JP4727185B2 - Ion trap device - Google Patents

Description

  The present invention relates to an ion trap apparatus used in analysis techniques such as a mass spectrometer, that is, identification and quantification of organic substances and inorganic substances.

  Conventionally, a mass spectrometer using a quadrupole ion trap device has been proposed.

  As shown in Patent Documents 1 to 6, the quadrupole ion trap apparatus has a configuration in which a ring electrode is sandwiched between two end cap electrodes.

  FIG. 8 is a cross-sectional view showing a configuration of a hyperboloid type quadrupole ion trap apparatus.

  FIG. 9 is a cross-sectional view showing the configuration of the cylindrical quadrupole ion trap apparatus.

  Each of the hyperboloid type quadrupole ion trap apparatus and the cylindrical quadrupole ion trap apparatus has a configuration in which the ring electrode 101 is sandwiched between two end cap electrodes 102 and 103, and the center of the ring electrode 101. It has a configuration that is rotationally symmetric with respect to the z-axis. In the hyperboloid type quadrupole ion trap apparatus, the surfaces facing the inner sides of the ring electrode 101 and the end cap electrodes 102 and 103 have a shape of a rotating hyperboloid. In the cylindrical quadrupole ion trap apparatus, the surfaces facing the inner side of the ring electrode 101 and the end cap electrodes 102 and 103 are a cylindrical surface and a flat surface.

  In each of these quadrupole ion trap apparatuses, a space surrounded by the ring electrode 101 and the end cap electrodes 102 and 103 is a trap space. These ion trap apparatuses are apparatuses intended to capture ions generated outside and inside the trap space.

  In these quadrupole ion trap devices, the ring electrode 101 and the end cap electrodes 102 and 103 are supplied with high frequency (alternating current) power for trapping.

  Each of these quadrupole ion trap devices has substantially the same function although the size of an effective space as an ion trap is different. All the simulations shown below were performed in a cylindrical quadrupole ion trap apparatus.

  By the way, in such a quadrupole ion trap apparatus, there is a problem that the trap efficiency does not increase if the trapping high-frequency voltage is continuously applied to the ring electrode 101 and the end cap electrodes 102 and 103.

  Therefore, conventionally, in such a quadrupole ion trap apparatus, when trapping ions, the voltage amplitude of the high frequency voltage for trapping is temporarily lowered to lower the effective potential of the ion trap, Making it possible to enter.

  Conventionally, a buffer gas is introduced into the ion trap, ions entering the ion trap collide with the buffer gas, and ions are trapped by reducing the kinetic energy of the ions.

Furthermore, a quadrupole ion trap apparatus has also been proposed in which a voltage amplitude of a trapping high-frequency voltage is temporarily reduced when ions are captured and a buffer gas is introduced into the ion trap.
JP-A 64-97350 Japanese Patent Laid-Open No. 2-103856 JP-A-8-329882 Japanese Patent Laid-Open No. 9-274885 Japanese Patent Laid-Open No. 10-208692 Japanese National Patent Publication No. 11-513187

In the ion trap apparatus as described above, a buffer gas is introduced into the cylindrical ion trap, the ions that have entered the central direction of the ion trap collide with the buffer gas, and the kinetic energy of the ions is reduced. The simulation result when trapping is shown. The simulation conditions at this time are shown in [Table 1].

  Ions are from the inner peripheral surface (point A in FIG. 9) of the ring electrode 101 of the cylindrical quadrupole trap within a two-dimensional range (see Table 1) of the initial ion energy and the AC voltage phase during ion generation. A predetermined generation number (2 million) was randomly generated.

  After the ions are generated, they fly toward the center of the trap space with ion initial kinetic energy. In this simulation, a collision occurred once in the trap space, and the kinetic energy change of ions after the collision was calculated using the Monte Carlo method.

  FIG. 10 is a graph showing the relationship between the initial kinetic energy of ions that can be trapped and the alternating voltage phase for trapping.

  From the results shown in FIG. 10, it can be seen that only ions having a specific kinetic energy are trapped when the trapping AC voltage has a certain phase.

  That is, in such a conventional ion trap apparatus, since the relationship between the phase of the ion trap AC voltage and the kinetic energy of ions entering the trap space is not considered, the trapping efficiency is poor.

  Furthermore, in the conventional ion trap apparatus, when a method of applying a pulsed AC voltage at the time of ion capture is adopted, the electric circuit becomes complicated and the apparatus becomes expensive.

  Therefore, the present invention has been proposed in view of the above-mentioned circumstances, and the object of the present invention is to apply a rectangular pulse voltage when capturing ions without complicating the apparatus configuration. An object of the present invention is to provide an ion trap apparatus with improved trapping efficiency.

  Another object of the present invention is to consider that there is a correlation between the kinetic energy of ions that can be trapped and the AC voltage phase for trapping when the ions reach (or occur) a certain point. Thus, an ion trap apparatus with improved ion capture efficiency is provided.

  In order to solve the above-described problems, an ion trap apparatus according to the present invention aims to confine an ion beam from the outside or an ion beam generated in a pulse manner inside the multipole ion trap in the multipole ion trap. An ion trap apparatus characterized by applying a rectangular pulse voltage for improving the ion trapping efficiency to the electrodes constituting the multipole ion trap at the time of ion trapping in the multipole ion trap It is.

  Further, the present invention is characterized in that, in the above-described ion trap apparatus, the multipole ion trap is a quadrupole ion trap including a ring electrode and a pair of end cap electrodes.

  Furthermore, the present invention is characterized in that, in the ion trap apparatus described above, the trapping AC voltage phase and the kinetic energy of the ions to be captured are synchronized when ions are captured by the multipole ion trap.

  The present invention provides a rectangular pulse voltage to be applied to the ring electrode when the ion beam has a positive polarity and is incident from the side of the ring electrode forming a quadrupole ion trap in the ion trap apparatus described above. The voltage is lower than the voltage of the end cap electrode.

  Then, the present invention provides a rectangular pulse voltage to be applied to the ring electrode when the ion beam has a negative polarity and is incident from the side of the ring electrode forming the quadrupole ion trap in the ion trap apparatus described above. The voltage is higher than the voltage of the end cap electrode.

  The present invention provides a rectangular pulse voltage applied to the end cap electrode when the ion beam has a positive polarity and is incident from the end cap electrode side forming a quadrupole ion trap. Is a voltage lower than the voltage of the ring electrode.

  The present invention provides a rectangular pulse voltage to be applied to the end cap electrode when the ion beam has a negative polarity and is incident from the end cap electrode side forming a quadrupole ion trap in the ion trap device described above. Is a voltage higher than the voltage of the ring electrode.

  In the ion trap apparatus according to the present invention, the ion trapping efficiency is improved by applying a rectangular pulse voltage without switching the trapping AC voltage.

  Further, by synchronizing the phase of the alternating voltage and the kinetic energy of ions, the ion capture efficiency can be dramatically improved.

  That is, the present invention can provide an ion trap device that improves the ion trapping efficiency by applying a rectangular pulse voltage during ion trapping without complicating the device configuration.

  In addition, the present invention takes into account that there is a correlation between the kinetic energy of ions that can be trapped and the AC voltage phase for trapping when the ions reach (or when generated) a certain point, An ion trap apparatus with improved ion capture efficiency can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a cross-sectional view showing the configuration of the ion trap apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, this ion trap device is a cylindrical quadrupole ion trap device, and has a configuration in which the ring electrode 1 is sandwiched between two end cap electrodes 2 and 3. This ion trap apparatus has a rotationally symmetric configuration with respect to the z axis, which is the central axis of the ring electrode 1. The inward surfaces of the ring electrode 1 and the end cap electrodes 2 and 3 are a cylindrical surface and a flat surface.

  The ion trap device according to the present invention may be configured as a hyperboloid type quadrupole ion trap device in each embodiment described later.

  In this ion trap apparatus, a space surrounded by the ring electrode 1 and the end cap electrodes 2 and 3 is a trap space. This ion trap apparatus captures ions generated outside and inside the trap space.

  In this ion trap apparatus, the ring electrode 1 is supplied with a trapping high-frequency (AC) power supply 4 from a trapping high-frequency (AC) power supply 4, and a DC pulse power supply 5 has a rectangular pulse voltage superimposed on the trapping high-frequency. Supplied. In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner.

  In the ion trap apparatus in this embodiment, a trapping AC voltage is always applied to the end cap electrodes 2 and 3 and the ring electrode 1.

  In this ion trap apparatus, ions are generated in a pulsed manner inside the ion trap (point A in FIG. 1: 10 mm from the center of the trap space). These ions have initial energy and fly toward the center of the trap space.

  FIG. 2 is a waveform diagram showing voltages applied to the ring electrode and the end cap electrode in the first embodiment of the ion trap device according to the present invention.

  In this ion trap apparatus, as shown in FIG. 2, at the time of generating an ion beam, a rectangular pulse voltage having a polarity opposite to the polarity of the ion is applied to the ring electrode 1 with respect to the center voltage of the ion trap. A rectangular pulse voltage having the same polarity as the ion polarity is simultaneously applied to the cap electrodes 2 and 3 with respect to the center voltage of the ion trap.

  The relationship between the kinetic energy of ions that can be captured in the first embodiment of the ion trap device and the AC voltage phase at the time of generation was simulated by calculation.

The conditions of the simulation are as shown in [Table 2].

  FIG. 3 is a graph showing the results of a simulation that calculates the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation in the first embodiment of the ion trap device according to the present invention.

  In this ion trap apparatus, as shown in FIG. 3, although the introduction of a buffer gas is not assumed, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG. You can see that it is increasing.

  Furthermore, ion trapping efficiency can be improved by optimizing the initial energy of ions and the AC voltage phase during ion generation.

  When the ion beam has a positive polarity and is incident from the side of the ring electrode 1 forming a quadrupole ion trap, the rectangular pulse voltage applied to the ring electrode 1 is the voltage of the end cap electrodes 2 and 3. It is desirable that the voltage be lower than that.

  When the ion beam has a negative polarity and is incident from the side of the ring electrode 1 forming a quadrupole ion trap, the rectangular pulse voltage applied to the ring electrode 1 is the voltage of the end cap electrodes 2 and 3. It is desirable that the voltage be higher than that.

  The same applies to the second and third embodiments described later.

[Second Embodiment]
In this embodiment, using an ion trap device having the same configuration as in the first embodiment described above, as shown in FIG. The case where the ion beam enters the ion trap as a continuous ion beam from the outside will be considered.

  Also in this ion trap apparatus, the ring electrode 1 is supplied with a trapping high-frequency (AC) power source 4 from a trapping high-frequency (AC) power source 4 and a DC pulse power source 5 is supplied with a rectangular pulse voltage superimposed on the trapping high-frequency signal. The In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner. A trapping AC voltage is always applied to the end cap electrodes 2 and 3 and the ring electrode 1.

  In this ion trap apparatus, in order to capture ions, a rectangular pulse voltage having a polarity opposite to the polarity of the ions is applied to the ring electrode 1 with respect to the center voltage of the ion trap, and the end cap electrodes 2 and 3 are applied. In this case, a rectangular pulse voltage having the same polarity as the ion polarity with respect to the center voltage of the ion trap is simultaneously applied in synchronization with the AC voltage phase.

  Then, among the ions existing at point B (30 mm from the center of the trap space) at the start of rectangular pulse voltage application, the relationship between the kinetic energy of ions that can be trapped and the AC voltage phase at the start of rectangular pulse voltage application Was investigated by simulation.

The simulation conditions are shown in [Table 3].

  FIG. 4 is a graph showing the results of a simulation in which the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation is calculated in the second embodiment of the ion trap device according to the present invention.

  Even in this ion trap apparatus, as shown in FIG. 4, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG. You can see that it is increasing.

  Furthermore, in this ion trap apparatus, the ion trapping efficiency can be improved by optimizing the kinetic energy of the ion beam at the point B in FIG. 1 and the AC voltage phase when the rectangular pulse voltage is applied.

[Third Embodiment]
In this embodiment, using an ion trap device having a configuration similar to that in the second embodiment described above, as shown in FIG. The case where it enters into an ion trap as a continuous ion beam from the outside is considered.

  Also in this ion trap apparatus, the ring electrode 1 is supplied with a trapping high-frequency (AC) power source 4 from a trapping high-frequency (AC) power source 4 and a DC pulse power source 5 is supplied with a rectangular pulse voltage superimposed on the trapping high-frequency signal. The In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner. A trapping AC voltage is always applied to the end cap electrodes 2 and 3 and the ring electrode 1.

  In this ion trap apparatus, when the ions reach point B in FIG. 1, a rectangular pulse voltage having a polarity opposite to the polarity of the ions is applied to the ring electrode 1 with respect to the center voltage of the ion trap. A rectangular pulse voltage having the same polarity as the ion polarity with respect to the center voltage of the ion trap is simultaneously applied to the end cap electrodes 2 and 3 in synchronization with the AC voltage phase.

  Then, among the ions existing at point B (30 mm from the center of the trap space) at the start of rectangular pulse voltage application, the relationship between the kinetic energy of ions that can be trapped and the AC voltage phase at the start of rectangular pulse voltage application Was investigated by simulation.

  In this ion trap apparatus, the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation is assumed to be the introduction of a buffer gas, as shown in FIG. 4, as in the second embodiment described above. Despite this, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG.

  Furthermore, in this ion trap apparatus, the ion trapping efficiency can be improved by optimizing the kinetic energy of the ion beam at the point B in FIG. 1 and the AC voltage phase when the rectangular pulse voltage is applied.

[Fourth Embodiment]
In this embodiment, while the ions are generated on the ring electrode 1 side in the first to third embodiments, the trapping of the pulse ion beam generated on the end cap electrodes 2 and 3 side is considered. .

  FIG. 5 is a cross-sectional view showing the configuration of the ion trap apparatus according to the fourth embodiment of the present invention.

  The ion trap apparatus in this embodiment is a cylindrical quadrupole ion trap apparatus as shown in FIG. 5, and has a configuration in which the ring electrode 1 is sandwiched between two pairs of end cap electrodes 2 and 3. is doing. This ion trap apparatus has a rotationally symmetric configuration with respect to the z axis, which is the central axis of the ring electrode 1. The inward surfaces of the ring electrode 1 and the end cap electrodes 2 and 3 are a cylindrical surface and a flat surface. In this ion trap apparatus, a space surrounded by the ring electrode 1 and the end cap electrodes 2 and 3 is a trap space.

  In this ion trap apparatus, a rectangular pulse voltage is supplied to the ring electrode 1 from a DC pulse power supply 5. In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner. In the ion trap apparatus in this embodiment, the trapping AC voltage is always applied to the end cap electrodes 2 and 3.

  In the simulation, the ring electrode 1 is grounded, and the trapping AC voltage is applied only to the end cap electrodes 2 and 3. Ions were generated in a pulsed manner inside the ion trap. These ions have initial energy and fly toward the center of the trap space.

  In this ion trap apparatus, ions are generated in a pulsed manner inside the ion trap (point C in FIG. 5: 10 mm from the center of the trap space). These ions have initial energy and fly toward the center of the trap space.

  In this ion trap apparatus, at the time of generating an ion beam, a rectangular pulse voltage having a polarity opposite to the polarity of the ions is applied to the end cap electrodes 2 and 3 with respect to the center voltage of the ion trap. A rectangular pulse voltage having the same polarity as the ion polarity is simultaneously applied to the center voltage of the ion trap.

  The relationship between the kinetic energy of ions that can be captured in the first embodiment of the ion trap device and the AC voltage phase at the time of generation was simulated by calculation.

The simulation conditions are shown in [Table 4].

  FIG. 6 is a graph showing the results of a simulation in which the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation is calculated in the fourth embodiment of the ion trap device according to the present invention.

  In this ion trap apparatus, as shown in FIG. 6, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG. You can see that it is increasing.

  Furthermore, also in this embodiment, the ion trapping efficiency can be improved by optimizing the initial energy of ions and the AC voltage phase at the time of ion generation.

  When the ion beam has a positive polarity and is incident from the end cap electrodes 2 and 3 forming a quadrupole ion trap, the rectangular pulse voltage applied to the end cap electrodes 2 and 3 is a ring electrode. It is desirable that the voltage be lower than the voltage of 1.

  When the ion beam has a negative polarity and is incident from the end cap electrodes 2 and 3 forming a quadrupole ion trap, the rectangular pulse voltage applied to the end cap electrodes 2 and 3 is a ring electrode. It is desirable that the voltage be higher than the voltage of 1.

  These are the same in the fifth and sixth embodiments described later.

[Fifth Embodiment]
In this embodiment, using an ion trap device having the same configuration as in the above-described fourth embodiment, ions are passed through an entry hole 9 in the end cap electrode 2 as shown in FIG. In this case, the incident ion beam enters the ion trap as a continuous ion beam from the outside.

  Also in this ion trap apparatus, a rectangular pulse voltage is supplied to the ring electrode 1 from the DC pulse power supply 5. In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner. A trapping AC voltage is always applied to the end cap electrodes 2 and 3.

  In this ion trap apparatus, in order to capture ions, a rectangular pulse voltage having a polarity opposite to the polarity of the ions is applied to the end cap electrodes 2 and 3 with respect to the center voltage of the ion trap. In this case, a rectangular pulse voltage having the same polarity as the ion polarity with respect to the center voltage of the ion trap is simultaneously applied in synchronization with the AC voltage phase.

  Then, among the ions existing at point D (30 mm from the center of the trap space) at the start of rectangular pulse voltage application, the relationship between the kinetic energy of ions that can be trapped and the AC voltage phase at the start of rectangular pulse voltage application Was investigated by simulation.

  In the simulation, the ring electrode 1 is grounded, and the trapping AC voltage is applied only to the end cap electrodes 2 and 3.

The simulation conditions are shown in [Table 5].

  FIG. 7 is a graph showing the results of a simulation in which the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation is calculated in the fifth embodiment of the ion trap device according to the present invention.

  In this ion trap apparatus as well, as shown in FIG. 7, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG. You can see that it is increasing.

  Furthermore, in this ion trap apparatus, the ion trapping efficiency can be improved by optimizing the kinetic energy of the ion beam at point D in FIG. 5 and the AC voltage phase when the rectangular pulse voltage is applied.

[Sixth Embodiment]
In this embodiment, using an ion trap device having the same configuration as in the fifth embodiment described above, ions are passed through the entry hole 9 in the end cap electrode 2 as shown in FIG. In this case, the incident ion beam enters the ion trap as a continuous ion beam from the outside.

  Also in this ion trap apparatus, a rectangular pulse voltage is supplied to the ring electrode 1 from the DC pulse power supply 5. In this ion trap apparatus, the end cap electrodes 2 and 3 are supplied with a trapping high-frequency (AC) power source 6 from a trapping high-frequency (AC) power source 6, and a rectangular pulse voltage is supplied from the DC pulse power source 7. Is supplied in a superimposed manner. A trapping AC voltage is always applied to the end cap electrodes 2 and 3.

  In this ion trap apparatus, when the ions reach point D in FIG. 5 (30 mm from the center of the trap space), the end cap electrodes 2 and 3 have ion ions with respect to the center voltage of the ion trap. A rectangular pulse voltage having a polarity opposite to the polarity is applied, and a rectangular pulse voltage having the same polarity as the ion polarity with respect to the center voltage of the ion trap is simultaneously applied to the ring electrode 1 in synchronization with the AC voltage phase.

  Then, at the start of rectangular pulse voltage application, among the ions present at point D in FIG. 5, the relationship between the kinetic energy of trappable ions and the alternating voltage phase at the start of rectangular pulse voltage application was examined by simulation.

  In the simulation, the ring electrode 1 is grounded, and the trapping AC voltage is applied only to the end cap electrodes 2 and 3.

  In this ion trap apparatus, the relationship between the kinetic energy of ions that can be captured and the AC voltage phase at the time of generation is assumed to be the introduction of a buffer gas, as shown in FIG. 7, as in the fifth embodiment described above. Despite this, the number of ions that can be trapped is considerably larger than that of the conventional ion trap apparatus shown in FIG.

  Furthermore, in this ion trap apparatus, the ion trapping efficiency can be improved by optimizing the kinetic energy of the ion beam at point D in FIG. 5 and the AC voltage phase when the rectangular pulse voltage is applied.

It is sectional drawing which shows the structure in 1st Embodiment of the ion trap apparatus which concerns on this invention. It is a wave form diagram which shows the voltage applied to a ring electrode and an end cap electrode in 1st Embodiment of the ion trap apparatus which concerns on this invention. It is a graph which shows the result of the simulation which calculated the relationship between the kinetic energy of the ion which can be trapped in 1st Embodiment of the ion trap apparatus which concerns on this invention, and the alternating voltage phase at the time of generation | occurrence | production. It is a graph which shows the result of the simulation which calculated the relationship between the kinetic energy of the ion which can be trapped in 2nd Embodiment of the ion trap apparatus which concerns on this invention, and the alternating voltage phase at the time of generation | occurrence | production. It is sectional drawing which shows the structure in 4th Embodiment of the ion trap apparatus which concerns on this invention. It is a graph which shows the result of the simulation which calculated the relationship between the kinetic energy of the ion which can be trapped in 4th Embodiment of the ion trap apparatus concerning this invention, and the alternating voltage phase at the time of generation | occurrence | production. It is a graph which shows the result of the simulation which calculated the relationship between the kinetic energy of the ion which can be trapped in 5th Embodiment of the ion trap apparatus which concerns on this invention, and the alternating voltage phase at the time of generation | occurrence | production. It is sectional drawing which shows the structure of the conventional hyperboloid type | mold quadrupole ion trap apparatus. It is sectional drawing which shows the structure of the conventional cylindrical quadrupole ion trap apparatus. It is a graph which shows the relationship between the initial kinetic energy of the ion which could be trapped in the conventional ion trap apparatus, and the alternating voltage phase for traps.

Explanation of symbols

1 Ring electrode 2, 3 End cap electrode 4, 6 High frequency (AC) power supply for trap 5, 7 DC pulse power supply 8, 9 Entrance hole

Claims (4)

An ion beam from the outside or an ion beam generated in a pulsed manner inside the quadrupole ion trap is captured from the ring electrode side of the ring electrode and the pair of end cap electrodes constituting the quadrupole ion trap. An ion trap device,
An AC voltage for ion trap is continuously applied to the ring electrode of the ion trap, and a rectangular pulse voltage having a polarity opposite to the polarity of the ion with respect to the center voltage of the ion trap is captured with respect to the AC voltage. To be superimposed and applied in a desired phase according to the kinetic energy of the ions,
An ion having a rectangular pulse voltage having the same polarity as the polarity of the ion with respect to the center voltage of the ion trap applied to the end cap electrode of the ion trap simultaneously with the rectangular pulse voltage to the ring electrode Trap device.   When the polarity of the ion beam is positive and incident from the ring electrode side forming the quadrupole ion trap, a rectangular pulse voltage applied to the ring electrode is set to a voltage lower than the voltage of the end cap electrode. In the case where the ion beam has a negative polarity and is incident from the side of the ring electrode forming the quadrupole ion trap, the rectangular pulse voltage applied to the ring electrode is set to be higher than the voltage of the end cap electrode. The ion trap apparatus according to claim 1, wherein a high voltage is used. Lee Onbimu from outside, or an ion beam generated in a pulsed manner within a quadrupole ion-trap, out of the ring electrode and a pair of end cap electrodes side constituting the quadrupole ion-trap, said end cap electrodes An ion trap device for capturing from the side,
The AC voltage of the ion trap is continuously applied to the end cap electrode of the ion trap, and a rectangular pulse voltage having a polarity opposite to the polarity of the ion with respect to the center voltage of the ion trap is captured with respect to the AC voltage. To be superimposed and applied in a desired phase according to the kinetic energy of the ions
An ion characterized by applying a rectangular pulse voltage having the same polarity as the polarity of the ion to the ring electrode of the ion trap at the same time as the rectangular pulse voltage to the end cap electrode. Trap device.   When the ion beam has a positive polarity and is incident from the side of the end cap electrode forming the quadrupole ion trap, a rectangular pulse voltage applied to the end cap electrode is lower than the voltage of the ring electrode. A rectangular pulse voltage to be applied to the end cap electrode when the ion beam has a negative polarity and is incident from the end cap electrode side forming the quadrupole ion trap. The ion trap apparatus according to claim 3, wherein the voltage is higher than that of the ion trap apparatus.

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