CN102263003B - Method and mapping meter for mapping flight time and momentum energy of refraction type charged particle - Google Patents

Abstract

The present invention relates to refractive charged particle flight time momentum and energy mapping method and mapper,The following steps are included: 1. form axially uniform reflected field in vacuum test pipe; 2. generating charged particle by charged particle source in one end of vacuum test pipe; 3. charged particle carries out retarded motion in reflected field,Until axial velocity is kept to zero; 4. charged particle is engraved in mirror field and is reversed accelerated motion,Until reaching the position sensitive detector at charged particle source position; 5. with position sensitive detector detect record charged particle location information (x,Y) initial momentum of charged particle is finally mapped out with flight time ttotal With energy ε i. Bottleneck of the present invention for current charged particle flight time momentum and energy spectrometer between energy resolution, energy detection range and charged particle collect three parameters such as effect in terms of comprehensive raising, improves the charged particle flight time to realize.

Description

Refractive charged particle flight time momentum and energy mapping method and mapper

Technical field

The invention belongs to charged particle flight time energy disperse spectroscopy technical field

Background technology

Flight time (Time-Of-Flight, TOF) be very important concept in the electron optics, in the electron optics energy analyzer, often utilize the energy dispersion of charged particle flight time in the system to come analysis and identification and final its energy that has that obtains.And the Position-Sensitive Detector of succeeding in developing in recent years (Position-Sensitive Detector, the flight time information that PSD) can record simultaneously particle with and the positional information of collision detector, can obtain simultaneously primary power and the initial momentum of particle according to the mapping relations between this time and positional information and the charged particle initial velocity.This is the basic principle of charged particle flight time momentum and energy spectrometer.The main performance parameter of charged particle flight time momentum and energy spectrometer has energy resolution, energy detection range and particle collection efficient.According to the motion state of charged particle between particle source and detector, it is broadly divided into field-free formula and contains two types of formulas: in field-free formula system, charged particle is with at the uniform velocity drifting state motion; Contain a formula mapper then on the basis of field-free formula system, for improve the entire system performance introduced electric field or (with) magnetic field, this is so that charged particle presents the variable motion state.The momentum and energy mapper overwhelming majority who commonly uses in the world at present belongs to and contains a formula system.

According to energy disperse spectroscopy energy resolution basic theories as can be known, the raising of system capacity resolution can finally be summed up as the most basic method: the aerial flight time that increases charged particle.To this, two kinds of methods commonly used are in the world: the aerial flight length that increases charged particle; Reduce the energy of electronics to be measured.For first method, its simplest implementation method is the length that directly increases energy disperse spectroscopy system pipe.But the increase of tube length always is subject to the restriction of many factors in actual applications, such as the vacuum degree of tube interior and the restriction of lab space etc.Simultaneously, the increase of tube length will cause reducing of charged particle acceptance angle and finally reduce its collection efficiency.These limiting factors are so that generally adopt in the world the special structure settings such as element of more efficiently method-employing to keep in the constant situation of tube length, indirectly increase the aerial flight distance of charged particle, such as line reflection formula or camber line gauche form flight time energy disperse spectroscopy system.Second method can realize that by introduce the rejection field in system its defective is that the existence of rejection field can cause system capacity to survey dwindling of range and charged particle collection efficiency.To this in the world generally by the way introducing electric field or magnetic field or introduce simultaneously Electric and magnetic fields to reach the purpose of energy resolution, energy detection range and the charged particle collection efficiency parameter of optimizing simultaneously energy disperse spectroscopy, such as the double-colored Electric field time-of-flight spectrometer of being used widely (acceleration of charged particle in electric field is different) or double-colored electromagnetic field type time-of-flight spectrometer (introducing simultaneously Electric and magnetic fields).On the basis of adopting above optimization method, although the charged particle flight time momentum and energy spectrometer that exists at present can satisfy the requirement of Practical Project in certain scope of application, the bottleneck aspect the overall system performance raising that is determined by its operation principle exists all the time.Existing flight time momentum and energy spectrometer all can be summed up as structure as shown in Figure 1 in essence, motion of a charged particle can be decomposed into axial motion and radial motion in the system, wherein radial motion is determining its positional information on detector, and axial motion is determining the aerial flight temporal information of charged particle.So structural to be arranged so that such situation becomes inevitable: can be detected under the established condition that device receives, different initial conditions (comprise primary power ε _iWith initial transmissions angle θ _i) charged particle all experienced identical effective axial distance before receiving being detected device.Thereby in such system, the electronics that axial velocity is little has the larger flight time, and this means that directly system possesses relatively high energy resolution to the charged particle with larger initial transmissions angle; And in the engineering application system of reality, obviously only have the charged particle at less initial transmissions angle that larger collection probability is just arranged.Simultaneously, system capacity resolution sharply worsens along with the increase of charged particle energy to be measured, and this usually becomes a key factor of restriction system energy detection range.Thereby, as by the fact proved, optimization setting in any case all can not be so that system finds a relative preferably balance between energy resolution, three major parameters of energy detection range and charged particle collection efficiency, so that entire system possesses higher combination property.

Summary of the invention

For present charged particle flight time momentum and energy spectrometer bottleneck aspect the comprehensive raising between three parameters such as energy resolution, energy detection range and charged particle collection effect, the present invention proposes a kind of refractive charged particle flight time momentum and energy mapping method and mapper, be intended to finally increase by the energy resolution of less initial transmissions angle charged particle in the raising system charged particle collection efficiency of system; Further improve simultaneously the energy detection range of system with the deterioration speed of charged particle primary power by the relieving system energy resolution, to realize finally improving the purpose of charged particle flight time momentum and energy mapper overall performance.

Technical solution of the present invention:

A kind of refractive charged particle flight time momentum and energy mapping method, its special character is: may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle carries out retarded motion in reflected field, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum initial kinetic energy for charged particle to be measured;

m _qRest mass for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

4] charged particle namely is engraved in and is reversed accelerated motion in the mirror field, until arrive the position sensitive detector of charged particle source position;

5] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle

With energy ε _i:

${\mathrm{\ϵ}}_i=\frac{p_i^2}{{2m}_q}.$

A kind of refractive charged particle flight time momentum and energy mapping method may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field and axial uniformly pre-acceleration field; Described reflected field is arranged on the rear of pre-acceleration field;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle carries out accelerated motion in the pre-acceleration field; Then in reflected field, carry out retarded motion, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

L is that charged particle source is to the axial distance of reflecting electrode;

NL is the axial distance of pre-acceleration field;

4] charged particle is reversed accelerated motion in mirror field, then carries out retarded motion in the pre-acceleration field, until arrive the position sensitive detector of charged particle source position;

5] position sensitive detector is surveyed positional information (x, y) and the flight time t of record charged particle _TotalFinally to map out the initial momentum of charged particle

With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{v_{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+2n{a}_{1}L}]$ Try to achieve;

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q}.$

A kind of refractive charged particle flight time momentum and energy mapping method may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field and axial uniformly magnetic field;

The span of the magnetic field intensity B of described axial uniform magnetic field is:

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{\mathrm{<figure-callout\; id="2"\; label="q\; m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">q</figure-callout>}}\sqrt{\frac{m_q}{}}\sqrt{\frac{{}_{}}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

Wherein, q is the electric charge of charged particle;

m _qRest mass for charged particle;

ε _MinMinimum primary power for charged particle to be measured;

K is natural number;

R is the radius of position sensitive detector;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle is axially carrying out screw in the uniform magnetic field vertically; Simultaneously in reflected field, carry out retarded motion, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

4] charged particle is axially carrying out screw in the uniform magnetic field vertically; In mirror field, be reversed simultaneously accelerated motion, until arrive the position sensitive detector of charged particle source position;

5] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle With energy ε _i

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q}.$

Refractive charged particle flight time momentum and energy mapping method may further comprise the steps:

1] select mode of operation:

For given charged particle primary power scope ε to be measured _Min～ε _Max, when satisfying following condition, system parameters must select to be operated in the o pattern:

$\frac{2}{3}\&le;n<1;$

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000041.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{q}L,$ $0<n<\frac{2}{3}.$

When satisfying following condition, system parameters must select to be operated in the e pattern:

${\mathrm{\&epsiv;}}_{\min }\&GreaterEqual;\frac{n{\mathrm{Lm}}_q{a}_2^2}{a_1^2+2a_1{a}_2}+\frac{q^2{\mathrm{<figure-callout\; id="2R"\; label="B"\; filenames="HDA0000066140270000032.png"\; state="\{\{state\}\}">B</figure-callout>}}^2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">R</figure-callout>}}^2}{{8m}_q}$

Wherein,

ε _MinMinimum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

a ₂Be the axial acceleration of charged particle in the reflected field district;

L is that charged particle source is to the axial distance of reflecting electrode;

N is pre-acceleration place axial distance and the ratio of charged particle source to the reflecting electrode axial distance;

R is the radius of position sensitive detector, also is the radius of mapper of the present invention;

B is the axial uniform magnetic field that mapper of the present invention is introduced;

2] in the vacuum test pipe, form axial evenly pre-acceleration field, axially uniform reflected field and axially uniform magnetic field; Described reflected field is arranged on the rear of pre-acceleration field;

Select to be operated in the o pattern when the mapper system, axially the scope of the magnetic field intensity B of uniform magnetic field is determined by following conditional relationship formula:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

Select to be operated in the e pattern when the mapper system, the scope of the magnetic field intensity B of its axial uniform magnetic field is determined by following conditional relationship formula:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_2\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

Wherein,

θ _c(ε _Min) by formula ${\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)=\frac{\mathrm{<figure-callout\; id="2"\; label="qRB"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">qRB</figure-callout>}}{2\sqrt{2m_q{\mathrm{\&epsiv;}}_{\min }}}$ Determine;

ε _MinMinimum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

a ₂Be the axial acceleration of charged particle in the reflected field district;

L is that charged particle source is to the axial distance of reflecting electrode;

N is pre-acceleration field axial distance and the ratio of charged particle source to the reflecting electrode axial distance;

R is the radius of position sensitive detector;

B is the axial uniform magnetic field that mapper of the present invention is introduced;

K is natural number;

3] end at the vacuum test pipe produces charged particle by charged particle source;

4] charged particle is axially carrying out screw in the uniform magnetic field vertically; Charged particle carries out accelerated motion first in the pre-acceleration field simultaneously, then carries out retarded motion in reflected field, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

NL is the axial distance of pre-acceleration field;

L is that charged particle source is to the axial distance of reflecting electrode;

5] charged particle is axially carrying out screw in the uniform magnetic field vertically; Simultaneously, charged particle is reversed accelerated motion first in mirror field, then carry out retarded motion in the pre-acceleration field, until arrive the position sensitive detector of charged particle source position;

6] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle

With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+2n{a}_{1}L}]$ Try to achieve;

${\mathrm{\&epsiv;}}_i=\frac{{\mathrm{<figure-callout\; id="2"\; label="p\; i"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">p</figure-callout>}}_i^{}}{{2m}_q};$

Above-mentioned steps 1] also further comprising the steps of:

According to the test request of charged particle to be measured, adjust in the following manner the mode of operation of mapping method:

When charged particle receiving efficiency during for research parameter relatively important in surveying, according to relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured ₁To satisfy following condition, make system works in the o pattern:

$\frac{2}{3}\&le;n<1,$

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000041.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{e}L,$ $0<n<\frac{2}{3};$

When charged particle energy resolution during for research parameter relatively important in surveying, according to relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured ₁And the axial magnetic field B that introduces to be to satisfy following condition, makes system works in the e pattern:

v _min≥v _ch。

A kind of refractive charged particle flight time momentum and energy mapper, described momentum and energy mapper comprise the vacuum test pipe, be arranged on the charged particle source of testing tube one end, be arranged on charged particle source the place ahead and be positioned at the testing tube other end reflecting electrode, be arranged on the position sensitive detector at charged particle source rear; Described reflecting electrode can make charged particle reflex to position sensitive detector;

The acceleration a of described reflecting electrode electric field region charged particle ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum initial kinetic energy for charged particle to be measured;

m _qRest mass for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode.

Above-mentioned mapper also comprises the uniform magnetic field that is applied to testing tube, and it is axial that the direction in described magnetic field is parallel to testing tube;

The span of the magnetic field intensity B of described axial uniform magnetic field is:

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{\mathrm{<figure-callout\; id="2"\; label="q\; m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">q</figure-callout>}}\sqrt{\frac{m_q}{}}\sqrt{\frac{{}_{}}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

Wherein, q is the electric charge of charged particle;

m _qRest mass for charged particle;

ε _MinMinimum primary power for charged particle to be measured;

K is natural number;

R is the radius of position sensitive detector.

Above-mentioned mapper also comprises the first aperture plate that is arranged between charged particle source and the reflecting electrode, the second aperture plate that is arranged on the charged particle source rear; Between described the first aperture plate and the second aperture plate pre-acceleration place is set;

The acceleration a2 of described reflecting electrode electric field region charged particle should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL；

Wherein:

ε _Maxε max is the maximum primary power of charged particle to be measured;

a ₁Acceleration for pre-acceleration place charged particle;

m _qQuality for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

NL is the axial distance of pre-acceleration place.

Above-mentioned uniform magnetic field is produced by Helmholtz coil.

The advantage that the present invention has:

1, the main performance parameter of charged particle flight time momentum and energy spectrometer has energy resolution, energy detection range and particle receiving efficiency, and mapper of the present invention system can suppress energy resolution effectively with the speed of worsening of primary power.Under the identical condition of detector temporal resolution, such good characteristic will increase the energy detection range of system undoubtedly.

2, existing mapper system has relatively high energy resolution to the charged particle of wide-angle; The present invention then has higher energy resolution to low-angle charged particle.The present invention has quite high resolution capability to the charged particle of large primary power, the little angle of departure.

3, the radial motion that magnetic field can the operative constraint charged particle improves the receiving efficiency of charged particle;

4, the receiving efficiency of charged particle is improved by shortening the charged particle flight time in the pre-acceleration field.

Description of drawings

Fig. 1 is existing field-free formula momentum and energy spectrometer;

Fig. 2 is refractive charged particle flight time momentum and energy mapper of the present invention; Wherein: 1 is reflecting electrode; 2,3 is aperture plate; 4 is position sensitive detector; 5 is tube wall; 6 is charged particle source;

Fig. 3. be refractive charged particle flight time momentum and energy mapper charged particle maximum axial displacement s of the present invention _m(v _z) and corresponding flight time t _m(v _z) and v _zVariation relation figure;

Fig. 4 is the radial motion trajectory diagram of charged particle;

Fig. 5 is the graph of relation of charged particle radial displacement r and flight time t in this discovery mapper system;

Fig. 6 distributes the flight time that is detected electronics under the different magnetic field constraints; Wherein: (a) B=5.00Gs; (b) B=3.50Gs; (c) B=2.00Gs; (d) B=1.00Gs

Fig. 7 is that magnetic field is to the effect of restraint schematic diagram of different primary power electronics;

Fig. 8 is o pattern of the present invention and the comparison schematic diagram that has field-free formula mapper system capacity resolution now;

Fig. 9 is e pattern of the present invention and the comparison schematic diagram that has field-free formula mapper system capacity resolution now;

Figure 10 is e pattern of the present invention and the comparison schematic diagram of existing field-free formula mapper system relative energy resolution;

Figure 11 is that magnetic field is to the effect of restraint schematic diagram of different primary power electronics;

Embodiment

The refractive charged particle flight time momentum and energy mapper that the present invention proposes as shown in Figure 2.Compare with existing momentum and energy mapper shown in Figure 1 system, its most important difference is the reflecting electrode introducing of (as among the figure 1).Acting as of reflecting electrode: for the energy range of charged particle to be measured, by suitable decelerating field is provided so that different initial condition charged particle can be in system's pipe the reflection of diverse location place make fold return motion and receive to be detected device, have correlation with initial condition with the effectively axially flying distance that reaches such purpose-not only make charged particle, and increase effective Longitudinal Flight distance of charged particle.The introducing of charged particle accelerating field is in order to obtain larger charged particle acceptance angle between first (as among the figure 3) and the second aperture plate (as among the figure 2), the introducing of vertical uniform magnetic field B that Helmholtz coil provides then is the transverse movement that causes owing to its radial velocity at the radial constraint charged particle, to reach the purpose of further raising charged particle acceptance angle.Acting as of position sensitive detector (as among the figure 4): the flight time information t of record charged particle with and collision detector on positional information (x, y).About technical scheme explanation of the present invention, mainly comprise following 3 points: the classification of mode of operation, the reconstruction of charged particle momentum and energy, and the axially selection of uniform magnetic field.

(1) classification of mode of operation:

To supposing that the highest initial kinetic energy that may have in the charged particle to be detected is ε _Max, all charged particles that the system that guarantee allows can both be made back and forth movement in pipe, then should satisfy following condition:

a ₂≥a _min. (1)

Wherein, a _Min=(ε _Max+ na ₁m _qL)/(1-n) m _qL.Motion of a charged particle can be decomposed into axial motion and radial motion in the system, is ε for the initial transmissions state _iAnd θ _iCharged particle, its initial axial velocity

Initial radial velocity

Then maximum axial displacement and the corresponding flight time of this charged particle in system's pipe is:

$s_m\left(v_z\right)=\mathrm{nL}+\frac{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+{2\mathrm{na}}_{1}L}{a_2},---\left(2\right)$

$t_m(\mathrm{\&epsiv;},\mathrm{\&theta;})=-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_i}{m_{\mathrm{<figure-callout\; id="2"\; label="q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">q</figure-callout>}}}{\cos }^{}{}^2{\mathrm{\&theta;}}_i}+\frac{A}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_i}{m_{\mathrm{<figure-callout\; id="2"\; label="q\; cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">q</figure-callout>}}}{\cos }^{}{}^2{\mathrm{\&theta;}}_i+2{\mathrm{na}}_{1}L},---\left(3\right)$

$t_m\left(v_z\right)=-\frac{v_z}{a_1}+\frac{A}{a_1}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+{2\mathrm{na}}_{1}L}.---\left(4\right)$

Here parameter A=(a ₁+ a ₂)/a ₂Consider the fold return motion of charged particle, then its effectively axially fly distance and corresponding flight time are

s _total(v _z)＝2s _m(v _z). (5)

t _total(v _z)＝2t _m(v _z). (6)

Can corresponding to the axial velocity of minimum flight time, be referred to as the system features speed v here by formula (6) _Ch:

$v_{\mathrm{ch}}=\sqrt{\frac{2{\mathrm{na}}_{1}L}{A^2-1}}.---\left(7\right)$

To find out in the analysis below that this system features speed is the classification foundation of two mode of operations of system just.

s _m(v _z) and t _m(v _z) and v _zVariation relation as shown in Figure 3, the charged particle of wherein considering is electronics.As seen from the figure, the charged particle of different initial axial velocities has corresponding maximum axial displacement, and initial axial velocity is larger, and its maximum axial displacement that has is also just larger.This characteristic is very similar to the optical dispersion medium to the dispersion of different wave length light wave, also just is being based on this, and we are defined as color dispersion-type with this mapped system.This and existing momentum and energy mapper system characteristic in this regard shown in Figure 1 are diverse.Simultaneously, the existence of system features speed is so that the charged particle flight time presents a kind of nonmonotonicity with initial axial velocity changes, and curve is at v _ChThe left and right sides have distinct characteristic: its left side part, though the charged particle that initial velocity is large has larger maximum axial displacement (also i.e. larger effectively axially flight distance), has the flight time (also namely less flight time) of less; And its right side part, the large charged particle of initial velocity also has the relatively large flight time when having larger maximum axial displacement.Formal according to the difference on this characteristic, we are defined as the o pattern with the part in its left side, and the part on right side is the e pattern.

For given charged particle primary power scope ε to be measured _Min≤ ε _i≤ ε _Max, that considers the initial transmissions angle affects its total primitive axis that exists to velocity interval v _Min≤ v _z≤ v _Max, wherein

From subsequent analysis, can find out v _MinThe system magnetic field of introducing is closely related therewith.Then system works in the condition of o pattern is:

v _max≤v _ch. (8)

This means

$\frac{2}{3}\&le;n<1,---\left(9\right)$

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000041.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{e}L,0<n<\frac{2}{3},---\left(10\right)$

In like manner, system works in the condition of e pattern is:

v _min≥v _ch. (11)

As mentioned before, v _MinBe not a relatively independent parameter and the system magnetic field of introducing is closely related therewith, thereby this condition is usually selected the restrictive condition of problem as system magnetic field.

(2) reconstruction of charged particle momentum and energy

Under the constraint of system axial magnetic field B, the radial motion of charged particle in the XY plane as shown in Figure 4.Wherein, (0,0) is the position at charged particle source place, and the center of itself and detector is all on the central symmetry axis of system; (x, y) is the position of charged particle collision detector; ω=Bq/m _q, R _i=m _qv _r/ Bq is respectively cyclotron frequency and the radius of gyration of charged particle in magnetic field.

$p_x=\frac{\mathrm{Bq}}{2}[x\cot \left(\frac{\mathrm{\&omega;t}}{2}\right)+y],---\left(12\right)$

$p_y=\frac{\mathrm{Bq}}{2}[y\cot \left(\frac{\mathrm{\&omega;t}}{2}\right)-x].---\left(13\right)$

Therefore, utilize charged particle flight time information and the positional information of position sensitive detector record, can finally try to achieve according to formula (6), (12) and (13) initial momentum information and the primary power information of charged particle:

${\mathrm{\&epsiv;}}_i=\frac{{p_x}^2+{{\mathrm{<figure-callout\; id="2"\; label="p\; y"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">p</figure-callout>}}_y}^2+{{\mathrm{<figure-callout\; id="2"\; label="p\; z"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">p</figure-callout>}}_z}^2}{2m_q}.---\left(15\right)$

(3) the axially selection of uniform magnetic field

By upper Fig. 4 as can be known, charged particle at the radial distance at the motion process middle distance detector center of spinning is

$r=2R_i\left|\sin \left(\frac{\mathrm{\&pi;t}}{T}\right)\right|.---\left(16\right)$

T=2 π m _q/ (qB) be the cycle of charged particle circumnutation.R～t relation curve as shown in Figure 5, wherein the moment of r=0 is called " magnetic node ", the time zone between two magnetic nodes is called " magnetic nodes domains ", such as k=1, k=2 etc.

In the occasion of using magnetic field with restriction charged particle transverse movement disperse, the principle that magnetic field is selected is: can be dropped between two magnetic field nodes, namely in the same magnetic nodes domains flight time of all charged particles to be measured.Make t _Max, t _MinRepresent respectively the maximum and minimum flight time of charged particle to be measured, if electronics to be measured drops on k node in the time limit, then must satisfy following condition

t _max≤kT， (17)

t _min≥(k-1)T. (18)

As shown in Figure 4, charged particle can be detected the condition that device receives and is

2R _i≤R， (19)

Different primary power ε in other words _iThe charged particle initial transmissions angle that will have maximum as follows, be referred to as critical angle here.Here be noted that in fact critical angle herein is exactly half collection angle of relevant charged particle receiving efficiency.

${\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_i\right)=\frac{\mathrm{<figure-callout\; id="2"\; label="qRB"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">qRB</figure-callout>}}{2\sqrt{2m_q{\mathrm{\&epsiv;}}_i}},---\left(20\right)$

Obviously, the charged particle that primary power is less has larger critical angle.For the o pattern, given charged particle primary power scope ε to be measured _Min≤ ε _i≤ ε _Max, initial condition is ε _MinAnd θ _c(ε _Min) charged particle have maximum flight time t _Max, and initial condition is ε _MaxAnd θ _i=0 charged particle has minimum flight time t _MinAnd for " e mode ", initial condition is ε _MinAnd θ _c(ε _Min) charged particle have minimum flight time t _Min, and initial condition is ε _MaxAnd θ _i=0 charged particle has maximum flight time t _MaxTherefore, be at o pattern situation following formula (17)

$-s{\mathrm{in\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right){\cos \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+{A\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)\sqrt{{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+C_o}\&le;D_o,---\left(21\right)$

Here parameter

$C_o=\frac{{\mathrm{nm}}_e{a}_{1}S}{{\mathrm{\&epsiv;}}_{\min }},$ $D_o=\frac{\mathrm{k\&pi;}{a}_1{\mathrm{<figure-callout\; id="4"\; label="Rm\; e"\; filenames="HDA0000066140270000041.png"\; state="\{\{state\}\}">Rm</figure-callout>}}_e}{{4\mathrm{\&epsiv;}}_{\min }}.$

And be at e pattern situation following formula (18)

$-\sin \left[{\mathrm{\&theta;}}_{\mathrm{ca}}\left({\mathrm{\&epsiv;}}_{\min }\right)\right]\cos \left[{\mathrm{\&theta;}}_{\mathrm{ca}}\left({\mathrm{\&epsiv;}}_{\min }\right)\right]+A\sin \left[{\mathrm{\&theta;}}_{\mathrm{ca}}\left({\mathrm{\&epsiv;}}_{\min }\right)\right]\sqrt{{\cos }^2\left[{\mathrm{\&theta;}}_{\mathrm{ca}}\left({\mathrm{\&epsiv;}}_{\min }\right)\right]+C_e}\&GreaterEqual;D_e,---\left(22\right)$

Wherein,

$C_e=\frac{{\mathrm{nm}}_e{a}_{1}S}{{\mathrm{\&epsiv;}}_{\min }},$ $D_e=\frac{(k-1)a_1{\mathrm{\&pi;<figure-callout\; id="4"\; label="Rm\; e"\; filenames="HDA0000066140270000041.png"\; state="\{\{state\}\}">Rm</figure-callout>}}_e}{{4\mathrm{\&epsiv;}}_{\min }}$

To sum up, this system works restrictive condition that magnetic field is selected in o pattern situation is formula (17) and (21), and being operated in the restrictive condition that magnetic field is selected in the e pattern situation is formula (11), (17) and (22).

The concrete analysis of the technology of the present invention effect:

As aforementioned, the main performance parameter of charged particle flight time momentum and energy spectrometer has energy resolution, energy detection range and particle receiving efficiency, thereby we will be from the superiority of these three aspect analytic explanation refractive charged particle of the present invention flight time momentum and energy mapper with respect to existing mapper here.

According to the energy resolution rate theory, the energy resolution of mapper of the present invention system is

${\mathrm{\&delta;\&epsiv;}}_i{|}_r=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i|-\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}+\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}},---\left(23\right)$

By top analysis to charged particle flight time characteristic in o pattern of the present invention and the e pattern situation as can be known, the energy resolution of charged particle can be reduced to respectively under two kinds of patterns:

${\mathrm{\&delta;\&epsiv;}}_i{|}_o=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i[\sqrt{\frac{m_{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">q</figure-callout>}}}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}-\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}]},---\left(24\right)$

${\mathrm{\&delta;\&epsiv;}}_i{|}_e=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i[-\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}+\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}]},---\left(25\right)$

Here the temporal resolution of supposing used position sensitive detector is Δ t _MinFor the purpose of comparative descriptions is convenient, also listed energy resolution and the relative energy resolution of field-free formula mapper shown in Figure 1 system here, as follows.

${\mathrm{\&delta;\&epsiv;}}_i{|}_d=\frac{\mathrm{\&Delta;}{t}_{\min }\cos {\mathrm{\&theta;}}_i}{\mathrm{<figure-callout\; id="8"\; label="L"\; filenames="HDA0000066140270000081.png"\; state="\{\{state\}\}">L</figure-callout>}}\sqrt{\frac{8{{\mathrm{\&epsiv;}}_i}^3}{m_q}}.---\left(26\right)$

${\frac{{\mathrm{\&delta;\&epsiv;}}_i}{{\mathrm{\&epsiv;}}_i}|}_d=\frac{\mathrm{\&Delta;}{t}_{\min }\cos {\mathrm{\&theta;}}_i}{\mathrm{<figure-callout\; id="8"\; label="L"\; filenames="HDA0000066140270000081.png"\; state="\{\{state\}\}">L</figure-callout>}}\sqrt{\frac{8{\mathrm{\&epsiv;}}_i}{m_q}}.---\left(27\right)$

For ease of Semi-qualitative relatively, consider the special case n=0 in the e pattern here.As energy resolution and the relative energy resolution of system of the present invention are respectively as follows in the case

${\mathrm{\&delta;\&epsiv;}}_i{|}_r=\frac{\mathrm{\&Delta;}{t}_{\min }{\mathrm{\&epsiv;}}_{\max }}{2L{\cos \mathrm{\&theta;}}_i}\sqrt{\frac{2{\mathrm{\&epsiv;}}_i}{m_e}},---\left(28\right)$

${\frac{{\mathrm{\&delta;\&epsiv;}}_i}{{\mathrm{\&epsiv;}}_i}|}_r=\frac{\mathrm{\&Delta;}{t}_{\min }{\mathrm{\&epsiv;}}_{\max }}{2L{\cos \mathrm{\&theta;}}_i}\sqrt{\frac{2}{m_q{\mathrm{\&epsiv;}}_i}}.---\left(29\right)$

Formula (23) illustrates existing its energy resolution δ ε of momentum and energy mapper system _i| _d∝ ε _i ^3/2And by formula (27) as can be known, its energy resolution of mapper of the present invention δ ε _i| _d∝ ε _i ^1/2Obviously, mapper of the present invention system can suppress energy resolution effectively with the speed of worsening of primary power.Under the identical condition of detector temporal resolution, such good characteristic will increase the energy detection range of system undoubtedly.Simultaneously, comparison expression (26) and formula (28) also can be found out the dependence of both energy resolutions and angle: existing mapper system has relatively high energy resolution to the charged particle of wide-angle; The present invention then has higher energy resolution to low-angle charged particle.Both comparisons aspect the energy resolution size can be illustrated by following formula.

$\frac{{\mathrm{\&delta;\&epsiv;}}_i{|}_r}{{\mathrm{\&delta;\&epsiv;}}_i{|}_d}=\frac{{\mathrm{\&epsiv;}}_{\max }}{{4\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000021.png,HDA0000066140270000032.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}.---\left(30\right)$

By formula (30) as can be known, compare existing momentum and energy mapper system, the present invention has quite high resolution capability to the charged particle of large primary power, the little angle of departure.

Because the charged particle acceptance angle do not have analytical expression to illustrate, thereby will give quantitative explanation about the e pattern in " embodiment " part in correlation analyses such as the key property that improves characteristic aspect the charged particle acceptance angle and o pattern-improve charged particle receiving efficiency.

Embodiment

We elaborate embodiments of the present invention in connection with concrete example this part, wherein mainly are the selection problems in magnetic field, and the explanation the present invention of simultaneous quantitative ground is in the superiority of its aspect of performance.Below content according to two mode of operations of the present invention-e pattern and o pattern-be divided into two large divisions.

Consider that structure is the pattern refractive charged particle flight time momentum and energy mapper of cylinder symmetric form, its parameter is set to: L=400mm, R=30mm, n=0.6, a ₁=2 * 10 ¹³M/s ², a ₂=a _Min, 10.0eV≤ε _i≤ 50.0eV.Here our charged particle of consideration is electronics.Set up by formula (10), therefore this moment, system works was in the o pattern.The conditional (17) of then being selected by magnetic field and formula (18) can be tried to achieve the effective magnetic field scope of corresponding different magnetic nodes domains, and be as shown in table 1.The flight time distribution curve of electronics has confirmed the correctness of " technical solution " part correlation analysis well under the different magnetic field constraints shown in Figure 6.

The axially selection in magnetic field under the table 1. refraction type electronic flight time momentum and energy mapper o pattern

The contribution of axial magnetic field aspect raising system charged particle acceptance angle as shown in Figure 7.Compare as shown in Figure 1 half acceptance angle of field-free formula system 4.3 degree, o pattern of the present invention has very high charged particle receiving efficiency, and magnetic field is larger, and its charged particle receiving efficiency is higher.This is for the main feature of o pattern of the present invention.As when adopting the axial magnetic field of 5.00Gs, its average collection angle has reached 25 degree.O pattern of the present invention and existing field-free formula mapper system capacity resolution more as shown in Figure 8, " c mode " representative wherein be as shown in Figure 1 field-free formula mapper system.Except pre-acceleration part (also being that length is the part of nL among Fig. 2) has reduced the energy resolution of o pattern of the present invention slightly, both are identical in energy resolution to the dependence at charged particle initial transmissions angle: system has relatively high energy resolution ability to the charged particle at larger initial transmissions angle.

For the embodiment of e pattern is described, consider that equally structure is the pattern refraction type electronic flight time momentum and energy mapper of cylinder symmetric form, its parameter is set to: L=500mm, R=60mm, n=0.05 and a ₁=1 * 10 ¹³M/s ²The kinetic energy scope of electronics to be measured is 17.15eV≤ε _i≤ 32.65eV.The effective magnetic field scope of corresponding different magnetic nodes domains can be tried to achieve in the conditional (11) of then being selected by magnetic field in the e pattern situation, (17) and (22), and is as shown in table 2.

The axially selection in magnetic field under the table 2 refraction type electronic flight time momentum and energy mapper e pattern

E pattern of the present invention and existing field-free formula mapper system aspect energy resolution and relative ability resolution more respectively such as Fig. 9, shown in Figure 10.Fig. 9 clearly shows the characteristics-high energy resolution of e pattern of the present invention, and energy resolution has comparatively slowly variation relation with the charged particle primary power.In the situation of given position sensitive detector temporal resolution, such characteristic will significantly increase the energy detection range of mapper system undoubtedly.Simultaneously, Fig. 9 has illustrated clearly that also both are at the different qualities of energy resolution aspect the dependence at charged particle initial transmissions angle.Both differences aspect relative energy resolution curve tendency shown in Figure 10 have also illustrated the high energy resolution characteristic of e pattern of the present invention again.E pattern and field-free formula system aspect the charged particle collection efficiency more as shown in figure 11.Obviously, the introducing of axial magnetic field has increased the collection efficiency of charged particle equally.

Claims (9)

1. refractive charged particle flight time momentum and energy mapping method is characterized in that: may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle carries out retarded motion in reflected field, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum initial kinetic energy for charged particle to be measured;

m _qRest mass for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

4] charged particle namely is engraved in and is reversed accelerated motion in the mirror field, until arrive the position sensitive detector of charged particle source position;

5] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle

With energy ε _i:

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q}.$

2. refractive charged particle flight time momentum and energy mapping method is characterized in that: may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field and axial uniformly pre-acceleration field; Described reflected field is arranged on the rear of pre-acceleration field;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle carries out accelerated motion in the pre-acceleration field; Then in reflected field, carry out retarded motion, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

L is that charged particle source is to the axial distance of reflecting electrode;

NL is the axial distance of pre-acceleration field;

4] charged particle is reversed accelerated motion in mirror field, then carries out retarded motion in the pre-acceleration field, until arrive the position sensitive detector of charged particle source position;

5] position sensitive detector is surveyed positional information (x, y) and the flight time t of record charged particle _TotalFinally to map out the initial momentum of charged particle

With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{v_z^2+2n{a}_{1}L}]$ Try to achieve;

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q}.$

3. refractive charged particle flight time momentum and energy mapping method is characterized in that: may further comprise the steps:

1] in the vacuum test pipe, forms axially uniformly reflected field and axial uniformly magnetic field;

The span of the magnetic field intensity B of described axial uniform magnetic field is:

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{q}\sqrt{\frac{m_q}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

Wherein, q is the electric charge of charged particle;

m _qRest mass for charged particle;

ε _MinMinimum primary power for charged particle to be measured;

K is natural number;

R is the radius of position sensitive detector;

2] end at the vacuum test pipe produces charged particle by charged particle source;

3] charged particle is axially carrying out screw in the uniform magnetic field vertically; Simultaneously in reflected field, carry out retarded motion, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

4] charged particle is axially carrying out screw in the uniform magnetic field vertically; In mirror field, be reversed simultaneously accelerated motion, until arrive the position sensitive detector of charged particle source position;

5] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle

With energy ε _i

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q}.$

4. refractive charged particle flight time momentum and energy mapping method is characterized in that: may further comprise the steps:

1] select mode of operation:

For given charged particle primary power scope ε to be measured _Min～ε _Max, when satisfying following condition, system parameters must select to be operated in the o pattern:

$\frac{2}{3}\&le;n<1;$

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3n}^4+{8n}^3-{6n}^2+1}}{2(2-3n)}{a}_1{m}_{q}L,0<n<\frac{2}{3}.$

When satisfying following condition, system parameters must select to be operated in the e pattern:

${\mathrm{\&epsiv;}}_{\min }\&GreaterEqual;\frac{\mathrm{nL}{m}_q{a}_2^2}{a_1^2+{2a}_1{a}_2}+\frac{q^2{B}^2{R}^2}{8m_q}$

Wherein,

ε _MinMinimum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

a ₂Be the axial acceleration of charged particle in the reflected field district;

L is that charged particle source is to the axial distance of reflecting electrode;

N is pre-acceleration place axial distance and the ratio of charged particle source to the reflecting electrode axial distance;

R is the radius of position sensitive detector, also is the radius of mapper of the present invention;

B is the axial uniform magnetic field that mapper of the present invention is introduced;

2] in the vacuum test pipe, form axial evenly pre-acceleration field, axially uniform reflected field and axially uniform magnetic field; Described reflected field is arranged on the rear of pre-acceleration field;

Select to be operated in the o pattern when the mapper system, axially the scope of the magnetic field intensity B of uniform magnetic field is determined by following conditional relationship formula:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{m_q}{\cos }^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{m_q}{\cos }^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

Select to be operated in the e pattern when the mapper system, the scope of the magnetic field intensity B of its axial uniform magnetic field is determined by following conditional relationship formula:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{m_q}{\cos }^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{m_q}{\cos }^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

Wherein,

θ _c(ε _Min) by formula ${\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)=\frac{\mathrm{qRB}}{2\sqrt{2m_q{\mathrm{\&epsiv;}}_{\min }}}$ Determine;

ε _MinMinimum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

a ₂Be the axial acceleration of charged particle in the reflected field district;

L is that charged particle source is to the axial distance of reflecting electrode;

N is pre-acceleration field axial distance and the ratio of charged particle source to the reflecting electrode axial distance;

R is the radius of position sensitive detector;

B is the axial uniform magnetic field that mapper of the present invention is introduced;

K is natural number;

3] end at the vacuum test pipe produces charged particle by charged particle source;

4] charged particle is axially carrying out screw in the uniform magnetic field vertically; Charged particle carries out accelerated motion first in the pre-acceleration field simultaneously, then carries out retarded motion in reflected field, until axial velocity is kept to zero;

Described charged particle carries out the axial acceleration a of retarded motion in reflected field ₂Should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL

Wherein:

ε _MaxMaximum primary power for charged particle to be measured;

m _qQuality for charged particle to be measured;

a ₁Be the acceleration of charged particle in the pre-acceleration field;

NL is the axial distance of pre-acceleration field;

L is that charged particle source is to the axial distance of reflecting electrode;

5] charged particle is axially carrying out screw in the uniform magnetic field vertically; Simultaneously, charged particle is reversed accelerated motion first in mirror field, then carry out retarded motion in the pre-acceleration field, until arrive the position sensitive detector of charged particle source position;

6] survey positional information (x, y) and the flight time t that records charged particle with position sensitive detector _TotalFinally to map out the initial momentum of charged particle With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{v_z^2+2n{a}_{1}L}]$ Try to achieve;

${\mathrm{\&epsiv;}}_i=\frac{p_i^2}{{2m}_q};$

5. refractive charged particle flight time momentum and energy mapping method according to claim 4 is characterized in that: described step 1] also further comprising the steps of:

According to the test request of charged particle to be measured, adjust in the following manner the mode of operation of mapping method:

When charged particle receiving efficiency during for research parameter relatively important in surveying, according to relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured ₁To satisfy following condition, make system works in the o pattern:

$\frac{2}{3}\&le;n<1,$

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3n}^4+{8n}^3-{6n}^2+1}}{2(2-3n)}{a}_1{m}_{e}L,0<n<\frac{2}{3};$

When charged particle energy resolution during for research parameter relatively important in surveying, according to relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured ₁And the axial magnetic field B that introduces to be to satisfy following condition, makes system works in the e pattern:

v _min≥v _ch。

6. refractive charged particle flight time momentum and energy mapper is characterized in that: described momentum and energy mapper comprises the vacuum test pipe, be arranged on the charged particle source of testing tube one end, be arranged on charged particle source the place ahead and be positioned at the testing tube other end reflecting electrode, be arranged on the position sensitive detector at charged particle source rear; Described reflecting electrode can make charged particle reflex to position sensitive detector;

The acceleration a of described reflecting electrode electric field region charged particle ₂Should satisfy following condition:

a ₂≥ε _max/m _qL；

Wherein:

ε _MaxMaximum initial kinetic energy for charged particle to be measured;

m _qRest mass for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode.

7. refractive charged particle flight time momentum and energy mapper according to claim 6, it is characterized in that: described mapper also comprises the uniform magnetic field that is applied to testing tube, it is axial that the direction in described magnetic field is parallel to testing tube;

The span of the magnetic field intensity B of described axial uniform magnetic field is:

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{q}\sqrt{\frac{m_q}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

Wherein, q is the electric charge of charged particle;

m _qRest mass for charged particle;

ε _MinMinimum primary power for charged particle to be measured;

K is natural number;

R is the radius of position sensitive detector.

8. according to claim 6 or 7 described refractive charged particle flight time momentum and energy mapper, it is characterized in that: described mapper also comprises the first aperture plate that is arranged between charged particle source and the reflecting electrode, the second aperture plate that is arranged on the charged particle source rear; Between described the first aperture plate and the second aperture plate pre-acceleration place is set;

The acceleration a2 of described reflecting electrode electric field region charged particle should satisfy following condition:

a ₂≥(ε _max+a ₁m _qnL)/(1-n)m _qL；

Wherein:

ε _Maxε max is the maximum primary power of charged particle to be measured;

a ₁Acceleration for pre-acceleration place charged particle;

m _qQuality for charged particle to be measured;

L is that charged particle source is to the axial distance of reflecting electrode;

NL is the axial distance of pre-acceleration place.

9. refractive charged particle flight time momentum and energy mapper according to claim 8, it is characterized in that: described uniform magnetic field is produced by Helmholtz coil.

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