CN105425273A - Apparatus and method of absorber array for measuring high flux X-ray power spectrum - Google Patents

Abstract

The invention discloses an apparatus and method of an absorber array for measuring high flux X-ray power spectrum. The apparatus includes a lead collimating body, absorber arrays and photoelectric detectors. A row of holes is disposed inside the lead collimating body. The front portion of each hole is a collimating hole used for holding one corresponding absorber array. The rear portion of each hole is a photoelectric detector containing hole used for containing one corresponding photoelectric detector. The collimating holes and the photoelectric detector containing holes are coaxial and connected with each other, but are different in diameter. The absorber arrays and the photoelectric detectors are arranged next to each other. X rays pass through the collimating holes and also are partially attenuated by the built-in absorber arrays, and outgoing X rays are detected by the photoelectric detectors. The collimating holes, absorbers and the detectors are installed in the same body, the adopted equal energy interval design principle enables a group of measured data to be discrete and to less affect each other, and therefore the spectrum unfolding is more accurate.

Description

A kind of device and method of the absorber array for measuring high flux X-ray energy spectrum

Technical field

The present invention relates to a kind of device and method of the absorber array for measuring high flux X-ray energy spectrum, belonging to X-ray energy spectrum field of measuring technique.

Background technology

The power spectrum of current domestic measurement high flux medium energy X_ray has multiple method, wherein has MLS (Multi-LayerStack) method, harmonics elimination etc.

MLS method is that one deck medium and detector form one and detect and save, and multiple detection joint is along measuring axle lineal layout and composition measuring apparatus.The intensity of multilayered medium to X ray repeatedly decays, pass through response function, solve ray energy spectrum (see " the MLS method for high-energy X-rays spectral measurement " Chen Nan, Jing Xiaobing, peak, Zhang Linwen, cloudy pool is outstanding, Li Shiping, Fluid Physics Inst., China Engineering Physics Academy, modern physics system of China Science & Technology University).As shown in Figure 1, one deck medium and a detector are alternately placed, and have a detector, thus can obtain a series of by the X-ray intensity after Absorption of Medium, by certain anti-resolving Algorithm, calculate X-ray energy spectrum after every layer of medium.

Harmonics elimination is that incident X ray changes fluorescence into after filter disc, is detected device and receives, by fluorescent line computing formula, calculate the power spectrum of X ray.(see " filtering one fluorescence method measures the analog computation of x-ray spectroscopy " Wang Dong, nuclear physics and chemistry institute)

Prior-art devices shortcoming is structurally that volume is large, inconvenient operation; Shortcoming is technically, the data after absorber or filter disc, inevitably there is certain crosstalk each other, the final anti-degree of accuracy of separating power spectrum of impact.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome high flux X-ray energy spectrum measurement mechanism volume large, inconvenient operation, crosstalk between data, the coarse deficiency of spectrum unscrambling, provides a kind of device and method of the absorber array for measuring high flux X-ray energy spectrum, and its collection collimating aperture, absorber, detector are placed in one, adopt the principle of design at homenergic interval, make one group of data of measurement more discrete, influence each other little, thus spectrum unscrambling is more accurate.

Technical solution of the present invention: a kind of absorber array apparatus for measuring high flux X-ray energy spectrum, comprising: plumbous collimation body, photodetector, absorber array.Have a round in lead collimation body inside, the forward part in hole is collimating aperture, for placing absorber array, the rear portion in hole is divided into photodetector placement hole, for installing photodetector, collimating aperture and photodetector placement hole are link together coaxial, but pore diameter size is different.X ray is by collimating aperture, and decayed by the absorber array portion of built-in different length, the X ray of outgoing is detected by photodetector simultaneously.

Absorber array is made up of the absorber of different length, and absorber is placed in collimating aperture, and photodetector is placed in photodetector placement hole, because two holes are spatially adjacent, so absorber array and photodetector are adjacent.The Design of length principle of absorber array is homenergic interval decay principle, namely when the X-ray energy of incidence in tested energy range be uniformly distributed time, after the decay of absorber array, the energy attenuation of the X ray of outgoing is equally spaced.

When the X-ray energy of incidence in tested energy range be uniformly distributed time, emanated energy is respectively the 100%-x of incident gross energy, 100%-2x, 100%-3x ... 100%-nx, (0<x<1/n), n represents absorber array number, and x represents attenuation percentage.

Collimating aperture is adjacent array type collimating aperture, mutual close together, but crosstalk does not occur again each other, and the diameter of collimating aperture is determined according to the flux of incident X-rays and required spatial resolution.

Described collimating aperture is adjacent array type collimating aperture, mutual close together, but crosstalk does not occur again each other, and such as, when highest energy is 200K, the spacing between adjacent hole wall is that 4.7mm can ensure do not have crosstalk between hole.The diameter of collimating aperture is determined according to the flux of incident X-rays and required spatial resolution, and such as, when requiring 0.6m external space resolution 2cm, the diameter of this hole when is 2mm length is 80mm.The arrangement mode of described array type collimating aperture be circular arrangement or the arrangement of some rows.

For measuring an absorber array approach for high flux X-ray energy spectrum, performing step is as follows:

(1) incident X-rays is collimated through collimating aperture, is built in the absorber array portion decay in collimating aperture simultaneously;

(2) X ray of outgoing is detected by photodetector, spreads out of the electronic system of outside;

(3) main electronic system detects the intensity of the X ray of one group of outgoing;

(4) by the response function of absorber array, in conjunction with certain algorithm, the anti-power spectrum solving incident X-rays.

The present invention's advantage is compared with prior art:

(1) apparatus of the present invention collect collimation body, absorber, detector be arranged as one, and structure is ingenious, compact, easy to use.Existing various device, collimation body, absorber array, detector are settled and are separated, and the large use of volume is inconvenient.

(2) the absorber selection principle of different length is homenergic interval, this brand-new design philosophy, and advantage is that measurement data compares dispersion, and do not interfere with each other mutually, therefore error is little, and the X-ray energy spectrum obtained thus is more accurate, measures energy spectrum larger., inevitably there is the mutual crosstalk between data in existing measuring method, affects the scope of measuring accuracy and measurement power spectrum.

Accompanying drawing explanation

Fig. 1 is that MLS method measures X-ray energy spectrum;

Fig. 2 is the absorber array measurement device overall schematic in the inventive method;

Fig. 3 collimates body front schematic view in the present invention;

Fig. 4 collimates body schematic rear view in the present invention;

Fig. 5 is absorber array schematic diagram in the present invention;

Fig. 6 is the relation curve of transmission X-ray energy and absorber length.

Embodiment

As shown in Figure 2, apparatus of the present invention comprise collimation body 1, collimating aperture 2, detector placement hole 3, built-in absorber array 4, detector 5.

Figure 3 shows that plumbous matter collimation body front, it having row's diameter be the 2mm degree of depth to be the collimating aperture 2 of 80mm, for placing aluminium matter absorber array 4.

The body back side of collimation shown in Fig. 4 is detector placement hole 3, and diameter is the 6.3mm degree of depth is 20mm.Spacing between adjacent holes axle is 11mm.Plumbous matter collimation body, not only can the X ray of collimated incident, can also shield the crosstalk between external interference and each passage.

Figure 5 shows that the array 4 that the aluminium matter absorber of different length is formed, the Design of length principle of absorber array is homenergic interval decay principle, length is respectively 3mm, 6mm, 9mm, 13mm, 19mm, 25mm, 36mm, 54mm is namely after absorber decay, and the energy attenuation of the X ray of outgoing is equally spaced.When the X-ray energy of incidence in tested energy range be uniformly distributed time, emanated energy is respectively 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% of incident gross energy, as shown in Figure 6.

X ray passes through collimating aperture, decayed by the absorber part of built-in different length simultaneously, the X ray of outgoing is detected by photoelectric probe, the varying strength of the X ray after a series of decay is obtained through the process of backend electronics system, again in conjunction with the response function of absorber, utilize anti-resolving Algorithm, the power spectrum of anti-X ray when solving high flux.

Anti-resolving Algorithm is as follows:

If X-ray energy spectrum is by ENERGY E discretize, Q conventional point E can be obtained _k, then the discrete power spectrum of X ray can be expressed as namely energy is E _kthe intensity share of X ray, wherein K=1,2 ..., Q;

One has 8 detectors, and the absorbed thickness that i-th detector is corresponding is d _i, i=1,2 ..., 8, be E for energy _kx ray, if its do not decayed by absorber before intensity be I ₀(E _k), and set the absorption coefficient of absorber as μ (E _k), then absorber the decaying to X ray that i-th detector is corresponding:

$\frac{I_i\left(E_k\right)}{I_0\left(E_k\right)}=e^{-u\left(E_k\right)d_i}$

Wherein I _i(E _k) for energy be E _kx ray through thickness be d _iabsorber after intensity in transmission, i=1 ..., 8, so the total intensity of X ray that i-th detector receives is:

$I_{\det \mathrm{ected}}^i=\underset{k=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&epsiv;}\left(E_k\right)I_0\left(E_k\right)e^{-\mathrm{\&mu;}\left(E_k\right)d_i}$

ε (E _k) be detector be E to energy _kthe detection efficiency of X ray.

Wherein, ε (E _k), μ (E _k), d _iknown quantity, can be obtained in conjunction with electronic system measurement by detector.Therefore only I is had ₀(E _k) be unknown number, be equivalent to a Q unit linear function group.

Measured string number is less than pulse height and quantizes number Q, needs to adopt iteration in conjunction with the method for MC to separate this system of equations.

This measuring method is for medium energy X_ray plasma measurement system at present, measures and obtains high flux X-ray energy spectrum, achieve good effect.

There is provided above embodiment to be only used to describe object of the present invention, and do not really want to limit the scope of the invention.Scope of the present invention is defined by the following claims.Do not depart from spirit of the present invention and principle and the various equivalent substitutions and modifications made, all should contain within the scope of the present invention.

Claims (7)

1. one kind for measuring the absorber array apparatus of high flux X-ray energy spectrum, it is characterized in that comprising: plumbous collimation body (1), absorber array (4), photodetector (5), a round is had in lead collimation body (1) inside, the forward part of one round is collimating aperture (2), for placing absorber array (4), the rear portion of one round is divided into photodetector placement hole (3), for installing photodetector (5), collimating aperture (2) is coaxial with photodetector placement hole (3) and be connected, but pore diameter size is different, absorber array (4) and photodetector (5) are close to placement, X ray is by collimating aperture (2) simultaneously by the decay of built-in absorber array (4) part, and the X ray of outgoing is detected by photodetector (5).

2. the absorber array apparatus for measuring high flux X-ray energy spectrum according to claim 1, is characterized in that: described absorber array (4) is made up of the absorber of different length, and each absorber is placed in collimating aperture (2).

3. the absorber array apparatus for measuring high flux X-ray energy spectrum according to claim 1, it is characterized in that: the Design of length principle of described absorber array (4) is homenergic interval decay principle, namely when the X-ray energy of incidence in tested energy range be uniformly distributed time, after the decay of absorber array, the energy attenuation of the X ray of outgoing is equally spaced.

4. the absorber array apparatus for measuring high flux X-ray energy spectrum according to claim 1, it is characterized in that: when the X-ray energy of incidence in tested energy range be uniformly distributed time, the X-ray energy of described outgoing is respectively the 100%-x of incident gross energy, 100%-2x, 100%-3x ... 100%-nx, 0<x<1/n, n represent absorber array number, and x represents attenuation percentage.

5. the absorber array apparatus for measuring high flux X-ray energy spectrum according to claim 1, it is characterized in that: described collimating aperture (2) is adjacent array type collimating aperture and the mutual close together of collimating aperture, when highest energy is 200K, spacing between adjacent hole wall is 4.7mm, ensures do not have crosstalk between hole; The diameter of collimating aperture (2) is determined according to the flux of incident X-rays and required spatial resolution, and when requiring 0.6m external space resolution 2cm, the diameter of this hole when is 2mm length is 80mm.

6. the absorber array apparatus for measuring high flux X-ray energy spectrum according to claim 5, is characterized in that: the arrangement for circular arrangement or some rows of the arrangement mode of described array type collimating aperture.

7., for measuring an absorber array approach for high flux X-ray energy spectrum, it is characterized in that performing step is as follows:

(1) incident X-rays is collimated through collimating aperture, is built in the absorber array portion decay in collimating aperture simultaneously;

(2) X ray of outgoing is detected by photodetector, spreads out of the electronic system of outside;

(3) main electronic system detects the intensity of the X ray of one group of outgoing;

(4) by the response function of absorber array, in conjunction with certain algorithm, the anti-power spectrum solving incident X-rays.