CN105093262A - Digital neutron spectrometer response matrix obtaining method - Google Patents

Abstract

The invention relates to a digital neutron spectrometer response matrix obtaining method. The method includes the following steps that: the response function of monoenergetic neutrons of a digital neutron spectrometer at an experimental energy point can be obtained through the experimental calibrations of the monoenergetic neutrons; an equation solution module is established, and a high-order inhomogeneous equation residual least square method is adopted to get solutions; relevant parameters of the response function of the neutron spectrometer can be obtained based on the combination of the above two steps, namely, luminosity factors, zero track positions and energy per-channel; a response matrix calculation module is established; and a complete response matrix of neutrons to be measured is obtained. With the response matrix obtaining method adopted, a parameter adjusting process in response matrix obtaining can be simplified, and time cost for obtaining the response function can be deceased, and the calculation accuracy of the response function can be improved, and intelligent operation can be realized.

Description

A kind of digitizing neutron spectrometer response matrix acquisition methods

Technical field

The invention belongs to radioactive substance field of detecting, be specifically related to a kind of digitizing neutron spectrometer response matrix acquisition methods.

Background technology

Liquid scintillation bulk detector belongs to the one in organic scintillator detector, and for organic scintillator, its advantage is that hydrogeneous density is large, and thus neutron detection efficiency is high, and time response is fast.In addition again because it has good particle discrimination performance, so they are widely used in fast-neutron detection.Simply introduce the developing history of liquid scintillator below.

The measuring principle utilizing organic liquor to dodge detector measurement neutron spectrum is: when incident neutron and H atom core generation elastic scattering, the direction of motion of neutron changes, energy also reduces to some extent, and the energy transferring that neutron reduces, to H atom core, makes H atom core move with certain speed.This H atom core is just called recoil proton, and it has certain electric charge, can carry out record as charged particle.Have recorded recoil proton and detect neutron exactly.Recoil proton energy is relevant to incident neutron energy, dodges detector response function can be finally inversed by incident neutron spectral information according to recoil proton energy deposition spectra and liquid.

When utilizing pulse form analysis technology to carry out spectrum unscrambling to the pulse amplitude spectrum that detector is directly measured, need the response function of clearly calculating detector, namely describe the function of the stochastic relation between the energy of incident particle and its pulse height caused, can be expressed as:

$R(E_0,h)=\mathrm{\η}\left(E_0\right){\∫}_0^{E_0}D(E_0,E)G(E,h)dE---\left(1\right)$

In formula, E0 is the energy of incident particle; R (E0, h) is response function; G (E, h) is Gaussian resolution function; D (E0, E) is energy deposition spectra; D (E0, E) dE represents that projectile energy is photon sedimentary energy probability in (E, E+dE) in detector of E0; η (E0) is detection efficiency, is the particle counting of primary first-order equation and the ratio of the number of particles incided on detector at least occur in crystal.Also be the normalizing factor of D (E0, E), that is:

$\mathrm{\η}\left(E_0\right)={\∫}_0^{E_0}D(E_0,E)dE---\left(2\right)$

The object obtaining response function is just to build response matrix R, utilizes it to separate neutron spectrum.

The accuracy of response matrix directly determines the precision of neutron spectrum after spectrum unscrambling, and the mode that the acquisition of current neutron response matrix often adopts theory calculate and monoenergetic point experiment scale to combine carries out the acquisition of response matrix.By theory calculate energy interested district single-end neutron response function, the NRESP7 program that calculation procedure adopts Germany technology physical study institute (PTB) to develop.Then according to single-end neutron experiment measuring pulse amplitude spectrum, matching correction is carried out to experimental spectrum, obtain experimental spectrum and theoretical compressibility factor of composing, compressibility factor is revised, thus obtains the identical good response function with single-end neutron pulse amplitude spectrum (experimental spectrum).

The main deficiency of this response function obtain manner is: 1.NRESP7 process simulation luminescence process hides user, and user cannot carry out response function calculating for some special feature detector.2.NRESP7 program cannot consider that liquid dodges the final number of electrons that produces and has statistics stochastic distribution.

3. theory calculate spectrum does not consider the correction of experimental spectrum zero track.

List of references: NeutronSpectrometryinMixedFields:NE213/BC501ALiquidScint illationSpectrometers.RadiationProtectionDosimetryVol.10 7, Nos1-3, pp, 95-109 (2003); .

Summary of the invention

For the defect existed in prior art, the invention provides a kind of digitizing neutron spectrometer response matrix acquisition methods, this process simplify and obtain response matrix parameter testing process, saved response function acquisition time cost, improve the computational accuracy of response function.

For reaching above object, the technical solution used in the present invention is: provide a kind of digitizing neutron spectrometer response matrix acquisition methods, comprise the following steps:

A, the response function can put in experiment by the single-end neutron of single-end neutron experiment scale acquisition digitizing neutron spectrometer;

B, set up and to solve an equation module, utilize high order nonhomogeneous equation residual error least square method to solve;

C, in conjunction with above-mentioned steps a and step b, obtain the response function correlation parameter of neutron spectrometer, i.e. luminosity, zero track position and per pass energy;

D, set up response matrix computing module;

E, obtain the complete response matrix of neutron to be measured.

Further, step a) in, described single-end neutron by swindletron nuclear reaction method obtain, the energy point pulse amplitude spectrum of each single-end neutron need meet following equations

$\mathrm{\Λ}E\×(Ch-{\mathrm{Ch}}_0)=\frac{dE}{1+kB\frac{dE}{dX}}---\left(4\right)$

Wherein: in (4) formula, Δ E is multiple tracks spectrum energy interval; Ch ₀it is 0 corresponding number of channels; K and B is constant, and this constant only relies on the chemical composition of scintillator, has nothing to do with incident particle; DE/dx is the energy that charged particle consumes on the unit path of scintillating medium; By the system of equations of simultaneous more than three, obtain corresponding energy Δ E, 0 corresponding number of channels Ch of each single-end neutron experimental point detector per pass ₀and normal kB.

Further, in stepb, described high order nonhomogeneous equation residual error least square method solves, and adopts and repeatedly attempts algorithm in conjunction with the minimum judgement of variance, final acquisition and all experiments result immediate per pass energy Δ E, zero track position Ch ₀and luminosity kB tri-parameters.

Further, in steps d, described response matrix computing module, has worked out main function, and definition initialization class and user behavior class, define visualization interface simultaneously.

Further, in described user behavior class, be provided with proton and electron luminescence function based on above-mentioned equation (4).

Further, described response matrix module computing method are as follows:

1) judge whether have energy deposition in minimum simulation material calculation Step, if there is energy deposition, judgement by what particle is produced, if this particle is photon, then destroys this tracing process and the secondary reaction road that its photon is produced closedown.

2) if the particle types of the energy deposition of this minimum simulation material calculation Step generation is proton, then the luminous function that experimental spectrum scale obtains is added, proton sedimentary energy is obtained by GetTotalEnergyDeposit () function, the path of particle is obtained by GetStepLength () function, obtained the luminous function of Birks by Calibration Experiment, determine the photon number that this step produces.

3) if judging that this minimum simulation material calculation Step follows the tracks of particle is electronics, the fluorescence number produced according to electronics and electron energy are linear relationships, the photon number produced by proton and electronics in all minimum simulation material calculation Step is sued for peace, is the photon number summation that this neutron event produces.

Further, in step 2) in, add Gaussian distribution spread function, described spread function adopts experimental calibration method to determine.

Advantageous Effects of the present invention is:

(1) the present invention is provided with a kind of experimental calibration method, develops a high order nonhomogeneous equation group residual error minimal solution equation module based on Window window writing routine; Thus, simplify the computing time of response function, improve the computational accuracy of response function;

(2) this invention exploits a set of liquid and dodge response matrix computing module, this response matrix computing module is the luminosity of scale, electronics zero track position, energy bite that per pass is corresponding experimentally, set up the liquid shwoot photophysical process almost identical with experimental detection system, real system electronics zero track is revised, simulates the random statistical distribution in fluorescence production process simultaneously; Thus, simplify and obtain response matrix parameter testing process, save time.

Accompanying drawing explanation

Fig. 1 is the structural representation of digitizing neutron spectrometer response matrix acquisition methods of the present invention;

Fig. 2 is the schematic diagram of 1.15MeV single-end neutron calculated response function and 1.15MeV single-end neutron test of pulse amplitude spectrum;

Fig. 3 is response function after the compressed factor correction of 4MeV neutron energy NRESP7 result of calculation and 4MeV neutron energy experimental spectrum;

Fig. 4 is that ergodic algorithm solves KB factor program window figure.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

As shown in Figure 1, be the method that neutron spectrometer response matrix provided by the invention obtains, obtain digitizing neutron spectrometer 1MeV-20MeV single-end neutron by the experiment scale of single-end neutron and testing the response function that can put; Foundation is solved an equation module, utilizes high order nonhomogeneous equation residual error least square method to solve; Above-mentioned two kinds of steps are combined and obtains the correlation parameter of response function of neutron spectrometer, be i.e. luminosity, zero track position and per pass energy; Set up response matrix computing module; Obtain the response matrix that neutron to be measured is complete.

Specifically comprise two large divisions's content:

1. response function correlation parameter experiment scale

Response function correlation parameter experiment scale refers to by accelerator generation single-end neutron radiation field, obtain the response function at several single-end neutron experimental points, determined three parameters such as the actual neutron energy that the kB factor, 0 position and per pass represent by formula 4 hereinafter.Each experimental point sets up equation shown in a formula 4, and several experimental points set up a system of equations, and the best obtaining above-mentioned three parameters by separating high order nonhomogeneous equation may be separated.Finally these three parameters all can be put the input parameter of response matrix as calculating.Thus final acquisition full energy range neutron spectrometer response matrix.

In following relation between the energy dE/dx that charged particle consumes on the unit path of scintillating medium and its photon number dS/dx produced on unit path:

$\frac{dS}{dx}=A\frac{dE}{dx}/\[1+k\left(B\frac{dE}{dx}\right)\]---\left(1\right)$

This formula is exactly Bai Kesi law (Birks ' Law).Wherein, A is absolute luminescence efficiency, and k is the relative rate constant of Stern-Volmer equation, and B × dE/dx is the ionizing event density that charged particle produces.

The Bai Kesi law integration of statement ionization cancellation can be obtained:

$S=A\underset{0}{\overset{E}{\∫}}\frac{dE}{1+kB\left(\frac{dE}{dx}\right)}---\left(2\right)$

Because k and B in formula all only relies on the chemical composition of scintillator, be all the constant irrelevant with incident particle,

Definition multiple tracks spectrum energy is spaced apart Δ E, then:

$\mathrm{\Δ}E\×Ch=\frac{dE}{1+kB\frac{dE}{dX}}---\left(3\right)$

Due to absolute 00 road might not composed in multiple tracks of electronics, suppose that 0 corresponding number of channels of electronics is Ch0, then above formula becomes:

$\mathrm{\Δ}E\×(Ch-{\mathrm{Ch}}_0)=\frac{dE}{1+kB\frac{dE}{dX}}---\left(4\right)$

Experiment scale can choose single-end neutron energy point as much as possible in district at 1MeV-20MeV, and single-end neutron obtains to adopt and produces based on swindletron nuclear reaction method.Utilize p (T, n) ³he reaction produces 1.2MeV single-end neutron, utilizes d (D, n) ³he reaction produces 2.5MeV, 5MeV single-end neutron, utilizes d (T, n) ⁴he reaction produces 14.8MeV, 19MeV single-end neutron.Each single-end neutron energy point pulse amplitude spectrum meets equation (4).The system of equations of such simultaneous more than three, can obtain the per pass corresponding energy Δ E that adopted liquid dodges detection system, Ch ₀, three parameters such as kB.

The simultaneous of this system of equations is the nonhomogeneous equation group of more than 3 times, there is no unique analytic solution, develop this system of equations based on VC6.0 to solve an equation module, this system of equations module of solving an equation is utilized to carry out solving equations, adopt and repeatedly attempt algorithm in conjunction with the minimum judgement of variance, finally can obtain immediate Δ E, Ch with all experiments result ₀, three parameters such as kB.

2. response matrix modular algorithm

Based on Geant4 program, develop liquid and dodge response matrix computing module.Work out main function, define DetectorConstruction detector structure class and the necessary initialization class of PhysicsList physical process class two and four user behavior classes: RunAction operational management class, EventAction incident management class, PrimaryGeneratorAction primary particle produce administrative class and StepAction minimum simulation step-length administrative class.Define the visualization interface based on a kind of visual class HepRep visualization engine simultaneously.

In StepAction class, with the addition of the functional procedure of giving out light of proton and electronics based on Birks formula.Specific algorithm is as follows:

1) judge whether have energy deposition in minimum simulation material calculation Step, if there is energy deposition, judgement by what particle is produced, owing to having carried out neutron in actual measurement, gamma has screened, so in calculation procedure, if this particle is photon, then destroy this tracing process and the secondary reaction road that its photon is produced closedown.

2) if the particle types of the energy deposition of this minimum simulation material calculation Step generation is proton, then the luminous function that experimental spectrum scale obtains is added, the proton energy of this step product is obtained by GetTotalEnergyDeposit () function, the path of this step particle is obtained by GetStepLength () function, the luminous function of the Birks obtained by Calibration Experiment, determines the photon number that this step produces.

Because the luminous physical process of reality has random distribution nature, in order to the actual luminescence process of real simulation, Gaussian distribution spreading process must be added.Spread function adopts experimental calibration method to determine.Light output computation process is updated to by testing the spread function determined.Finally obtain the fluorescence number that this Step process is produced by proton.In all Step, the summation of the fluorescence number that proton produces is the fluorescence number produced by recoil proton in this neutron event.

3) if judging that this Step follows the tracks of particle is electronics, the fluorescence number produced according to electronics and electron energy are linear relationships, by above-mentioned three processes, the photon number produced is sued for peace, be the photon number summation that this neutron event produces in all Step by proton and electronics.

Thus, this invention simplifies and obtain response matrix parameter testing process, improve the precision of response matrix.After the NRESP7 program computation liquid adopting German PTB to develop dodges explorer response matrix, then according to single-end neutron pulse height experimental spectrum, compressibility factor correction is carried out to response matrix, after obtaining compressibility factor by experiment, also need manual being multiplied with compressibility factor by each response matrix, and then the Winspekt spectrum process software utilizing German PTB to develop carries out relevant correction to theory calculate spectrum.Data handling procedure is very loaded down with trivial details, approximately needs 1 week even a few time-of-week; Require that data processing operation person needs skilled spectrum process physics skill.And adopting this response matrix obtain manner, data handling procedure needs the time hardly.Because response matrix correlation parameter is once through overtesting scale, can automatically consider relevant corrected parameter in response matrix computation process, the response matrix calculated directly can be used as the input matrix of spectrum unscrambling, greatly simplify data handling procedure and time cost.Once program is determined, particular/special requirement be there is no to operator, achieve intelligent processing method.

Because energy corresponding to system zero track deviation, luminosity, per pass is because of each detector system, adopt single-end neutron experimental point pulse amplitude spectrum scale, employing solution high order nonhomogeneous residual error least square method acquisition system zero track deviation, luminosity, the energy error that per pass is corresponding control within 1%.As shown in Figure 2, A curve is 1.15MeV calculated response function, B line is 1.15MeV single-end neutron test of pulse amplitude spectrum, known in figure, this method response function and monoenergetic experimental point consistent degree is utilized to reach more than 98% (wherein experimental spectrum falls Electronics noice due to needs card, and threshold value is in 50 roads).As shown in Figure 3, for adopt the response function of German PTBNRESP7 program computation after the correction of the Compression Correction factor with the comparing of experimental result.Can find out this method response function and experimental result consistance higher.In figure, A is the response function after the compressed factor correction of 4MeV neutron energy result of calculation, and B is 4MeV neutron spectrum experimental spectrum.

Be described below by experiment:

1. response function correlation parameter experiment scale obtains

Dodge in detector single-end neutron scale at liquid, scale energy is respectively: E1=1.15MeV, E2=2.42MeV, E3=4.92MeV, E4=14.8MeV, and the multiple tracks spectrum energy limit corresponding to it is respectively Ch1=65, Ch2=175, Ch3=439, Ch4=1620.Utilize the range of SRIM program computation proton in BC501A organic solution, as shown in the table.

The range of table 1. proton in BC501A organic solution

Proton energy MeV	Range cm
		1	0.002502
1.1	0.00292
		1.2	0.003368
1.3	0.003845
		1.4	0.004351
1.5	0.004886
		1.6	0.00545
1.7	0.006042
		1.8	0.00666
2	0.007977
		2.2	0.009397
2.4	0.010919
		2.6	0.012539
2.8	0.014258
		3	0.016073
3.3	0.018973

3.6	0.022086
		4	0.026562
4.5	0.032674
		5	0.039353
5.5	0.046595
		6	0.054392
6.5	0.062739
		7	0.07163
8	0.091009
		9	0.113
10	0.136
		11	0.162
12	0.189
		13	0.219
14	0.25
		15	0.283

SRIM calculation level does not overlap with experiment energy point, we utilize Matlab to carry out cubic spline interpolation to calculation level, and the proton range obtaining experimental point E1=1.15MeV, E2=2.42MeV, E3=4.92MeV, E4=14.8MeV corresponding is respectively: X1=0.003144cm, X2=0.011081cm, X3=0.039353cm, X4=0.283cm.

Table 2. single-end neutron experiment scale and corresponding proton calculation of range result

Neutron energy/MeV	Maximum by-pass number	Corresponding proton range/cm
			1.15	65	0.003144
2.42	175	0.011081
			4.92	439	0.039353
14.8	1620	0.283

Parameter corresponding in upper table is substituted into formula then:

$\mathrm{\Δ}E\×({\mathrm{Ch}}_1-{\mathrm{Ch}}_0)=\frac{E_1}{1+kB\frac{E_1}{X_1}}$

$\mathrm{\Δ}E\×({\mathrm{Ch}}_2-{\mathrm{Ch}}_0)=\frac{E_2}{1+kB\frac{E_2}{X_2}}$

$\mathrm{\Δ}E\×({\mathrm{Ch}}_3-{\mathrm{Ch}}_0)=\frac{E_3}{1+kB\frac{E_3}{X_3}}$

$\mathrm{\Δ}E\×({\mathrm{Ch}}_4-{\mathrm{Ch}}_0)=\frac{E_4}{1+kB\frac{E_4}{X_4}}$

Simultaneous solution above formula, unknown number is Δ E, Ch ₀, kB; Because above formula simultaneous is nonhomogeneous ternary quadratic equation group, adopt Analytical Solution way of equation group to be difficult to provide solution of equations, therefore utilize VC++ to develop standard variance min algorithm and calculate this solution of equations.

Suppose Ch ₀namely electronics 0 road scope is between-100-100 road, due to actual electronics 0 road departs from can not be very large, therefore this hypothesis must be set up.Adopt variance min algorithm principle, calculate Ch ₀when between-100-100 road, 4 equations simultaneousness calculating kB1, kB2, kB3, kB4 standard variances are minimum, Ch ₀for actual electronics 0 road.KB value Ch for this reason ₀the mean value of kB1, kB2, kB3, kB4 under condition.Exploitation program interface as shown in Figure 4.

Core code fragment is as follows:

Final calculation result is as shown in the table:

Table 3.kB factor result of calculation

Have developed the Monte-Carlo code based on Geant4, Geant4 program can direct modeling lepton, meson, baryon, boson, random life-span particle, ion etc.Liquid dodges the particle related in response simulation computation process neutron, proton and photon etc., utilizes Geant4 program directly to simulate.6LiF-SSD response simulation calculates the physical process related generally to and comprises: electromagnetic interaction, strong interaction, parameterized procedure and PARTICLE TRANSPORT FROM process.Geant4 simulation tracing neutron, from being transported to generation (n, p) reaction, the transport process of the neutron that reaction produces, proton, electronics and luminescence process, finally provides light output spectrum.From program language, Geant4 adopts object oriented language C++ programming, and inheritance, packaging effects and portability all have more advantage than procedural language Fortran.

Work out main function, defined the necessary initialization class of DetectorConstruction and PhysicsList two and four user behavior classes: RunAction, EventAction (RunAction), PrimaryGeneratorAction (RunAction) and StepAction (RunAction) class.Define the visualization interface based on HepRep visualization engine simultaneously.

In StepAction class, with the addition of the functional procedure of giving out light of proton and electronics based on Birks formula.Specific algorithm is as follows:

1. judge whether have energy deposition in this Step, if there is energy deposition, judgement by what particle is produced, owing to having carried out neutron in actual measurement, gamma has screened, so in calculation procedure, if this particle is photon, then destroy this tracing process and the secondary reaction road that its photon is produced closedown.

If the particle types of the energy deposition of 2. this Step generation is proton

The resolution function of BC501A neutron pulse is as follows:

dL/L＝[A2+(B2/L)+(C2/L2)]1/2

Above formula is neutron pulse amplitude resolution function.A item is the position continuous item of light output for photomultiplier, and B item is statistic fluctuation, and C item is electronic system noise.Parameter can carry out optimized design.Be coupled particular light guide between scintillator and photomultiplier, and A item from (5% drops to 2%), can utilize the photocathode that quantum effect is high, (B ≈ 8%), low Electronics noice (C < 1%)

The proton energy of this step product is obtained by GetTotalEnergyDeposit () function, the path of this step particle is obtained by GetStepLength () function, the luminous function of the Birks obtained by Calibration Experiment, determines the photon number that this step produces.

Because the luminous physical process of reality has random distribution nature, in order to the actual luminescence process of real simulation, Gaussian distribution spreading process must be added.Spread function adopts experimental calibration method to determine.Light output computation process is updated to by testing the spread function determined.Finally obtain the fluorescence number that this Step process is produced by proton.In all Step, the summation of the fluorescence number that proton produces is the fluorescence number produced by recoil proton in this neutron event.

If 3. judging that this Step follows the tracks of particle is electronics

The fluorescence number produced due to electronics and electron energy are linear relationships, test calibration results in EventAction class according to gamma:

ElectronCountPhoto＝ElectronEnergyAbs*206.00152+35.66795；

By above-mentioned three processes, the photon number produced is sued for peace, be the photon number summation that this neutron event produces in all Step by proton and electronics.

Digitizing neutron spectrometer response matrix acquisition methods of the present invention is not limited to above-mentioned embodiment, and those skilled in the art's technical scheme according to the present invention draws and other embodiment belongs to technological innovation scope of the present invention equally.

Claims (7)

1. a digitizing neutron spectrometer response matrix acquisition methods, comprises the following steps:

A, the response function can put in experiment by the single-end neutron of single-end neutron experiment scale acquisition digitizing neutron spectrometer;

B, set up and to solve an equation module, utilize high order nonhomogeneous equation residual error least square method to solve;

C, above-mentioned steps a and step b to be combined, obtain the correlation parameter of the response function of neutron spectrum, i.e. luminosity, zero track position and per pass energy;

D, set up response matrix computing module;

E, obtain the complete response matrix of neutron to be measured.

2. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 1, it is characterized in that: step a) in, described single-end neutron is obtained by swindletron nuclear reaction method, and the energy point pulse amplitude spectrum of each single-end neutron need meet detector response function, i.e. equation

$\mathrm{\&Delta;}E\&times;(Ch-{\mathrm{Ch}}_0)=\frac{dE}{1+kB\frac{dE}{dX}}---\left(4\right)$

Wherein: in (4) formula, Δ E is multiple tracks spectrum energy interval; Ch ₀it is 0 corresponding number of channels; K and B is constant; DE/dx is the energy that charged particle consumes on the unit path of scintillating medium; By the system of equations of simultaneous more than three, obtain corresponding energy Δ E, 0 corresponding number of channels Ch of each single-end neutron experimental point detector per pass ₀and constant kB.

3. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 2, it is characterized in that: in stepb, described high order nonhomogeneous equation residual error least square method solves, adopt and repeatedly attempt algorithm in conjunction with the minimum judgement of variance, final acquisition and all experiments result immediate per pass energy Δ E, zero track position Ch ₀and luminosity kB tri-parameters.

4. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 1, it is characterized in that: in steps d, described response matrix computing module, has worked out main function, defines initialization class and user behavior class, defines visualization interface simultaneously.

5. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 4, is characterized in that: in described user behavior class, is provided with proton and electron luminescence function based on above-mentioned equation (4).

6. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 5, is characterized in that: described response matrix module computing method are as follows:

1) judge whether have energy deposition in minimum simulation material calculation Step, if there is energy deposition, judgement by what particle is produced, if this particle is photon, then destroys this tracing process and the secondary reaction road that its photon is produced closedown.

2) if the particle types of the energy deposition of this minimum simulation material calculation Step generation is proton, then the luminous function that experimental spectrum scale obtains is added, proton sedimentary energy is obtained by GetTotalEnergyDeposit () function, the path of particle is obtained by GetStepLength () function, obtained the luminous function of Birks by Calibration Experiment, determine the photon number that this step produces.

3) if judging that this minimum simulation material calculation Step follows the tracks of particle is electronics, the fluorescence number produced according to electronics and electron energy are linear relationships, the photon number produced by proton and electronics in all minimum simulation material calculation Step is sued for peace, is the photon number summation that this neutron event produces.

7. a kind of digitizing neutron spectrometer response matrix acquisition methods as claimed in claim 6, is characterized in that: in step 2) in, add Gaussian distribution spread function, described Gaussian distribution spread function adopts experimental calibration method to determine.