Spectrum unfolding method for neutron energy spectrum with integral weight

A neutron and energy spectrum technology, applied in the field of weighted neutron energy spectrum analysis, can solve problems such as incorrect spectrum analysis, incomplete measurement of activation rate, and no weight of activation foil

A neutron and energy spectrum technology, applied in the field of weighted neutron energy spectrum analysis, can solve problems such as incorrect spectrum analysis, incomplete measurement of activation rate, and no weight of activation foil

CN106569251AInactive Publication Date: 2017-04-19NORTHWEST INST OF NUCLEAR TECH
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  • Spectrum unfolding method for neutron energy spectrum with integral weight
  • Spectrum unfolding method for neutron energy spectrum with integral weight
  • Spectrum unfolding method for neutron energy spectrum with integral weight

Examples

Experimental program
Comparison scheme
Effect test

specific Embodiment approach

[0081] 1. Irradiate a series of activated foils in the neutron radiation field to be measured. These activated foils are irradiated to induce radioactivity. After the irradiation is over, take out these activated foils, measure their radioactivity, and process to obtain the measured activation rate. (is the method's data preparation).

[0082] 2. Use MCNP software or past experience data to calculate or estimate a hypothetical neutron spectrum (data preparation for the method)

[0083] 3. Divide the neutron energy spectrum to be measured into N energy groups, then

[0084]

[0085] In the formula: A i measure the mononuclear activation rate for experiments with the i-th nucleus;

[0086] A ij is the activation rate of the interaction between the i-th nucleus and the j-th group of neutrons;

[0087] σ ij is the activation cross section of the i-th nuclear reaction interacting with the j-th group of neutrons, cm 2 ;

[0088] Φ j is the neutron flux density in the jth ...

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Abstract

The invention provides a spectrum unfolding method for a neutron energy spectrum with integral weight. An activation foil weight factor is introduced into an iterative process, and a new truncation condition and a morbid data culling method are used. Neutron energy spectrum unfolding is accurately completed under a condition consistent with the physical reality. The method is based on statistical theory to deduce that the judgment truncation condition has a theoretical basis and is more in line with the physical reality compared with error truncation and truncation of iteration number of times of other methods.

Description

technical field [0001] The invention belongs to the technical field of nuclear testing, in particular to a weighted neutron spectrum resolution method. Background technique [0002] When the multi-foil activation method is used to measure the neutron energy spectrum, a group of foil detectors with known cross-sections are put into the neutron field to be irradiated. Due to the nuclear reaction between the neutrons and the detectors, the irradiated foil detectors It is activated to produce induced radioactivity; by measuring the radioactivity of the foil detector after irradiation, the mononuclear activation rate of a group of nuclides can be obtained, and the relationship between the irradiated neutron energy spectrum and the mononuclear activation rate can be determined. Measure the neutron spectrum. [0003] Under steady-state conditions, the illuminated foil detector satisfies the activation equation: [0004] [0005] In the formula: I is the total number of activat...

Claims

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Application Information

Patent Timeline
19 Apr 2017
Publication
CN106569251A
IPC
G01T3/00
CPC
G01T3/001
Inventors
李达; 余小任