DE2040521A1 - mass spectrometry - Google Patents

Description

THE BENDIX CORPORATION, a company incorporated under the laws of the State of Delaware,
Southfield, Michigan 480 75 (V. St. A.)

mass spectrometry

The invention relates to mass spectrometers and, more particularly, to a time of flight mass spectrometer which is a device for separating charged particles according to their mass / charge ratio by measuring the Travel time of each particle between an injection point and a measurement reference point.

There are different mass spectrometer designs known. An overview of such devices is given in the book "Dynamic Mass Spectrometers" E. W. Blauth, Elsevier Publishing Company, New York (1966). The following is a brief description of those in above-mentioned reference described. Spectrometer given who come closest to the invention.

Z / m-h

10 9 8 28/1199 CONSTRUCTION ORIEINAL,

In a basic version of a time-of-flight mass spectrometer, charged particles are accelerated to a certain energy by a pulsating electric field and thereby moved away from a source through a field-free space where they are moved according to their mass / variation ratio (m / e) separated and fed to a jet detector. Ions with different m / e ratios are distinguished by recording their arrival times on the detector. Ions with smaller m / e ratios are accelerated by learning electrostatic impulses more strongly than ions with larger m / e ratios. The time interval between "successive m / e species" decreases with increasing mass and increases with the length of the available space.

Another device known as an acceleration spectrometer uses the transit time principle indirectly in order to achieve a mass / charge resolution. Ions travel through a path of alternately arranged spaces with electrical acceleration fields and field-free running spaces and then hit a jet detector. Voltage pulses are applied with such mutual phase that only those ions Bescnleunigungsimpulse hold erfc and reach a Jetektor, which reach /.u precisely defined times in successive Besc hl eunigungsräume to the acceleration spaces. :) ie m / e ratios of other ions are such that they do not m of an acceleration pulse of the way are driven that they einnnnmen a form suitable for acceleration in the direction of the detector from subsequent pulses location. An example of such a performance is a Bennett mass spectrometer. Jiρ resolution in the previously described types of spectrometers is limited in dt; r (Juelio due to changes in the kinetic energies as well as the spatial positions of the ions.

BATH ORIGINAL

109828/1 199

There is also a group of mass spectrometers in which the separation of the ions according to their m / e ratios thereby takes place that the ions are set in a dynamic electric field in oscillation, with only a single m / e species is selected, the ions of which oscillate with a sufficiently small amplitude to reach a detector. The quadrupolar and monopolar mass spectrometers are examples of such devices. In the dynamic field Ions introduced into such spectrometers are accelerated by the field and depending on the m / e ratios the ion species and the field parameters are subjected to either uniform or non-uniform motion. One Ions (stable ions) that carry out uniform movement in the field oscillate with a limited amplitude. Stable ions, whose amplitudes are smaller than the spatial dimensions determined by the limits of the dynamic field a detector. Unstable ions are subjected to vibrations, the amplitude of which increases continuously, so that they are lost at the electrodes of the spectrometer and are therefore excluded from the measurement. The area of stable m / e species depends on the parameters of the dynamic field. The resolution is achieved by adjusts these parameters so that only ions of a single m / e ratio are stable, which alone reach the detector.

In addition to stability, there is an essential measurement criterion in that the oscillation amplitude dependent on the initial conditions is smaller than the spatial dimensions of the dynamic Field is. A stray or interference field, which 'Extends from the analyzer into the source, impaired when exposed to ions entering the dynamic field the transfer of the ions into the dynamic field. With transmission losses is also to be expected due to the fact that the setting of the field parameters for the purpose of stabilization in a single m / e way to restrict the

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Initial conditions, such as the initial divisions and energies which carries ions. The limitations of the initial conditions the ions get more weight when the resolution increases will.

One group of mass spectrometers uses a high frequency electric field to accelerate the ions in a static potential hole. Only ions with certain m / e ratios get enough energy to escape from the potential hole and be measured. Ji e interactions between the dynamic field and W is the ion (quadrupole, monopolar, etc.) in the spectrometer identical to that in the previously described dynamic field spectrometers. The difference is that this type of spectrometer measures unstable ions.

In another group of mass spectrometers, charged particles are vibrated in order to separate them according to their m / e ratios. These spectrometers are known as Palletron principle spectrometers. Ions vibrate in a static, parabolic electric potential hole. The ions interact with the electric * field and perform a periodic movement at a characteristic frequency, which is determined by their m / e ratios and the field. The applied voltages forming the potential hole are periodically changed so that the selected m / e species can break out of the potential hole. Detector devices are provided which determine either the ion group which could break out of the hole or the groups remaining in the hole. A disadvantage of this device is that, after a corresponding number of oscillations in the hole, one m / e species is shifted or separated from another by a cycle of oscillation, making it impossible to distinguish between the two species.

109828/1199

The mass spectrometer according to the invention has a device for generating a dynamic field, which with the ions introduced into the field interact and they differ in time according to their m / e ratios separates. The spectrometer has a device for measuring the transit time of the ions in the dynamic field. This spectrometer produces an excellent resolution of the charged particles according to their m / e ratios direct measurement of the transit times of the ions in the dynamic field. This measuring principle distinguishes the invention from all known ones Mass Spectrometer ^ The term "charged particle" or "ion" as used herein means any particle with a purely electrical charge. The term "dynamic electric field" refers to an electric field with both a static and a vibration component or on a field that has only one vibration component having.

In the preferred embodiment described here, the dynamic field is an axially symmetric dynamic electric Field which has both a static and a sinusoidally changing field component. A sample of ions is accelerated from a source along the symmetry axis of the field into the dynamic field. The static Field component π eyes the ions in the field, the vibration component of the field drives the charged particles alternately in the direction of and against the forces exerted on them by the static field component, so that the charged Particles perform a complex movement. Depending on the field parameters and the mass / charge ratios the ions are separated into stable and unstable groups as a result of their interaction with the dynamic field. Unstable particles are caused by an oscillatory motion unlimited amplitude. The stable species whose oscillation amplitudes are smaller than those of the limits the spatial or physical distance defined in the field

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measurements are returned to the injection or entry zone and hit a detector. For fixed field parameters every returning ra / e-species has a certain running time in the dynamic field, which in the following is called characteristic Term of the respective type in the particular dynamic field is designated. The dissolution of various Types of stable particles according to their m / e ratios is therefore achieved by identifying the stable species and recording the differences in their transit times. They don't stable particles are lost on the walls of the spectrometer.

The dynamic FeIdparameter include the frequency and the SpannungsamplituJe the vibration component of the field, the size ier static field component and dip characteristic field dimensions which determine the field geometry. The usual mode of operation is based on a device with constant geometry, so that; A change in the Pel! parameters affects the frequency; ler · Sohwi η nngskomponente, the amplitude of the 5chwin ( ^T ungsKomponente and the strength of the static field component. These parameters are set to change the number (aes! Reichs) of the m / e species, which are subject to a stable movement, that is, the field parameters are set in an analysis or a tent no, since a special m / e-Ar-t is one of the easiest types that carry out a stable movement Peldparameter set dai.- the same m / e-type, either one of the one stanile BEWE, ^rr ung exporting serious types, or performing an unstable Pewt'.omg. modifications both in terms of the characteristic term of a particular m / e art in dynamic pel? as &uc> h with regard to the relative differences in the characteristic transit time for different? types of lonrn werien achieved by setting the field parameters.

BATH ORIGINAL 109828/1199

The source parameters include the length of time during which ions are generated, the time interval during which ions are introduced or injected into the dynamic field, the phase of the vibration component of the skin at which all the clays are introduced into the dynamic field, and the energy of the injected ions. As will be explained in more detail below, a suitable choice and change in the field and source parameters results in measurements which determine the composition of an ion sample and in relation to changes in both the kinetic energies and in the spatial positions of the ions in are relatively insensitive to the source.

Some of the embodiments on which the invention is based have different designs of the devices for Generating the dynamic electric fields and different arrangements for the devices forming the ion sources, the ion detectors and the devices for generating the dynamic electric field. There will be techniques for field adjustment of ions with different kinetic energies and spatial positions at the time of their introduction discussed in the field. According to one embodiment According to the invention, particles can be stored for a selectable period in order to increase the sensitivity through periodic Introduce identical samples into the dynamic field too and increase the concentration of a stable ion species before measuring that species.

There are many different geometries for the dynamic field, different configurations of the source and the detector. tors and various devices for controlling the field and source parameters possible in order to achieve different results, these change possibilities form an essential one Advantage of the present invention. As will be explained in more detail below, the runtime measurement is in the Invention relatively insensitive to changes in both kinetic energy and spatial

109828/1199

BAD ORiQINAt

Position of the clays in the source. Furthermore, the mode of oscillation at: ipr T3ewegun, r: der Tonen genuii. of the present invention so, there !? the clay tracks folded spatially on top of each other are. The advantage of this "fall ...-" is that (r the length of the analysis required to reach the target area with resolution possible with the known time-of-flight spectrometers g-eringer can be.

The inventively provided ongoing interaction between the ions and the dynamic field creates a separation between different kinds of ions, wherein an overtaking of a major ψ <h, the other-p ion species is not possible. Here in

is a considerable advantage over spectrometers, which work according to the Pa] 1 eton principle.

As will be explained in more detail below, the transit time measurement according to the invention improves the n / e measurement in comparison to devices such as monopolar, quadropolar and corresponding devices, which use dynamic fields to separate the tones, but only the spatial separation of the ions in the dynamic field to the E; aim to take advantage of the resolution. Ui e transit time measurement according to / the present invention makes it possible to use a Area or group of m / e ratios instead of one ^ to determine and record a single type of ion in an analysis

^ to redeem. ) Ureh suitable setting of the source and field parameters is greater ion permeability through the Field achievable; Furthermore, ions are in the dynamic field introduced without the KinfluT; of interference or interference fields to be exposed.

In the following the invention is based on in the drawing illustrated Aupführunrsbeispiel s explained in more detail. In the Drawing shows:

BAD ORIGINAL 109828/1199

- ■ 9 -: ■

Fig. 1 is a block diagram of an embodiment of the indune-sized mass spectrometer;

Fig. 2 Pin D lock diagram of the one used in Fig. 1 control circuit;

Fir. ^J ) a partial view of the in Pig. 1 ire shows a spectrometer, the device for generating the dynamic analysis field being omitted and the trajectories of various types of ions in the Φ / η ami rs c he η field being shown;

. 4 is a graphical representation of the a1 and q2 values for ions whose movement in the x, y and z directions in the dynamic field is stable;

. ^r i is the relationship between the duration of the participation

in the dynamic field and the m / e ratio of the Particles for a given setting of the spectrometer operating conditions;

G. L · a graphical representation of the relationship between the particle travel time in the dynamic field and the phase of the dynamic field after the particles have been introduced into the field;

Fig. 7 is a graph showing the dashed lines Areas showing a, q values, which are the limit solutions for the Mathieu equations and therefore the stable ion movement in the corresponding direction in the dynamic field indicate;

Fig. 6 is a block diagram of a second embodiment

according to the invention; ·

Y shows a block diagram of that part of the control electronics of the spectrometer shown in Fig. 8 ^ which of the control electronics of the spectrometer differs according to Figure 1;

10 shows a third embodiment of the invention trained spectrometer;

Pi"'*:. 11 is a detailed view of the programmed optic circuit the embodiment of FIG. 10;

Fig. 1? a two-dimensional so-themed view of another Device for generating a dynamic analysis field gemäl? of the invention, in which the in and Outputs for stable clays at different. borrowed points of the field lie;

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13 shows a second view of the A'isführerun ^ nforr.i α ach Fir. ¹ 2 seen in hichtuii / r der! 'Feile Ρ, -1] in Fifr. 12;

14 shows a vain ochema of an aluminum guide _; -i; form with; an ion store; and

Fip. 15 eirif? second view on the in ^ i _e- . 14 Aui-sführun / i'ezeigte 'oforra in Riohtunr the 1'feile one ^he - ^1' - ■ * *?. ¹ 4.

A) Description of the spectrometer device!

Fi # i. 1 shows an embodiment form 10 of the new!.! Nn ^ ensper.t, rometer with a thin analysis field defining device ¹ 2 for the abbreviation: a dynamic electrical Pe'Jdop, soft ions soles ev; ni * Tt; and decelerates, whereby ion types with different m / e ratios are separated in time. The spectrometer 10 also has a device 1Ί for injecting or introducing clays into Jas dynamic elements and a detector 16 for determining and displaying the transit times of the different types of ions. A iiteuersichallurii- 18 controls the operation of the analyzer field defining Vorrichtuni 'x ¹ 2, the loneninjektorn 14 and the detector? ¹ <. Kin evacuable tubular piston 20 encompasses the device 12 defining the analysis:. '»" »Id, the ion injector 14 and a Toii -iiis Detector U.

The device 14 for introducing the ions into the dynamic field has a device for ionizing among other things in a region close to the dynamic field / ^ ele ^ etici: .. 22 , The device for ionizing the gas particles - :; t known; it comprises an electron-emitting filament and a control pitter for determining the amount of electrons from the filament 24 into the ionization space 2. initiated. An electrostatic Sanunel lens 23 focuses the flow of electrons through the ioni r.ationskiunn.er 22. B-ne anoae Ό controls the strength of the ion. Nut ionselek separates romu. : »«; · Jneninjektor 1Λ also has a second control vitter |? IUF which the Hinsum Dynami nchen field i ^r eKeniiner: ie ^ r *. i -inrnonlnet is and

BATH 109828/1199.

serves to inject the ions into the field. One to analyze A gas sample is introduced from a sample dispenser 34 through a valve 36 into the evacuated tubular flask 20 and the chamber 22. After the gas sample has been ionized, the ions are applied to the second grid 32 by means of a Voltage pulse injected into the dynamic analysis field.

The device 16 for determining the various separated types of ions and for measuring the differences in their relative transit times is of known design and comprises a detector 37, which is designed either as a secondary electron ^{multiplier or as a Faraday 1} shear cage and is struck by ions leaving the dynamic analysis field. The device 16 also has a display device 38, which includes a broadband amplifier and an oscilloscope for measuring and displaying the differences in the transit times of different types of ions. The display device 38 is controlled by the control circuit 18.

The device 12 defining the analysis field, which the dynamic electric field, has a series of ring-shaped, metallic field electrodes 39 and one with a Opening 41 provided end electrode 40, which forms the inlet and outlet of the ions to and from the dynamic field and has a cone-shaped inner wall 42 resting on the z-axis of the spectrometer 10 is arranged. Each of the annular field electrodes 39 has an inner radius · R, the field electrodes 39 are lined up one behind the other via spacers 43 made of dielectric material. They form with the spacers a solid association. Composite AC and DC voltages are from the control circuit 18 via a voltage divider 44 is applied to the ring electrodes 39. The electrode 40 is held at ground or mass potential.

The design of the voltage divider 44 and the applied voltages are chosen so that a dynamic electric field

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is developed whose potential distribution 0 (x, y, z, t) depends on the form

1 ο ^{X +} ""
0 (x, y, z, t) - _Tj (7.,) (V _dc + V _ac cob wt) (1)

where ζ is the longitudinal coordinate and χ and y are the radial coordinates of the dynamic analysis field; w = · *> = 2 ~ f is the oscillation frequency of the field, t is the time; V, is the DC component of the electrical potential; _{ν_ η} is the amplitude of the oscillation component of the electrical potential; and G is a geometric constant represented by the equation

G = L -

is defined, where L is the length of the structural unit defining the analysis field, length of the z-axis and R is the inner radius of the structural unit.

The special design of the device; and the distribution of the dynamic electric field, as described above, are only to be regarded as examples to illustrate the essence of the invention. The spatial arrangement of the Field of required components Can be changed. Of course other dynamic fields can also be used, which one or more of the characteristic quantities of the previous described dynamic-n field using the ■ instructions according to the invention. For example, the spectrometer can operated at V. = 0 while still having a Dissolution of the mass types achieved. A more general configuration of the electric field which can be used in the present invention is given by the following potential distribution defined field:

0 (x, y, z, t) = f (t) Ux ² + _y y ² + 7z ² ) (2)

109828/1199 BADORHS.NAL

■ - 13 -

where f (t) is any periodic time function and J. , tf and η are constants which satisfy the condition ot + γ + * η = O. Dynamic potential distributions larger than square ones can also be used. '

The control circuit 18 is set up so that an operator can give a signal of the desired strength and frequency to the voltage divider 44 in order ^to feed the ring electrodes 39 which determine the electrical field. The control circuit 18 also provides a signal of appropriate strength to the two control grids 26 and 32 at appropriate times during the operation of the spectrometer.

FIG. 2 shows in a block diagram the individual structural units of the control circuit 18 shown as an individual block in FIG Control circuit has a 1 MHz crystal oscillator 46, which generates a square wave signal (clock signal) and a highly stable time base for the oscillation component of the dynamic Field and for the control voltage of the grid 26 and 32 supplies. The square wave signal from the oscillator 46 becomes a counting logic or buckets of multistage counter 48. This reduces the frequency of the 1 MHz signal and delivers a mother pulse to trigger a time base for the spectrometer operation. Of the Counter 48 also reduces the 1 MHz signal to generate trigger pulses for controlling grids 26 and 32 and to Formation of a signal of the desired frequency, from which the oscillation component of the dynamic field is derived. The dynamic electrical Fexd is formed by a square-wave signal from the counting logic 48, which is first a square-wave signal into a sine signal converting low-pass filter 50 is supplied. A preamplifier 52 and a power amplifier 54 allow variable gain control to be achieved the desired amplitude of the vibration component. of the dynamic field. The output of the power amplifier 54 not only becomes a voltage divider 44, but also back to the preamplifier 52 via a (constant) regulator 56 directed. The feedback via the constant regulator enables the adjustment of the amplitude of the sinusoidal voltage to a

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the desired value and the maintenance of the amplitude Net voltage and load fluctuations. The static component of the dynamic electric field is supplied by a controllable direct current source 58.

The control circuit 18 furthermore has a pulse generator 60 which controls the actuation of the grid 26, a pulse generator 62 which controls the ion injection and a pulse generator 64 which controls the ion removal. The generators 62 and 64 control the potential of the grid 32. The pulse generator 60, which controls the strength of the ionization of a sample, is designed to generate a positive going pulse of variable amplitude, width, reference coordinate and phase with respect to that of the Counting logic 48 delivers derived mother pulse. The pulse generator 62 controlling the introduction or injection of the ions into the dynamic field generates a positive pulse, the amplitude, width and phase of which can be varied with respect to the mother pulse recorded by the counting logic 48. Since both the operation of the generator 62 and the frequency of the vibrational component of the field are controlled by the counting logic 48, the start of ion injection and the period in which the ions are injected into the dynamic field can be determined as a function of the phase of the vibrational component of the field to be changed. The pulse generator 64 generates a negative going pulse, the amplitude, width and phase of which can be changed with respect to the ion injection pulse to accelerate the ions returning to a detector 37 (FIG. 1). The output signals of the pulse generators (> 2 and 64 are transmitted to a pulse generator 66, which combines the ion injection pulse and the ion extraction pulse in one signal for controlling the grid 32.

109828/1199 BADORKäJNAL

B) Description of how the spectrometer works

The mode of operation of the spectrometer 10 according to FIG. 1 can be seen from FIGS. 3 to 7. In operation, the gas particles of the sample are bombarded by a stream of electrons and ionized by the electrons in the space 22 near the dynamic electric field (FIG. 1). The stream of electrons is generated by the filament 24. The direction and intensity of the electron flow through the ionization space 22 are controlled by the control grid 26, the electrostatic lens 28 and the anode 30. After their ionization, the gas particles are injected into the dynamic electric field by a voltage pulse applied to the control grid 32. The movement of the respective types of ions in the dynamic field is shown in the split view of the spectrometer 10 according to FIG. 3. The dynamic electric field accelerates and decelerates ion types of certain m / e ratios in such a way that they carry out an oscillation of unlimited amplitude and are lost at the electrodes of the device 12 which determines the analysis field. These ions follow orbits similar to orbits 68 and 70 when under unstable motion in the dynamic field. Other types of ions follow paths similar to path 72 and vibrate with limited amplitude so that they do not strike the walls of the device defining the analysis field and return to detector 37. These types of ions are subject to stable movement in the dynamic field. The graph of FIG. 4 shows that for each particular setting of the operating conditions there is a group of ions which carry out stable movement in the dynamic field, and that there are other ion groups which are subject to unstable movement in the dynamic field. In the graphic representation according to FIG. 4, all the particles lie on the line marked "u ¹ *" at a fixed ratio of V _dc / V _{a (J.} All species that are on the line between the (3 = 0 and ß = 1, the vibrations in the dynamic electric field are limited by '.- 10 9828/1199

Subject to amplitude. All other types of ions are subject to Vibrations of unlimited amplitude with fixed work conditions. Each of the types of tones returning to the area 22 has a specific transit time in the dynamic electrical Field.

Fig. 5 represents the fixed working or operating conditions Relationship between the ion travel time and the m / e ratio of the ions for those particles which have stable motion run in dynamic field. As can be seen from Fig. 5, light particles, i. H. Ions with small m / e ratios, which in Fig. 4 are closer to the line ρ = 1 than the

^ Line | 3 = O, to detector 37 in front of the heavier particles larger m / e ratios. The differences in the relative transit times for light particles with small m / e ratios are, as can be seen from Fig. 5, less than the differences between the transit times for heavy particles with closely spaced m / e ratios. Because of special Choice of dynamic field parameters a particular type of ion can have such a ratio that it is either a stable one or is subject to an unstable movement or is either one of the lightest or the heaviest of those ions which are subject to a stable movement in the dynamic field, the resolution between special ion types by appropriate change in dynamic field parameters increased

^ will. The dynamic field parameters are set by changing the operation of the counting logic 48 to change the frequency of the vibrational component of the field, the preamplifier 52 and power amplifier 54 to control the amplitude of the vibrational component of the field and the DC power source 58 to control the strength of the static component of the Field can be set. As can be seen from FIG. 4, the transit time of a specific type of ion can be changed by changing the operating parameters in that? the ratio of V _dc to V _ac and thus the slope of the u-line is changed. The field parameters and the ion transit time can also be

10 9 8 287119 9

stantera V ·. / V ratio by moving the position of a particular particle on a given u-line can be changed.

In addition to the operating characteristics described above of the spectrometer shown, Fig. 6 shows that the period while the particle of a particular ion type hits the detector 3-7, less than the time interval is during the particle This type of ion can be shot into the dynamic analysis field, provided that these particles occur during a suitable period of time. Interval related to the phase of the vibrational component of the field «Any injection interval In relation to the phase of the vibrational component of the field can be selected, and a particular injection pulse can be caused by the counting logic 48 or the injection pulse generator 62 is set.

C) Detailed description of the principles of operation of the mass spectrometer

1. Mathematical parameters

Which in describing the operating principles of the POS spectrometer The symbols used are defined as follows

0 »electrical potential distribution x, y, z ~ rectangular coordinates t * time

χ β Velocity in χ direction (first derivative after the time)

x a acceleration in χ direction (second down, line according to the time)

f β Frequency of the alternating field in Hz w * 2trf * Frequency of the alternating field in rad / e * 3jr * independent time variable in the Mathitu equations

10982171t

ORKSINAL INSPECTED

a _t q = canonical parameters in the Mathieu equations

V = amplitude of the alternating current component of the ■ ^a potential

V, = strength of the direct current component of the potential ^ac ti as

L - length of the dynamic field area R - radius of the dynamic field area

2 H ^ - G - L .- x- = geometrical factor

m = mass of the charged particle e = electrical charge of the charged particle

u - a / q = ratio of the canonical parameters in the Mathieu equations

f = charged particle - transit time in rad t_ _ - charged particle - transit time in see

^{The paths followed by the charged particles 1} oscillating in the dynamic electrical potential distribution according to equation (1) are defined by the following component of the Mathieu equations in canonical form:

a _f 2H ₁ cor

Jy + (n. + Pn ₁ ooa ? T) y = 0 O)

rt

dz ± (a ₉ ■ ♦ ■ 2q _P cos ? t) ζ = 0,

where 2 £ ■ - wt - ? .trf \ < and the parameters α and q are given by the following expressions

2a, =. -

Green (4)

^{4e V} ac 0 mw ^l

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- 19 2. Stable and unstable movement of charged particles

Depending on the values of the dimensionless parameters a and q is that given by the Mathieu equation

, 2 _Y

^tt - ^A + (a + 2q cos 2t) X = O (5)

German

described movement either stable or instdibil (limited or unlimited). Fig. 7 shows a range of a and q values for stable solutions (dashed area). The movement of the charged particles relative to this stability range is primarily of interest when operating the dynamic mass spectrometer, although operation is also possible for a-q values which define other ranges. Values for a and q at which the charged particles moving in the x, y-plane describe a stable movement are described by the dashed area in the first and fourth quadrants, values for a and q at which in the direction of the Charged particles moving z-coordinate describe a stable movement are defined by the dashed area in the second and third quadrants of FIG. Three dimensional © stability values for the parameters can be achieved by superposing the dashed areas of the second and third quadrants with the areas of the first and fourth quadrants. Since the sizes of a ^ and a ₂ , q ^ and q ₂ differ by a factor of 2, the areas in the second and third quadrants have a different scale than those in the first and fourth quadrants. The combined stability range (Fig. 4) defines values of a ₂ , q ₂ , at which charged particles describe a three-dimensional limited movement in the dynamic field. The combined range has the form shown, since V. can assume either positive or negative values. Corresponding values for aj, qj can be calculated from equations (4). Although the selection of stable a, q values ensures that the associated charged particles describe a limited motion.

109 828 / VI9 &

ben, the actual size of the envelope of the limited motion of the initial conditions of the particles at their Entry into the dynamic field is determined as well as by the values of a and q.

3. Mass range stability

For the sake of simplicity, only the first quadrant is used as the graphic View according to FIG. 4 viewed. To a spectrometer with fixed spatial geometry or geometric factor G and fixed to operate at a dynamic field frequency f, values for V, and V \ selected, which is a mass type operating characteristic u

W & c

which runs through the combined stability region of FIG. 4. Using equation (4), each m / e value of a charged particle is assigned certain values of ag, qp. Since a, q are inverse functions of m / e, the larger m / e ratios are closer to the a, q origin. The group of m / e particles, whose assigned a, q values on the operating characteristic u are in the range of the combined stability, describe a stable movement. Those m / e-particles which lie on the line u to the left of the curve P = O carry out an unlimited movement in the direction of the z-coordinate. Those m / e particles which are to the right of the curve (5 = 1, carry an unlimited movement in the _direction: of the z-coordinate W of nate.

Ee it can be seen that the a, q positions of all m / e particles can be shifted along the operating characteristic u by _{changing the quantities V & c} and V. while keeping the ratio V. / V constant. By changing the stresses in the manner described above, the m / e particles are pushed into or out of the area of combined stability. In this way, the mass range of the charged particles within which stable limited movement of the particles occurs can be changed. A repeated systematic change of the potentials V__ and V forms a basis

ctC ClC

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for scanning the mass species spectrum. The slope of the operating characteristic u can be changed by changing the ratio ^v _dc / ^v _ac . This leads to a change in the mass range of stable charged particles.

4. Running time of the charged particles

The essential parameter of the movement of stable particles is the runtime behavior of the ions in the dynamic field. For a fixed setting of the operating parameters, each has a stable Ion type a certain transit time between the point in time at which the associated ion enters the field at ζ = O and the Point in time at which it returns to the point ζ = O. Because the equations of the ion movement are independent of each other, all that is needed is the entry time and the transit time in the ζ Direction to be considered. The general solution of the component equation for the coordinate ζ with stable motion is:

ζ (£) = a £ c cos (2n + ß) (I + £ )

C _2n sin <2n + ß) it + I ₆ ) (6)

η = - * β

where the P-value for stable solutions is in the range OSLβ ^ - 1, g ₀ = wt ^ a the entry time of the ions into the dynamic field · at z = 0 relative to the phase of the vibration component of the FeI-. des, £ the operating time variable, and A and B the constants representing the initial conditions of the ions in injection.

To simplify the general solution equation (6), the sum products can be replaced by C (Z + Z _Q ) and S (E + t) , from which Bich results?

= AG (E + I ₀ ) + BS (S + Z ₀ )

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The initial conditions are used to solve the constants A and B ζ, β O, z (o) = 0, z (o) = ζ, and we get:

s (E ₊ E ₀ ) - S (E ₀ ) c & +%)] (8)

where the initial speed at E = E ζ = »

OO Cl t '

is and W =

ε = ε,

In order to calculate the transit time E _TO p of the particles which enter at ζ = ο and return from the field at ζ = ο, the left side of equation (8) ζ (Ε _τορ ) = ο is set:

⁰ = w

Since the initial velocity and the Wronsky determinant W are not equal to ο, C ", _O p results from:

c C5 ₀ ) s (t _WF + l _Q ) - s (E ₀ ) c (E _TOp + E ₀ ) = ο (10)

ε TOP _ .., _TO p = of that

The m / e ratio of the charged particle, the parameters of the dynamic field through ß and the coefficients Cpn ' ^{un <} ^ ^{on the} initial phase of the injection? In contrast, Bm _O p is independent of the initial velocity or energy of the particle. There is a practical limit to the particle velocity in introducing the particle into an analysis field with finite limits. Since the entry of the particle into the oscillation field is proportional to the velocity, the range of possible entry velocities is limited. A typical relationship between the particle travel time t _r n _O p and m / e is shown in FIG. Injection phase £ are kept constant. The arbitrary

109828/1199

Common m / e and tm _O p coordinates are given special scale values if V _QO , G, V ,. and the frequency w can be determined.

, SC. Q.C

It follows that the scale divisions for m / e and the particle travel time tm _O p can easily be changed by using the appropriate parameters V, V, and w, so that

eic CLC

the stability range of the masses, transit times and m / e resolution can be changed within wide limits.

5. Mass resolution

The relationship between t _T0 "and m / e in Pig. 5 shows that the running time of the charged particles increases rapidly with m / e. The difference in the transit time for neighboring m / e values also increases with the mass. This favorable situation exists for m / e values that lie on a u-line that runs through the stability range and approaches the β = 0-K curve or the left instability edge of ζ of the stability diagram. Since the mass types are separated more in time with increasing mass, there is another characteristic of the Mathieu alternating current field to increase the m / e resolution. Particles which enter the alternating current field at z = o over a period Αΐ * ₀ are bundled in time during the interaction with the alternating field and return within a period of time Λέ _τορ , which. is shorter than ΔΕ _ο . This time bundling is in Pig. 6 expressed where Εφ _{0 {!} is determined as the puncture of the entry phase £ ₀ from equation 10 for fixed values of a and q.

6. Bulk scanning

A method for displaying a resolved mass spectrum for mass ranges that are not too large presupposes that all types of charged particles are determined by a suitable choice of V "and V _-3 -

ac dc

Potentials and the operating frequency w lie simultaneously within the combined stability diagram. The mass spectrum can be displayed on an oscilloscope for each analysis cycle,

109828/1139

ORIGINAL INSPECTED

A second display method involves measuring the arrival of the ions at the detector 37 at a predetermined time and a programmatic increase or decrease of V and V,

B-C Gl C

to continuously change the transit times of the m / e species in such a way, that each type successively the given duration achieved. An example of this method is shown in FIG.

^{2 V} dc placed where the voltage ratio u = - and w constant

^V ac

and all types of mass are on this u-curve, which runs through the stability diagram. In fact, each a2 "q ₂ ~ point in the stability diagram of a loading" voting test _TO p assigned. The predetermined delay is as

TOP -4 »

- written, wherein the particular * _{'Τ Λρ} ^the

Values a ^f ₀ and η · _{5 is} assigned. If V and V, then

d. ^ c. clC QC

that m. at a'p and q * _? (Fig. 4), then nu and πκ have shorter transit times than t '^ ™ · m .. and m, - are unstable. As V and V i increase, it shifts

ac QC

in the direction of a ' ₂ , q' ₂ »where the associated transit time t '

is. As V and V i are decreased, nu, mp and m _{1 are} sequentially shifted to point a ' _or q' _o

2 2. ··

and appear successively in the mass-time spectrum at f _Top .

Successive scans of all types of mass of a gas sample can be achieved by a short gate opening time of τ · ' _το _ at the output of the detector multiplier. The output signal of this gate Aua briefly opening provides an indication of the mass spectrum types, if the potentials V_ _n and V _dc in the one or other direction while keeping constant the ratio V 2, _ / V_ "are changed.

Q CT & C

109828/1199

There are other techniques for scanning the mass spectrum. The frequency w of the AC field can be continuously changed to move any type of mass through point a ' ₂ , q' ₂ .

D) Other embodiments of the mass spectrometer

Figures 8-14 illustrate other embodiments. of the new mass spectrometer. The following description is based on the structural and functional differences between these embodiments and the spectrometer IO directed. A detailed explanation of the components used in these different types of embodiment is omitted, as far as they have already been described for the spectrometer 10. Such elements are shown in FIGS. 8-14 provided with the same reference numerals as in FIGS.

Fig. 8 shows a spectrometer 74, which differs from the spectrometer 10 in that. The sample gas to be analyzed can be introduced directly into the ionization chamber 22 to the sample dispenser 34 through a drill hole 76. The gas particles can av-f *? This way, ionized immediately and then injected into the dynamic analysis field with minimal migration of neutral gas particles into the vicinity of the evacuated tubular piston 20. The spectrometer 74 further differs from the spectrometer characterized ^ _f 0 that the annular field and the electrical standoff 43 is replaced by a single tubular resistive electrode unit 78! Ektroden. 39 The electrical resistance of a particular part of the resistive electrode is chosen so that when a potential of de? Control circuit 80 via line 82 to one end of the electrode creates an analysis field within the space defined by the electrode, which field is described by the potential distribution defined in equation (2). The tax-

109828/1199

circuit 80, part of which is shown in FIG. 9 as a block diagram is different from the control circuit 18 in that it has a rectifier 84, which the static component of the dynamic electric field forms. The rectifier 84 is supplied by the power amplifier 54 A sinusoidal alternating voltage is supplied, which is converted into a direct voltage in the rectifier. As the power amplifier 54 provides the input signal for the rectifier 84 and also the amplitude of the oscillation component of the field, an adjustment of the gain of the power amplifier 54 changes the dynamic field parameters in k in such a way that a constant V, / V ratio is maintained preserved.

Figure 10 illustrates another embodiment 86 of the spectrometer which includes an electron multiplier detector 88 of the type known under the trademark Spiraltron which determines the types of ions resolved by the spectrometer device. The spectrometer 86 also has a grounded, cone-shaped electrode and a cable corner electrode 92 with a surface 93 which defines a revolution hyperboloid for generating a dynamic analysis field. The electrode shapes are chosen so that? they give a potential distribution of the form described by equation (2). A ψ suitable electrical signal is given by a programmed optimization circuit 94 to the conductive electrode 92, whereby a dynamic electric field is created in the space defined by the conductive electrode 92 and the conical electrode 90. The optimization circuit also controls ionization and ion introduction into the dynamic field by controlling the voltages on grids 26 and \ 2. In this regard, circuit 94 corresponds to control circuits 18 and 80.

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The programmed optimization circuit also includes 94 an electronics (Pig. 11) for optimizing the signals representing the different types of ions and for measuring them optimized signals. The programmed optimization circuit 94 is therefore designed so that the resolution or separation of the neighboring ion types in one test series and the strength of the different types in other test series representing signals is brought to the greatest possible value.

In order to achieve this signal optimization, the circuit is provided with a main control or logic circuit 96, a device 98 for determining the maximum signal value and a signal processing device 100 equipped. In the main control circuit 96 are the control commands for the ion source and programmed in the dynamic field parameters; it is responsive to pulses from other portions of the programmed optimization circuit 94 to control the operation of the circuit 94. The device 98 is supplied with the various signals from the detector 88 and combined in the device in order to determine the maximum values of these signals. The device 98 determining the maximum values includes a signal measuring device 102, which are the incoming from the Spiraltron detector 88 and caused by the impact of ions on the detector Measures signals. In a threshold value discriminator 104, a lower signal threshold is set so that the Measuring device 102 only measures values above the signal threshold, whereby a measurement of noise signals is avoided. One determined above the preset threshold voltage Signal value is stored in memory 106. If a signal is already stored in the memory 106, the last one will be averaged the signal with this already stored signal 'compared by a comparator 108, and only the larger of the two signals is stored in the memory 106. After this all signals of interest of a work cycle recorded

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and measured by the device 98, that is largest of the received signals is stored in memory 106. This maximum signal is passed through an AND gate 110, which from the main control circuit at the appropriate time to Display device 38 is controlled.

The signal processing device 100 is used to determine and store the field parameters corresponding to the maximum signal value for a special ion species. Furthermore, in the device 100, the maximum resolution or separation between the signals representing neighboring types of ions is determined. An optimal resolution exists when the difference between the ^v _ac -WQrt, which delivers the largest ion signal value for a first ion species, and the V value, which delivers the largest ion signal value for a second ion species, is greatest . For this purpose the device 100 has a V / V, control circuit 112 for changing the dynamic field parameters. The control circuit 112 can be designed similarly to the control circuit according to FIG. 2 or that according to FIG. The values of the amplitude of the oscillation component (V) of the field, which result from setting the control circuit 112, are measured with the aid of a voltmeter 114 and stored in a shift register 116. As soon as a largest signal value has been determined by the comparator 108, both this signal value and the V, which led to this signal value, are transmitted to a memory unit 118. The storage unit 118 can store a large amount of information, such as is necessary for determining all types of ions contained in a sample to be examined. Comparison measurements and difference measurements between the various signal values stored in memory 118 are carried out in a subtraction unit 120 and a comparison unit 122. The difference between the different stored values is stored on the one hand in the memory unit 118 and on the other hand transmitted to the main control circuit 96,

109828/1199

which uses the difference value to control the further operation of the programmed optimization circuit.

The spectrometer 86 and the optimization circuit 94 are preferably operated in such a way that a mass scanning process is carried out in which only the signals generated by the ions impinging on the detector 88 within a predetermined time are measured. Identical ion samples are introduced into the dynamic analysis field in a test series. The dynamic field parameters are changed before each test in order to change the ion transit time. In operation, the main control circuit 36 initiates ionization by triggering the pulse generator 60. It controls the actuation of the control circuit 112 in order to set the V "and V, values according to a predetermined

ac eic

to change the given program. In addition, it controls the measuring device 102 in such a way that output signals from the detector 88 are measured only at a predetermined time with respect to the ionization time. When the output signal of the detector 88 reaches the threshold value given by the threshold value discriminator 104, the detector output signal is stored in the memory 106. In a subsequent test, the signal value obtained after slightly adjusting the V_ "and V, values is compared with the value previously stored in memory 106. If the subsequent value is greater, it takes the position of the previously stored value in memory 106. This process is repeated while V _{& c} and V ^ _{0 are} scanned or changed according to the predetermined program until the incoming signal from detector 88 is less than the signal stored in memory 106, whereupon the stored signal is transferred to the memory 118. This signal stored in the memory unit 118 is subsequently bettered as the peak value and represents the maximum signal value for a given setting of source parameters and for Pßld parameters falling within a given narrow range. Simultaneously supplies

109820/1199

the comparator 108 sends a pulse to the shift register 116, which controls the register so that the measured V "value

EIC

corresponding to the maximum peak value of the storage unit is allocated. The processes of mass scanning and signal comparison are then continued until the peak value of a second mass or ion type in a similar manner Way has been processed.

As soon as the size of the peak values of two adjacent masses has been identified, the scanning process is interrupted, and the measured V values for the two peaks are fed into the subtraction unit 120, in which their difference

P is determined. This difference is shown along with the associated Operating savings providers are stored in memory 118. the Main control circuit 96 then directs the signal measurements to a new measurement time, with the source and field parameters be set to suitable new values. The bulk scan cycle is then carried out again for the same two masses. The resulting V difference is compared with the previously in the difference stored in the memory unit 118 from the comparator 122 compared. If it is greater, this difference becomes together with the associated operating parameters in replacement of the information stored in the memory 118 in the memory 11 θ stored. The change in operating parameters will be like this

fe continued until the program has finished. Thereafter the main control circuit directs the controls for the source and operating parameters to adjust to those Values which have been identified as the values corresponding to the maximum V difference. To this In this way, an optimal resolution is achieved for these masses. The UNTD ßatter 110 then activates the display device 38 and controls the V /V. control circuit 112 so that the resolved Tips are scanned. This scan is displayed or written on the display device 38.

109828/1199

If, during the resolution optimization process, a new mass peak occurs between previously identified peaks occurs, the main control circuit 96 causes the optimization circuit 94f the first of the previously identified peaks and to dissolve the new tip «This process continues, until the two peaks are resolved in the best possible way.

During operation, the memory unit 118 is continuously updated with the peak values of each of the two resolved Hassen and the operating parameters assigned to them. After the ore has reached the optimum resolution, the main control circuit returns 96 relating to the operating parameters stored in the memory unit 118 which produced the greatest peak value for the first hater during the resolution optimization. The source and field parameters are then programmed with an index, and the measured peak value for each index is matched with that of the previous index compared. Is the. If the peak value of the new index is greater than the previous one, it forms the new status of the storage unit 118. After the end of the program, the maximum The peak value is transmitted to the read-out or display device 38, and the optimization process is then carried out for the second of the two resolved peaks repeatedly. These processes are repeated until a complete scan of the mass spectrum is obtained is carried out.

FIGS. 12 and 13 show a further embodiment in two views 126 of the spectrometer, different from those previously described Spectrometer designs are distinguished by the field generator 128 generating the dynamic analysis field. «The field generator is a monopolar structure with a rod-shaped one conductive electrode 130, the surface 131 of which can be either cylindrical or hyperbolic, and two grounded plates 132 and 134, 'spaced from the

109828/1199

Rod-shaped electrode 130 and are also arranged at a mutual distance and a gap between them 136 form, through which the ions enter the dynamic analysis field and exit from it / If the rod-shaped Electrode 130 an appropriate signal with a V ""

EIC

or vibration component is supplied from the control circuit 18 a dynamic electric field is created

of the form 0 (x, y, z, t) = f (t) i (y ² - z ² ) (11)

ο where x, y, ζ are the rough coordinates in the in Figures 12 13 and 13 and Z is the length of the dynamic field along the z-axis in that of the rod-shaped Electrode 130 and plates 132 and 134 is limited area.

The field defined by equation (11) is similar to the dynamic fields previously defined in that it is in the field injected different types of ions accelerated and decelerated and thus in time according to their m / e ratios separates from each other. The field according to equation (11) differs from the previously defined fields in that that it has no component along the x-axis. Therefore, when subject to stable movement in the dynamic field Ions with a component of motion in the direction of the x-axis are injected into the field, their motion becomes in the direction the x-axis is not reversed by the dynamic field. The ion injector 14 is arranged in the spectrometer 126 so that it delivers ions with a component of movement in the direction of the x-axis. Because the dynamic field affects the ions in relation to this If the movement component is not reversed, the detector 37 is arranged at a distance from the injector 14 in the direction of the x-axis. Ions emerging from the dynamic field therefore do not have to pass through the ion injector 14 in order to reach the detector 37 to arrive.

109828/1199

FIGS. 14 and 15 show an embodiment in two views 138 of the spectrometer with an ion storage device. the Spectrometer style 138 differs from the spectrometer 10 in that it has two identical structures 12 and 140 for generating dynamic analysis fields. the the field-generating devices or structures 12 and HO are arranged opposite one another and axially aligned. The field established by structure 140 is a mirror image of the field created by structure 12. Stable ions will therefore swing back and forth in such a field from one field to the other and thus in the spectrometer 138 can be saved. The stored ions are voltage pulses supplied by a grid 142 (Fig. 15) are removed from the dynamic field and to the detector accelerated. The potential of the grid 142 is controlled by a control circuit 144 which is similar to the control circuit 18 is constructed, but a counting logic and a pulse generator for controlling the actuation of the grille 142 having. This additional device is similar to that shown for controlling the actuation of grids 26 and 32 Devices.

There are several modes of operation with the spectrometer 138 possible. As in the previously described embodiments, several different types of ions are subject to dynamic Field at the same time as a stable * movement. Any stable or stored ion species can be used if desired pulled out of the dynamic field within a period of time and resolved by measuring the differences in the impact times of the various types of ions on the detector 37 will. For this purpose an ion is made from the substance 22 to the detector 37 pulling signal to the grid 142 and maintained while successive ions enter area 22. In an alternative mode of operation, ion species with certain ir / e ratios are used individually subtracted from the dynamic field by the grid

10932871199

voltage is only applied at those times when the selected types of ions are in space 22. In a similar manner, a single ion species can be stored by the spectrometer 138 by continuously acting on the grid 142 to withdraw the ions from the dynamic field, with the exception of the period during which the selected ion species to be stored passes through the area 22 runs. During this period of time, the grid remains unaffected, so that the movement of this type of ion in the adjacent field is unaffected. In this way, all types of ions, with the exception of the one selected type of ion, are thrown back from the resolving dynamic field. The intensity or strength of this type of ion can be increased to facilitate the determination of this type of ion by periodically injecting additional ion samples with many types of ions into the dynamic field while the previously stored ions are in the region 22. Undesired species are withdrawn from the field by renewed exposure to the grid 142, the exposure times being selected so that, with the exception of the preselected ion type, all ion types are sucked out of the field. When a sufficient ion concentration has been achieved, the grid 142 is acted upon in order to accelerate the selected, enriched ion species to the detector 37. The storage time for ions of some species is determined by the time required for the ions of one species to spatially overtake the ions of another species due to the difference in their transit times, which is equal to an oscillation period around the region 22.

From the Bosch description above: that shown in the figures Many corresponding embodiments result for the person skilled in the art Modification option for the new spectrometer. It is obvious that known components, such as the ionization and injection device 14 according to FIG. 1, by other known structures that fulfill the function of the corpse

109828/1 199

elements can be replaced. Furthermore, a in the an embodiment shown element in the spectrometer can be used according to other embodiments. Such is the programmed optimization circuit, for example not to the field electrode structure shown in this context with a grounded cone-shaped electrode and a Line electrode with hyperbolic surface (Fig. 10) gunden, but can be used together with the field generator, which is shown for example in FIG. 1, and which generates a dynamic analysis field 12 can be used. The electrodes 132 and 134 (Fig. 12 and 13) can be used as a single electrode with suitable slots be designed for the entry and exit of ions. Furthermore, the detector 37 in the embodiment according to the figures 14 and 15 also on the z-axis at the outer end of one of the structures 12 or 140 be arranged. With such a design, the ions are passed through after a specified period of oscillation Application of a voltage to the grid 32 to the detector 37 is accelerated. To support the ion flow to the detector 37, the signal to the ring electrodes 39 can be separated.

109 828/1199

Claims (13)

Expectations Device for separating charged particles according to their mass / charge ratio by measuring the transit time of each particle between an injection point and a measurement reference point, thereby characterized in that the charged particles at least over part of their path between the injection point (14, 41) and the Measurement reference point (37; 88) are exposed to a dynamic electrical Pe] d with the coordinates x, y and ζ, the charged Particles are set in vibrations in such a way that some of them do not reach the measurement reference point. 2. Apparatus according to claim 1, characterized in that the field strength of the dynamic electric field along the z-axis increases with distance from the injection point (14, 41), so that the charged particles entering the electric field leave the electric field at the entrance end. 3. Apparatus according to claim 1 or 2, characterized in that the injection point (14, 41) and the measuring reference point (37; 88) are located at the same end of the dynamic electric field, 4. Device according to one of claims 1 to 3, characterized in that the dynamic field has an electrical potential distribution of the generally square form 0 (s _t y, z, t) = 2 2? f (t) (<A / X + Ty + V ^z ) ^na "t» where x, y, ζ are right-angled spatial coordinates, t is time, A ,, Tf, η, constants satisfying the equation ei / + JT + m - O and f (t) is a time-varying function. 5. Device according to one of claims 1 to 4, characterized in that a device (14) for introducing or Inji decorating the charged particles is provided in the dynamic field 109828/1 199 is, which an ionization device (22 to 30) for Ionizing the types of gas samples and an ion injector (32) for introducing charged particles into the dynamic pulse-wise Field. 6. Device according to one of claims 1 to 5, characterized by the runtime of the time in the dynamic field device (94) measuring separated types of charged particles, which a circuit (18; 80; * 96) for initiating the timing at a given point in the orbit of the charged particles and a detector (16; 88) whose output signal represents the run-in time of the temporally separated particles at a certain point. 7. Device according to one of the preceding claims, characterized by means (48, 52, 54, 56, 58; 96, 112; 144) for changing the field parameters of the dynamic field. 8. The device according to claim 7, characterized in that the dynamic electrical PeId has both a vibration _{component (V ac} ) and a static component (V ^ ₀ ); and that with the device (4δ, 52-58; 96, 112; 144) for changing the field parameters of the dynamic field, the amplitude of the oscillation coraponent and the size of the static component can be changed independently of one another and in such a way that a fixed ratio ( ^v _ac / ^v ^ - _c ) between the "amplitude of the vibration component and the strength of the static component" is maintained. 9. The device according to claim 7 _r, characterized in that the device (94) for changing the field parameters of the dynamic field is constructed so that different Esr-eicne or groups of a stable movement in the dynamic field descriptive masses / charge types selected, the temporal resolution between the charge / mass types is changed and the characteristic transit times of stable mass / charge types are changed. 10882871198 10. The device according to claim 9, characterized in that the measuring device (16) has a detector (88) with a secondary electron multiplier and an electronic device (96) for generating the run-in times of the various temporal output signals representing separate types of particles; also an electronic device for measuring the time between the entry of the charged particles into the dynamic field and the arrival of different, temporally separated types of charged particles on the detector (88); and an electronic device (39) having substantially all of the output signals simultaneously indicating a mass / charge spectrum ^ of types of particles arriving at the detector at different times " is shown. 11. The device according to claim 10, characterized in that the particle injector (14) is constructed so that it can carry out a test series introduced charged particles periodically into the dynamic field, and that one of the simultaneous Signal-dependent control device (96) for controlling the particle injector, the means (112) for changing the field parameters and the measuring device (16, 10?) is provided to the simultaneous signals in a display of an optimized To convert a sequence of selected individual output signals. H 12. Apparatus according to claim 7, characterized in that the particle injector (14) comprises a device (94, 12) which periodically injects charged particles in order to carry out a series of tests introduces the dynamic fold; that dip MeP device (98) is structured in such a way that it only evaluates such charged particles, their runtime within a specified runtime range lies; and that the device for changing the field parameters is controlled so that the field panimeter for each in the dynamic Field introduced Mansen / Ladun ^ s species, the term of which is in falls within the specified runtime range, can be changed to to achieve a mass scan of the charged particles. 108828/1 199 13. The device according to claim 12, characterized in that that the measuring device with the device (96 »112) for Changing the field parameters and using the injector device (14) is coupled to form an optimized display of a sequence of output signals, the different in the Represent the masses / types of charges introduced in the field. 109828/1199 HO Blank page