TW200819778A - Mesurement and calibration method of volume source calibration phantom - Google Patents

Abstract

A volume calibration phantoms is disclosed in the present invention, which comprises a container; a plurality of plates stacking up inside the container, at least one slab of radioactive source, each of which is disposed between the adjacent plates and comprises a plurality of radionuclides. With the volume calibration phantoms, the present invention further provides a calibration method which is an improvement over conventional calibration methods of space geometric center point source and relative penetration factor ratios. The method comprises the steps of generating a calibration curve of density vs. counting efficiency corresponding to the several different volume calibration phantoms; calculating the density of a radioactive waste specimen to obtain a corresponding radioactive activity according to the calibration curve, and then revising the corresponding radioactive activity according to the energy dependency and equation of gamma gross radioactivity for multiple radionuclides so as to obtain the correct gamma gross radioactivity of the radioactive waste specimen. By means of the method disclosed in the present invention, a precise and accurate result can be obtained.

Description

200819778 IX. INSTRUCTIONS: [Technical Field] The present invention relates to a correction prosthesis and a correction method, and more particularly to a calibration curve for directly using a body source correction prosthesis of different densities to obtain density and measurement efficiency. According to the measurement of the density of the nuclear waste sample to be measured, the total efficiency of the nuclear waste samples of different materials can be measured, and the total activity of the nuclear waste samples can be measured. A body source calibration prosthesis and a method for measuring and correcting the same. [Prior Art] As far as the purpose is concerned, the total activity of the extremely low activity volume nuclear waste is measured by the waste activity monitoring of the large area of the scintillation mixture (Waste Curie Monitor). The advantages are high radiation sensitivity, =I rate, short sample measurement time, unlimited waste volume, and the weight of the waste sample. However, the calibration method of the conventional waste activity monitor has the following disadvantages: (1) the measurement of the low or the overestimation of the live measurement, usually considering only the weight and neglecting the density self-absorption effect caused by the density of the sample material of the discarded material. (2) Measurement application, generally use single substance in the shield of the monitor to build the function ^ efficiency 'ignoring the sample non-single material composition (7) sample measurement position fish; ^ in / f sample correction law (four) placed in the screen (four) There is an error in the position of the inner and lower azimuths. (4) The sample volume does not match, the distance between the device and the volume is different from the volume, and the efficiency of the correction is determined by the safety of each of the scintillation detection safety managers. Therefore, the radiation protection μ reading activity cannot be satisfied. / knife analysis accuracy requirements. (5) There is no correction for the total live measurement error caused by the radiant energy of various nuclear species in the waste sample and the multi-nuclear species plus the horse activity meter. In recent years, researchers have further developed 玎 to replace the original method of correcting the source efficiency of the geometric center point of the activity monitor, and to perform the measurement of the total activity of nuclear waste plus horses as a judgment of nuclear waste and general non-radiation waste. Classification of objects, the current efficiency correction method for plastic scintillation detectors is (1) Themo-Eberline Company uses the transmission factor to correct the self-absorption effects of different standard masses. The formula is TF = net of shielded source. Count/ranly shield the net count of the source, its general TFS1·〇, as the compensation efficiency of the shielded source at the geometric center in the compensation air, and the penetration of the water prosthesis correction efficiency that will be established in the efficiency correction file The factor parameter is set to 1, and the weight is input in the mass parameter (one unit per 10kg); the sample weight of the different materials to be tested will be set relative to the weight of the set penetration factor 丨, and the corrected sample will be added to the total Activity; (2) multi-density correction efficiency of single material iron plate used by German raDoS company; (3) Japan (japan Nuclear Energy Safety Organizatio n) Multi-nuclear calibration efficiency consisting of metal tubes and metal plates; (4) ® US Tech Tech (10)logy uses multi-core seed source and single material Brazilian logs (length 1) to make more weight (〇~6〇Kg) Correction efficiency. However, these correction methods widely used at present still only consider the approximate weight and geometry, but do not fully correct the material mass self-absorption effect of the sample and various factors, the factor of reaction between the shell and the moon ' can not get the correct sample of the horse activity. In summary, there is a need for a body source calibration prosthesis and its measurement and correction methods to solve the problems associated with conventional techniques. [Description of the Invention] 200819778 The project is to provide a body-source calibration prosthesis and its amount to use a variety of different density of the body source to correct the prosthesis correction curve, according to the body source of the school waste sample to be tested Correcting the measurement efficiency of the prosthesis, measuring the total horse-plus activity or specific activity of different objects, and achieving accurate measurement of the flute of the invention -

The method of measurement and correction, = the purpose is to provide a kind of difficult to test positive prosthesis and its amount of various additions. _ heart: the amount of two energy:, for the preparation of the sample - α, the use of the same size and volume as the plate positive prosthesis The $ „ 皿 / 内 is inside, the inside of the monitor has a tolerance

The first measurement and correction method of the present invention is to obtain the purpose of multi-density nuclear waste sample corresponding to the density and the measurement density.曰r The plurality of radiation activity detectors are disposed in the accommodating space, and the two positive rice bodies comprise: a container; a plurality of plates stacked in the container;;, ^ to) - a source The plate body has a plurality of emitters, and the at least one-shot system and the plurality of plates are stacked in the container. Source board. Preferably, the plate body can be a metal material. The metal material is a piece of iron. Preferably, the dry plate body can be - each selected from cardboard, wood, plaster, and press. Non-metallic materials. The non-metallic material may be one of acryl, rubber and glass. The 7-ray source may be a preferred one, which is a τ source. Among them, 8 200819778 was selected as one of 57 cobalt, 137 absolutely, 54 manganese, (9) titanium and its composition. Preferably, the source is a circular source. Preferably, the source plate further comprises: a lower shell layer; a leakproof filter paper layer formed on the lower shell layer, the leakproof filter layer There is a finer number of emitters; the money-upper layer is attached to the layer of leak-proof paper to provide protection for the plurality of sources. "

In order to achieve the above object, the present invention further provides a measurement correction $t' which includes the following steps: First, providing a plurality of body source correction bodies, the mother-individual source correction prosthesis has different densities respectively ^ = several kinds of body source correction prosthesis in the monitor to obtain a calibration curve of the relationship between density and rate; then, a waste, strong, and 'spring: one to the one of the _ products corresponding to the total life of the horse In the end, the positive mode corrects the corresponding total activity of the horse to 彳 (4) the total activity of the drink. The r is t: the correction method is to correct the corresponding gamma activity according to the energy dependence factor and the calculation formula of the total gamma total activity. [Embodiment] The members of the present invention will be more fully aware of the features, objects, and functions of the present invention. also. The reason for the tenth reason is explained so that the reviewing committee can understand the characteristics of the present invention, and the detailed explanation is as follows: —, 200819778

Referring to Figure 1, the figure is a schematic diagram of the waste activity monitor and body source calibration prosthesis. The waste activity monitor 1 is a six-sided cubic shield 10 having a lead combination of the same thickness. The shield 10 has a detection space 100 therein, and has six walls on the wall in the detection space 1〇〇. The radiation activity detector 11 of the same large area is in the embodiment, the radiation activity detector n is a plastic scintillator detector. A weight gauge is disposed in the detection space 1 , to measure the weight of the object to be tested. The activity monitor further has a microcomputer processor 12, which can calculate the total light activity (3⁄4) or specific activity (Bq/g) and efficiency correction of the sample scene by using the built-in computing software and the calibration parameters of the microcomputer. The instrument is capable of minimizing measurable activity and can print and display the analysis results. In the speculative space 100, there is a body source correction prosthesis for uniform activity. Referring to FIG. 2A, the periphery of the body source calibration prosthesis 2 is a system of troughs 2 to 0. The standard container 2 There is an internal space 21 in the crucible. Please refer to Figure - B. This figure is a schematic diagram of the stacking of the plate body and the source plate body. A plurality of plates 22 of the uniform material f and the source plate body 23 may be stacked in the internal space 21. The material of the a-plate body 22 may be a metal material or a non-metal material. The material of the genus is iron plate; the non-metal material is cardboard, wood board, gypsum: acrylic, rubber, glass. In the local application system, seven different materials will be cut into a large area of uniform material of 33c^yang2 and thick enamel (10), and then divided into each piece. The sample size of the sample container is similar to the length of H33cm and height 3. 〇c for 1 ^ prosthesis, the weight range is 5 kg ~ (10), so the material weight is the average density of the corrected prosthesis, and by: two, wood (density (four) slightly gypsum (10) plant money (money 1.1 W) , rubber (density glass 200819778 degrees 2. 5gcm, and iron plate (density 3gcm 3) to form a variety of density of the prosthesis. In the seven density of individual correction prosthesis 'placed symmetrically equally spaced seven large areas of the The source plate body. Please refer to FIG. 3A, which is a cross-sectional view of a preferred embodiment of the source plate body of the present invention. The image has a top cover layer, a source layer 231, and a leakproof filter paper. The layer micro-body is:: a lower shell layer 233. The leak-proof filter paper layer 232 is formed on the lower shell layer 2>#' layer 231 _ on the leak-proof filter, paper layer 232' The source layer paper sound source/the upper layer 23G is formed on the leakage prevention filter, S, 5, and the mussel layer 23〇 and the lower guard The layer 233 can provide the source layer 231 of the crucible can. The source and the source are: a 7 source, wherein the 7 source can be selected as 57, 137 sources, and one of them. Next, the formation of the complex evenly divided /, May tea - as shown in Figure 3B 'drop on the leak-proof filter paper layer 232: point, the mother point evenly drops into the 〇. 2cc liquid source 231 〇 a total of 36 Park 2: 7 source 2310 is about to diffuse into a diameter below 5 - Shipina „ nuclear co Cs Mn and 6Qc〇 each of the seven large-area sources of total activity are β:] 4 nuclear species%, (3) Cs, 54叮收和90 _. Through the above-mentioned seven 锸 force and Co,, can form four different energy main species of different density of uniform activity of the body source to correct the prosthesis. The implementation of the map is the measurement and The preferred method of the calibration method is not to be considered. The steps are as follows: (1) The initial 'degree and measurement efficiency correction ~ ΐ correction method 3 The steps are as follows: first, step 3G is used - the combination of the complex and the multi-nuclear large-area surface shot The source and the seven kinds of (four) paid positive prosthesis, including the benefits of the day, and the body of the source of the slaves 3 wide target _ saki and density. Then into 200819778 measured The cutting position obtains the calibration curve of the _shoot rate attack. (2) The photon energy depends on the difference of the ns energy_value. In the geometric center of the waste activity detector, a large area plus the horse source, 57c 〇 (energy 122 keV *l36keV), 7Cs (|4 662 keV), 54Mn (^^^ 834 keV), "and Co (energy 1173 keV and 1332 keV)), and the addition of 7Co, 54Mn, 6GCo and 137Cs The nuclear nucleus measurement efficiency is divided by the energy branch ratio of each nucleus (57C〇 is 96%, mCs is 2〇〇%), and the nucleus species, 54Mn, 6〇c〇&(3) are obtained at different averages. After the time, the energy and photon detection efficiency are shown in Figure 7. It shows that the photon detection rate increases with increasing energy. At high energy, the density change has a great influence on the photon detection rate. On the contrary, it is low. The change of energy density has little effect on the photon detection efficiency; in addition, the photon energy of different densities, μ n, ^, 2^r± 137^ JL〇, the detection efficiency of the 10 Cs, such as the sample i 'as a sample Non-single activity calculation. Total density in Gama (g/cm3)

Cs 54Mn / 137Cs 60c〇 / Acne 5?Γπ / 137Γγ. 54^7~~13^~~— 7Cs 0.15 0.5 0.75 1.13 1.8 2.5 3.0 0.40 0.32 0. 26 0.23 0. 17 0. 16 0.08 1.25 1. 18 1. 13 1.01 0.79 0. 77 Π • 49 • 44 • 41 .30 • 11 I· 99 200819778 (3) Sample measurement then proceed to step 32 to fill a waste sample with the body source correction prosthesis The same format is used to form a sample, a sample. Next, proceed to + step 33 ‘the weight of the test sample is weighed by the monitor stone, and then the density (weight/volume) of the ruthenium sample is obtained, and then the calibration curve is obtained to obtain the corresponding total activity of the test sample. Finally, proceed to step 34, and then rely on energy

The formula for calculating the total activity of the horse (relative to 13 Cs nuclear energy) and multinuclear species is corrected, and the correct total activity of the horse is obtained. (4) Verification and analysis The equipment for the whole box live measurement needs to have the correct calculation method of the total activity of the horse to meet the requirements of the nuclear activity limit. It is also verified that when the waste sample is multinuclear, it is mainly 137Cs, 54Mn. , Co), the activity of its individual nucleus: the results of the analysis, whether the difference in accuracy is within the acceptable range. (4-1) Minimum measurable activity (MDA) The minimum measurable activity of the US Nuclear Regulatory Commission's nureg_15〇7 (1998) is calculated as follows: ^ MDA ~ 3 + 4.65 x

Χχί where 3+ illusion: (detector limit, 95% trustworthiness)

Gg: background count rate (cps);: nuclear measurement efficiency dance t: measurement time (sec) > two average monthly scene count is 15 〇〇, by this monitor wCM" 〇 pc different 2 minutes of various average density of 57C 〇 , 54Mn, 137Cs and 60C 〇 can be measured at the lowest 200819778 ▲ live, the results are shown in Table 2 and Figure 5, at the same density. And the lowest measurable activity of ~ has a value of -, the average density of Co& mCs at 丄g/cm3~2 g/cm is the smallest; when the average density is <lg/cm3 and > The _ values of 6ΐ〇 and % at g/cm3 are slightly higher than 2 times the MDA value of i (10) 3~2 g/cm3, which is about 〇· 〇〇3 Bq /g and 〇· 〇1〇Bq /g, Mainly the change in the rate of gravity is a linear trend, while the change in the efficiency of the geometric center of the nuclear species is an exponential trend. Therefore, when the weight is too light or too heavy, the change in efficiency is greater than the weight of the weight at the same density, which is lower than i37Cs. The maximum measurable activities of ® Mn, Co and 37Cs are 〇. 〇〇9Bq /g, 0· 001 Bq/g and 〇· 〇1〇Bq/g, 54Mn and 137(:s energy are closer to their The various tempering materials such as cloth, water, iron pipe and steel bar are very similar. In addition, the minimum measurable activity (Bq/g) of Mn, Co and Cs can be consistent with the release of the control by the competent authority. The limit value 'the minimum measurable activity of the measuring instrument shall be less than 10 times the nuclear export derivation limit of the IAEA IAEA specification (eg 5% ι, 6 ΐο and 137 Cs is 〇·1 Bq /g). Refer to the American Antech Company's Type 3300-200 Cleaning Waste Monitor Operation Manual. The minimum measurable activities of the 6GCo and 137Cs instruments measuring 2 minutes back are 〇.〇〇9Bq /g and 0· 015 Bq /g, which is similar to the minimum measurable activity of the instrument of the activity monitor of this study. In addition, observe the relationship between the minimum measurable activity (MDA) of the plastic flash detector and the time, when the measurement time is The changes of the lowest measurable activity (Bq) of 6GCo and 137Cs are shown in Figure 6 for lmin, 2 min, 5 min, 8 min and l〇min. When the measurement time is extended from lmin to 5 min, the lowest measurable activity of 60C〇 and 137Cs is reduced by 1.9 times and 2.0 times, respectively. When the measurement time is extended from lmin to 10 min, the minimum of 6GCo and 137Cs can be reduced. The measured activity decreased by 2.5 times and 2.7 times respectively. When the frequency was extended from 8 111丨11 to 1〇1^11, the minimum measurable activity of 6()〇:〇 and 137〇3 14 200819778 did not change much, only Decrease by 9% and 15% respectively. Table 2. Minimum measurable activity (Bq/g) of waste activity monitor Density (g/cm3) 57Co 54Mn 137Cs 60C〇0.15 0. 059 0. 018 0.019 0.0095 0.5 0.021 0.0058 0.0061 0. 0029 0.75 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (4-2) Calculation formula Total count two A: 5 / Α· ΣΓ / + ruler c where: 137Cs nuclear activity (Bq) 10 h: i37Cs energy 662 keV photon detection efficiency (%) A· : 137Cs Photon branching ratio of energy 662 keV (%) Brother: Activity ratio of each nucleus to 137Cs: ratio of detection efficiency of each nucleus to 137Cs * (a) nucleus activity / Λ: a nuclear activity (HPGe analysis results) (b) nuclear detection efficiency ratio two Z / f / waste detection a certain horse energy photon efficiency (%): a nuclear emission photon branch ratio (%) 200819778 m (c) shows that the total activity of the horse is = A / / watt · ' : 137Cs detection efficiency is the best • (6) indicator nuclear activity is =, any nuclear activity ^ χ ^ Λ X X Rx

(6) External release derived limit value $ loyalty / UY 圮, 〇: activity limit of a certain i-type (export limit) (4-3) Multi-nuclear analysis Place seven uniform surface source i37cs in the correction prosthesis ( 721〇5Bq), ® 54Mn (45309Bq), 6°Co (86048Bq) and 57Co (42777Bq), the standard total activity is 246239Bq, the nuclear activity ratio is 57C〇: 54Mn:6GCo: 137Cs is 0.593 : 0.628 : 1.19 : 1. Using 137Cs efficiency to calculate the total activity of the density of l"gcm_3, 1·8 gem*3 and 2·5 gem·3 samples is shown in Table 3, and the four nuclear species of the sample were corrected by the above-mentioned calculation formula. The difference in the accuracy of the standard spot source total activity was 1.82%, 2.59% and 1.74%, respectively. _ (4-3-1) Density 1. 137cs efficiency measurement index of igcnf3 prosthesis nucleus activity Ai is 137Cs total activity At = 321197 Bq, 57Co, 54Mn and 60C 〇 relative to 137Cs 仄 23 23, 1· 01 and 1· 30 : Ai-Αΐ/Σ(1+^^ν) - 321197 / [ l+(0.593x0.23)+(0.628xl.01)+(L19x \ 130)) = 73500 Bq , Ax -Ai χ Rx^ 57Co -Ai x 0.593 = 43586 Bq 54Mn=Ai x 0.628= 46158 Bq 60Co=Ai x 1.19 287465 Bq Modified total activity of the gamma At = 250709 Bq 200819778 Standard point source plus horse total activity =246239 Bq ' The difference between the corrected total activity and the standard total activity is 2.36% 蓼- (4-3-2) Density 1·8gcm 3 The 137Cs efficiency measurement index of the prosthesis The total activity of the nuclear activity Ai is i37Cs At = 327780 Bq, 57Co, 54Mn and 60C〇 relative] 37Cs is 〇·17,0·79 and 1·11 : Ai-At/X(l+^^) - 327780 / [ 1+(0.593x0.17 )+(0.628x0.79)+(U9x • Ul)]Two 74058 Bq

Ax = Ai x brother, 57Co = Ai x 0.593 = 43916 Bq 54Mn II Ai x 0.628 = 46508 Bq 60Co=Ai x 1.19- 88129 Bq Modified total activity of the gamma At = 252611 Bq Standard point source plus horse total activity 2246239 Bq corrected total activity and standard total activity difference = 2 · 5 9 % (4-3-3) density 2. 5 gem-3 prosthesis 137Cs efficiency measurement index nuclear activity Ai is 137Cs total Activity At = 325651 BQ, 57Co, 54Vln and 60c〇 relative to 137Cs & 0.16, 0· 77 and 0·99 : , At , ^ 325651 / C 1+(0.593χ0.16)+(0.628χ0.77 )+(1.19χ °·") ) - 185345 Bq ^ Ai x Rx 5 57Co = Ai x 0.593 = 43552 Bq 54Mn-Ai x 0.628 -46123 Bq 17 200819778 60Co=Ai χ 1.19 - 87398 Bq Modified Jiama Total activity At = 250517 Bq Standard point source plus horse total activity = 246239 Bq Corrected difference between total activity and standard total activity = 1.74 % Parameter gem'3 57Co 54Mn 60C〇丨37Cs Rx 0.593 0.628 1.19 1 Ρχ 96% 100% 200 % 85%

A 1.1 1.8 2.5 3.5% 14.5% 16.6% 17.7% 2.5% 11.4% 14.1 % 14.5 % 2 A % 1U% 12.7 % 13.2% £ χ ^合μ本发状体体_Correction (4) and calibration method ^ Receive =, ^^ I, and the finest magnification of % = seeking, === standard nuclear species derived limit estimation results, such as the sample is non-read. (2) System performance ^ Correspondence value, energy dependence and efficiency are 5%. (3) Four __ single ____2 shot = degree difference The uniformity of activity of the positive prosthesis <7 9 *, the density and energy of the sacral prosthesis The accuracy of the external release material of the school JE is wide, and the measurement efficiency is high.

The above is only the preferred embodiment of the present invention, and the modifications and modifications will remain without departing from the scope of the present invention. 19 200819778 [Simple description of the diagram] Figure 1 is a schematic diagram of the dental activity monitor and the body source calibration prosthesis. Figure 2A is a perspective view of a standard container. Figure 2B is a schematic diagram of stacking of the plate body and the source plate body. Figure 3A is a cross-sectional view showing a preferred embodiment of the source plate of the present invention. FIG. 3B is a schematic diagram showing the source distribution of the source plate body of the present invention. Figure 4 is a schematic diagram of a preferred embodiment of the measurement and correction method of the present invention. Figure 5 shows the minimum measurable activity of instruments of different density nuclear species. Figure 6 shows the relationship between the minimum measurable activity of the instrument and the measurement time. Figure 7 shows the various energy photon efficiencies of different density corrected prostheses. [Main component symbol description] 1- Waste activity monitor 10 - Shield 100 - Detection space 11 - Radiation activity detector 12 - Microcomputer processor 2 - Body source calibration prosthesis 20 - System container 21 - Internal Space 22 - Plate 23 - Source plate 230 - Upper shell layer 20 200819778 231 - Source layer 2310 - Source 232_ Leak proof > Paper layer 233 - Lower shell layer 3 - Correction method 30~34- Process

Claims (1)

200819778 X. Patent application scope··1·1 body-source correction prosthesis, which is disposed in a monitor, the inside of the monitor 1 has a receiving space, and a plurality of radiation activities are arranged in the receiving space. The body detection source correction prosthesis includes: a container; a plurality of plates stacked in the container; And a source plate having a plurality of emitters, the at least one source plate system and the plurality of plates being stacked in the container. 2. The body source calibrated prosthesis of claim 1, wherein the plate body is a metal material. 3. If applying for a body-source calibration prosthesis as described in item 2 of Weiwei, the metal material is an iron plate. 4. The body source calibrating prosthesis of claim 1, wherein the body is a non-metallic material. 5 • The body source calibration prosthesis of claim 4, wherein the non-metallic material can be selected from the group consisting of cardboard, wood, plaster, acrylic, rubber, and broken glass. 6. The body source calibration prosthesis of claim i, wherein the source is a T source. 7. If the body-source calibration prosthesis described in item 6 of the patent application is applied, the source of the basin may be selected from 57, 137, 54, 6 and its composition. 8. = Patent application scope silk! The calibrated prosthesis of the item, wherein the source, a circular source. </ br> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; The body-source-corrected prosthesis of claim 1, wherein the source plate further comprises: a lower shell layer; and a filter paper layer formed on the lower shell layer, the leak-proof layer The paper layer further has the plurality of emitters; and an upper shell layer formed on the leakproof filter paper layer to provide protection for the plurality of emitters. In addition, the U.S. type correction method includes the following steps: · Raising the number of faces (10) Correcting the prosthesis 'Every-individual test positive prosthesis has different densities respectively; Using the number of observations to detect the prosthesis Obtaining a calibration curve of the relationship between the density and the juice measuring efficiency in the monitoring; loading the U sample into the trough state of the same volume as the body source calibration prosthesis to form a test sample; Detecting the density of the sample, and correcting the total activity of the corresponding gamma to obtain the correct measurement and correction method as described in Item 11 of the patent scope. A metal material and a non-metal material 13. ^=^_12 (4) 戦 correction method, wherein the jade material is an iron plate. 23 200819778 14. The method of measuring and correcting according to claim 12, wherein the 'non-metallic material can be selected from the group consisting of cardboard, wood, gypsum, acrylic, rubber, and glass. 15. The method of measuring and correcting according to claim 12, wherein the source of the body source correction prosthesis is a source of radiation. 16. The method of measuring and correcting according to claim 15 wherein the seven sources are selected from the group consisting of 57 drills, 137 turns, 54 manganese, 60 drills and one of the components thereof. The method of measuring and correcting according to claim 11 , wherein the correction method is that the corresponding gamma activity is calculated according to an energy dependency factor and a total activity of the multi-nuclear gamma Make corrections. twenty four