CN203786305U

CN203786305U - Multi-unit 4 [Pi] solid angle detection system of Gd carrier liquid scintillation

Info

Publication number: CN203786305U
Application number: CN201320831119.4U
Authority: CN
Inventors: 于国梁
Original assignee: North China Electric Power University
Current assignee: North China Electric Power University
Priority date: 2013-12-07
Filing date: 2013-12-07
Publication date: 2014-08-20
Anticipated expiration: 2023-12-07

Abstract

The utility model relates to a multi-unit 4 [Pi] solid angle detection system of a Gd carrier liquid scintillation; the multi-unit 4 [Pi] solid angle detection system comprises 10 regular pentagon detectors and 30 regular hexagon detectors; each regular pentagon detector is surrounded and seamlessly connected by 5 hexagon detectors; a housing of the Gd carrier liquid scintillation detector is hard aluminium having preferably thickness of 3mm; an EJ-331 type liquid scintillation is arranged in the Gd carrier liquid scintillation detector; the liquid scintillation is doped with Gd isotope of mass percent concentration being 0.5%. The multi-unit 4 [Pi] solid angle detection system can reduce dead time, improves detection efficiency, and has certain (n, gamma) distinguish ability.

Description

The multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle in a kind of year

Technical field

The utility model belongs to neutronics field, is specifically related to the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle in a kind of year.

Background technology

(n, 2n) nuclear reaction plays the value-added effect of neutron in reactor, so the Measurement accuracy of (n, 2n) reaction cross-section of fissionable nucleus has very important significance aspect utilizing in nuclear energy and nuclear technology ^[1].People adopt several different methods to carry out this work, and activation method is a kind of means of wherein commonly using, but it requires residual nucleus to have the suitable half life period, and in addition, the purity of the method to sample and the intensity of neutron source have higher requirement ^[2].Prompt gamma ray method is a kind of measuring method combining with nuclear reaction theoretical model, but it depends on nuclear reaction theoretical model strongly, brings larger uncertainty to measurement result ^[2].

As the one of the direct method of measurement, the large scintillating liquid ball method that the people such as Frehaut proposed in 1976 has higher detection efficiency, its ultimate principle is, the liquid scintillator that carries Gd is housed in the spherical container of two halves, container embedding is around with tens photomultipliers, in order to collect light pulse signal.Monoenergetic pulsed neutron source irradiates the sample that is positioned at system geometric center after collimation, and the neutron that neutron and sample occur to produce after (n, 2n) nuclear reaction is dodged slowing down by liquid very soon, and produces neutron pulse (being commonly referred to fast signal).Because Gd isotope has higher thermal-neutron capture cross-section, so neutron is finally captured by Gd.Can launch in the Gd of excited state isotope the successive gamma ray that gross energy is 8MeV left and right, the pulse signal that these gamma-rays cause is called slow signal, by can determine the size of (n, 2n) reaction cross-section to the measurement of this successive gamma ray.This method has higher neutron detection efficiency (80% left and right), does not rely on nuclear reaction theoretical model, to the half life period of residual nucleus also not requirement.But this method, in the time measuring (n, 2n) cross section of fissionable nucleus, can not be distinguished two neutron events and derive from (n, 2n) reaction or fission reaction.In addition, system has larger sensitive volume, and it is obvious that gamma-ray in environment, sample meets additive effect, and this has caused higher γ background.Because the gamma-rays producing in detection system can make all photomultiplier responses, make system there is too high counting rate.

Utility model content

For above-mentioned problems of the prior art, the utility model provides a kind of have higher neutron detection efficiency, stronger (n, γ) the multiple-unit 4 π solid angle detection systems in resolving power and lower dead time, the utility model is formed, is applicable to the detection system of the multiple-unit 4 π solid angles of the surveying work that (n, 2n) nuclear reaction cross section is lower by 40 liquid scintillator detectors.

To achieve these goals, the utility model is taked following technical scheme:

The multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle in a kind of year, formed by 40 liquid scintillator detectors that carry Gd, the liquid scintillator detector shape of cross section of described year Gd is respectively pentagon and hexagon, the utility model comprises detector and 30 hexagon detectors of 10 regular pentagons, 5 hexagon detectors of surrounding's seamless link of described regular pentagon detector, described 40 liquid scintillator detector xsects that carry Gd have formed a ball inpolyhedron, a cavity is left at described detection system center, be used for placing testing sample, be provided with neutron streaming passage along ball inpolyhedron central shaft.

Further, described neutron streaming channel cross-section is regular pentagon.

The liquid scintillator detector shell of described year Gd is duralumin, and described duralumin thickness is preferably 3mm.

The liquid that EJ-331 type is housed in the liquid scintillator detector of described year Gd dodges, and liquid is mixed the Gd isotope taking mass percent concentration as 0.5% in dodging.

Further, between detector, be screwed.

Described detection system cavity radius is 15cm.

Preferably, the thickness of described detection system detector is 30cm.

The length of side of the forward and backward xsect of positive 5 limit shape detector is respectively 5.24cm and 15.71cm, and the length of side of hexagon detector front and rear surfaces is 5.24cm, 6.03cm and 15.71cm, 18.08cm.

The thickness of described regular pentagon and hexagon detector is 30cm.

C, the H ratio of institute's liquid of containing sudden strain of a muscle is about 3:4 in detector, and density is 0.87g/cm ³, the mass density of mixing after Gd is 0.9g/cm ³.

The beneficial effects of the utility model are:

1) this multiunit structure can reduce the counting rate of single detector, thereby reduces the dead time.

2) it also has certain (n, γ) resolving power, can effectively reduce the impact of environmental γ background on measurement result, at (the n to fissionable nucleus, when 2n) cross section is measured, sample is placed in fission chamber, does anticoincidence with fission chamber signal and can reduce the impact of fission neutron on measurement result.

3) be many targets sheet fast fission chamber for the fission chamber of this detection system, there is approximately 90% detection efficiency.

4) fission chamber and this liquid dodge this research platform that detection system forms, and also can be used for the measurement in (n, 2n) cross section of non-fissioning nucleus, and the measurement of the distribution of the angle of neutron and angular correlation etc.

Brief description of the drawings

Fig. 1 is structural representation of the present utility model;

Fig. 2 is neutron streaming access diagram;

Fig. 3 is regular pentagon panel detector structure schematic diagram;

Fig. 4 is hexagon panel detector structure schematic diagram;

Fig. 5 is regular pentagon detector xsect;

Fig. 6 is hexagon detector xsect.

In figure, 1-ball inpolyhedron, 2-regular pentagon detector, 3-hexagon detector, 4-neutron streaming passage.

Embodiment

For the ease of understanding, below in conjunction with accompanying drawing, by embodiment, the utility model is further described in detail:

The multiple-unit 4 π solid angle detection systems that year Gd liquid dodges, comprise ball inpolyhedron 1; In described ball inpolyhedron 1, be provided with 2 and 30 hexagon detectors 3 of ten regular pentagon detectors;

Five hexagon detectors 3 of surrounding's seamless link of described each regular pentagon detector 2.In order to cover the solid angle that approaches 4 π, every two the adjacent probe units of detection system are all realized seamless link, and simultaneously in order there to be equal efficiency, each unit all has approximately uniform solid angle to system geometric center.The xsect that meets each probe unit of above condition has formed a ball inpolyhedron 1; The cavity that Radius is 15cm is left at described detection system center, for placing testing sample.

Be provided with along ball inpolyhedron central shaft the neutron streaming passage 4 that xsect is regular pentagon.

Shell in described each regular pentagon detector 2 and hexagon detector 3 is duralumin, and described duralumin thickness is preferably 3mm; The liquid that EJ-331 type is housed in each regular pentagon detector 2 and hexagon detector 3 dodges, and liquid is mixed the Gd isotope taking mass percent concentration as 0.5% in dodging.C, the H ratio of institute's liquid of containing sudden strain of a muscle is about 3:4 in detector, and density is 0.87g/cm ³, the mass density of mixing after Gd is 0.9g/cm ³.

Between described each regular pentagon detector 2 and hexagon detector 3, be screwed.

As shown in the figure, the length of side of regular pentagon detector 2 forward and backward xsects is respectively 5.24cm and 15.71cm to single detector structure, and the length of side of hexagon detector 3 front and rear surfaces is 5.24cm, 6.03cm and 15.71cm, 18.08cm.The thickness of regular pentagon detector 2 and hexagon detector 3 is all 30cm.

Claims

1. one kind carries the multiple-unit 4 π solid angle detection systems that Gd liquid dodges, formed by 40 liquid scintillator detectors that carry Gd, the liquid scintillator detector shape of cross section of described year Gd is respectively pentagon and hexagon, described detector is regular pentagon detector and hexagon detector, the liquid scintillator detector shell of described year Gd is duralumin, described 40 liquid scintillator detector xsects that carry Gd have formed a ball inpolyhedron, the liquid that EJ-331 type is housed in the liquid scintillator detector of described year Gd dodges, liquid is mixed the Gd isotope taking mass percent concentration as 0.5% in dodging, a cavity is left at described detection system center, in order to place testing sample, be provided with neutron streaming passage along ball inpolyhedron central shaft.

2. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 1 year, it is characterized in that: the liquid scintillator detector of 40 years Gd comprises detector and 30 hexagon detectors of 10 regular pentagons, 5 hexagon detectors of surrounding's seamless link of described each regular pentagon detector.

3. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 1 and 2 year, is characterized in that: the thickness of described detector is 30cm.

4. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 1 and 2 year, it is characterized in that: the length of side of the forward and backward xsect of described regular pentagon detector is respectively 5.24cm and 15.71cm, the length of side of hexagon detector front and rear surfaces is 5.24cm, 6.03cm and 15.71cm, 18.08cm.

5. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 4 year, is characterized in that: the thickness of described regular pentagon and hexagon detector is 30cm.

6. the multiple-unit 4 π solid angle detection systems that according to claim 5 year Gd liquid dodges, is characterized in that: C, the H ratio that in detector, institute's liquid of containing dodges is 3:4, and density is 0.87g/cm ³, the mass density of mixing after Gd is 0.9g/cm ³.

7. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 6 year, is characterized in that: between described detector, be screwed.

8. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 7 year, is characterized in that: described duralumin thickness is 3mm.

9. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 8 year, is characterized in that: described neutron streaming channel cross-section is regular pentagon.

10. the multiple-unit 4 π solid angle detection systems of Gd liquid sudden strain of a muscle according to claim 9 year, is characterized in that: described detection system cavity radius is 15cm.