CN104034740B - Charged particle photographic means based on energy loss focal imaging - Google Patents
Charged particle photographic means based on energy loss focal imaging Download PDFInfo
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Abstract
Charged particle photographic means based on energy loss focal imaging, including beam-flow transmission line and optical imaging system, it is characterised in that beam-flow transmission line is divided into first half section and the second half section of axial symmetry distribution, and described optical imaging system is positioned at beam-flow transmission line end；The transmission matrix of described first half section is six rank matrix A: transmission matrix A meets dispersion conditions to release: A12=0、A26=0、A21=0、A34=0、A43=0；Forward and backward subscript represents the row, column at this element place respectively.The invention has the beneficial effects as follows: utilize deflection magnet and quadrupole electromagnet composition de-dispersion imaging system, define the function of focal imaging, energy collimator is set in energy discrimination plane simultaneously, formed the contrast of image by the energy loss of charged particle.
Description
Technical field
The present invention relates to charged particle camera technique, in particular it relates to a kind of based on energy loss focal imaging charged
Particle photographic means.
Background technology
Charged particle photograph is a kind of in-duction linac technology.Utilize quasi-monoenergetic charged particle beam through sample with acquisition figure
Picture, and then obtain the information being needed concern by the density of product sample interior, space in the same old way etc..
Charged particle photograph can be there to be two kinds of forms, and the first is direct in-duction linac, and the second is to use electromagnetic lens
The in-duction linac focused on.Use condenser lens can improve the resolution of image, present invention relates solely to the second photographic means.
Focused electromagnetic lens also have two kinds of forms, and the first is axially symmetric structure, and the second is nonaxisymmetric structure.
The focussing force of axially symmetric structure electromagnetic lens is more weak, can only use the particle that energy is relatively low, shine relatively thin sample
Phase.The focused electromagnetic lens of nonaxisymmetric structure can form much higher focussing force, thus is applicable to the photograph of thick sample.
Present invention relates solely to the condenser lens of nonaxisymmetric structure.
When charged particle moves in the sample, acted on by sample material atom, three kinds of effects can be formed, be grain respectively
Quantum count reduces, and particle angle scatters, and particle energy loses.When photograph, the image obtained all can be caused shadow by these effects
Ring, namely carry the information of sample interior.
In the most conventional nonaxisymmetrical focusing magnetic lenses, it is possible to use the information that number of particles reduces forms image
Contrast, it is also possible to utilize the information that particle angle scatters to form the contrast of image.But the letter for particle energy loss
Breath, not only can not be used, and is the principal element forming image blur on the contrary, has a strong impact on the quality of obtained image.
Summary of the invention
For overcoming existing charged particle imaging technique that particle energy can not be utilized to lose, cause image blurring, become picture element
The technological deficiency of amount difference, the present invention provides a kind of charged particle photographic means based on energy loss focal imaging.
Charged particle photographic means based on energy loss focal imaging of the present invention, including beam-flow transmission line and light
Learn imaging system, it is characterised in that beam-flow transmission line is divided into first half section and second half section, the described optical imagery system of axial symmetry distribution
System is positioned at beam-flow transmission line end；Described first half section is focused on section by include energy collimator second, before being positioned at the second focusing section,
After the first focusing section and tertiary focusing section composition, described first focuses on section and second focuses between section, second focuses on section and the
Being respectively arranged with the first deflection magnet and the second deflection magnet between three focusing sections, the transmission matrix of described first half section is six rank squares
Battle array A:
Transmission matrix A meets dispersion conditions to release: A12=0、A26=0、A21=0、A34=0、A43=0 ；Forward and backward subscript table respectively
Show the row, column at element place.
Concrete, make transmission matrix A meet dispersion conditions to release by arranging quadrupole electromagnet in each focusing section.
Concrete, described energy collimator is made up of two pieces of parallel metal sheets.
Concrete, described optical imaging system is made up of opto-electronic conversion screen and CCD camera
The invention has the beneficial effects as follows: utilize deflection magnet and quadrupole electromagnet composition de-dispersion imaging system, define poly-
The function of burnt imaging, arranges energy collimator in energy discrimination plane simultaneously, forms figure by the energy loss of charged particle
The contrast of picture.
Accompanying drawing explanation
Fig. 1 is a kind of detailed description of the invention schematic diagram of charged particle photographic means of the present invention；
Fig. 2 is the structural representation of energy collimator of the present invention；
Fig. 3 is classical De-dispersion structural representation；
Fig. 4 is that particle is accurate at energy in the case of 35Mev Proton-Induced Reactions embodiment standard energy (i.e. 35MeV) of the present invention
The distribution situation of straight device position；
Fig. 5 be 35Mev Proton-Induced Reactions embodiment energy of the present invention have 2% deviation time particle at energy collimator
The distribution situation of position；
Labelling and corresponding parts title in accompanying drawing: 1-deflection magnet, 2-defocuses quadrupole electromagnet, and 3-focuses on quadrupole magnetic
Ferrum, 4-first section of focusing, 5-second section of focusing, 6-tertiary focusing section, the geometirc symmetry axis that 7-is forward and backward half section, 8-energy collimates
Device, 9-charged particle electron gun, 10-is by product in the same old way, 11-electro-optic conversion screen, 12-CCD camera, 13-Particle Delivery track.
Detailed description of the invention
Below in conjunction with embodiment and accompanying drawing, to the detailed description further of present invention work, but embodiments of the present invention
It is not limited to this.
Charged particle photographic means based on energy loss focal imaging of the present invention, including electronic imaging system, its
Being characterised by, also including into first half section and the second half section of axial symmetry distribution, described electronic imaging system is positioned at second half section end；Institute
State first half section and focused on section by include energy collimator second, be positioned at the first focusing section and trimerization that the second focusing section is forward and backward
Burnt section composition, described first focuses on section and second focuses between section, is respectively arranged with between the second focusing section and tertiary focusing section
First deflection magnet and the second deflection magnet, the transmission matrix of described first half section is:
Transmission matrix A meets dispersion conditions to release: A12=0, A26=0, A21=0, A34=0, A43=0；
Described energy collimator meets energy collimation condition.
For the transmission system of monoenergetic charged particle, if needing imaging, also implying that, particle is in the position of image plane
It is dependent only on its position at object plane, and unrelated in the angle of object plane with it.
If charged particle is not monoenergetic, also the requirement of De-dispersion, namely particle can not in the position of image plane
Relevant at the energy of object plane to it.In the present invention, if the transmission matrix of first half section is A, the transmission matrix of second half section is
B, overall transmission matrix is R.Here the horizontal coordinate of particle, level angle and energy it are concerned only with.
According to " charged particle beam optics " (Lu builds and writes by the emperor himself, Higher Education Publishing House, 2004), and in view of first half section and after
Half section becomes axial symmetry distribution, then transmission matrix A, B of first half section, second half section and entirety is respectively as follows:
(1)
In wherein A, B matrix, the element of labelling X is unrelated in the calculating process of X-plane with the present invention, A, B is abbreviated as
,
In this specification, the matrix appeared below is six rank matrixes, but all according to the method writing a Chinese character in simplified form A, B, only represents
First and second, the first and second of six row, six row totally nine elements, remaining is all not written out.
Then overall transfer matrix R is the product of B and A
(3)
In charged particle transmission system, generally represent the state of particle by six-dimensional coordinate, represent with sextuple transmission matrix
The performance of system.
Charged particle six-dimensional coordinate expression formula is as follows.
(4)
In formulaFor six-dimensional coordinate,Represent particle levels coordinate,Represent particle levels angle,Represent that particle is vertical
Coordinate,Represent particle vertical angle,Represent the particle position coordinate in transmission direction,Represent the deviation of particle energy.This
In transmit direction and represent the direction of motion of particle beam, the most all retouch in the plane being perpendicular to transmission direction
State.
Can obtain the particle position coordinates in image plane:
I.e. (6)
In order in X-plane imaging, namely particle is unrelated with its initial angle x ' in the position of image plane, needs its coefficient
A12*A22=0, due to A22It is positioned on the diagonal of transmission matrix A, is generally difficult to be embodied as zero, therefore the side of most convenient
Method is order
(8)
According to (6) formula, for De-dispersion, namely make particle unrelated with its primary power in the position of image plane,
I.e. withUnrelated, Ke Yiqu
A12*A26=0
WhenTime, naturally, also meet A12*A26=0。
For Y plane imaging, utilize identical derivation method, similar condition can be obtained.
In actual system, typically there is energy deviation due to particle, it is therefore desirable to De-dispersion.Even if the color of single order
Dissipating and eliminated, high-order aberration is likely to affect the quality of image.
When utilizing A12=A26After=0 eliminates 1st order chromatic dispersion, (6) formula is reduced to
(10)
To its Taylor expansion to second order, with momentum spreadLaunch for variable,
(11)
Assuming that the particle beam of input is band modulation, the namely angle of particleIt is and particle positionLinear correlation.
I.e. (12)
In formulaIt is the index of modulation,It it is an addition Item causing of non-ideal factor.
Recycling image-forming condition is that the particle position on imaging plane is unrelated with particle initial angle, i.e., will
(12) formula substitutes into (11) formula, can obtain:
(13)
From (13) formula, in order to eliminate the second order aberration item relevant to position, i.e.Coefficient is zero, needs to meet
Second order color matching condition can be met. when meeting second order color matching condition, i.e. meet image-forming condition, can
With imaging.
According to (5) formula,, to the element R in R matrix11With momentum spreadFor variable derivation, and consider
In image-forming conditionIf, order
(15)
(16)
Then (14) formula is set up.
Utilize identical derivation method, obtain the second order color matching condition of vertical plane.
Meeting of discussion below energy collimation condition.
Assuming that the transmission matrix of energy collimator location mid-shaft is T from system entry to first half section.
The transmission matrix further assuming that the first focusing section 4 is；The deflection radius of deflection magnet is R, and deflection angle is,
The transmission matrix of deflection magnet is；Second transmission matrix focusing on section 5 is, the wherein biography of the first half section of the second focusing section
Defeated matrix is；The transmission matrix of tertiary focusing section 6 is.According to " charged particle beam optics ", (Lu builds and writes by the emperor himself, higher education
Publishing house, 2004), the expression of these matrixes is as follows, wherein、、Matrix element be arbitrarily designated.
(18)
(19)
(20)
(21)
(22)
Theoretical according to accelerator beam transfer, can write out from entrance to the transmission matrix of energy collimator axis:
Transmission matrix from particle beam incidence starting point to the axis of symmetry of forward and backward half section can be written as:
(24)
Each matrix is multiplied successively, launches (24) formula, order,, and in view of (11) formula, letter can be solved
The expression formula of c and h, substitutes intoIn, can obtain:
, subscript represents the residing ranks number of element. (25)
The six-dimensional coordinate of particle final state is that transmission matrix is multiplied by the initial six-dimensional coordinate of particle, and therefore particle position is accurate at energy
The strict expression formula of straight plane is:
(26)
According to (15) formula, the parallel incidence of particle, in the case of ignoring non-ideal factor,, in conjunction with, obtain
(27)
Visible now in energy collimation plane, the position of particle is solely dependent upon the energy deviation that it is initial, therefore full
Foot energy collimation condition.
Calculate process more than utilizing, De-dispersion and the energy collimation condition of Y plane can be obtained
For: A34=A43=0.
Summary is various, meets A12=A21=A26=A34=A43The first half section transmission matrix A of=0 condition and complete with first half section
The holosymmetric second half section can realize De-dispersion and energy alignment function.
For realizing meeting the transmission matrix A of above-mentioned condition, can adopt and realize with the following method, first according to used charged
The energy of particle beam, selects to be suitable for the quadrupole electromagnet of this energy and deflection magnet, according to beam energy, and during actual application
Specific requirement, such as site space size, the ability etc. of existing Magnet processing technique, determine the magnetic field gradient of quadrupole electromagnet, length
Degree, aperture, the parameter such as the deflection radius of deflection magnet, deflection angle, magnetic pole gap；Then section, the second focusing are focused on first
In section, tertiary focusing section, the situation according to matching primitives places a number of quadrupole electromagnet, in actual application, and each focusing section
Quadrupole electromagnet can not be placed as required, it is also possible to place 3 pieces or 4 pieces or more quadrupole electromagnet.
Utilize the coupling of existing ripe software such as Transport, Trace3D etc. that accelerator beam transfer theory works out
Function, the transmission matrix calculating first half section is meeting A12=A21=A26=A34=A43Under the conditions of=0, the design parameter of each block of Magnet；?
Obtain according to matching primitives afterwardsParameter, rationally arranges the parameter of energy collimator.
According to (27) formula, particle horizontal level on energy collimator is the most relevant with its primary power, and therefore energy is accurate
The gap of straight two pieces of pole plates of device determines the particle energy scope that can pass through, by arranging between two pieces of pole plates of energy collimator
Gap, makes。
Such as the proton source that energy is 35MEV (million-electron-volt), according to above-mentioned calculating process, final selection is as follows
Technical scheme:
First focuses on section uses 3 blocks of quadrupole electromagnets, and tertiary focusing section uses two blocks of quadrupole electromagnets, and second focuses on section does not make
Use quadrupole electromagnet.In first half section, from each component parameters of particle incidence starting point to axis of symmetry as shown in Table 1, the second half section each
Components and parts are full symmetric with first half section, whole system total length 26.904 meters, use altogether 4 blocks of deflection magnets, 10 blocks of quadrupole electromagnets.
In table one magnetic field gradient on the occasion of time be focus magnet, for time negative for defocusing Magnet.
Table one
Utilize analogue G4Beamline that said system is set up model, and be simulated calculating.Fig. 4 and Tu
5 give primary in the case of different-energy, the particle distribution situation of energy collimator position.Wherein Fig. 4 is standard energy
In the case of amount (this example is 35MeV), particle is in the distribution situation of energy collimator position, when Fig. 5 is the deviation that energy has 2%
Particle is in the distribution situation of energy collimator position.
From Fig. 4 and Fig. 5, in the horizontal direction, the particle of energy collimation plane is distributed in a scope the least, this
The effect of the energy collimation plane that theory analysis is given just；Simultaneously as the energy deviation of 2%, the mean place of particle distribution
There is a change of about 11mm, and the result be given according to design software Transport, particle energy deviation 1%, particle is at energy
Position deviation at collimator will be for 5.57mm.Visible therebetween close to consistent.
As it has been described above, the present invention can preferably be realized.
Claims (4)
1. charged particle photographic means based on energy loss focal imaging, including beam-flow transmission line and optical imaging system, its
Being characterised by, beam-flow transmission line is divided into first half section and the second half section of axial symmetry distribution, and described optical imaging system is positioned at line and passes
Defeated line end；Described first half section is focused on section by include energy collimator second, is positioned at the first focusing that the second focusing section is forward and backward
Section and tertiary focusing section form, and described first focuses on section and second focuses between section, second focuses between section and tertiary focusing section
Being respectively arranged with the first deflection magnet and the second deflection magnet, the transmission matrix of described first half section is six rank matrix A:
Transmission matrix A meets dispersion conditions to release: A12=0、A26=0、A21=0、A34=0、A43=0 ；Forward and backward subscript represents unit respectively
The row, column at element place.
Charged particle photographic means based on energy loss focal imaging the most according to claim 1, it is characterised in that logical
Cross and focus on section at each and quadrupole electromagnet is set makes transmission matrix A meet dispersion conditions to release.
Charged particle photographic means based on energy loss focal imaging the most according to claim 1, it is characterised in that institute
State energy collimator to be made up of two pieces of parallel metal sheets.
Charged particle photographic means based on energy loss focal imaging the most according to claim 1, it is characterised in that institute
State optical imaging system to be made up of opto-electronic conversion screen and CCD camera.
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| CN104914119B (en) * | 2015-06-15 | 2017-10-27 | 中国工程物理研究院流体物理研究所 | It is a kind of to match the charged particle photographic means that line is parallel beam |
| CN107846771A (en) * | 2017-10-31 | 2018-03-27 | 华中科技大学 | A kind of method and system for adjusting rotary frame isocenter point beam spot size |
| CN110944446B (en) * | 2019-10-29 | 2020-09-25 | 清华大学 | Electron beam group storage ring and extreme ultraviolet light source with same |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4851670A (en) * | 1987-08-28 | 1989-07-25 | Gatan Inc. | Energy-selected electron imaging filter |
| US6384412B1 (en) * | 1998-06-27 | 2002-05-07 | Leo Elektronenmikroskopie Gmbh | Electron microscope with an energy filter having hexapole correctors which are coupled with a projective system downstream of the energy filter |
| CN101405596A (en) * | 2006-01-24 | 2009-04-08 | 北卡罗来纳大学查珀尔希尔分校 | Systems and methods for detecting an image of an object by use of an X-ray beam having a polychromatic distribution |
| US8632448B1 (en) * | 2009-02-05 | 2014-01-21 | Loma Linda University Medical Center | Proton scattering analysis system |
| CN203849186U (en) * | 2014-05-12 | 2014-09-24 | 中国工程物理研究院流体物理研究所 | Charged particle picture-taking device for focusing and imaging based on energy loss |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5414261A (en) * | 1993-07-01 | 1995-05-09 | The Regents Of The University Of California | Enhanced imaging mode for transmission electron microscopy |
| DE112009002439A5 (en) * | 2008-10-09 | 2012-05-10 | California Institute Of Technology | 4D imaging in an ultrafast electron microscope |
-
2014
- 2014-05-12 CN CN201410196408.0A patent/CN104034740B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4851670A (en) * | 1987-08-28 | 1989-07-25 | Gatan Inc. | Energy-selected electron imaging filter |
| US6384412B1 (en) * | 1998-06-27 | 2002-05-07 | Leo Elektronenmikroskopie Gmbh | Electron microscope with an energy filter having hexapole correctors which are coupled with a projective system downstream of the energy filter |
| CN101405596A (en) * | 2006-01-24 | 2009-04-08 | 北卡罗来纳大学查珀尔希尔分校 | Systems and methods for detecting an image of an object by use of an X-ray beam having a polychromatic distribution |
| US8632448B1 (en) * | 2009-02-05 | 2014-01-21 | Loma Linda University Medical Center | Proton scattering analysis system |
| CN203849186U (en) * | 2014-05-12 | 2014-09-24 | 中国工程物理研究院流体物理研究所 | Charged particle picture-taking device for focusing and imaging based on energy loss |
Non-Patent Citations (7)
| Title |
|---|
| An 800-MeV proton radiography facility for dynamic experiments;King,N.S.P. et al.;《Nuclear Instruments and Methods in Physics Research A》;19991231;第424卷;第84-91页 * |
| Image blur in high energy proton radiography;Wei Tao et al.;《Chinese Physics C》;20131231;第37卷(第6期);第068201-1至068201-6页 * |
| MAGNETIC OPTICS FOR PROTON RADIOGRAPHY;Mottershead,C.T. et al.;《17th Particle Accelerator Conference》;19981231;第1397-1399页 * |
| PROTON RADIOGRAPHY;Hogan,G.E. et al.;《Proceedings of the 1999 Particle Accelerator Conference》;19991231;第579-583页 * |
| 利用能损信息成像的磁透镜设计初步研究;杨国君等;《高能量密度物理》;20131231(第4期);第164页摘要，第164页引言部分第3段，第165页第4部分至第168页第5部分 * |
| 质子照相磁透镜的优化设计;何小中等;《强激光与粒子束》;20080229;第20卷(第2期);第297-300页 * |
| 高能质子照相的研究进展;许海波等;《物理》;20081231;第37卷(第11期);第783-787页 * |
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