JP6551264B2 - Mass spectrometer - Google Patents

Description

  The present invention relates to a mass spectrometer, and more particularly to a mass spectrometer characterized by a connection structure for electrically connecting an electrode and a power source of the mass spectrometer.

  As an example of the mass spectrometer, there is a time-of-flight mass spectrometer described in Patent Document 1. As shown in FIG. 9, this time-of-flight mass spectrometer 90 has an ion introduction unit 91 for introducing ions to be measured, an extrusion electrode 921 as an ion acceleration unit 92 for accelerating the ions and a grid electrode (extraction Electrode) 922, and a reflective electrode 94 made up of a number of plate-like electrodes is arranged at the end of the flight space 93. At the time of measurement, the time-of-flight mass spectrometer 90 is brought into a high vacuum state by the vacuum pump 80. The ions to be measured are introduced into the ion introduction part 91 and accelerated toward the flight space 93 by the electric field formed by the extrusion electrode 921 and the grid electrode 922. The accelerated ions fly in the flight space 93, are turned back by the action of the reflected electric field formed by the reflection electrode 94, fly again in the flight space 93, and reach the ion detector 98. The mass-to-charge ratio of the ions can be measured based on the time from when the ions begin to accelerate to when they enter the ion detector 98.

  As described above, the time-of-flight mass spectrometer 90 includes various electrodes for forming an electric field, and a predetermined voltage is supplied to each electrode. For example, the reflective electrode 94 is connected to the power supply board 95 disposed on the side of the flight space 93 via the connection line 97. The power supply board 95 is connected to a power supply 99 provided outside the time-of-flight mass spectrometer 90 via a vacuum feedthrough 96.

JP 2014-165053 Unexamined-Japanese-Patent No. 2015-118887 (FIGS. 1-4) US Patent No. 5689111 (Fig. 2) U.S. Pat.No. 6812453

  The power supply board 95 is usually a printed circuit board, and the connection line 97 connecting the power supply board 95 and each electrode is electrically connected by soldering. The reflective electrode 94 is usually made of a metal plate such as aluminum or stainless steel, and the reflective electrode 94 and the connection wire 97 are electrically connected by spot welding. On the other hand, the vacuum pump 80 used to evacuate the inside of the time-of-flight mass spectrometer 90 as described above rotates at a high speed inside the vacuum pump 80, so that vibration generated by this rotation is generated. Thus, the time-of-flight mass spectrometer 90 is vibrated. If the reflection electrode 94 and the connection wire 97 are not fixed sufficiently by spot welding, for example, there is a problem that the reflection electrode 94 and the connection wire 97 are separated due to this vibration. Further, in addition to the vibration caused by the vacuum pump 80, the reflection electrode 94 and the connection line 97 may be disconnected in the same way due to vibration or impact during transportation. In particular, in the case of a laminated electrode composed of a large number of electrodes such as the reflective electrode 94 of the time-of-flight mass spectrometer described in Patent Document 1, when the connecting line 97 for supplying voltage to each electrode is disconnected, conventional spot welding is performed. Etc., it was difficult to reconnect and repair at the site. In addition, if the fixing of such a spot welded portion is not sufficient, the contact state is weak even if the electrical contact itself is maintained, so that the voltage supplied from the power supply 99 becomes unstable due to the vibration of the vacuum pump or the like. The problem is that the mass accuracy, mass resolution, and sensitivity of the mass spectrometer become unstable.

  Such a problem also occurs in the extrusion electrode 911 and the grid electrode 912. It can also occur in the laminated ion guide electrode which is an acceleration electrode in the flight space described in Patent Document 2 or the laminated ion guide electrode provided in front of the ion introduction part described in Patent Document 3. In addition to the time-of-flight mass spectrometer, the same problem may occur in general laminated electrodes used in the mass spectrometer, such as a multiple aperture ion guide electrode disclosed in Patent Document 4, for example.

  The problem to be solved by the present invention is that the connection state between the electrode and the power source can be satisfactorily maintained even when vibration and shock due to transportation, vibration due to a rotational drive mechanism, etc. are applied. It is to provide a mass spectrometer which can be easily reconnected even if the

The mass spectrometer according to the present invention, which was made to solve the above problems,
a) electrodes,
b) a power supply unit which supplies power to the electrodes at a predetermined voltage and / or current;
c) a conductive wire having elasticity, and a connection wire for electrically connecting the electrode and the power supply unit;
d) a connector portion provided at one end of the connection wire;
e) a seat provided on the electrode and in contact with the connector;
f) a fixing portion provided on the connection line and fixed to the power supply portion;
g) A spring portion that is formed between the connector portion and the fixing portion of the connection line or formed in the connector portion and biases the connector portion toward the seat portion.

  In the mass spectrometer according to the present invention, the connecting part is fixed to the power supply part, and the connector part is in contact with the electrode seat, so that the power supply part and the electrode are electrically connected via the connecting line. It is done. Here, since the connector portion is biased to the seat portion by the spring portion, the connector portion is pressed against the seat portion by the spring force of the spring portion, and both may be separated even if some vibration is applied to the device. Absent. Further, when vibration exceeding the frictional force of the connector portion is applied, the connector portion is displaced to absorb the vibration, so that no excessive force is applied to the connection wire or the connector portion, and the electrical connection is good. Maintained. When a greater vibration is applied, the connector portion is disconnected, so that the electrical connection is interrupted. However, it is possible to avoid a situation where the connection line is broken or the connection portion (connector portion) is damaged. And in such a case, it can be easily reconnected without soldering or welding.

  The power supply unit supplies power to the electrodes at a predetermined voltage and / or current, and usually includes an electric circuit for adjusting power from a commercial power supply or a battery to the predetermined voltage and / or current. In addition, in the case of distributing power to a plurality of electrodes, the power supply unit may have an electric circuit for the distribution. The fixing portion of the connection line can be fixed to, for example, a printed board on which these electric circuits are formed. In that case, fixing to the printed circuit board can be performed by inserting the connection line into a hole provided in the printed circuit board and soldering the connection line to the printed circuit board.

  The spring portion can be formed by winding the connecting wire in the shape of a torsion spring or a string spring. Further, the spring portion may be provided between the connector portion and the fixing portion separately from the connector portion to bias the connector portion to the seat portion of the electrode, or the connecting wire is wound a plurality of times. In addition, the spring part itself can be used as a connector part by sandwiching an electrode seat part between two adjacent winding parts.

  As for the said connector part and the said seat part, it is desirable to have an insertion structure where one is a male and the other is a female. As a result, the connector portion is further less likely to be detached from the seat portion.

  The connection structure of the electrode and the power supply in the mass spectrometer according to the present invention can be suitably applied to a laminated electrode used for transporting ions in the flight space of a time-of-flight mass spectrometer. As an example of such a laminated electrode, an electrode in which a plurality of acceleration electrodes are laminated, an electrode in which an extrusion electrode, a lead-out electrode, and a plurality of acceleration electrodes are laminated, a reflective electrode (reflectron) or an ion introducing portion The lamination | stacking electrode provided is mentioned. In addition, the connection structure between the electrode and the power source of the mass spectrometer according to the present invention can be suitably used not only for the time-of-flight mass spectrometer but also for ion guide electrodes and reflective electrodes used in general mass spectrometers.

  According to the mass spectrometer of the present invention, even if vibration is applied, the connection line with the power supply unit is not easily disconnected from the electrode, and the connection state between the electrode and the power supply can be maintained well. Also, even if the connection between the electrode and the power supply is disconnected, it can be easily reconnected.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the time-of-flight type mass spectrometer which concerns on this invention. The figure which shows the connection structure of an electrode and a power supply part. The figure explaining the connection of a seat part and a connector part. The figure which shows the connection structure of the electrode of a modification 1, and a power supply part. The figure which shows the connection structure of the electrode of a modification 2, and a power supply part. The figure which shows the connection structure of the electrode of the modification 3, and a power supply part. The schematic block diagram of the time-of-flight type mass spectrometer which arrange | positioned the power supply board | substrate to the exterior of the housing | casing. The schematic block diagram of the principal part of the time-of-flight type mass spectrometer which has an acceleration electrode. The schematic block diagram which shows an example of the conventional time-of-flight type mass spectrometer.

  A mass spectrometer according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of a time-of-flight mass spectrometer 10 according to an embodiment of the present invention. The time-of-flight mass spectrometer 10 includes an ion introduction unit 11 that introduces ions to be measured into a housing 20 and an extrusion electrode 121 that serves as an ion acceleration unit 12 that accelerates ions introduced from the ion introduction unit 11. And a grid electrode (extraction electrode) 122, a flight space 13 in which ions fly with the ion acceleration unit 12 as a start point, a reflection electrode 14 disposed at the end of the flight space 13, and ions reflected by the reflection electrode 14 And an ion detector 18. Each of the reflective electrode 14 and the detector 18 is fixed to the housing 20 at a predetermined position. A power supply substrate 15 is further fixed inside the housing 20, and the reflective electrode 14 is electrically connected to the power supply substrate 15 via a plurality of connection lines 17. The power supply substrate 15 is connected to a power supply 19 provided outside the housing 20 via a vacuum feedthrough 16 provided on the wall surface of the housing 20. The power supply 19, the vacuum feedthrough 16 and the power supply substrate 15 correspond to the power supply unit of the present invention. Outside the housing 20, a vacuum pump 30 for discharging the gas in the housing 20 is provided.

  The reflective electrode 14 is composed of a set of laminated electrodes configured by arranging a plurality of plate-like electrodes 141 made of a stainless steel metal plate at a predetermined interval. The plate-like electrode 141 is provided with a hole in the center for allowing ions to pass through except for the last one. A rectangular seat portion 1411 protruding outward is provided on the outer edge of each plate electrode 141 (FIG. 2A). In the time-of-flight mass spectrometer 10, the reflective electrode 14 is used as a reflectron that reverses the traveling direction of ions. For each plate-like electrode 141 of the reflective electrode 14, a metal such as aluminum may be used other than stainless steel.

  The power supply substrate 15 is a printed circuit board on which an electric circuit 151 for converting a power supply voltage from the power supply 19 into a predetermined voltage and applying the voltage to each plate-like electrode 141 is formed.

  The connecting wire 17 is made of a conductive wire having elasticity, and a spring portion 172 is formed by winding a part of the connecting wire 17 in a torsion spring shape as shown in FIG. A female flat crimp terminal is attached to one end of the connection line 17 as a connector portion 173. The other end of the connection line 17 is inserted into a hole provided in the power supply board 15 and fixed to the power supply board 15 by solder 152 so as to be electrically connected to the electric circuit 151. The portion of the connection line 17 which is fixed to the power supply substrate 15 in this manner is the fixing portion 171 in the present invention. As in the case of the connector portion 173, a connection portion having a connector attached to the other end of the connection line 17 can be used as a fixed portion. In this case, a connection mechanism corresponding to the connector is provided on the power supply board 15 for connection. .

  The connection line 17 is bent into a rectangle as shown in FIG. 2B, and the connector part 173 is arranged so as to face the seat part 1411 of the plate electrode 141. The spring part 172 is arranged so as to bias the connector part 173 in the direction of the seat part 1411.

  The connector part 173 and the seat part 1411 have a corresponding insertable structure in which the former is a female and the latter is a male. FIGS. 3A and 3B are cross-sectional views showing a state after the seat portion 1411 is inserted into the connector portion 173 and after the seat portion 1411 is inserted. The connector part 173 has a leaf spring 174 inside. In a state where the seat portion 1411 is inserted into the connector portion 173, the leaf spring 174 presses the seat portion 1411 against the inner wall surface of the connector portion 173 parallel to the insertion direction (FIG. 3B). The leaf spring 174 does not correspond to the spring portion of the present invention.

  The extrusion electrode 121 and the grid electrode 122 are also connected to a power supply substrate provided in the vicinity thereof by the same configuration as each plate electrode 141 of the reflection electrode 14.

  Next, the operation of the time-of-flight mass spectrometer 10 will be described. First, the inside of the housing 20 is brought into a high vacuum state by the vacuum pump 30. A voltage is applied from the power source 19 to each electrode. When ions to be measured are introduced into the ion introducing unit 11, they are transported as follows by the electric field formed by each electrode. First, the electric field formed by the push electrode 121 and the grid electrode 122 accelerates toward the flight space 13. The accelerated ions fly in the flight space 13, are turned back by the action of the reflected electric field formed by the reflection electrode 14, fly again in the flight space 13, and reach the ion detector 18. The mass-to-charge ratio of the ions is measured based on the time from when the ions start to accelerate to when they enter the ion detector 18.

  When the vacuum pump 30 is operated, vibrations generated by the rotation mechanism in the vacuum pump 30 are transmitted to the entire time-of-flight mass spectrometer 10. As a result, the reflective electrode 14 and the power supply substrate 15 vibrate, but since the spring portion 172 biases the connector portion 173 to the seat portion 1411 of the plate-like electrode 141, both are separated even if some vibration is applied. No electrical contact is maintained with the contact resistance between the two being suppressed. Therefore, the electric field in the reflective electrode 14 is stabilized, and it is possible to prevent the mass accuracy, mass resolution, and sensitivity from becoming unstable.

  Even when a greater vibration is applied and the connector portion 173 is detached from the seat portion 1411, the reflective electrode 14, the connecting wire 17 and the like are not damaged at that time. In addition, after disconnection, the site worker can easily reconnect by inserting the connector portion 173 into the seat portion 1411.

  In the above embodiment, the seat portion 1411 is a male and the connector portion 173 is a female connector structure. However, the connector portion may be a male and the seat portion may be a female.

  Next, another connection structure of the reflective electrode 14, the power supply board 15, and the connection line 17 will be described with reference to FIG. In this modification, the structure and arrangement of the spring portion 172A are different from those of the above embodiment, but the other structures are the same. The spring portion 172A is a compression spring provided in a compressed state of a string-wound spring in which the wire rod of the connection wire 17 positioned in the immediate vicinity of the connector portion 173 is formed into a string-wound shape. Also in this modification, since the connector portion 173 is urged in the insertion direction of the seat portion 1411 by the spring portion 172A being compressed, the same effect as that of the above embodiment can be obtained.

  A second modified example of the connection structure of the reflective electrode 14, the power supply substrate 15, and the connection line 17 is shown in FIG. 5. In this modification, the connection portion 17 and the plate electrode 141 are connected by using a spring portion as a tension spring and sandwiching a seat portion 1411 of the plate electrode 141 between the winding portions. That is, the spring part also serves as a connector part (spring part / connector part 1723). In this connection structure, the connection wire 17 can be easily manufactured because the connection wire 17 is formed only of the wire.

  A third modification of the connection structure of the reflective electrode 14, the power supply substrate 15, and the connection line 17 is shown in FIG. 6. In this modification, the spring portion 172 is a torsion spring, one end of the connection line 17 is bent into a U shape, and the bottom of the U shape is a connector portion 173A. The plate-like electrode 141 is not provided with a seat portion that protrudes outward from the outer edge. Instead, the connector portion 173A is brought into contact with a part of the plate surface, and the contact portion is used as a seat portion 1411A. When relatively weak vibration is applied, the connector portion 173A is fixed to the seat portion 1411A by a static friction force with the seat portion 1411A. When vibration stronger than that is applied, the connector portion 173A slides on the surface of the seat portion 1411A, but no excessive force is applied to the plate-like electrode 141 and the connection wire 17, and the electrical connection is maintained. Since such a slide occurs, it is preferable to plate the seat 1411A to protect the surface of the plate-like electrode 141. Further, when strong vibration is applied, the connector portion 173A is disengaged from the seat portion 1411A, thereby cutting off the electrical connection between the two, but neither disconnection of the connection wire 17 nor damage to the connector portion 173A occurs. Further, even if the connector portion 173A is detached from the seat portion 1411A, it can be easily reconnected by simply returning the connector portion 173A to the seat portion 1411A. Also in this modification, since the connection wire 17 is made of only a wire, the connection wire can be easily manufactured.

  In the above embodiment, the power supply board is arranged inside the casing, but the power supply board may be arranged outside the casing. In this case, as shown in FIG. 7, the vacuum field throughs 16 corresponding to the plate-like electrodes 141 can be provided and connected by the connecting wires 17. In addition, the fixing portion of the connection wire 17 may be configured by attaching a connector corresponding to the vacuum feedthrough to one end of the wire.

  Although only the connection structure of the reflective electrode and the power supply unit for the electrode has been described, the same connection structure is applied to the other electrodes and the power supply unit that contribute to the transport of ions in the flight space, such as an extrusion electrode and a grid electrode. be able to. For example, as shown in FIG. 8, in addition to the extrusion electrode 121 and the grid electrode (extraction electrode) 122, one or a plurality of holes through which ions pass in the center of the flight space 13 side than the grid electrode 122 A single acceleration electrode 123 may be arranged. In this example, a laminated electrode is configured by combining the extrusion electrode 121, the grid electrode 122, and the acceleration electrode 123, and a connection structure similar to the above is used for each electrode. In addition, a laminated electrode for transporting ions to the ion introducing unit 11 may be provided in front of the ion introducing unit 11, and the same connection structure as described above may be applied to the laminated electrode. Furthermore, the connection structure shown in this embodiment can be applied to all laminated electrodes used as ion guide electrodes of mass spectrometers other than time-of-flight mass spectrometers.

DESCRIPTION OF SYMBOLS 10, 90 ... Time-of-flight mass spectrometer 11, 91 ... Ion introduction part 12, 12A, 92 ... Ion acceleration part 121, 921 ... Extrusion electrode 122, 922 ... Grid electrode (extraction electrode)
123 ... Accelerating electrodes 13, 93 ... Flight spaces 14, 94 ... Reflecting electrodes 141 ... Plate electrodes 1411, 1411A ... Seats 15, 95 ... Power supply board 151 ... Electric circuit 152 ... Solder 16, 96 ... Vacuum feedthroughs 17, 97 ... Connection line 171 ... Fixed part 172, 172A ... Spring part 173, 173A ... Connector part 1723 ... Spring part / connector part 174 ... Plate spring 18, 98 ... Ion detector 19, 99 ... Power supply 30, 80 ... Vacuum pump

Claims (6)

a) electrodes,
b) a power supply unit which supplies power to the electrodes at a predetermined voltage and / or current;
c) a conductive wire having elasticity, and a connection wire for electrically connecting the electrode and the power supply unit;
d) a connector portion provided at one end of the connection wire;
e) a seat provided on the electrode and in contact with the connector;
f) a fixing portion provided on the connection line and fixed to the power supply portion;
g) A mass spectrometer comprising: a spring portion that urges the connector portion against the seat portion, formed between the connector portion and the fixing portion of the connection line or in the connector portion.   The mass spectrometer according to claim 1, wherein the connector part and the seat part have an insertion structure in which one is a male and the other is a female.   The mass spectrometer according to claim 1, further comprising a stacked electrode in which a plurality of the electrodes are arranged at a predetermined interval.   The mass spectrometer according to claim 3, wherein the laminated electrode is an ion guide electrode.   The mass spectrometer according to claim 3 or 4, wherein the stacked electrode is an electrode used for transport of ions in a flight space of a time-of-flight mass spectrometer.   The mass spectrometer according to claim 5, wherein the stacked electrode is a reflectron.

Images