Spectrum unfolding method for neutron energy spectrum with integral weight

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...

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Problems solved by technology

[0034] 1. The truncation condition is inaccurate. The goal of solving the spectrum is to achieve formula (5), but in fact, considering that the measured activation rate is not completely correct, it should be more correct to achieve the deviation between the measured activation rate and the calculated activation rate in line with statistical expectations.

Therefore, the error is not as small as possible

[0035] 2. The activation foil has no weight. The activation foil itself has energy coverage. Small weight is right

Method 2) or in the method published now, the weight is not reflected, that is, an activated foil with a small response to neutrons, if it is in the activated foil group, it also plays a greater role in the neutron energy spectrum when decomposing the spectrum. effect, which is obviously inappropriate

[0036] 3. Due to the existence of errors in the activated foil data, sometimes there will be conflicts and incorrect spectral interpretation. In this case, it is necessary to remove the activated foils that are inconsistent with other activated foils. The elimination method used to be based on experience and trial and error.

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