CN115755153A - Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method - Google Patents
Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method Download PDFInfo
- Publication number
- CN115755153A CN115755153A CN202211392618.8A CN202211392618A CN115755153A CN 115755153 A CN115755153 A CN 115755153A CN 202211392618 A CN202211392618 A CN 202211392618A CN 115755153 A CN115755153 A CN 115755153A
- Authority
- CN
- China
- Prior art keywords
- counting
- tube
- length
- tubes
- counting tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Abstract
The invention relates to the field of nuclear radiation detection, in particular to a device for measuring the neutron multiplicity of different measurement cavities 3 And (5) a He tube matching method. The technical problem to be solved by the invention is as follows: provides a device for measuring the neutron multiplicity of different measurement cavities 3 The He tube matching method is determined on the premise of meeting the size requirement and detection efficiency of the measurement cavity 3 He count tube length, number, spacing distance and layout mode, minimize the total amount of count tube used.
Description
Technical Field
The invention relates to the field of nuclear radiation detection, in particular to a device for measuring the multiplicity of neutrons in different measurement cavities 3 And (5) a He counting tube matching method.
Technical Field
With the development of the nuclear industry, uranium and plutonium materials are increasing worldwide, and the prevention of nuclear diffusion has become a common concern in the international society nowadays. Uranium and plutonium materials can generate fission neutrons, so that the uranium and plutonium materials are the most commonly used means in the field of nuclear security by utilizing a neutron detection technology and combining isotopic abundance to perform nondestructive analysis on the uranium and plutonium materials. In China, the detection of uranium and plutonium materials in nuclear facilities and the classification and treatment of a large amount of radioactive solid wastes generated in long-term operation and decommissioning processes become a difficult task gradually. The development of nuclear radiation detection technology, neutron measurement technology becomes an important means in the field of nondestructive analysis technology of nuclear radiation detection technology, and has important significance in the field of nuclear security, especially nuclear material balance.
The neutron has the characteristics of strong penetrating power and difficulty in shielding, becomes the only feasible and rapid technology capable of meeting the detection requirement when the neutron is subjected to medium-density, high-density and large-volume sample block analysis, and has wide application prospect in the classification detection of the medium-low-emission solid radioactive waste. In the above related fields, the technology plays a positive role in the precise quantitative analysis of U/Pu materials, including conventional sample analysis, warehouse inventory, U/Pu production line closing balance and the like.
The neutron multiplicity measurement technology is a rapid NDA technology for realizing accurate quantitative analysis on nuclear materials by measuring the multiplicity distribution of fission neutrons of the nuclear materials, and standard sample calibration is not needed in the measurement process, so that the influence of standard sample use on the measurement result is avoided. Fission neutrons are temporally related, and the number of neutrons released by a fission event has a certain probability distribution, i.e., a multiplicity distribution. The method can distinguish fission neutrons from non-fission neutrons, so that the interference of the non-fission neutrons and the influence of matrix materials on measurement are reduced to the maximum extent, and the neutron multiplicities can be measured by the following equation:
Singles＝Fεν sf,1 (1+α)M (1)
in the formula, singles, doublets and triplets are respectively the one-fold, the two-fold and the three-fold counting rates, v sf,1 、ν sf,2 V and v sf,3 Respectively, a second and third order factorial moment, v, of the spontaneous fission emission neutron number distribution i1 、ν i2 And v i3 Respectively, the first, second and third order factorial moments of neutron number distribution of fission emission, epsilon is neutron detection efficiency of detector, f d 、f t The two-fold triple coincidence gate factors of the detector are respectively, M is a multiplication coefficient, alpha is the ratio of the number of neutrons to the number of spontaneous fission neutrons, and F is the average reaction rate of the spontaneous fission neutrons.
In order to enable the neutron multiplicity measurement technology to meet the actual requirements of different measurement objects, the neutron multiplicity measurement device needs to be designed according to the volume of the object to be measured and the detection efficiency requirement, and when the neutron multiplicity measurement device meets the same or similar main body structure, electronic system and measurement cavity, the detection efficiency is influenced mainly in the detection assembly 3 The choice of He counter tubes, i.e. the positive correlation of the length and number detection efficiencies, and 3 the configuration structure of the He counting tube, namely the space and the layout mode, is subjected to analog simulation by using MCNPX to obtain the detected neutron number, verify whether the detection efficiency can be met or not, and determine whether the detection efficiency can be met or not according to the verification result 3 And (4) selecting and matching a He counting tube. It is therefore necessary to study a device for measuring the multiplicity of neutrons in different measurement chambers 3 The He counting tube matching method can meet the requirement of quick matching.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: provides a device for measuring the neutron multiplicity of different measurement cavities 3 The He counting tube matching method is used for determining the size requirement of the measurement cavity and the detection efficiency on the premise of meeting the requirement 3 He count tube length, number, spacing distance and layout mode, minimize the total amount of count tube used.
The concept and technical scheme of the invention are described as follows:
the first step is as follows: determining the size of the measuring cavity and the requirement of neutron detection efficiency epsilon, and determining the target with the minimum total amount of the counting tube;
the second step is that: from the diameter of the measurement chamber, determining 3 He counts the number range of the tubes, and selects the value range of the number 3 He counts the number of tubes;
the third step: from the height of the measuring chamber 3 The value range of the length of the He counting tube is selected in the value range of the length 3 He count tube length;
the fourth step: determining 3 The He counting tube can select a layout mode, and one layout mode can be selected in the selectable layout mode;
the fifth step: determining 3 The value range of the space between the He counting tubes is selected 3 The distance between the He counting tubes;
and a sixth step: according to the selection 3 The length, the number, the spacing and the layout mode of the He counting tubes are judged whether the detection efficiency meets the requirements or not through MCNP simulation, the scheme is output if the detection efficiency meets the requirements, and otherwise, the length, the number, the spacing and the layout mode of the He counting tubes are adjusted 3 The length, the number, the spacing distance and the layout mode of the He counting tubes are adopted, and then whether the detection efficiency meets the requirement or not is judged through MCNP simulation until the obtained scheme meets the requirement of the detection efficiency epsilon.
The seventh step: the output meets the requirement of detection efficiency epsilon, and 3 scheme for minimizing He usage as the measurement under the size of measurement cavity 3 And (5) selecting and matching a He counting tube.
The specific implementation steps are as follows:
s1, determining the size requirement phi A multiplied by B of a measuring cavity, wherein A is the diameter of the measuring cavity, B is the height of the measuring cavity, and determining the detection efficiency delta ε A required value of (c);
step S2, establishing 3 An objective function and a constraint condition function of the He counting tube matching method,
wherein L is 3 Length of He counter tubeDegree, N is 3 The number of He counting tubes is equal to the detection efficiency value calculated through MCNP simulation;
and step S3: from the diameter of the measurement chamber, determining 3 The number range of He counting tubes is [ N ] l ，N h ]Wherein N is l To count the lower limit of the number of tubes
N h Is the upper limit of the number of counting tubes
N i Counting the number of tubes each time;
s4, determining the size of the measuring cavity 3 The value range of the He counting tube length is [ L l ，L h ]Wherein L is l Is the lower limit of the length of the counting tube, and L l ＝B，L h Is the upper limit of the length of the counting tube, and 2B is more than or equal to L h >B，L i Taking the value of the length of the counting tube each time;
step S5, according to 3 He count tube diameter, first determine 3 The value range of the He counting tube interval is [ d ] l ，d h ]Wherein d is l To lower limit of the distance between the counting tubes, take d l ＝1，d h Taking d as the upper limit of the counting tube spacing h ＝10，d i Taking values for the interval of the counting tubes each time;
step S6, determining a set of alternative layout methods { p } 1, ... j }；
Step S7, mixing<p j ,N h ,L h ,d l >,<p j ,N h ,L h ,(d l +d h )/2>,<p j ,N h ,L h ,d h >Respectively used as an input item combination to be input into an MCNP model, and the MCNP model is used for simulation to judge whether the detection efficiency meets the requirement, if yes, epsilon is more than or equal to delta ε Determining the spacing and layout method in the entries and moving to step S8 if ε < δ ε Then respectively increasing the upper limit of the number of the counting tubes and the length of the counting tubes by 10 percentUpper limit, go to step S7, let i =1;
step S8, adding p j ，N l ，d i As the determination input items, and,
if epsilon is more than or equal to delta ε Then output<p j ,N l ,L i ,d i >And go to step S11 if ε < δ ε Let i = i +1 and go back to S8 if L i ≥L h If yes, let i =1 go to step S9;
step S9, adding p j ，L l ，d i As the determination input items, and,
if epsilon is larger than or equal to delta ε Then output<p j ,N i ,L l ,d i >And go to step S11 if ε < δ ε Let i = i +1 and go back to S9 if N i ≥N h If yes, let i =2 go to step S10;
step S10, adding p j ，d i As the determination input items, and,
if epsilon is more than or equal to delta ε Then output<p j ,N i ,L i ,d i >And go to step S11 if ε < δ ε If so, let i = i +1, and go back to S10;
and step S11, ending.
Preferably, in step S4, the size of the measurement cavity is determined first 3 The value range of the He counting tube length is [ L l ，L h ]Wherein L is l Is the lower limit of the length of the counting tube, and L l ＝B，L h Is the upper limit of the length of the counting tube, and L h ＝1.25B，L i Taking the value of the length of the counting tube each time;
compared with the prior art, the invention has the advantages that the invention provides a device for measuring the multiplicity of neutrons in different measuring cavities 3 The invention relates to a He counting tube matching method, which fully considers 3 The positive correlation between the length and the number of the He counting tubes and the neutron multiplicity measurement detection efficiency, and the nonlinearity between the spacing and the layout mode and the neutron multiplicity measurement detection efficiency are used, the requirement of national standard related requirements or actual requirements for determining the detection efficiency epsilon are used as targets, the total using amount of the counting tubes is minimized, the counting tube matching scheme meeting the related requirements can be rapidly and effectively determined, and a feasible method facing different measurement cavity requirements is provided.
Drawings
FIG. 1 shows a device for measuring the multiplicity of neutrons 3 He counting tube matching method flow chart
Detailed Description
Following is combined with the attached figure 1, to the neutron multiplicity measuring device of different measuring cavities 3 The He counter tube selection method is explained in detail, and it is obvious that the described embodiment is only a part of examples in the present invention, and not all examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as specifically described herein, and it will be appreciated by those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the present invention and that the present invention is not limited by the specific embodiments disclosed below.
The calculation method of the invention comprises the following steps:
s1, determining the size requirement phi 40cm multiplied by 40cm of a measurement cavity, and determining the detection efficiency delta ε ＝30％；
Step S2, establishing 3 An objective function and a constraint condition function of the He counting tube matching method,
wherein L is 3 Length of He counter tube, N being 3 The number of He counting tubes is equal to the detection efficiency value calculated through MCNP simulation;
and step S3: from the diameter of the measuring chamber 3 The number range of He counting tubes is [ N ] l ，N h ]Wherein N is l Lower limit N for counting tube number l ＝25，N h Upper limit N for counting tube number h ＝52，N i Counting the number of tubes each time;
s4, determining the size of the measuring cavity 3 The value range of the He counting tube length is [ L l ，L h ]Wherein L is l Is the lower limit of the length of the counting tube, and L l ＝40，L h Is the upper limit of the length of the counting tube, and L h ＝50，L i Taking values for the length of the counting tube each time;
step S5, according to 3 He count tube diameter, first determine 3 The value range of the He counting tube spacing is [ d ] l ，d h ]Wherein d is l To lower limit of the distance between the counting tubes, take d l ＝1，d h Taking d as the lower limit of the distance between the counting tubes h ＝10，d i Taking values for the interval of the counting tubes each time;
step S6, determining a set of alternative layout methods { p } 1 = single turn, p 2 = double turn };
step S7, adding<Single turn, 52,50,1>,<Single turn, 52,50,5.5>,<Single turn, 52,50,10>，<Double loop, 52,50,1>,<Double loop, 52,50,5.5>,<Double loop, 52,50,10>Inputting the MCNP model as an input item combination respectively and simulating by the MCNP, wherein<Double loop, 52,50,5.5>The detection efficiency of is epsilon is more than or equal to delta ε Determining the space and the layout method in the input items, and turning to the step S8;
step S8, using the double circle, 25,5.5 as the determination input item, and,
has L i ≥L h And epsilon < delta ε If so, let i =1, go to step S9;
step S9, the double circles, 40,5.5 are used as the determination input items, and,
with N i ≥N h And epsilon < delta ε If so, let i =2, go to step S10;
step S10, adding p j ，d i As the determination input items, and,
when in use<Double loop, 50,48,5.5>If epsilon is more than or equal to 30.7, the output is<Double loop, 50,48,5.5>Device for measuring multiple properties of neutrons in phi 40cm multiplied by 40cm measuring cavity 3 The matching scheme of the He counting tube is changed to the step S11
And step S11, ending.
The above embodiments are provided only for the purpose of describing the present invention, and do not limit the scope of the present invention. Various equivalent substitutions and modifications can be made without departing from the spirit and principles of the invention, and are intended to be included within the scope of the invention.
Claims (2)
1. Device for measuring neutron multiplicity of different measurement cavities 3 The He counting tube matching method is characterized in that the bagThe method comprises the following steps:
s1, determining the size requirement phi A multiplied by B of a measuring cavity, wherein A is the diameter of the measuring cavity, B is the height of the measuring cavity, and determining the detection efficiency delta ε A required value of (c);
step S2, establishing 3 An objective function and a constraint condition function of the He counting tube matching method,
min L×N
stε≥δ ε
wherein L is 3 Length of He counter tube, N being 3 The number of the He counting tubes is equal to epsilon, and the epsilon is a detection efficiency value calculated through MCNP simulation;
and step S3: from the diameter of the measurement chamber, determining 3 The number range of He counting tubes is [ N ] l ，N h ]Wherein N is l To count the lower limit of the number of tubes
N h Is the upper limit of the number of counting tubes
N i Counting the number of tubes each time;
s4, determining the size of the measuring cavity 3 The value range of the He counting tube length is [ L l ，L h ]Wherein, L l Is the lower limit of the length of the counting tube, and L l ＝B，L h Is the upper limit of the length of the counting tube, and 2B is more than or equal to L h >B，L i Taking the value of the length of the counting tube each time;
step S5, according to 3 He count tube diameter, first determine 3 The value range of the He counting tube spacing is [ d ] l ，d h ]Wherein d is l To lower limit of the tube pitch, take d l ＝1，d h Taking d as the upper limit of the interval of the counting tubes h ＝10，d i Taking values for the interval of the counting tubes each time;
step S6, determining a set of alternative layout methods { p } 1,...j }；
Step S7Will be<p j ,N h ,L h ,d l >,<p j ,N h ,L h ,(d l +d h )/2>,<p j ,N h ,L h ,d h >Respectively used as an input item combination to be input into an MCNP model, and the MCNP model is used for simulation to judge whether the detection efficiency meets the requirement, if yes, epsilon is more than or equal to delta ε Determining the spacing and layout method in the entries and moving to step S8 if ε < δ ε Respectively increasing the upper limit of the number of the counting tubes and the upper limit of the length of the counting tubes by 10%, and turning to the step S7 to enable i =1;
step S8, adding p j ，N l ，d i As the determination input items, and,
if epsilon is larger than or equal to delta ε Then output<p j ,N l ,L i ,d i >And go to step S11 if ε < δ ε Let i = i +1 and go back to S8 if L i ≥L h If yes, let i =1 go to step S9;
step S9, adding p j ，L l ，d i As the determination input items, and,
if epsilon is more than or equal to delta ε Then output<p j ,N i ,L l ,d i >And go to step S11 if ε < δ ε Let i = i +1 and go back to S9 if N i ≥N h If yes, let i =2 go to step S10;
step S10, adding p j ，d i As the determination input items, and,
if epsilon is larger than or equal to delta ε Then output<p j ,N i ,L i ,d i >And go to step S11 if ε < δ ε If so, let i = i +1, and go back to S10;
and step S11, ending.
2. The device of claim 1 for measuring the multiplicity of neutrons in different measurement chambers 3 The He counting tube selecting and matching method is characterized in that the step S4 is to firstly determine the size of the measuring cavity 3 The value range of the He counting tube length is [ L l ，L h ]Wherein L is l Is the lower limit of the length of the counting tube, and L l ＝B，L h Is the upper limit of the length of the counting tube, and L h ＝1.25B，L i And taking the value of the length of the counting tube each time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211392618.8A CN115755153A (en) | 2022-11-08 | 2022-11-08 | Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211392618.8A CN115755153A (en) | 2022-11-08 | 2022-11-08 | Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115755153A true CN115755153A (en) | 2023-03-07 |
Family
ID=85368618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211392618.8A Pending CN115755153A (en) | 2022-11-08 | 2022-11-08 | Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115755153A (en) |
-
2022
- 2022-11-08 CN CN202211392618.8A patent/CN115755153A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Abbondanno et al. | New experimental validation of the pulse height weighting technique for capture cross-section measurements | |
| Argan et al. | Two-body photodisintegration of 3He and 4He in the Δ (1236) region | |
| Chichester et al. | Statistical estimation of the performance of a fast-neutron multiplicity system for nuclear material accountancy | |
| Boyer et al. | Determination of the 233Pa (n, γ) capture cross section up to neutron energies of 1 MeV using the transfer reaction 232Th (3He, p) 234Pa∗ | |
| Mihailescu et al. | A measurement of (n, xnγ) cross sections for 208Pb from threshold up to 20 MeV | |
| Ogren et al. | Discriminating uranium isotopes based on fission signatures induced by delayed neutrons | |
| Neudecker et al. | Templates of expected measurement uncertainties for average prompt and total fission neutron multiplicities | |
| Valentine | Review of subcritical source-driven noise analysis measurements | |
| Seo et al. | Optimization of hybrid-type instrumentation for Pu accountancy of U/TRU ingot in pyroprocessing | |
| Menlove et al. | Manual for the epithermal neutron multiplicity detector (ENMC) for measurement of impure MOX and plutonium samples | |
| CN115755153A (en) | Device for measuring neutron multiplicity of different measurement cavities 3 He counting tube matching method | |
| Croft et al. | The measurement of passive neutron multiplicity counter gate utilisation factors and comparisons with theory | |
| Weldon Jr et al. | Preliminary RAM-RODD results for the MUSiC subcritical configurations | |
| Boutoux et al. | The extrapolated-efficiency method, a new technique to determine the γ-cascade detection efficiency in experiments based on the surrogate-reaction method | |
| Goddard et al. | Evaluation of Am–Li neutron spectra data for active well type neutron multiplicity measurements of uranium | |
| Simone et al. | Performance of a boron-coated-straw-based HLNCC for international safeguards applications | |
| Hollas et al. | Determination of neutron multiplication of subcritical HEU systems using delayed neutrons | |
| Bourva et al. | Monte Carlo calculations of the neutron coincidence gate utilisation factor for passive neutron coincidence counting | |
| Seo et al. | Development of prototype induced-fission-based Pu accountancy instrument for safeguards applications | |
| Seo et al. | ASNC upgrade for nuclear material accountancy of ACPF | |
| Peerani et al. | Computational modelling of NDA instruments for nuclear safeguards | |
| El-Gammal et al. | A proposed semi-empirical method for 235U mass calibration of the active-well neutron coincidence counter | |
| Jurado et al. | Investigation of the surrogate-reaction method via the simultaneous measurement of gamma-emission and fission probabilities | |
| van Belle et al. | Calibration of the JET neutron yield monitors using the delayed neutron counting technique | |
| Peerani et al. | Non-Destructive Assay for Nuclear Safeguards |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |