CN102263003A - 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] axially uniform reflected field is formed in vacuum test pipe; 2] charged particle is generated 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 was important concept in the electron optics TOF), in the electron optics energy analyzer, often utilizes the energy dispersion of charged particle flight time in the system to analyze discriminated union and finally obtains the energy that it had.And the Position-Sensitive Detector of succeeding in developing in recent years (Position-Sensitive Detector, PSD) the flight time information that can write down particle simultaneously with and the positional information of collision detector, can obtain the primary power and the initial momentum of particle simultaneously 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 to survey 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 makes charged particle present the variable motion state.The momentum and energy mapper overwhelming majority commonly used 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 fundamental method: the aerial flight time that increases charged particle.To this, Chang Yong two kinds of methods 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 subjected to the restriction of multiple factor 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 make and generally adopt the special structure settings such as element of more efficiently method-employing to keep under the constant situation of tube length in the world, increase the aerial flight distance of charged particle indirectly, such as line reflection formula or camber line gauche form flight time energy disperse spectroscopy system.Second method can realize that its defective is that the existence of rejection field can cause system capacity to survey dwindling of range and charged particle collection efficiency by introduce the rejection field in system.To this in the world generally by the way introducing electric field or magnetic field or introduce electric field and magnetic field simultaneously to reach the energy resolution of optimizing energy disperse spectroscopy simultaneously, the purpose that energy is surveyed range and charged particle collection efficiency parameter, such as double-colored Electric field time-of-flight spectrometer of being used widely (the acceleration difference of charged particle in electric field) or double-colored electromagnetic field type time-of-flight spectrometer (introducing electric field and magnetic field simultaneously).On the basis of adopting above optimization method, though the charged particle flight time momentum and energy spectrometer that exists can satisfy the requirement of actual engineering in certain scope of application at present, is existed all the time by the bottleneck aspect the overall system performance raising that its operation principle determined.Existing flight time momentum and energy spectrometer all can be summed up as structure as shown in Figure 1 in essence, the motion of 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 bigger flight time, and this means that directly system possesses higher relatively energy resolution to the charged particle with big initial transmissions angle; And in the application of practical project system, obviously have only the charged particle at less initial transmissions angle that bigger collection probability is just arranged.Simultaneously, system capacity resolution is rapid deterioration along with the increase of charged particle energy to be measured, and this usually becomes the key factor that the restriction system energy is surveyed range.Thereby, as by the fact proved, the system that all can not make of optimization setting in any case surveys between three major parameters of range and charged particle collection efficiency at energy resolution, energy and finds a relative balance preferably, so that entire system possesses higher combination property.

Summary of the invention

Survey the bottleneck aspect the comprehensive raising between three parameters such as range and charged particle collection effect at present charged particle flight time momentum and energy spectrometer at energy resolution, energy, the present invention proposes a kind of refractive charged particle flight time momentum and energy mapping method and mapper, be intended to finally increase the charged particle collection efficiency of system by the energy resolution of less initial transmissions angle charged particle in the raising system; Further improve the energy of system simultaneously by the deterioration speed of the sub-primary power of relieving system energy resolution electrochondria going along with and survey range, 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 reflected field uniformly;

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

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

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 the axial distance of charged particle source to reflecting electrode;

4] charged particle promptly is engraved in and is reversed accelerated motion in the mirror field, until the position sensitive detector that arrives the charged particle source position;

5] (x is y) with flight time t to survey the positional information that writes down 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 reflected field and axial pre-acceleration field uniformly uniformly; 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, be kept to zero until axial velocity;

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 the axial distance of charged particle source to 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 the position sensitive detector that arrives the charged particle source position;

5] (x is y) with flight time t for the positional information of position sensitive detector detection record charged particle _TotalFinally to map out the initial momentum of charged particle With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{v_{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+2n{a}_{1}L}]$ 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 reflected field and axial magnetic field uniformly uniformly;

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

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{\mathrm{<figure-callout\; id="2"\; label="q\; m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">q</figure-callout>}}\sqrt{\frac{m_q}{}}\sqrt{\frac{{}_{}}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

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 a 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; In reflected field, carry out simultaneously retarded motion, be kept to zero until axial velocity;

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 the axial distance of charged particle source to 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 the position sensitive detector that arrives the charged particle source position;

5] (x is y) with flight time t to survey the positional information that writes down 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

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{q}L,$ $0<n<\frac{2}{3}.$

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

${\mathrm{\&epsiv;}}_{\min }\&GreaterEqual;\frac{n{\mathrm{Lm}}_q{a}_2^2}{a_1^2+2a_1{a}_2}+\frac{q^2{\mathrm{<figure-callout\; id="2R"\; label="B"\; filenames="HDA0000066140270000032.png"\; state="\{\{state\}\}">B</figure-callout>}}^2{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">R</figure-callout>}}^2}{{8m}_q}$

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 the axial distance of charged particle source to 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;

The axial uniform magnetic field that B introduces for mapper of the present invention;

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:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

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:

$\left\{\begin{array}{c}-\frac{1}{a_1}\sqrt{\frac{{2\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_2\left({\mathrm{\&epsiv;}}_{\min }\right)}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\min }}{{\mathrm{<figure-callout\; id="2"\; label="m\; q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{\cos }^{}{}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+2n{a}_{1}L}\&GreaterEqual;\frac{(k-1)\mathrm{\&pi;}{m}_q}{\mathrm{Bq}}\\ -\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{\frac{2{\mathrm{\&epsiv;}}_{\max }}{m_q}+2n{a}_{1}L}\&le;\frac{\mathrm{k\&pi;}{m}_q}{\mathrm{Bq}}\end{array}\right.$

Wherein,

θ _c(ε _Min) by formula ${\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)=\frac{\mathrm{<figure-callout\; id="2"\; label="qRB"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">qRB</figure-callout>}}{2\sqrt{2m_q{\mathrm{\&epsiv;}}_{\min }}}$ Decision;

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 the axial distance of charged particle source to 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;

The axial uniform magnetic field that B introduces for mapper of the present invention;

K is a 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 earlier in the pre-acceleration field simultaneously, then carries out retarded motion in reflected field, is kept to zero until axial velocity;

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 the axial distance of charged particle source to reflecting electrode;

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

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

With energy ε _i

Can be by equation $t_{\mathrm{total}}\left(v_z\right)=2[-\frac{v_z}{a_1}+\frac{a_1+a_2}{a_1{a}_2}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+2n{a}_{1}L}]$ Try to achieve;

${\mathrm{\&epsiv;}}_i=\frac{{\mathrm{<figure-callout\; id="2"\; label="p\; i"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">p</figure-callout>}}_i^{}}{{2m}_q};$

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

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

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

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

Perhaps

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{e}L,$ $0<n<\frac{2}{3};$

When charged particle energy resolution during, according to the relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured for research parameter important relatively in surveying ₁And the axial magnetic field B that is introduced 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 the axial distance of charged particle source to 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:

$\left\{\begin{array}{c}B\&le;\frac{\mathrm{k\&pi;}{m}_q{a}_2}{\mathrm{<figure-callout\; id="2"\; label="q\; m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">q</figure-callout>}}\sqrt{\frac{m_q}{}}\sqrt{\frac{{}_{}}{2{\mathrm{\&epsiv;}}_{\max }}}\\ B\&GreaterEqual;\frac{2(k-1)\mathrm{\&pi;}{a}_2{m}_q^2}{q\sqrt{8m_q{\mathrm{\&epsiv;}}_{\min }-{\left(\mathrm{qBR}\right)}^2}}\end{array}\right.;$

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 a natural number;

R is the radius of position sensitive detector.

Above-mentioned mapper also comprises first aperture plate that is arranged between charged particle source and the reflecting electrode, second aperture plate that is arranged on the charged particle source rear; Between described first aperture plate and 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 the axial distance of charged particle source to 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 had:

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

2, existing mapper system has higher relatively 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 big 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 a 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 distributed for 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 the effect of restraint schematic diagram of magnetic field to different primary power electronics;

Fig. 8 is the comparison schematic diagram of o pattern of the present invention with existing field-free formula mapper system capacity resolution;

Fig. 9 is the comparison schematic diagram of e pattern of the present invention with existing field-free formula mapper system capacity resolution;

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

Figure 11 is the effect of restraint schematic diagram of magnetic field to 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: at 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 the effectively vertically flying distance of charged particle.The introducing of charged particle accelerating field is in order to obtain bigger charged particle acceptance angle between first (as among the figure 3) and second aperture plate (as among the figure 2), the introducing of vertical uniform magnetic field B that Helmholtz coil provided 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.The motion of 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:

$s_m\left(v_z\right)=\mathrm{nL}+\frac{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+{2\mathrm{na}}_{1}L}{a_2},---\left(2\right)$

$t_m(\mathrm{\&epsiv;},\mathrm{\&theta;})=-\frac{1}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_i}{m_{\mathrm{<figure-callout\; id="2"\; label="q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">q</figure-callout>}}}{\cos }^{}{}^2{\mathrm{\&theta;}}_i}+\frac{A}{a_1}\sqrt{\frac{2{\mathrm{\&epsiv;}}_i}{m_{\mathrm{<figure-callout\; id="2"\; label="q\; cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">q</figure-callout>}}}{\cos }^{}{}^2{\mathrm{\&theta;}}_i+2{\mathrm{na}}_{1}L},---\left(3\right)$

$t_m\left(v_z\right)=-\frac{v_z}{a_1}+\frac{A}{a_1}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="v\; z"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">v</figure-callout>}}_z^{}+{2\mathrm{na}}_{1}L}.---\left(4\right)$

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 be referred to as the system features speed v here corresponding to the axial velocity of minimum flight time 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, wherein the charged particle of Kao Lving is an electronics.As seen from the figure, the charged particle of different initial axial velocities has corresponding maximum axial displacement, and initial axial velocity is big more, and the maximum axial displacement that it had is also just big more.This characteristic is very similar to the chromatic dispersion of optical dispersion medium to the 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 makes the charged particle flight time present a kind of nonmonotonicity variation with initial axial velocity, 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 big has bigger maximum axial displacement (also promptly bigger effectively axially flight distance), has the less relatively flight time (also being the less flight time); And its right side part, the big charged particle of initial velocity also has the relatively large flight time when having bigger 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 influences its total primitive axis that exists to velocity interval v _Min≤ v _z≤ v _Max, wherein

From subsequent analysis, can find out v _MinThe magnetic field that system introduced 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

${\mathrm{\&epsiv;}}_{\max }\&le;\frac{{3n}^2-1+\sqrt{-{3\mathrm{<figure-callout\; id="4"\; label="n"\; filenames="HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^4+{8n}^3-{6\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">n</figure-callout>}}^2+1}}{2(2-3n)}{a}_1{m}_{e}L,0<n<\frac{2}{3},---\left(10\right)$

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 system introduced therewith magnetic field is closely related, 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 the charged particle flight time information and the positional information of position sensitive detector record, can finally try to achieve the initial momentum information and the primary power information of charged particle according to formula (6), (12) and (13):

${\mathrm{\&epsiv;}}_i=\frac{{p_x}^2+{{\mathrm{<figure-callout\; id="2"\; label="p\; y"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">p</figure-callout>}}_y}^2+{{\mathrm{<figure-callout\; id="2"\; label="p\; z"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">p</figure-callout>}}_z}^2}{2m_q}.---\left(15\right)$

(3) the axially selection of uniform magnetic field

By last 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.

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

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 in other words primary power ε _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.

${\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_i\right)=\frac{\mathrm{<figure-callout\; id="2"\; label="qRB"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">qRB</figure-callout>}}{2\sqrt{2m_q{\mathrm{\&epsiv;}}_i}},---\left(20\right)$

Obviously, the less charged particle of primary power has bigger 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)

$-s{\mathrm{in\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right){\cos \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+{A\sin \mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)\sqrt{{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_c\left({\mathrm{\&epsiv;}}_{\min }\right)+C_o}\&le;D_o,---\left(21\right)$

Here parameter

$C_o=\frac{{\mathrm{nm}}_e{a}_{1}S}{{\mathrm{\&epsiv;}}_{\min }},$ $D_o=\frac{\mathrm{k\&pi;}{a}_1{\mathrm{<figure-callout\; id="4"\; label="Rm\; e"\; filenames="HDA0000066140270000021.png"\; state="\{\{state\}\}">Rm</figure-callout>}}_e}{{4\mathrm{\&epsiv;}}_{\min }}.$

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,

$C_e=\frac{{\mathrm{nm}}_e{a}_{1}S}{{\mathrm{\&epsiv;}}_{\min }},$ $D_e=\frac{(k-1)a_1{\mathrm{\&pi;<figure-callout\; id="4"\; label="Rm\; e"\; filenames="HDA0000066140270000021.png"\; state="\{\{state\}\}">Rm</figure-callout>}}_e}{{4\mathrm{\&epsiv;}}_{\min }}$

To sum up, this system works restrictive condition that magnetic field is selected under o pattern situation is formula (17) and (21), and being operated in the restrictive condition that magnetic field is selected under 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 to survey range and particle receiving efficiency, thereby we will be from the superiority of these three aspect analysis explanation refractive charged particle flight time momentum and energy mapper of the present invention with respect to existing mapper here.

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

${\mathrm{\&delta;\&epsiv;}}_i{|}_r=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i|-\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}+\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}},---\left(23\right)$

By top analysis to charged particle flight time characteristic under 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:

${\mathrm{\&delta;\&epsiv;}}_i{|}_o=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i[\sqrt{\frac{m_{\mathrm{<figure-callout\; id="2"\; label="q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">q</figure-callout>}}}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}-\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}]},---\left(24\right)$

${\mathrm{\&delta;\&epsiv;}}_i{|}_e=\frac{\mathrm{\&Delta;}{t}_{\min }{a}_1{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{{2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i[-\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}}+\frac{a_1+a_2}{a_2}\sqrt{\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; q"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">m</figure-callout>}}_q}{2{\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i+2n{a}_1{m}_{e}L}}]},---\left(25\right)$

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

${\mathrm{\&delta;\&epsiv;}}_i{|}_d=\frac{\mathrm{\&Delta;}{t}_{\min }\cos {\mathrm{\&theta;}}_i}{L}\sqrt{\frac{8{{\mathrm{\&epsiv;}}_i}^3}{m_q}}.---\left(26\right)$

${\frac{{\mathrm{\&delta;\&epsiv;}}_i}{{\mathrm{\&epsiv;}}_i}|}_d=\frac{\mathrm{\&Delta;}{t}_{\min }\cos {\mathrm{\&theta;}}_i}{L}\sqrt{\frac{8{\mathrm{\&epsiv;}}_i}{m_q}}.---\left(27\right)$

For ease of semidefinite relatively, consider the special case n=0 in the e pattern here.So the energy resolution and the relative energy resolution of system of the present invention is respectively as follows under the situation

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

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

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 the speed of worsening of energy resolution with primary power effectively.Under the identical condition of detector temporal resolution, such good characteristic will increase the energy of system undoubtedly and survey range.Simultaneously, comparison expression (26) and formula (28) also can be found out the dependence of both energy resolutions and angle: existing mapper system has relative higher 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.

$\frac{{\mathrm{\&delta;\&epsiv;}}_i{|}_r}{{\mathrm{\&delta;\&epsiv;}}_i{|}_d}=\frac{{\mathrm{\&epsiv;}}_{\max }}{{4\mathrm{\&epsiv;}}_i{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000066140270000012.png,HDA0000066140270000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_i}.---\left(30\right)$

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 big 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 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 about the e pattern.

Embodiment

We will elaborate embodiments of the present invention in conjunction with concrete example this part, wherein mainly be the selection problems in magnetic field, and the superiority of the present invention at its aspect of performance is described simultaneously quantitatively.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 an electronics.Set up by formula (10), therefore this moment, system works was in the o pattern.Then the conditional of being selected by magnetic field (17) 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 that " technical solution " part correlation is analyzed well under the different magnetic field constraints shown in Figure 6.

The axially selection in magnetic field under the table 1. refractive 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 half acceptance angle of field-free as shown in Figure 1 formula system 4.3 degree, o pattern of the present invention has very high charged particle receiving efficiency, and magnetic field is big more, and its charged particle receiving efficiency is high more.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 on the dependence of energy resolution to charged particle initial transmissions angle: system has higher relatively energy resolution ability to the charged particle at big initial transmissions angle.

For the embodiment of e pattern is described, consider that equally structure is the pattern refractive 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.Then the effective magnetic field scope of corresponding different magnetic nodes domains can be tried to achieve in the conditional of being selected by magnetic field under the e pattern situation (11), (17) and (22), and is as shown in table 2.

The axially selection in magnetic field under the table 2 refractive 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 as Fig. 9, shown in Figure 10.Fig. 9 clearly shows the characteristics-high energy resolution of e pattern of the present invention, and the sub-primary power of energy resolution electrochondria going along with has variation relation comparatively slowly.Under the situation of given position sensitive detector temporal resolution, such characteristic will significantly increase the energy of mapper system undoubtedly and survey range.Simultaneously, Fig. 9 has also clearly illustrated both different qualities aspect the dependence at the sub-initial transmissions of energy resolution electrochondria going along with 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 once more.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 reflected field uniformly;

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

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

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 the axial distance of charged particle source to reflecting electrode;

4] charged particle promptly is engraved in and is reversed accelerated motion in the mirror field, until the position sensitive detector that arrives the charged particle source position;

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

With energy ε _i:

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 reflected field and axial pre-acceleration field uniformly uniformly; 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, be kept to zero until axial velocity;

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 the axial distance of charged particle source to 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 the position sensitive detector that arrives the charged particle source position;

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

With energy ε _i

Can be by equation

Try to achieve;

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 reflected field and axial magnetic field uniformly uniformly;

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

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 a 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; In reflected field, carry out simultaneously retarded motion, be kept to zero until axial velocity;

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 the axial distance of charged particle source to 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 the position sensitive detector that arrives the charged particle source position;

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

With energy ε _i

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:

Perhaps

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

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 the axial distance of charged particle source to 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;

The axial uniform magnetic field that B introduces for mapper of the present invention;

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:

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:

Wherein,

θ _c(ε _Min) by formula

Decision;

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 the axial distance of charged particle source to 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;

The axial uniform magnetic field that B introduces for mapper of the present invention;

K is a 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 earlier in the pre-acceleration field simultaneously, then carries out retarded motion in reflected field, is kept to zero until axial velocity;

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 the axial distance of charged particle source to reflecting electrode;

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

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

With energy ε _i

Can be by equation Try to achieve;

。

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 the mode of operation of mapping method in the following manner:

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

Perhaps

When charged particle energy resolution during, according to the relevant parameter nL or a of the primary power Adjustment System pre-acceleration field of charged particle to be measured for research parameter important relatively in surveying ₁And the axial magnetic field B that is introduced 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 the axial distance of charged particle source to 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:

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 a 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 first aperture plate that is arranged between charged particle source and the reflecting electrode, second aperture plate that is arranged on the charged particle source rear; Between described first aperture plate and 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 the axial distance of charged particle source to 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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