for trapping.

[0004] In the development of ion clocks, the temperature of ions usually needs to be cooled to below K, and Doppler cooling of lasers is usually used. However, for high-valent ions, there is usually no available Doppler cooling laser, so cooperative cooling is required. Therefore, in the cooling of high-valent ions, it is necessary to first prepare cooperative ions in the ion trap. Contradictory to this, high-valent ions need to be injected externally. How to pass through the barriers of the ion trap to ensure ion injection without allowing the cooperative ions to escape becomes a difficulty that needs to be overcome. Summary of the invention:

[0005] In order to solve the above problems or defects, the present invention provides a device for high-valence ion beam trapping and cooling, and also provides a method for high-valence ion beam trapping and cooling.

[0006] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] A device for trapping and cooling a high-valence ion beam comprises a screening electrode, a deceleration electrode and a linear ion trap in sequence along the ion transmission direction;

[0008] After passing through the first and second parallel screening plates in the screening electrode, the ions enter the deceleration drift tube in the deceleration electrode and are transmitted along the central axis of the deceleration drift tube. The ions output from the deceleration drift tube are incident on the linear ion trap through the electrostatic lens group of the deceleration electrode.

[0009] The quadrupole in the linear ion trap includes four parallel rods, each of which includes a first cap electrode and a second cap electrode, which are respectively located at the two ends of the corresponding rod. A trap center electrode is located between the first cap electrode and the second cap electrode on each rod. A first additional cap electrode and a second additional cap electrode are respectively arranged on both sides of the quadrupole. The first additional cap electrode and the second additional cap electrode each include an additional cap electrode base and an additional cap electrode barrel. An opening is provided on the additional cap electrode base, and the opening of the additional cap electrode base is connected to the additional cap electrode barrel. The additional cap electrode barrel of the first additional cap electrode extends to the space between the first cap electrodes of the four rods of the quadrupole; the additional cap electrode barrel of the second additional cap electrode extends to the space between the second cap electrodes of the four rods of the quadrupole; ions entering the linear ion trap pass through the additional cap electrode base and the additional cap electrode barrel of the first additional cap electrode in sequence and then enter the space between the four trap center electrodes; cooling laser and back pump laser are irradiated to the space between the four trap center electrodes located in the linear ion trap;

[0010] The ions include cooperative ions and target high-valence ions;

[0011] The first screening plate, the second screening plate, the deceleration drift tube, the first additional cap electrode and the second additional cap electrode respectively and simultaneously perform corresponding voltage changes based on their respective corresponding voltage change timings.

[0012] A method for high-valence ion beam trapped cooling, using the above-mentioned device for high-valence ion beam trapped cooling, includes the following steps:

[0013] Step 1: construct a device for achieving trapped cooling of a high-valence ion beam, and set a CCD camera at the base of the additional cap electrode near the second additional cap electrode; prepare a cooperative ion crystal cluster in the linear ion trap under the action of cooling laser and back pump laser;

[0014] Step 2: Replace the CCD camera with a microchannel plate detector; the ion source continuously and periodically emits an ion beam to be screened towards the screening electrode, and the microchannel plate detector detects the pulse signal corresponding to the ion beam to be screened. The ions to be screened in the ion beam to be screened include target high-valence ions and ions to be screened out. The ions to be screened out are ions of the same atom as the target high-valence ions but with different valence states; determine the voltage change timings corresponding to the first screening plate voltage U1 and the second screening plate voltage U2 respectively; apply the first screening plate voltage U1 to the first screening plate and the second screening plate voltage U2 to the second screening plate, so that in the time period from t0 to t1 within each period T, U1 >> U2 or U1 << U2, and U1 = U2 in other time periods. Both t0 and t1 are timing points, so that the microchannel plate detector detects the pulse signal of the target high-valence ions of a single valence state;

[0015] Step 3: Determine the deceleration drift tube voltage U applied to the deceleration drift tube bias , x , end1 , end1 , end1 , end2 of the voltage change timing, and apply the deceleration drift tube voltage U to the deceleration drift tube d , so that the deceleration drift tube voltage U d starts to linearly decrease with time from the deceleration drift tube voltage initial value U x at the timing point t2 within each period T, and the deceleration drift tube voltage U d drops as a whole at the timing point t3; at the same time, apply corresponding voltages to each electrostatic lens of the electrostatic lens group; after applying the deceleration drift tube voltage U d , the flight duration of the pulse signal detected by the microchannel plate detector significantly increases, and there are still considerable ion pulse signals on the microchannel plate detector;

[0016] The flight duration is the time difference between the ion exiting from the ion source and the microchannel plate detector observing the corresponding pulse signal; when the change value of the flight duration is greater than the preset extension threshold, it is determined that the flight duration significantly increases;

[0017] Step 4: The ion source continues to continuously and periodically emit an ion beam to be screened; determine the voltage change timings corresponding to the first additional cap electrode voltage U end1 and the second additional cap electrode voltage U end2 respectively, and the reference voltage U of the linear ion trap bias , and apply the first additional cap electrode voltage U end1 to the first additional cap electrode, and the second additional cap electrode voltage U end2 to the second additional cap electrode, so that in each period T, when the target high-valence ions reach the first additional cap electrode, the first additional cap electrode voltage U end1 of the first additional cap electrode is at a low level, and the target high-valence ions can enter the linear ion trap; afterwards, the first additional cap electrode voltage U end1Restore to high level, and at the same time, the second additional cap electrode voltage U end2 It is always at a high level, so that the target high-valence ions are trapped in the linear ion trap; under the cooling laser and back-pump laser cooling, the target high-valence ions are cooled based on the cooperative cooling mechanism.

[0018] As mentioned above, step 1 includes the following steps:

[0019] Step 1.1, constructing a device for achieving high-valence ion beam trapping and cooling, and setting a CCD camera at the base of the additional cap electrode near the second additional cap electrode;

[0020] Step 1.2: Determine the type of the corresponding co-ion according to the charge-to-mass ratio of the target high-valent ion and determine the radio frequency potential field U required by the linear ion trap to trap the target high-valent ion and the co-ion. rf , electrostatic potential field U y , the additional cap electrode high-level voltage value U required to trap the target high-valence ions end ;

[0021] Additional cap electrode high level voltage value U end is the voltage value of the first additional cap electrode and the second additional cap electrode when the target high-valence ions are trapped;

[0022] Step 1.3: Apply a radio frequency potential field U to the first cap electrode, the second cap electrode and the center electrode of the trap of all the quadrupole rods. rf ; An electrostatic potential field U is also applied to the first cap electrode and the second cap electrode of each rod in the quadrupole y ; Set the first screening plate voltage U1 = 0 corresponding to the first screening plate, the second screening plate voltage U2 = 0 corresponding to the second screening plate, and the deceleration drift tube voltage U corresponding to the deceleration drift tube d =0, the voltage of each electrostatic lens in the electrostatic lens group is 0, and the first additional cap electrode voltage U corresponding to the first additional cap electrode end1 =0, the second additional cap electrode voltage U corresponding to the second additional cap electrode end2 =0;

[0023] Step 1.4, the ion source injects cooperative ions into the linear ion trap;

[0024] Irradiating the linear ion trap with cooling laser and pumping laser to optimize various cooperative ion trapped cooling parameters to achieve trapped cooling of cooperative ions, thereby obtaining cooperative ion crystal clusters. The cooperative ion trapped cooling parameters include the line width, power, frequency and wave vector direction of the cooling laser and pumping laser.

[0025] Step 1.5: Capture the image of the cooperative ion crystal cluster using a CCD camera.

[0026] When the size of the cooperative ion crystal cluster is greater than or equal to the crystal cluster size threshold, and the temperature of the cooperative ion crystal cluster is lower than 10 mK, executing step 2;

[0027] When the size of the cooperative ion crystal cluster is smaller than the crystal cluster size threshold, or the temperature of the cooperative ion crystal cluster is greater than or equal to 10 mK, return to step 1.4 until the size of the cooperative ion crystal cluster reaches the crystal cluster size threshold and the temperature of the cooperative ion crystal cluster is lower than 10 mK.

[0028] Step 2 as described above includes the following steps:

[0029] Step 2.1. Replace the CCD camera with a microchannel plate detector; the ion source continuously and periodically emits the ion beam to be screened toward the screening electrode, so that the microchannel plate detector detects the pulse signal corresponding to the ion beam to be screened, and the pulse signal corresponding to the ion beam to be screened reaches the strongest;

[0030] Step 2.2, selecting an auxiliary ion system, wherein the auxiliary ion beam corresponding to the auxiliary ion system includes auxiliary ions of multiple valence states corresponding to the same auxiliary atom, and the auxiliary ions are present in the auxiliary ion beam so that the charge-to-mass ratio of the ions to be screened in the ion beam to be screened is the same as the charge-to-mass ratio of the auxiliary ions; and the auxiliary ions having the same charge-to-mass ratio and the corresponding ions to be screened are used as reference auxiliary ions and reference ions to be screened, respectively;

[0031] Step 2.3, the ion source continues to emit the ion beam to be screened, and the microchannel plate detector detects the pulse signal peak of each valence state of the ion to be screened, and the number is recorded as i, and the corresponding flight time of the ion to be screened is recorded as

[0032] The ion source stops emitting the ion beam to be screened and switches to emitting the auxiliary ion beam. The microchannel plate detector detects the pulse signal peak corresponding to each valence state auxiliary ion, and the number is recorded as k; the flight time of the corresponding auxiliary ion is recorded as

[0033] Find The sequence number of the pulse signal peak of the ion to be screened is i, and the corresponding ion to be screened is the reference ion to be screened. The sequence number of the pulse signal peak of the reference ion to be screened is recorded as the reference sequence number i n ;

[0034] Step 2.4, according to i m -i n =V n -V m , confirm the number i of the pulse signal peak of the target high-valent ion m , V m is the valence state of the target high-valence ion, V nTo reference the valence state of the ions to be screened; according to the sequence number i of the pulse signal peak of the target high-valence ions m Find the flight time corresponding to the target high-valence ions

[0035] Step 2.5: The ion source stops emitting the auxiliary ion beam and switches to continuously and periodically emitting the ions to be screened; set the initial values of the timing points t0 and t1; set the voltage U1 of the first screening electrode plate and the voltage U2 of the second screening electrode plate, so that U'1 >> U2 or U1 << U2 during the time period from t0 to t1, and U1 = U2 in other time periods;

[0036] Step 2.6: Adjust the timing points t0 and t1 until the number of pulse signal peaks detected by the microchannel plate detector before the timing point t0 in the same period T is M H , and the number of pulse signal peaks detected by the microchannel plate detector after the timing point t1 in the same period T is M L , M H is the number of valence states in the ions to be screened that are higher than the valence state corresponding to the target high-valence ions, and M L is the number of valence states in the ions to be screened that are lower than the valence state corresponding to the target high-valence ions;

[0037] The voltage U'1 of the first screening electrode plate and the voltage U2 of the second screening electrode plate change according to the corresponding voltage change timing sequences and remain changed.

[0038] As described above, setting the initial values of the timing points t0 and t1 in Step 2.5 specifically includes the following steps:

[0039] The distance from the ion source to the screening electrode is denoted as distance L1; the distance from the ion source to the microchannel plate detector is denoted as distance L4; based on the flight time of the target high-valence ions Set the initial value of the timing point t'0 as The initial value of the timing point t1 is greater than or equal to

[0040] As described above, Step 3 includes the following steps:

[0041] Step 3.1: Set the initial values of the timing point t2 and the timing point t3, so that t3 > t2 > t1;

[0042] Step 3.2: Set the voltage change timing sequence of the deceleration drift tube voltage U d as:

[0043]

[0044] t represents time, T represents the period, N represents the number of periods, U xIndicates the starting value of the deceleration drift tube voltage;

[0045] Apply a deceleration drift tube voltage U to the deceleration drift tube d , gradually increase the deceleration drift tube voltage starting value U from 0 x , so that the number of pulse signals detected by the microchannel plate detector is the same as that without applying the deceleration drift tube voltage U d When the microchannel plate detector detects the same number of pulse signals, and compared with the case where the deceleration drift tube voltage U is not applied, d When , the flight time of the first pulse signal in a period T increases significantly;

[0046] Step 3.3: Based on step 3.2, change the deceleration drift tube voltage U d The voltage change sequence of the deceleration drift tube voltage U d satisfy:

[0047]

[0048] Among them, U x represents the starting value of the deceleration drift tube voltage, a represents the rate of change of the deceleration drift tube voltage, U low Indicates the low-level voltage value of the deceleration drift tube, U x The sign of U is the same as a. x and U low The signs of are opposite;

[0049] Step 3.4: Observe the pulse signal detected by the microchannel plate detector and adjust the low-level voltage value U of the deceleration drift tube. low , timing point t2 and timing point t3, so that the flight time corresponding to all pulse signals in the same period T is significantly increased;

[0050] Step 3.5: Adjust the starting value U of the deceleration drift tube voltage x , so that the time width of the pulse signal of the microchannel plate detector detecting the target high-valence ions is compressed to the narrowest.

[0051] Step 3.4 as described above includes the following steps:

[0052] Step 3.4.1. Observe whether the microchannel plate detector detects the pulse signal.

[0053] When the microchannel plate detector cannot detect the pulse signal, the low-level voltage value U of the deceleration drift tube is adjusted. low , until the microchannel plate detector detects a pulse signal; then proceed to step 3.4.2;

[0054] When the microchannel plate detector detects a pulse signal, execute step 3.4.2;

[0055] Step 3.4.2: Observe the flight time of the pulse signal detected by the microchannel plate detector.

[0056] When the flight duration of all pulse signals in the same cycle remains unchanged, the timing point t3 is individually increased or the timing point t2 is individually decreased until the flight duration of all pulse signals in one cycle is significantly increased;

[0057] When the flight duration corresponding to the first part of the pulse signals in the same cycle is extended, and the flight duration corresponding to the second part of the pulse signals does not change, increase the timing point t3 until the flight duration corresponding to all the pulse signals in the same cycle is significantly increased;

[0058] When the flight duration corresponding to the first part of the pulse signal in the same cycle does not change, the flight duration corresponding to the second part of the pulse signal is extended, and the timing point t2 is reduced until the flight duration corresponding to all pulse signals in the same cycle increases significantly;

[0059] When only the flight duration corresponding to the middle part of the pulse signal in the same cycle is extended, and the flight duration corresponding to the front and rear part of the pulse signals remains unchanged, the timing point t2 is reduced and the timing point t3 is increased until the flight duration corresponding to all pulse signals in the same cycle is significantly increased.

[0060] Step 4 as described above includes the following steps:

[0061] Step 4.1: Start the first additional cap electrode and the second additional cap electrode, the voltage of the second additional cap electrode is U end2 =0, then apply the first additional cap electrode voltage U to the first additional cap electrode end1 , the first additional cap electrode voltage U end1 The following timing is met:

[0062]

[0063] Among them, t4 and t5 are timing points, and t3 <t4<t5,U end is the high-level voltage value of the additional cap electrode, U′ end is the high and low voltage value of the additional cap electrode, U′ end end ;

[0064] Adjust the timing point t4 and the corresponding timing point t5 until the pulse signal on the microchannel plate detector is observed in one cycle T of ion implantation and the first additional cap electrode voltage U is not applied at the end of step 3. end1 The signal is consistent;

[0065] Then, the second additional cap electrode voltage U of the second additional cap electrode is raised. end2 make U end2 =U​end , maintain the first additional cap electrode voltage U end1 Voltage change timing;

[0066] The deceleration drift tube voltage U d The timing point t6 for returning to 0 in each cycle T is set after the timing point 4;

[0067] Step 4.2: Replace the microchannel plate detector with a CCD camera and use the CCD camera to observe the ion imaging in the linear ion trap.

[0068] When no dark circular area is observed in the bright area, the first additional cap electrode and the second additional cap electrode are restarted, and the reference potential U of the linear ion trap is adjusted as a whole. bias , and adjust the high level voltage value U of the additional cap electrode at the same time end , and make U end >U bias ; until a dark circular area is observed in the bright area;

[0069] When a dark circular area appears in the bright area, proceed to step 4.3;

[0070] Step 4.3: Under the cooling laser and pumping laser cooling, the target high-valence ions are cooled based on the synergistic cooling mechanism.

[0071] The initial value of timing point t3 in step 3.1 is The distance L3 is the distance from the ion source to the deceleration drift tube.

[0072] As described above, the timing point t5 and the timing point t4 maintain (t5-t4)<1 microsecond.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] Based on the composition, kinetic energy distribution, and distribution of ions of different valence states of the ion beam to be screened, including target high-valence ions, the present invention employs a screening electrode to apply sequential voltages to achieve ion screening and concurrent ion beam divergence adjustment; a deceleration electrode to apply sequential voltages to achieve ion deceleration and concurrent ion kinetic energy compression; and a linear ion trap equipped with an additional cap electrode to achieve cooperative ion trapped cooling, as well as injection and trapped cooling of high-valence ions. This entire process is supplemented by real-time pulse signal monitoring by a microchannel plate detector and ion imaging observation by a CCD camera. This allows for the complete trapped cooling of a high-valence ion beam from a complex initial state, such as high energy, outside the ion trap to high-valence ions. This is of great significance for the research and application of a new generation of ion clocks based on high-valence ions.

[0075] The present invention can realize both the screening of single high-valence ions and the adjustment of ion beam divergence on a screening electrode composed of two simple screening plates. Compared with the traditional Wien velocity selector that only realizes ion screening through electric and magnetic fields, it is more simple and efficient, and has diversified functions. It can adjust the ion beam divergence during screening.

[0076] The present invention can simultaneously apply a sudden initial voltage and an additional voltage that changes linearly with time to the existing drift tube, which can simultaneously achieve the reduction of ion beam energy and the compression of ion beam energy broadening. This is more efficient and more versatile than the traditional electrode lens that applies a fixed voltage and can only decelerate. At the same time, it can realize the modulation of the time width of the ion beam.

[0077] The present invention adopts a method of controlling the voltage change timing of the additional cap electrode of the linear ion trap, which can inject external high-valent ions while ensuring stable trapped cooling of the co-ions inside the ion trap, solving the problem of external high-valent ion injection into the ion trap and trapped cooling that cannot be achieved in the prior art.

[0078] The present invention can effectively overcome the problem that the existing technology can only achieve trapped cooling of low-valent ions. It can achieve high-energy, complex-composition high-valent ions generated externally through screening, deceleration and injection into ion traps, and achieve trapped cooling of high-valent ions under the action of cooperative cooling ions. It is expected to advance the current ion optical clock that refers to monovalent ions to a high-valent ion optical clock that refers to a better system, thereby expanding the field of high-valent ion optical clocks. Description of the drawings:

[0079] Figure 1 is a flow chart of the method steps of an embodiment of the present invention;

[0080] Figure 2 Schematic diagram of the device and the pulse voltage applied in the embodiment of the present invention;

[0081] Figure 3 is a schematic structural diagram of a deceleration electrode according to an embodiment of the present invention;

[0082] Figure 4 1. It is a timing diagram of voltage changes corresponding to the first screening plate, the second screening plate, the deceleration drift tube, the first additional cap electrode and the second additional cap electrode according to an embodiment of the present invention;

[0083] Figure 5 is the cooperative ion Be obtained in the embodiment of the present invention + Imaging of captive cooling;

[0084] Figure 6 The high-valent ion Ni obtained in the embodiment of the present invention is 11+ Imaging of captive cooling;

[0085] Figure 7 is the high-valent ion Ar obtained in the embodiment of the present invention 7+ Imaging of captive cooling;

[0086] Figure 8 It is a schematic diagram of the structure of the linear ion trap;

[0087] Among them, U1-first screening plate voltage, U2-second screening plate voltage,

[0088] U a -First electrostatic lens voltage, U b -Second electrostatic lens voltage, U c -Third electrostatic lens voltage, U d -Deceleration drift tube voltage,

[0089] U rf -RF potential field, U y - electrostatic potential field,

[0090] U end1 - First additional cap electrode voltage, U end2 - second additional cap electrode voltage,

[0091] U low -Deceleration drift tube low level voltage value, U s - Screening plate high level voltage value, U x -Deceleration drift tube voltage starting value, U end - Additional cap electrode high level voltage value, U bias - reference voltage,

[0092] t0~t4 are timing points, t represents time, and T represents period.

[0093] Among them, 1-screening electrode, 101-first screening plate, 102-second screening plate, 2-deceleration electrode, 201-deceleration drift tube, 202-first electrostatic lens, 203-second electrostatic lens, 204-third electrostatic lens, 3-linear ion trap, 301-quadrupole, 302-linear ion trap base, 303-first additional cap electrode, 304-second additional cap electrode, 3011-first cap electrode, 3012-second cap electrode, 3013-trap center electrode, 4-microchannel plate detector. Specific implementation method:

[0094] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0095] Example 1

[0096] like Figure 2 As shown, a device for trapping and cooling a high-valence ion beam comprises, in sequence along the ion transmission direction, a screening electrode 1, a deceleration electrode 2, a linear ion trap 3, and a microchannel plate detector 4 (or a CCD camera). The voltages of the screening electrode 1, the deceleration electrode 2, and the linear ion trap 3 are controlled by corresponding voltage change timings to achieve high-energy, high-valence ion beam trapping and cooling.

[0097] like Figure 2 As shown, the screening electrode 1 includes a first screening plate 101 and a second screening plate 102 which are parallel to each other. After passing through the first screening plate 101 and the second screening plate 102 which are parallel to each other in the screening electrode 1, the ions enter the deceleration drift tube 201 in the deceleration drift tube 2 and are transmitted along the central axis direction of the deceleration drift tube 201. The ions output from the deceleration drift tube 201 are incident on the linear ion trap 3 through the electrostatic lens group of the deceleration electrode 2. The quadrupole 301 in the linear ion trap 3 includes four parallel rods, each of which includes a first cap electrode 3011 and a second cap electrode 3012. The first cap electrode 3011 and the second cap electrode 3012 are respectively located at the two ends of the corresponding rod. The trap center electrode 3013 is located between the first cap electrode 3011 and the second cap electrode 3012 on each rod. A first additional cap electrode 303 and a second additional cap electrode 3012 are respectively provided on both sides of the quadrupole 301. The additional cap electrode 304, the first additional cap electrode 303 and the second additional cap electrode 304 all include an additional cap electrode base and an additional cap electrode barrel. An opening is set on the additional cap electrode base, and the opening of the additional cap electrode base is connected to the additional cap electrode barrel. The additional cap electrode barrel of the first additional cap electrode 303 extends to the space between the first cap electrodes 3011 of the four rods of the quadrupole 301; the additional cap electrode barrel of the second additional cap electrode 304 extends to the space between the second cap electrodes 3012 of the four rods of the quadrupole 301; the ions entering the linear ion trap 3 pass through the additional cap electrode base of the first additional cap electrode 303 and the additional cap electrode barrel of the first additional cap electrode 303 in turn and then enter the space between the four trap center electrodes 3013; the cooling laser and the back pump laser are irradiated to the space between the four trap center electrodes 3013 of the linear ion trap 3.

[0098] The ions include cooperative ions and target high-valence ions. The ion source injects the cooperative ions into the linear ion trap 3, and then uses cooling laser and pumping laser to prepare a cooperative ion crystal cluster. Afterwards, the first screening plate 101, the second screening plate 102, the deceleration drift tube 201, the first additional cap electrode 303, and the second additional cap electrode 304 simultaneously change their voltages based on their respective voltage change timings. At the same time, the ion source periodically emits a screening ion beam containing the target high-valence ions. Under the irradiation of the cooling laser and pumping laser, the target high-valence ions are cooled by the cooperative ion crystal cluster.

[0099] Screening Electrode 1:

[0100] In the screening electrode 1, different functions are achieved by adjusting the corresponding voltages on the first screening plate 101 and the second screening plate 102:

[0101] Function 1: Apply a first screening plate voltage U1 to the first screening plate 101 and a second screening plate voltage U2 to the second screening plate 102. When U1 ≠ U2, the direction of motion of ions entering screening electrode 1 is deflected, preventing them from passing through. Based on the ions' charge-to-mass ratio, velocity, composition, and other information, when the first and second screening plate voltages U1 and U2 satisfy U1>>U2=0, ions are deflected and prevented from passing through screening electrode 1. When the first and second screening plate voltages U1 and U2 are adjusted to satisfy U1=U2, ions pass through screening electrode 1 normally without interference. Therefore, within each cycle T, U1=U2 can be applied during the time period t0-t1, allowing ions entering screening electrode 1 to pass normally. During periods other than t0-t1 within cycle T, U1>>U2 or U2>>U1 is applied. Ions entering screening electrode 1 during these periods are deflected and prevented from passing through. t0 and t1 are timing points.

[0102] Function 2: Optimize the ion beam divergence perpendicular to the direction of ion movement (i.e., perpendicular to the direction of the first screening plate 101 and the second screening plate 102): the ion beam has a Gaussian distribution on the plane perpendicular to the direction of ion movement, that is, the ion beam has a high ion density in the middle and a low ion density at the edge of the ion beam perpendicular to the direction of ion movement. Throughout the ion's path, the space outside the screening electrode 1, deceleration electrode 2, and linear ion trap 3 is subject to the entire external cavity potential. The external cavity is connected to the ground, so the external cavity potential is zero. If the initial energy of ion extraction is U0*Q (U0 is the potential at the ion's initial position, and Q is the ion's charge), and U1=U2<0, the positive ions' energy will change from U0*Q to U0*Q-U1*Q as they pass through the edge of screening electrode 1 during their entry into screening electrode 1, accelerating them. When they pass through the edge of screening electrode 1 during their exit from screening electrode 1, the surrounding potential returns to zero, causing their energy to return to U0*Q and their velocity to return to its initial speed. Conversely, if U1=U2>0, the ions' velocity is first decelerated and then restored to its initial speed. By applying U1=U2≠0, while ensuring normal ion passage, the ion beam experiences a brief acceleration or deceleration upon entering screening electrode 1, returning to its initial velocity after passing through it. Due to the spatial distribution of the ion beam itself, the ions at the center and the ions at the edge of the beam are subjected to different forces from the electric field of the electrode. Therefore, when the ion beam passes through the first screening electrode 101 and the second screening electrode 102, the ion beam will diverge or focus in the vertical direction of ion transmission, but the speed of passing through the screening electrode 1 does not change, thereby optimizing the degree of divergence of the ion beam.

[0103] In this embodiment, the target high-valence ion is Ni 11+ ,like Figure 4 As shown in the timing diagram, the ion source continuously and periodically emits a pulsed ion beam to the screening electrode 1, with a period of T. In the period T corresponding to each ion beam, the first screening plate voltage U1 and the second screening plate voltage U2 are applied to the first screening plate 101 and the second screening plate 102 respectively. 11+ During the time period t0 to t1 when the first screening plate 101 and the second screening plate 102 pass through, U1=U2. 11+ Normally, the first screening plate 101 and the second screening plate 102 are passed through, and in other time periods of the same cycle, s =U2>>U1, U s =The high level voltage value of the screening plate, then the ions (such as ions Ni) that reach the screening electrode 1 during these time periods q+, Ni ions with valences q = 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, etc.) are all deflected and unable to pass through. The fact that ions of different valences arrive at the screening electrode 1 at different times is an inherent law in the process of ions being accelerated by the accelerating electrode preceding the screening electrode 1 after simultaneous generation. The present invention utilizes this characteristic of ions of different valences arriving at the screening electrode 1 at different times to accurately control the voltages of the first screening plate 101 and the second screening plate 102 at different times and design a precise timing sequence to screen the ions.

[0104] Retarder Electrode 2:

[0105] like Figure 3 As shown, the deceleration electrode 2 includes a deceleration drift tube 201 and an electrostatic lens group (in this embodiment, the electrostatic lens group includes a first electrostatic lens 202, a second electrostatic lens 203 and a third electrostatic lens 204; the first electrostatic lens 202, the second electrostatic lens 203 and the third electrostatic lens 204 are respectively applied with a first electrostatic lens voltage U a , the second electrostatic lens voltage U b and the third electrostatic lens voltage U c ). In this embodiment, the Ni screened by the screening electrode 1 11+ The ions usually have energies of hundreds of electron volts. The deceleration electrode 2 is used to compress the velocity of each ion beam, decelerate the whole beam, and focus the ion beam. The deceleration electrode 2 can achieve multiple functions. ① First, by applying a linearly changing deceleration drift tube voltage U d On the deceleration drift tube 201, the corresponding deceleration drift tube voltage U d The relationship over time is: U d =U x -a*(tN*T-t2)(U x represents the starting value of the deceleration drift tube voltage, a represents the rate of change of the deceleration drift tube voltage, t represents time, T represents the cycle, N represents the number of cycles, and t2 represents the timing point). The ions in the ion beam passing through the screening electrode 1 mainly include the target high-valence ions (in this embodiment, the ions Ni 11+ ), but at this time the target high-valence ion velocity still has a certain distribution, so the ions arriving at the deceleration electrode 2 have different time sequences, and the linearly changing deceleration drift tube voltage U d② After all the ions in the ion beam that have passed through the screening electrode 1 enter the deceleration drift tube 201, the potential value of the entire deceleration drift tube 201 is adjusted to the low-level voltage value U of the deceleration drift tube. low , U low <0, all ions will climb -U when leaving the deceleration drift tube 201 low The potential, thus the kinetic energy is reduced (-U low *V m )eV,V m ③ By applying appropriate voltages to the various electrostatic lenses in the electrostatic lens group, the ion beam decelerated by the deceleration drift tube 201 is focused to prevent the ions from diverging significantly after deceleration.

[0106] Linear Ion Trap 3:

[0107] like Figure 2 As shown, the linear ion trap 3 in this case includes a first additional cap electrode 303, a second additional cap electrode 304 and a quadrupole 301. The quadrupole 301 is arranged on a linear ion trap base 302. The quadrupole 301 includes four rods. Like a traditional ion trap, each rod in the quadrupole 301 is divided into three sections. The two ends of each rod are respectively a first cap electrode 3011 and a second cap electrode 3012 of the rod. A radio frequency potential field U is applied to the first cap electrode 3011, the second cap electrode 3012 and the trap center electrode 3013 of all rods of the quadrupole 301. rf To achieve radial ion trapping (radial direction is perpendicular to the extension direction of the pole), the first cap electrode 3011 and the second cap electrode 3012 of each pole in the quadrupole 301 also apply a constant electrostatic potential field U y Used to achieve axial confinement of ions (the axis is parallel to the direction of the pole).

[0108] Based on the traditional ion trap, the linear ion trap 3 additionally includes a first additional cap electrode 303 and a second additional cap electrode 304 at each end. Each of the first additional cap electrode 303 and the second additional cap electrode 304 includes an additional cap electrode base and an additional cap electrode barrel. An opening is provided in the center of the additional cap electrode base, which communicates with the additional cap electrode barrel. The additional cap electrode barrel of the first additional cap electrode 303 is inserted into the space between the first cap electrodes 3011 of the four rods of the quadrupole 301, while the additional cap electrode barrel of the second additional cap electrode 304 extends into the space between the second cap electrodes 3012 of the four rods of the quadrupole 301. In this embodiment, ions emitted from the third electrostatic lens 204 directly enter the opening of the additional cap electrode base of the first additional cap electrode 303.

[0109] like Figure 2 As shown, a first additional cap electrode voltage U with adjustable amplitude and trigger time is applied to the first additional cap electrode 303 and the second additional cap electrode 304 respectively. end1 and the second additional cap electrode voltage U end2 The switch control is realized when external high-valence ions are injected into the linear ion trap 3. And all electrodes of the four poles of the quadrupole 301 (excluding the first additional cap electrode 303 and the second additional cap electrode 304) are not grounded, but connected to the reference voltage U bias On, reference voltage U bias The value of is adjustable. The radio frequency potential field U applied by the four poles rf and the electrostatic potential field U y Both are referenced to the reference voltage U bias , so that for the trap center electrode 3013 of the quadrupole 301, the potential is U bias +U rf , the potential of the first cap electrode 3011 and the second cap electrode 3012 at both ends of the quadrupole 301 is U bias +U rf +U y The first additional cap electrode voltage U end1 and the second additional cap electrode voltage U end2 It also needs to be higher than the reference voltage U bias . Set the floating reference voltage U bias The purpose is to reduce the ion energy to a value close to U when the deceleration drift tube 201 is used to decelerate the ions, so as to further avoid ion divergence. bias *Q, so that when the ions enter the linear ion trap 3, they will also climb U bias The potential height, thus losing U bias *Q's energy reaches an energy value close to 0.

[0110] Microchannel plate detector 4:

[0111] In this embodiment, by observing the pulse signals displayed on the microchannel plate detector 4 after the ions pass through the screening electrode 1, the deceleration electrode 2, and the linear ion trap 3 in sequence, the voltage change timing corresponding to the first screening electrode 101, the second screening electrode 102, the deceleration drift tube 201, the first additional cap electrode 303 and the second additional cap electrode 304 is assisted in confirming the detection area of ​​the sensing surface of the microchannel plate detector 4 is 10mm*10mm, and the end face distance between the microchannel plate detector 4 and the additional cap electrode base of the second additional cap electrode 304 is less than 10mm, so that all passing ions are collected with the largest possible solid angle.

[0112] CCD Camera:

[0113] When preparing the cooperative ion crystal cluster corresponding to the target high-valence ion, the size of the cooperative ion crystal cluster is observed by a CCD camera at the additional cap electrode base close to the second additional cap electrode 304;

[0114] After confirming the voltage change timing corresponding to the first screening plate 101, the second screening plate 102, the deceleration drift tube 201, the first additional cap electrode 303 and the second additional cap electrode 304, the microchannel plate detector 4 is replaced with a CCD camera, and the ion imaging in the linear ion trap 3 is observed by the CCD camera to confirm whether the target high-valence ions are successfully trapped in the linear ion trap 3.

[0115] Example 2

[0116] A method for high-valence ion beam trapped cooling, using the device for high-valence ion beam trapped cooling described in Example 1, such as Figure 1 As shown, the specific steps include:

[0117] Step 1: Build a device for achieving trapped cooling of high-valence ion beams, and set a CCD camera at the base of the additional cap electrode near the second additional cap electrode 304; prepare a cooperative ion crystal cluster in the linear ion trap 3 under the action of cooling laser and back-pumping laser.

[0118] Step 1.1, constructing the above-mentioned device for realizing high-valence state ion beam trapping cooling, and setting a CCD camera at the additional cap electrode base near the second additional cap electrode 304;

[0119] Step 1.2: Determine the type of the corresponding co-ion according to the charge-to-mass ratio of the target high-valent ion, and determine the radio frequency potential field U required by the linear ion trap 3 to trap the target high-valent ion and the co-ion. rf , electrostatic potential field U y, the additional cap electrode high-level voltage value U required to trap the target high-valence ions end ;

[0120] Among them, the radio frequency potential field U rf The electrostatic potential field U is applied to the first cap electrode 3011, the second cap electrode 3012 and the trap center electrode 3013 of all the quadrupoles 301; y The additional cap electrode high level voltage value U end The first additional cap electrode voltage U is used to trap the target high-valence ions. end1 and the second additional cap electrode voltage U end2 The voltage value of the first additional cap electrode voltage U end1 The second additional cap electrode voltage U end2 A second additional cap electrode 304 will be applied.

[0121] The target high-valent ion selected in this embodiment is Ni 11+ ion;

[0122] Step 1.3: Apply a radio frequency potential field U to the first cap electrode 3011, the second cap electrode 3012 and the well center electrode 3013 of all the quadrupoles 301. rf Apply an electrostatic potential field U to the first cap electrode 3011 and the second cap electrode 3012 of each rod in the quadrupole 301 y ; Set the first screening plate voltage U1 = 0 corresponding to the first screening plate 101, the second screening plate voltage U2 = 0 corresponding to the second screening plate 102, and the deceleration drift tube voltage U corresponding to the deceleration drift tube 201 d =0, the voltage of each electrostatic lens in the electrostatic lens group is 0, and the first additional cap electrode voltage U corresponding to the first additional cap electrode 303 is end1 =0, the second additional cap electrode voltage U corresponding to the second additional cap electrode 304 end2 =0, so that the screening electrode 1 and the deceleration electrode 2 do not screen or decelerate any ions;

[0123] Step 1.4: Use a conventional ion trapping cooling method to trap and cool the co-ion. Conventional ion trapping cooling involves trapping and cooling the co-ion in the linear ion trap 3 using a cooling laser and a pumping laser:

[0124] The ion source injects cooperative ions into the linear ion trap 3;

[0125] Irradiating the linear ion trap 3 with cooling laser and pumping laser to optimize various cooperative ion trapped cooling parameters to achieve trapped cooling of cooperative ions, thereby obtaining cooperative ion crystal clusters. The cooperative ion trapped cooling parameters include the line width, power, frequency and wave vector direction of the cooling laser and pumping laser;

[0126] This implementation case uses Be + ions act as cooperative ions, because Be + The charge-to-mass ratio of the ion is 1:9, which is similar to that of Ni 11+ The ion charge-to-mass ratio is 11:58, which is very close. Using the traditional ion trapping cooling method, the trapped cooling Be + ions, and optimize and evaluate the parameters of the cooling laser and the pumping laser of the cooperative ions, including the optimization of the laser line width to 10kHz, the power greater than 1mW, the frequency between 957396.0GHz and 957396.6GHz, and the wave vector direction perpendicular to the axis of the linear ion trap 3 and passing through the center of the linear ion trap 3, thereby achieving Be + The trapped cooling of ions leads to the acquisition of cooperative ionic crystal clusters.

[0127] Step 1.5: Capture an image of the cooperative ion crystal cluster using a CCD camera to determine whether the size of the cooperative ion crystal cluster reaches a crystal cluster size threshold, and evaluate whether the temperature of the cooperative ion crystal cluster is less than 10 mK.

[0128] When the size of the cooperative ion crystal cluster is greater than or equal to the crystal cluster size threshold, and the temperature of the cooperative ion crystal cluster is lower than 10 mK, executing step 2;

[0129] When the size of the cooperative ion crystal cluster is smaller than the crystal cluster size threshold, or the temperature of the cooperative ion crystal cluster is greater than or equal to 10 mK, return to step 1.4 to continue optimizing the cooperative ion trapping cooling parameters until the size of the cooperative ion crystal cluster reaches the crystal cluster size threshold and the temperature of the cooperative ion crystal cluster is lower than 10 mK.

[0130] like Figure 5 As shown, the large cluster of cooperative ions Be obtained after step 1 is completed. + Prison Cooldown Chart.

[0131] Step 2: Screening of single valence ions

[0132] Replace the CCD camera with a microchannel plate detector 4; the ion source continuously and periodically emits an ion beam to be screened towards the screening electrode 1, and the microchannel plate detector 4 detects the pulse signal corresponding to the ion beam to be screened. The ions to be screened in the ion beam to be screened include target high-valence ions and ions to be removed. The ions to be removed are ions of the same atom as the target high-valence ions but with different valence states; determine the voltage change time sequences corresponding to the first screening plate voltage U1 and the second screening plate voltage U2 respectively; apply the first screening plate voltage U1 to the first screening plate 101 and apply the second screening plate voltage U2 to the second screening plate 102, so that in the time period from t0 to t1 within each period T, U1 >> U2 or U1 << U2, and U1 = U2 in other time periods. Both t0 and t1 are time sequence points, so that the microchannel plate detector 4 detects the pulse signal of the target high-valence ions of a single valence state. The specific steps are as follows:

[0133] Step 2.1: Replace the CCD camera with a microchannel plate detector 4; the ion source continuously and periodically emits an ion beam to be screened towards the screening electrode 1. The ion beam to be screened passes through the screening electrode 1, the deceleration electrode 2, and the linear ion trap 3 in sequence and reaches the microchannel plate detector 4, so that the microchannel plate detector 4 detects the pulse signal corresponding to the ion beam to be screened, and the pulse signal corresponding to the ion beam to be screened reaches the strongest; wherein, the ions to be screened in the ion beam to be screened include target high-valence ions and ions to be removed. The ions to be removed are ions of the same atom as the target high-valence ions but with different valence states;

[0134] In step 2.1, maintain the radio frequency potential field U applied to all the poles in the quadrupole 301 rf and the electrostatic potential field U y , at the same time, the first screening plate voltage U1 = 0, the second screening plate voltage U2 = 0, the deceleration drift tube voltage U d = 0, the voltages of each electrostatic lens in the electrostatic lens group are 0, the first additional cap electrode voltage U end1 = 0, the second additional cap electrode voltage U end2 = 0 (that is, the same as the setting in step 1), so that the screening electrode 1 and the deceleration electrode 2 do not screen and decelerate any ions;

[0135] In this embodiment, the ions to be screened included in the ion beam to be screened are ions Ni 8+ 、Ni 9+ 、Ni 10+ 、Ni 11+ 、Ni 12 + and Ni 13+ etc.

[0136] Step 2.2, selecting an auxiliary ion system, wherein the auxiliary ion beam corresponding to the auxiliary ion system includes auxiliary ions of multiple valence states corresponding to the same auxiliary atom, and the auxiliary ions are present in the auxiliary ion beam so that the charge-to-mass ratio of the ions to be screened in the ion beam to be screened is the same as the charge-to-mass ratio of the auxiliary ions; and the auxiliary ions having the same charge-to-mass ratio and the corresponding ions to be screened are used as reference auxiliary ions and reference ions to be screened, respectively;

[0137] In this embodiment, Ni 11+ Ions are target high-valence ions, Ni 11+ The ions to be screened of different valence states in the ion beam to be screened are simultaneously drawn out from the ion source, and reach the microchannel plate detector 4 in sequence after different flight times, which is displayed as a series of pulse signal peaks on the microchannel plate detector 4. The higher the valence state, the faster the speed of the ion to be screened and the shorter the required flight time. The auxiliary ion system selected in this embodiment is the Ar ion system, and the corresponding auxiliary ion beam includes ions Ar 4+ ,Ar 5+ ...Ar 9+ ,Ar 10+ Wait, Ni 11+ Ni in the ion system to be screened 12+ The mass-to-charge ratio of the ion and Ar 8+ The mass-to-charge ratio of the ions is the same, so Ni 12+ ions and Ar 8+ The speed of the ions is the same, Ni 12+ ions as reference ions to be screened, Ar 8+ ions serve as reference auxiliary ions; ions of different valence states in the Ar ion system are also simultaneously drawn out from the ion source, and reach the microchannel plate detector 4 in sequence after different flight times, and are displayed as a series of pulse signal peaks on the corresponding microchannel plate detector 4; Ni 12+ ions and Ar 8+ The flight time of ions from the ion source to the microchannel plate detector 4 is consistent; with the help of Ar 8+ Ion found Ni 12+ The flight time corresponding to the ion confirms Ni 12+ The number of the pulse signal corresponding to the ion can be used to deduce Ni 11+ The serial number of the pulse signal corresponding to the ion, and then find the Ni 11+ The flight time of ions from the ion source to the microchannel plate detector 4 is used to determine the voltage change timing corresponding to the first screening plate voltage U1 and the second screening plate voltage U2;

[0138] The flight time is the time difference between when the ions are emitted from the ion source and when the microchannel plate detector 4 observes the corresponding pulse signal.

[0139] Step 2.3, the ion source continues to emit the ion beam to be screened, and the microchannel plate detector 4 detects the pulse signal peak of each valence state of the ion to be screened, and the number is recorded as i, and the corresponding flight time of the ion to be screened is recorded as The corresponding valence of the ion to be screened In the subsequent steps, it is determined that a pulse signal peak of an ion to be screened corresponds to an ion to be screened in a valence state in the ion beam to be screened;

[0140] The ion source stops emitting the ion beam to be screened and switches to emitting the auxiliary ion beam. The microchannel plate detector 4 detects the pulse signal peak corresponding to each valence state auxiliary ion, and the number is recorded as k and the flight time of the corresponding auxiliary ion is recorded as The valence of the corresponding auxiliary ion is an unknown quantity;

[0141] Find The sequence number i of the pulse signal peak of the ion to be screened is taken as the reference ion to be screened, and the sequence number of the pulse signal peak of the reference ion to be screened is recorded as the reference sequence number i n The flight time of the reference ion to be screened is recorded as the reference time The sequence number i of the pulse signal peak of the ion to be screened detected by the counting microchannel plate detector 4 can be used to confirm which pulse signal peak corresponds to the reference ion to be screened;

[0142] In this embodiment, it is assumed that the initial time of the ion source emitting the ion beam (the ion beam is the ion beam to be screened or the auxiliary ion beam) is 0, then the time for ions of different valence states to reach the microchannel plate detector 4 is different. For example, the ion Ni in the ion beam to be screened selected in this embodiment is 13+ 、Ni 12+ 、Ni 11+ 、Ni 10+ 、Ni 9+ and Ni 8+ The flight time of the corresponding ions to be screened in order Then, multiple pulse signal peaks appear on the microchannel plate of the microchannel plate detector 4 in sequence, that is, multiple pulse signal peaks appear on the microchannel plate detector 4 with time as the coordinate; similarly, the ion source is converted to emit auxiliary ion beam, and the auxiliary ion beam selected in this embodiment is Ar 10+ 、Ar 9+ ,...,Ar 7+ ,...,Ar 4+ The plasma is emitted from the ion source (the corresponding initial time is 0), and the flight time of the corresponding auxiliary ion is After reaching the microchannel plate detector 4, the ion Ar 8+ and Ni 12+ The charge-to-mass ratio is the same, so the ion Ar8+ and Ni 12+ To achieve the same flight duration as that of the microchannel plate detector 4, it is only necessary to find the flight duration of the auxiliary ions and the flight duration of the ions to be screened equal pulse signal peaks, and the ions to be screened corresponding to them are the reference ions to be screened. In this embodiment, by finding the reference serial number i n = 2, and confirming the reference duration

[0143] Step 2.4: Record the serial number of the pulse signal peak of the target high-valence ions as i m , based on i m -i n =

[0144] V n -V m , confirm the serial number i of the pulse signal peak of the target high-valence ions m , V m is the valence state of the target high-valence ions, V n is the valence state of the reference ions to be screened; according to the serial number i of the pulse signal peak of the target high-valence ions m find the flight duration corresponding to the target high-valence ions

[0145] In this embodiment, it is necessary to confirm the pulse signal peak of the ions Ni 11+ , based on the reference serial number i corresponding to the ions Ni 12+ = 2, count the next pulse signal peak in sequence, which is the serial number i of the pulse signal peak of the target high-valence ions corresponding to the ions Ni n = 3, and the serial numbers of the pulse signal peaks of other valence state ions are类推. 11+ m m = 3, and the serial numbers of the pulse signal peaks of other valence state ions are类推.

[0146] Step 2.5: The ion source stops emitting the auxiliary ion beam and is converted to continuously and periodically emit the ions to be screened beam; set the initial values of the timing points t0 and t1; set the voltage U1 of the first screening electrode and the voltage U2 of the second screening electrode, so that U1 >> U2 or U1 << U2 during the period from t0 to t1, and U1 = U2 in other periods.

[0147] Among them, setting the initial values of the timing points t0 and t1 specifically includes the following steps:

[0148] The distance from the ion source to the screening electrode 1 is denoted as the distance L1; the distance from the ion source to the microchannel plate detector 4 is denoted as the distance L4; based on the flight duration of the target high-valence ions set the initial value of the timing point t0 as the distance L1 and the distance L4 The initial value of timing point t1 is greater than or equal to The sequence number of the pulse signal peak is (i m +1), that is, the flight time of the ions to be screened (the corresponding valence state is 1 less than the valence state of the target high-valence ions) that arrive at the microchannel plate detector after the target high-valence ions in the ion beam to be screened.

[0149] Step 2.6, adjust the timing point t0 and the timing point t1 until the number of pulse signal peaks detected by the microchannel plate detector 4 before the timing point t0 in the same cycle T is M H , after the timing point t1 of the same period T, the number of pulse signal peaks detected by the microchannel plate detector 4 is M L (M H M is the number of valence species in the ion beam to be screened whose valence is higher than the corresponding valence of the target high-valence ion, L The number of valence states of the ion beam to be screened that are lower than the corresponding valence state of the target high-valence ion is determined, thereby confirming the voltage change timing corresponding to the first screening plate voltage U1 and the second screening plate voltage U2, so that a single target high-valence ion passes through the screening electrode 1. The other ions to be screened in the ion beam to be screened, except for the target high-valence ion, are deflected in the screening electrode 1 and thus screened out. The specific process is as follows:

[0150] Adjust the timing point t0 and the timing point t1 until the number of pulse signal peaks detected by the microchannel plate detector 4 before the timing point t0 in the same cycle T is M. H , M H is the number of valence states in the ion system to be screened that are higher than the corresponding valence state of the target high-valence ion;

[0151] Then the timing point t0 is kept, and only the timing point t1 is adjusted so that after the timing point t1 in the same period T, the number of pulse signal peaks detected by the microchannel plate detector 4 is M L , M L is the number of valence states in the ion system to be screened whose valence is lower than the corresponding valence state of the target high-valence ion;

[0152] The first screening plate voltage U1 and the second screening plate voltage U2 keep changing according to their respective corresponding voltage change timings.

[0153] In this embodiment, the timing points t0 and t1 are first set. In order to easily observe the pulse signal peaks of one or more valence ions during debugging, the pulse signal peaks of the ions are completely invisible; the timing point t0 is adjusted so that two pulse signal peaks of the ions are detected before the timing point t0 (corresponding to the ions Ni 13+ and Ni 12+) After determining the approximate timing point t0, the timing point t0 remains unchanged, and the timing point t1 is decreased until 3 pulse signal peaks are detected after the timing point t1 (corresponding to ions Ni 10+ , Ni 9+ , and Ni 8+ ); Determine the voltage change timings of the first screening plate voltage U1 and the second screening plate voltage U2: within the time period from t1 to t0, U1 = U2, and in other time periods, U1 >> U2 or U1 << U2; thus, only the target high-valence ions can pass through the screening electrode 1 within the time period from t1 to t0. The voltage change timings of the first screening plate voltage U1 and the second screening plate voltage U2 determined at this time are as Figure 4 shown.

[0154] Step 3: Decelerate the target high-valence ions

[0155] The ion source continues to continuously emit the ion beam to be screened periodically; based on the voltage change timings corresponding to the first screening plate voltage U1 and the second screening plate voltage U2 confirmed in Step 2, determine the voltage change timing of the deceleration drift tube voltage U d applied to the deceleration drift tube 201, and apply the deceleration drift tube voltage U d to the deceleration drift tube 201, such that the deceleration drift tube voltage U d starts to linearly decrease with time from the deceleration drift tube voltage initial value U x at the timing point t2 in each period T, and the deceleration drift tube voltage U d decreases as a whole at the timing point t3; at the same time, apply corresponding voltages to each electrostatic lens of the electrostatic lens group; after applying the deceleration drift tube voltage U d , the flight duration of the pulse signal detected by the microchannel plate detector 4 significantly increases, and there are still considerable ion pulse signals on the microchannel plate detector 4.

[0156] The method for determining whether the flight duration significantly increases is: compare the change value of the flight duration with a preset extension threshold. When the change value of the flight duration is greater than the preset extension threshold, it is determined that the flight duration significantly increases;

[0157] The preset extension threshold is at the microsecond level, such as 10 microseconds to 11 microseconds. Because the time width of the pulse signal is only at the 100 ns level, a 1-microsecond extension shows that the flight duration has changed by nearly 10 pulse signal time widths.

[0158] Step 3 specifically includes the following steps:

[0159] Step 3.1: Set the initial value of the timing point t2 such that t2 > t1; Denote the distance from the ion source to the deceleration drift tube 201 as the distance L3, and set the initial value of the timing point t3 according to the distance L3 as Satisfy t3 > t2;

[0160] At this time, a radio frequency potential field U is maintained on all the poles in the quadrupole 301 rf and an electrostatic potential field U y , and at the same time, the first screening plate voltage U1 and the second screening plate voltage U2 respectively satisfy the voltage change time sequence determined in step 2.6, that is, U1 = U2 in the time period from t0 to t1, and U1 >> U2 or U1 << U2 in other time periods; the deceleration drift tube voltage U d = 0, the voltages of each electrostatic lens in the electrostatic lens group are 0, the first additional cap electrode voltage U end1 = 0, the second additional cap electrode voltage U end2 = 0;

[0161] Step 3.2, set the voltage change time sequence of the deceleration drift tube voltage U d as:

[0162]

[0163] t represents time, T represents period, N represents the number of periods, U x represents the starting value of the deceleration drift tube voltage;

[0164] Apply the deceleration drift tube voltage U d on the deceleration drift tube 201, and gradually increase the starting value U x of the deceleration drift tube voltage from 0, so that the number of pulse signals detected by the microchannel plate detector 4 is the same as that when the deceleration drift tube voltage U d is not applied, and compared with the case when the deceleration drift tube voltage U d is not applied, the flight duration of the first pulse signal in one period T is significantly increased. In this step, the starting value U x of the deceleration drift tube voltage is coarsely adjusted first to avoid excessive deceleration of the target high-valence ions caused by too large starting value U x of the deceleration drift tube voltage, and it is convenient to increase the low-level voltage value U d of the deceleration drift tube for a period of time in the voltage change time sequence of the deceleration drift tube voltage U low , and adjust the low-level voltage value U low of the deceleration drift tube;

[0165] Step 3.3, on the basis of step 3.2, change the voltage change time sequence of the deceleration drift tube voltage U d so that the deceleration drift tube voltage U d satisfies:

[0166]

[0167] Among them, U x represents the starting value of the deceleration drift tube voltage, a represents the rate of change of the deceleration drift tube voltage, t represents time, T represents cycle, N represents the number of cycles, U low Indicates the low-level voltage value of the deceleration drift tube, U x The sign of U is the same as a. x and U low The positive and negative signs are opposite; in this embodiment, U low <0, U x >0;

[0168] Step 3.4: Observe the pulse signal detected by the microchannel plate detector 4 and adjust the low-level voltage value U of the deceleration drift tube. low , timing point t2 and timing point t3, which significantly increases the flight time corresponding to all pulse signals in the same cycle.

[0169] Step 3.4.1, observe whether the microchannel plate detector 4 detects the pulse signal,

[0170] When the microchannel plate detector 4 does not detect the pulse signal, it means that the target high-valence ions are decelerated, but the deceleration amplitude is too large. Then the low-level voltage value U of the deceleration drift tube is adjusted. low , until the microchannel plate detector 4 detects a pulse signal; then execute step 3.4.2;

[0171] When the microchannel plate detector 4 detects a pulse signal, step 3.4.2 is executed;

[0172] Step 3.4.2: Observe the flight time of the pulse signal detected by the microchannel plate detector 4, and adjust the timing point t2 or timing point t3 according to the observation result.

[0173] (1) When the flight time of all pulse signals in the same cycle remains unchanged, it means that no ions are decelerated, that is, the target high-valence ions have not yet entered the deceleration drift tube 201. d Has been restored to 0 or even to the low level voltage value U of the deceleration drift tube low (This indicates that the timing point t3 is too small), or the target high-valence ions have already passed through the deceleration drift tube 201 before the deceleration drift tube voltage U is applied. d (Indicates that the timing point t2 is too large), then increase the timing point t3 alone or reduce the timing point t2 alone until the flight time of all pulse signals in one cycle is significantly increased;

[0174] (2) When the flight time corresponding to a portion of the pulse signals in the same cycle is extended, while the flight time corresponding to the other portion of the pulse signals remains unchanged, it indicates that some ions enter the deceleration drift tube 201 during the time period t2 to t3.

[0175] The flight duration corresponding to the first part of the pulse signals is extended, while the flight duration corresponding to the second part of the pulse signals remains unchanged. The timing point t3 is increased until the flight duration corresponding to all pulse signals in the same cycle is significantly increased.

[0176] The flight duration corresponding to the first part of the pulse signals does not change, while the flight duration corresponding to the second part of the pulse signals is extended, and the timing point t2 is reduced until the flight duration corresponding to all pulse signals in the same cycle increases significantly;

[0177] When only the flight duration corresponding to the middle part of the pulse signal is extended, and the flight duration corresponding to the front and rear parts of the pulse signal remains unchanged, the timing point t2 is reduced and the timing point t3 is increased until the flight duration corresponding to all pulse signals in the same cycle is significantly increased.

[0178] When adjusting timing point t2 and increasing timing point t3, keep t1 <t2<t3。

[0179] Step 3.5: Adjust the starting value U of the deceleration drift tube voltage x (The rate of change of the deceleration drift tube voltage a changes with the initial value of the deceleration drift tube voltage U x Change), so that the time width of the pulse signal of the microchannel plate detector 4 detecting the target high-valent ion is compressed to the narrowest;

[0180] The narrower the time width of the pulse signal, the smaller the spatial spread of the ions in the direction of motion, the more concentrated the ion space and energy distribution, that is, the higher the ion density, so that the first additional cap electrode voltage U can be controlled when the target high-valence ions are subsequently injected. end1 The higher the voltage change sequence, the higher the efficiency of injecting target high-valence ions into the linear ion trap 3. x The value of the voltage change rate a of the deceleration drift tube depends on the velocity distribution of the target high-valence ions when the target high-valence ions enter the deceleration drift tube 201. In this embodiment, the voltages U and V are randomly selected in the range of 10V to 500V. x =100V, U x =300V, U x =400V, observe the time width of the pulse signal of the target high-valent ion detected by the microchannel plate detector 4, and then select the deceleration drift tube voltage starting value U when the time width of the pulse signal of the target high-valent ion is relatively minimum x Continue to adjust the deceleration drift tube voltage starting value U near the value of x And the rate of change of the drift tube voltage is decelerated, so that the time width of the pulse signal of the target high-valence ion is compressed to the narrowest.

[0181] Step 4: Trapping and cooling the target high-valence ions

[0182] The ion source continues to periodically emit the ion beam to be screened; determine the first additional cap electrode voltage U end1 and the second additional cap electrode voltage U end2 The corresponding voltage change timing and the reference voltage U of the linear ion trap 3 are bias and the first additional cap electrode voltage U end1 Applied to the first additional cap electrode 303, the second additional cap electrode voltage U end2 It is applied to the second additional cap electrode 304 to trap the target high-valence ions in the linear ion trap 3; under the cooling effect of the cooling laser and the back-pumping laser, the target high-valence ions are cooled based on the cooperative cooling mechanism.

[0183] Step 4.1: Determine the first additional cap electrode voltage U end1 and the second additional cap electrode voltage U end2 Voltage change timing:

[0184] At this time, the radio frequency potential field U is applied to all the rods in the quadrupole 301. rf and the radio frequency potential field U y , while the first screening plate voltage U1 and the second screening plate voltage U2 respectively meet the voltage change sequence determined in step 2.6; the deceleration drift tube voltage U d Satisfy the voltage change timing determined in step 3.5;

[0185] The first additional cap electrode 303 and the second additional cap electrode 304 are started, and the second additional cap electrode voltage U end2 =0, then a first additional cap electrode voltage U is applied to the first additional cap electrode 303. end1 , the first additional cap electrode voltage U end1 The following timing is met:

[0186]

[0187] Among them, t4 and t5 are timing points, and t3 <t4<t5,U end is the high-level voltage value of the additional cap electrode, U′ end is the high and low voltage value of the additional cap electrode, U′ end end In this embodiment, (t5-t4) <1 microsecond, the additional cap electrode high level voltage value U end The initial value is 150V;

[0188] Adjust the timing point t4 and the corresponding timing point t5, keep (t5-t4) <1 microsecond, until the pulse signal on the microchannel plate detector 4 is observed in one cycle T of ion implantation and the first additional cap electrode voltage U is not applied at the end of step 3 end1 ​The signal is consistent with that of the first additional cap electrode voltage U end1 At the additional cap electrode low level U' end It passes through the first additional cap electrode 303 smoothly and passes through the linear ion trap 3;

[0189] Then, the second additional cap electrode voltage U of the second additional cap electrode 304 is raised. end2 make U end2 =U end , maintain the first additional cap electrode voltage U end1 Voltage change timing;

[0190] The deceleration drift tube voltage U d The timing point t6 that returns to 0 in each cycle T is defined as: several hundred nanoseconds to 1 microsecond after the timing point t4. The timing point t6 is usually set near the timing point t5 to ensure that within one cycle T, all target high-valence ions that enter the deceleration drift tube 201 leave the deceleration drift tube 201.

[0191] By applying the voltage U end1 The voltage change sequence including the low voltage is set to leave a time window for the target high-valence ions to enter the linear ion trap 3, so that when the target high-valence ions reach the first additional cap electrode 303, the first additional cap electrode voltage U end1 The voltage value U′ at the high and low level of the additional cap electrode end , the target high-valence ions can enter the linear ion trap 3; then, the first additional cap electrode voltage U end1 Restore to the high level voltage value U of the additional cap electrode end , while the second additional cap electrode voltage U of the second additional cap electrode 304 end2 Always at the high level voltage value U of the additional cap electrode end , thus ensuring that high-valent ions do not return and escape after injection.

[0192] Step 4.2: Determine the reference voltage U bias The value of

[0193] Replace the microchannel plate detector 4 with a CCD camera. Use the CCD camera to observe the ion imaging in the linear ion trap 3 and determine whether there is a dark circular area in the bright area:

[0194] When no dark circular area is observed in the bright area, the first additional cap electrode 303 and the second additional cap electrode 304 are restarted, and the reference potential U of the linear ion trap 3 is adjusted as a whole after waiting for 1 to 30 seconds. bias , and adjust the first additional cap electrode voltage U end1 and the second additional cap electrode voltage Uend2 At the high level voltage value U of the additional cap electrode end The value of U end =U bias +50V; until a dark circular area appears in the bright area;

[0195] When a dark circular area appears in the bright area, proceed to step 4.3.

[0196] Adjust reference voltage U bias That is, to adjust the residual energy of the target high-valence ions after entering the linear ion trap 3. Because the specific energy of the target high-valence ions is difficult to measure accurately, an estimated reference voltage U bias Fine-tune the value so that the energy of the target high-valent ions after entering the linear ion trap 3 can enable the target high-valent ions to be trapped and cooled, wherein the darkened circular area is the space occupied by the target high-valent ions.

[0197] The final first additional cap electrode voltage U end1 and the second additional cap electrode voltage U end2 The timing of Figure 4 As shown, at the timing point t4, the first additional cap electrode voltage U end1 The target high-valence ions enter the linear ion trap 3, and then the first additional cap electrode voltage U is lowered within 1 microsecond. end1 Raised to the high level voltage value U of the additional cap electrode end , so that the target high-valence ions are trapped in the linear ion trap 3.

[0198] Step 4.3: Under the cooling laser and pumping laser cooling, the target high-valence ions are cooled based on the synergistic cooling mechanism.

[0199] The cooperative cooling mechanism is as follows: high-valence ions will collide with co-ion under the Coulomb interaction force, and the collision will transfer energy. The energy of the co-ion is taken away by the cooling laser and the back-pumping laser. The high-valence ions originally have low energy, but after the collision, they will lose energy, and the co-ion will gain energy. Then the energy gained by the co-ion is taken away by the laser, and this cycle repeats, so that the high-valence ions are cooled down.

[0200] like Figure 4 As shown, it is a timing diagram of all electrodes to which a voltage change timing sequence is applied.

[0201] like Figure 6 As shown, it is the target high-valent ion Ni 11+ An image of trapped cooling, where the bright areas are Be + ions, the dark area is the trapped cooled Ni 11+ The space occupied by the ions is due to the Ni 11+Ions do not emit light, so the image appears as a dark area.

[0202] like Figure 7 For the embodiment, the target high-valence ion is changed to Ar 7+ An image of the trapped cooling of ions.

[0203] The present invention adopts a corresponding voltage change sequence for the first screening plate voltage U1 and the second screening plate voltage U2 of the screening electrode 1 to achieve the screening of target high-valence ions and the adjustment of the ion beam divergence of the ion beam to be screened; the deceleration drift tube voltage U1 of the deceleration drift tube 201 in the deceleration electrode 2 is adjusted. d A corresponding voltage variation sequence is employed to achieve ion deceleration and concomitant kinetic energy compression. A linear ion trap 3, comprising a first additional cap electrode 303 and a second additional cap electrode 304, achieves coordinated ion trapped cooling and injection and trapped cooling of target high-valence ions. This entire process is supplemented by real-time pulse signal monitoring by a microchannel plate detector 4 and ion imaging by a CCD camera, enabling trapped cooling of target high-valence ions from a complex initial ion beam. This approach is of great significance for the research and application of a new generation of ion clocks based on high-valence ions.

[0204] Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Those skilled in the art may modify or alter the above embodiments within the scope of the present invention. Therefore, any other corresponding changes and modifications made based on the technical concept of the present invention that do not depart from the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

[0205] The contents not described in detail in the specification of the present invention belong to the common knowledge of professionals in this field.

Claims

1. A device for high-valence ion beam trapping and cooling, characterized in that: The device includes a screening electrode (1), a deceleration electrode (2) and a linear ion trap (3) in sequence along the ion transmission direction; After passing through a first screening plate (101) and a second screening plate (102) parallel to each other in the screening electrode (1), the ions enter the deceleration drift tube (201) in the deceleration electrode (2) and are transmitted along the central axis direction of the deceleration drift tube (201). The ions output from the deceleration drift tube (201) are incident on the linear ion trap (3) through the electrostatic lens group of the deceleration electrode (2); The quadrupole (301) in the linear ion trap (3) includes four parallel poles, each of which includes a first cap electrode (3011) and a second cap electrode (3012), the first cap electrode (3011) and the second cap electrode (3012) being located at the two ends of the corresponding pole, respectively; a trap center electrode (3013) is located between the first cap electrode (3011) and the second cap electrode (3012) on each pole; a first additional cap electrode (303) and a second additional cap electrode (304) are respectively provided on both sides of the quadrupole (301); the first additional cap electrode (303) and the second additional cap electrode (304) both include an additional cap electrode base and an additional cap electrode barrel; an opening is provided on the additional cap electrode base, and the opening of the additional cap electrode base is provided on the bottom of the quadrupole (301). The port is communicated with the additional cap electrode barrel portion, the additional cap electrode barrel portion of the first additional cap electrode (303) extends to the space between the first cap electrodes (3011) of the four poles of the quadrupole (301); the additional cap electrode barrel portion of the second additional cap electrode (304) extends to the space between the second cap electrodes (3012) of the four poles of the quadrupole (301); the ions entering the linear ion trap (3) pass through the additional cap electrode base of the first additional cap electrode (303) and the additional cap electrode barrel portion of the first additional cap electrode (303) in sequence and then enter the space between the four trap center electrodes (3013); the cooling laser and the back pump laser are irradiated to the space between the four trap center electrodes (3013) of the linear ion trap (3); The ions include cooperative ions and target high-valence ions; The first screening plate (101), the second screening plate (102), the deceleration drift tube (201), the first additional cap electrode (303) and the second additional cap electrode (304) respectively and simultaneously perform corresponding voltage changes based on their respective corresponding voltage change timings.

2. A method for high-valence ion beam trapping and cooling, utilizing the device for high-valence ion beam trapping and cooling according to claim 1, characterized in that: The steps include: Step 1: constructing a device for achieving trapped cooling of a high-valence ion beam, and setting a CCD camera at the base of the additional cap electrode near the second additional cap electrode (304); preparing a cooperative ion crystal cluster in the linear ion trap (3) under the action of cooling laser and back-pumping laser; Step 2: Replace the CCD camera with a microchannel plate detector (4); the ion source continuously and periodically emits an ion beam to be screened toward the screening electrode (1); the microchannel plate detector (4) detects a pulse signal corresponding to the ion beam to be screened; the ions to be screened in the ion beam to be screened include target high-valence ions and ions to be screened out; the ions to be screened out are ions corresponding to the same atom as the target high-valence ions but having a different valence; Determine the voltage change time sequences corresponding to the first screening plate voltage U1 and the second screening plate voltage U2 respectively; apply the first screening plate voltage U1 to the first screening plate (101) and apply the second screening plate voltage U2 to the second screening plate (102), so that within each cycle inside during the time period, U1 >> U2 or U1 << U2, and U1 = U2 in other time periods. and are both time sequence points, so that the microchannel plate detector (4) detects the pulse signal of the target high-valence ions in a single valence state; Step 3: Determine the deceleration drift tube voltage applied to the deceleration drift tube (201) The voltage change sequence is obtained, and a deceleration drift tube voltage is applied to the deceleration drift tube (201). , which slows down the drift tube voltage In each cycle From the timing point The starting value of the deceleration drift tube voltage is It starts to decrease linearly with time, at the time point Time deceleration drift tube voltage At the same time, a corresponding voltage is applied to each electrostatic lens of the electrostatic lens group; Apply deceleration drift tube voltage Afterwards, the flight time of the pulse signal detected by the microchannel plate detector (4) increases significantly, and there is still a considerable ion pulse signal on the microchannel plate detector (4); The flight time is the time difference between the ion being emitted from the ion source and the corresponding pulse signal being observed by the microchannel plate detector (4); when the change in the flight time is greater than a preset extension threshold, it is determined that the flight time has significantly increased; Step 4: The ion source continues to periodically emit the ion beam to be screened; determine the voltage of the first additional cap electrode and the second additional cap electrode voltage The corresponding voltage change timing and the reference voltage of the linear ion trap (3) and set the first additional cap electrode voltage Applied to the first additional cap electrode (303), the second additional cap electrode voltage is applied to the second additional cap electrode (304) so ​​that each cycle When the target high-valence ion reaches the first additional cap electrode (303), the first additional cap electrode voltage of the first additional cap electrode (303) is At a low level, the target high-valence ions can enter the linear ion trap (3); then, the first additional cap electrode voltage Returning to a high level, the second additional cap electrode voltage of the second additional cap electrode (304) It is always at a high level, so that the target high-valence ions are trapped in the linear ion trap (3); under the cooling laser and the back-pump laser cooling, the target high-valence ions are cooled based on the cooperative cooling mechanism.

3. The method for high-valence ion beam trapping cooling according to claim 2, characterized in that: The step 1 comprises the following steps: Step 1.1, constructing a device for realizing trapped cooling of a high-valence ion beam, and setting a CCD camera at the additional cap electrode base close to the second additional cap electrode (304); Step 1.2: Determine the type of the corresponding co-ion according to the charge-mass ratio of the target high-valent ion, and determine the radio frequency potential field U required by the linear ion trap (3) to trap the target high-valent ion and the co-ion. rf , electrostatic potential field U y , the additional cap electrode high-level voltage required to trap the target high-valence ions ; Additional cap electrode high level voltage value voltage values ​​of the first additional cap electrode (303) and the second additional cap electrode (304) when trapping target high-valence ions; Step 1.3: Apply a radio frequency potential field U to the first cap electrode (3011), the second cap electrode (3012) and the well center electrode (3013) of all the quadrupoles (301). rf An electrostatic potential field U is also applied to the first cap electrode (3011) and the second cap electrode (3012) of each pole in the quadrupole (301). y ; Set the first screening plate voltage U1 corresponding to the first screening plate (101) to 0, the second screening plate voltage U2 corresponding to the second screening plate (102) to 0, and the deceleration drift tube voltage corresponding to the deceleration drift tube (201) to , the voltage of each electrostatic lens in the electrostatic lens group is 0, and the voltage of the first additional cap electrode (303) corresponding to the first additional cap electrode is , the second additional cap electrode voltage corresponding to the second additional cap electrode (304) is ; Step 1.4, the ion source injects cooperative ions into the linear ion trap (3); Irradiating the linear ion trap (3) with cooling laser and pumping laser, optimizing various cooperative ion trapped cooling parameters, realizing trapped cooling of cooperative ions, thereby obtaining cooperative ion crystal clusters, wherein the cooperative ion trapped cooling parameters include line width, power, frequency and wave vector direction of the cooling laser and pumping laser; Step 1.5: Capture the image of the cooperative ion crystal cluster using a CCD camera. When the size of the cooperative ion crystal cluster is greater than or equal to the crystal cluster size threshold, and the temperature of the cooperative ion crystal cluster is lower than 10 mK, executing step 2; When the size of the cooperative ion crystal cluster is smaller than the crystal cluster size threshold, or the temperature of the cooperative ion crystal cluster is greater than or equal to 10 mK, return to step 1.4 until the size of the cooperative ion crystal cluster reaches the crystal cluster size threshold and the temperature of the cooperative ion crystal cluster is lower than 10 mK.

4. The method for high-valence ion beam trapping cooling according to claim 2, characterized in that: The step 2 comprises the following steps: Step 2.1, replace the CCD camera with a microchannel plate detector (4); the ion source continuously and periodically emits the ion beam to be screened toward the screening electrode (1), so that the microchannel plate detector (4) detects the pulse signal corresponding to the ion beam to be screened, and the pulse signal corresponding to the ion beam to be screened reaches the strongest; Step 2.2, selecting an auxiliary ion system, wherein the auxiliary ion beam corresponding to the auxiliary ion system includes auxiliary ions of multiple valence states corresponding to the same auxiliary atom, and the auxiliary ions are present in the auxiliary ion beam so that the charge-to-mass ratio of the ions to be screened in the ion beam to be screened is the same as the charge-to-mass ratio of the auxiliary ions; and the auxiliary ions having the same charge-to-mass ratio and the corresponding ions to be screened are used as reference auxiliary ions and reference ions to be screened, respectively; Step 2.3, the ion source continues to emit the ion beam to be screened, and the microchannel plate detector (4) detects the pulse signal peak of each valence state of the ion to be screened and records the sequence number as , the corresponding flight time of the ion to be screened is recorded as ; The ion source stops emitting the ion beam to be screened and switches to emitting the auxiliary ion beam. The microchannel plate detector (4) detects the pulse signal peak corresponding to each valence state auxiliary ion and records it as ; The flight time of the corresponding auxiliary ion is recorded as ; Find The sequence number of the pulse signal peak of the ion to be screened at The corresponding ion to be screened is the reference ion to be screened, and the sequence number of the pulse signal peak of the reference ion to be screened is recorded as the reference sequence number. ; Step 2.4, based on , confirm the sequence number of the pulse signal peak of the target high-valent ion , is the valence state of the target high-valence ion, Refer to the valence of the ion to be screened; according to the sequence number of the pulse signal peak of the target high-valence ion Find the flight time corresponding to the target high-valence ion ; Step 2.5: The ion source stops emitting the auxiliary ion beam and is converted to continuously and periodically emit the ion beam to be screened; set the timing points and the timing point to their initial values; set the voltage U1 of the first screening plate and the voltage U2 of the second screening plate such that U1 >> U2 or U1 << U2 during the time period, and U1 = U2 during other time periods; Step 2.6: Adjust the timing points and timing points , until in the same cycle Timing point Previously, the number of pulse signal peaks detected by the microchannel plate detector (4) was M H , at the timing point of the same cycle T Then the microchannel plate detector (4) detects the number of pulse signal peaks M L , M H M is the number of valence species in the ion beam to be screened whose valence is higher than the corresponding valence of the target high-valence ion, L is the number of valence species in the ion beam to be screened whose valence is lower than the corresponding valence of the target high-valence ion; The first screening plate voltage U1 and the second screening plate voltage U2 keep changing according to their respective corresponding voltage change timings.

5. The method for high-valence ion beam trapping cooling according to claim 4, characterized in that: Set the timing point in step 2.5 and timing points The initial value of , specifically includes the following steps: The distance from the ion source to the screening electrode (1) is denoted as the distance ; The distance from the ion source to the microchannel plate detector (4) is recorded as distance ; Based on the flight time of the target high-valence ions ,distance and distance Set the timing point The initial value is , timing point The initial value is greater than or equal to .

6. The method for high-valence ion beam trapping cooling according to claim 5, characterized in that: The step 3 comprises the following steps: Step 3.1, set the timing point Initial value and timing point The initial value of ; Step 3.2: Set the deceleration drift tube voltage The voltage change timing is: ， Indicates time, Represents the cycle, represents the number of cycles, Indicates the starting value of the deceleration drift tube voltage; Applying a deceleration drift tube voltage to the deceleration drift tube (201) , gradually increase the starting value of the deceleration drift tube voltage from 0 , so that the number of pulse signals detected by the microchannel plate detector (4) is the same as that when the deceleration drift tube voltage is not applied. The number of pulse signals detected by the microchannel plate detector (4) is consistent, and compared with the case where no deceleration drift tube voltage is applied When, a cycle The flight time of the first pulse signal in the experiment is significantly increased; Step 3.3: Based on step 3.2, change the deceleration drift tube voltage The voltage change sequence slows down the drift tube voltage satisfy: ， in, Indicates the starting value of the deceleration drift tube voltage, represents the rate of change of the deceleration drift tube voltage, Indicates the low-level voltage value of the deceleration drift tube, and have the same sign, and The signs of are opposite; Step 3.4: Observe the pulse signal detected by the microchannel plate detector (4) and adjust the low-level voltage value of the deceleration drift tube. , timing point and timing points , so that the same cycle The flight time corresponding to all pulse signals in the image is significantly increased; Step 3.5: Adjust the starting value of the deceleration drift tube voltage , so that the time width of the pulse signal of the microchannel plate detector (4) detecting the target high-valence ion is compressed to the narrowest.

7. The method for high-valence ion beam trapping cooling according to claim 6, characterized in that: The step 3.4 includes the following steps: Step 3.4.

1. Observe whether the microchannel plate detector (4) detects a pulse signal. When the microchannel plate detector (4) cannot detect the pulse signal, the low level voltage value of the deceleration drift tube is adjusted. , until the microchannel plate detector (4) detects the pulse signal; Then proceed to step 3.4.2; When the microchannel plate detector (4) detects a pulse signal, step 3.4.2 is executed; Step 3.4.2: Observe the flight time of the pulse signal detected by the microchannel plate detector (4). When the flight time of all pulse signals in the same cycle remains unchanged, the timing point is increased individually Or reduce the timing point individually , until the flight time of all pulse signals in one cycle increases significantly; When the flight time corresponding to the first part of the pulse signal in the same cycle is extended, and the flight time corresponding to the second part of the pulse signal does not change, increase the timing point , until the flight time corresponding to all pulse signals in the same cycle increases significantly; When the flight time corresponding to the first part of the pulse signal in the same cycle does not change, the flight time corresponding to the second part of the pulse signal is extended, reducing the timing point , until the flight time corresponding to all pulse signals in the same cycle increases significantly; When only the flight duration corresponding to the middle part of the pulse signal in the same cycle is extended, and the flight duration corresponding to the front and back parts of the pulse signal remains unchanged, the timing point is reduced. and increase timing points , until the flight time corresponding to all pulse signals in the same cycle increases significantly.

8. The method for high-valence ion beam trapping cooling according to claim 7, characterized in that: The step 4 comprises the following steps: Step 4.1: Start the first additional cap electrode (303) and the second additional cap electrode (304), the second additional cap electrode voltage U end2 =0, then applying a first additional cap electrode voltage to the first additional cap electrode (303) , the first additional cap electrode voltage The following timing is met: ， in, and are all timing points, and , is the high-level voltage value of the additional cap electrode, is the high and low voltage value of the additional cap electrode, ; Adjust timing points and the corresponding timing points , until one cycle of ion implantation The pulse signal on the microchannel plate detector (4) is observed at the end of step 3 without applying the first additional cap electrode voltage. The signal is consistent; Then, the second additional cap electrode voltage of the second additional cap electrode (304) is raised. make , maintain the first additional cap electrode voltage Voltage change timing; The voltage of the drift tube will be reduced In each cycle The timing point at which the value is restored to 0 Set at the timing point after; Step 4.2: Replace the microchannel plate detector (4) with a CCD camera, and use the CCD camera to observe the ion imaging in the linear ion trap (3). When no dark circular area is observed in the bright area, the first additional cap electrode (303) and the second additional cap electrode (304) are restarted to adjust the reference potential of the linear ion trap (3) as a whole. , and adjust the high level voltage value of the additional cap electrode at the same time , and make ; until a dark circular area is observed in the bright area; When a dark circular area appears in the bright area, proceed to step 4.3; Step 4.3: Under the cooling laser and pumping laser cooling, the target high-valence ions are cooled based on the synergistic cooling mechanism.

9. The method for high-valence ion beam trapping cooling according to claim 7, characterized in that: The timing points described in step 3.1 The initial value is ;distance is the distance from the ion source to the deceleration drift tube (201).

10. The method for high-valence ion beam trapping cooling according to claim 8, characterized in that: The timing point and timing points Keep Microseconds.

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