CN102540233A - Determination method for effective range of electronic beam radiation and banding dosage indicating meter - Google Patents

Abstract

A method for measuring the effective range of electron beam radiation and a strip meter, which is characterized in that the glass dose indicator strips arranged in {m,n} matrix are first made of ordinary flat glass, and inserted obliquely into the product to be irradiated Carry out irradiation in the box, and then superimpose two adjacent rows of dosimeters with similar color difference in the dosimeter tape, and compare the color with the reference dosimeter placed on the top layer of the product box and irradiated at the same time, and find the dosimeter with the same color. The position of the dosimeter, the distance from this position to the top layer of the irradiation box is the effective range of electron beam radiation, and twice the distance is the optimal irradiation thickness of the product. The invention has the advantages of strong versatility, low cost, convenient and fast operation.

Description

Method for Measuring Effective Range of Electron Beam Radiation and Strip Dose Indicator

technical field

The invention relates to an electron beam irradiation dosimetry technology, in particular to a method for measuring the optimum depth of product irradiation and its dosimeter, in particular to a method for measuring the effective range of electron beam radiation and a strip dosimeter.

Background technique

As we all know, electron beam radiation processing has the advantages of large radiation power, high dose rate, fast processing speed and low cost, and has developed rapidly at home and abroad in recent years. According to incomplete statistics, the number of electron accelerators in my country has increased to more than 200, and it is also showing a rapid growth trend. With the rapid development of the electron beam radiation processing industry, there is an urgent need for a dose measurement system suitable for electron beam dose measurement. At present, the methods for quantitative determination of electron beam radiation dose are: calorimetry, electron beam current density meter, liquid chemical dosimeter and solid plexiglass dosimeter and glass dosimeter (patent number, 86105336, containing trace iron and titanium Measuring radiation dose glass) five. Among them, liquid chemical dosimeters are generally made into glass ampoules or polystyrene coins, and solid plexiglass dosimeters and film dosimeters are generally made into film sheets. Measurement method: Generally, a spectrophotometer is used to measure the optical density of liquid or thin film, and the radiation absorbed dose of the product is determined by comparing the difference in optical density before and after irradiation. The qualitative measurement method of radiation dose is: use dye to make a circular label and paste it on the surface of the object to be irradiated. Whether the product is irradiated or not is indicated by the color change (red and yellow) of the circular label before and after irradiation.

Compared with gamma rays, electron beams have weak penetrability (short range) in matter, and the selected dose measurement method must adapt to the above characteristics. The absorbed dose distribution of products in electron beam radiation processing is closely related to product density, product thickness, ray energy and scanning width, as shown in Figures 1 and 2.

Reducing the unevenness of product irradiation U (U=Dmax/Dmin) can improve the energy utilization rate of the device. Generally, the product needs to be irradiated on both sides (the product should be changed or flipped before the second irradiation), and at the same time according to The effective radiation range of the electron beam in the product is used to control the packaging thickness of the product. If it is thin, the radiation energy will be wasted, and if it is thick, it will not penetrate and cannot meet the minimum radiation dose requirements of the product.

The common method for measuring the effective range of the electron beam is: in the object to be irradiated, place dosimeters at a certain distance (the above five dosimeters are all acceptable), take them out after a certain period of irradiation, measure the dose value, and draw the dose depth curve. This determines the half-dose depth and effective range. This method is a quantitative measurement, suitable for accurate fixed-point measurement of the energy distribution of uniform matter after the electron accelerator is successfully built. Existing problems: 1) There is a dosimeter interference problem. If too few dosimeters are deployed, the measurement results will be unreliable, and if too many dosimeters are deployed, the original energy distribution of electron beam irradiation will be disturbed; 2) the deployment of dosimeters is time-consuming and laborious; 3) the cost is high.

In the daily irradiation production process, the types of products are varied and the quantity is uncertain. Therefore, it is necessary to predict the dose distribution of product irradiation before arranging the irradiation process. At the same time, in order to ensure the quality of product irradiation, the product irradiation process should be tracked to meet the minimum irradiation dose requirements. There is a need for an inexpensive and convenient method of estimating the effective radiation range of product exposures.

Contents of the invention

The object of the present invention is to provide a method for measuring the effective range of electron beam radiation and a belt dosimeter with wide applicability and low cost for the problems of complex and poor versatility in the existing radiation dosimetry methods.

Technical scheme of the present invention is one of:

A method for measuring the effective range of electron beam radiation is characterized in that it comprises the following steps:

First, cut the plate glass into a long block structure as the dosimeter basic unit of the glass dose indicator D, and arrange the dosimeter basic unit on the surface of cardboard, plastic, wood or cloth and fix it to form a glass dosimeter. Dose indicator D, the dosimeter basic units can be closely connected or arranged at intervals to form a glass dose indicator matrix arrangement {m; n}, where m is the number of dosimeter basic units in the length direction, m≥3; n is the number of dosimeter basic units in the width direction, n≥1, where each dosimeter basic unit is recorded as D _{(m, n)} , and the matrix arrangement of glass dosimeters is called "dose indicator belt" and is recorded as D _{(m ×n)} ;

Secondly, place an incident dose indicator tape D _in for incident reference on the upper surface of the irradiated product, and place at least one depth dose indicator tape D _d obliquely inserted for measuring depth dose in the product irradiation box, and ensure that The glass dose indicator matrix arrangement m≥3, that is, the number of dosimeter basic units in the length direction is not less than three, and the length of the depth dose indicator belt _D should be greater than half of the actual depth of the irradiated product; the depth dose indicator The included angle between the upper surface of the meter belt D _d and the electron beam current is not less than 30 degrees; the incident dose indicator belt D _in for incident reference and the depth dose indicator belt D _in for measuring the depth dose should be misplaced to ensure the same An electron beam incident ray is different with the incident dose indicator with D _in and the depth dose indicator with D _d ; at the same time, prepare a non-irradiated glass dose indicator D as the background reference dose indicator with D ₀ ; the incident dose indicator The belt D _in and the depth dose indicator belt D _d can be placed in the same product box when the width of the product packaging box is greater than the width, otherwise they should be placed in separate boxes;

Third, put the above-mentioned products with various dose indicator belts on the electron accelerator conveying device for irradiation; determine whether to perform surface-changing irradiation according to the electron beam energy, product box thickness and product density; After the operation is completed, remove all dosimeter tapes and make the following observations and determine the effective range:

1. Irradiation on both sides: Take a dose indicator from the incident and background reference dose indicators with D _in and D ₀ and superimpose them, denoted as A; from the depth dose indicator with D _d1(m×n) and depth The dosimeter belt D _d2(m×n) starts from the end m (assuming n=1), each takes a piece of dosimeter basic unit D _{d1(m, 1)} and D _{d2(m, 1)} to superimpose (denoted as B _m ) , compare the color difference between A and B _m , AB _m >0; for the second time, take a dosimeter basic unit D from the depth dose indicator tape D _{d1 (m×n)} and the depth dose indicator tape D _{d2 (m×n) d1(m-1, 1)} and D _{d2(m-1, 1)} are superimposed (denoted as B _m-1 ), compare the color difference AB _m-1 > 0...until the color difference AB _mi = 0; Take a piece of dosimeter basic unit D _{d1 (mi-1, 1) and} D _{d2 (mi- 1,1)} Superposition (denoted as B _mi-1 ), compare the color difference AB _mi-1 <0, and B _m-i+1 <B _mi <B _mi-1 , then the position of the mi-th dose indicator is approximately the electron beam Depth at half-incidence value for the test product;

Measure the distances R _d1 and R _d2 from the midpoint of the basic unit of the mi-th dosimeter to the upper and lower inner surfaces of the product box. For double-sided irradiation, the distance (R _d1 +R _d2 ) is the optimum effective thickness of the electron beam under this energy to irradiate the test product.

2. Irradiation on one side:

Take a piece of dose indicator from the incident reference dose indicator with D _in , and record it as A _in ; from the end of the depth dose indicator with D _{d1 (m×n)} (the depth dose indicator with D _{d2 (m×n)} is the same) Starting from m (assuming n=1), take a piece of dosimeter basic unit D _{d1(m, 1)} and record it as B _m , compare the color difference between A _in and B _m , A _in -B _m >0; the second time from the depth dose indication Take a piece of dosimeter basic unit D _{d1(m -1, 1) from meter belt D d1(m×n)} , record it as B _m-1 , compare the color difference A _in -B _m-1 >0...until Color difference A _in -B _mi ＝0; Take a dosimeter basic unit D _{d1(mi -1,1) from the depth dose indicator tape D d1} (m×n) for the ith time, record it as B _mi-1 , and compare the color difference A _in -B _mi-1 <0, and B _m-i+1 <B _mi <B _mi-1 , then the absorbed dose of the product at the mi-th tablet dose indicator is equal to the absorbed dose at the incident surface of the electron beam thickness of;

Measure the distance R _d1 from the far point of the lower edge of the basic unit of the mi-th dosimeter to the upper inner surface of the product box (or the lower inner surface, according to the placement position of the depth dose indicator belt D _{d (m×n)} ). When irradiating on one side, the distance R _d1 is the best effective thickness of the electron beam under this energy to irradiate the test product.

The length of the glass dose indicator is 1.414 times half the depth of the product to be irradiated.

The above-mentioned depth dose indicator belt D _d : one or more dose indicator belts are obliquely inserted in the product in the direction of the incident surface and the incident opposite surface respectively, and the dose indicator surface forms an angle of more than 30 degrees with the electron beam current; and The incident reference dosimeter bands are staggered.

The optimum irradiation thickness R _d1 +R _d2 of the product box under the surface-changing irradiation process.

In order to improve the observation accuracy and reduce the range error, the length of the basic unit of the dosimeter should be more than three times its width.

For low-dose irradiated products, the dose indicator belt made of the dosimeter basic unit with a thickness of less than 2 mm is used for irradiation, and multi-layer superimposed observation.

For complex products with uneven density, the depth dose indicator belt should be divided into several sections for irradiation, and the corresponding points should be superimposed and observed to obtain the effective range of the electron beam at each part of the product.

A belt-shaped electron beam radiation dose indicator for measuring the effective range of electron beam radiation, which is characterized in that it is composed of a glass plate 1 and a flexible fixing belt 2 as the basic unit of the dosimeter, and each flexible fixing belt 2 is fixed with at least one List not less than three pieces of glass 1.

The glass sheets 1 are fixed on the flexible fixing belt 2 at intervals or next to each other in rows, and the rows should be arranged at intervals.

The glass sheet 1 is colorless transparent glass or transparent ordinary glass with light background color.

Technical scheme of the present invention is two:

A belt-shaped electron beam radiation dose indicator for measuring the effective range of electron beam radiation, which is characterized in that it is composed of a glass plate 1 and a flexible fixing belt 2 as the basic unit of the dosimeter, and each flexible fixing belt 2 is fixed with at least one List not less than two pieces of glass 1.

The glass sheets 1 are fixed on the flexible fixing belt 2 at intervals or next to each other in rows, and the rows should be arranged at intervals.

The glass sheet 1 is colorless transparent glass or light background transparent glass.

Beneficial effects of the present invention:

1. It is convenient to obtain materials. Glass dosimeters can be purchased directly from the decoration market. Before application, it is only necessary to pre-irradiate and select glass materials with remarkable discoloration effects.

2. Low price. Common plexiglass dosimeters cost at least 2 yuan, while the dosimeters of the present invention cost only a few cents.

3. Easy and accurate color comparison. The color-changing label is non-transparent and cannot be superimposed for color comparison, making it difficult to judge with the naked eye.

4. The dosage can be measured continuously. Because the strip dosimeter is cheap, it can be deployed continuously, and its shape can change with the product, so it can measure the dead point of the product dose.

5. Save time and effort. The dosimeter can be directly inserted into the product, and the position is easy to determine, saving deployment time.

6. The method of the present invention is simple, easy to operate, accurate in quantification, and wide in adaptability. The number of dosimeter belts can be adjusted according to the density and uniformity of the product, thereby determining the effective range position.

Description of drawings

Fig. 1 is a graph showing the relationship between the product's absorbed dose distribution, product thickness (incidence depth), and ray energy at a certain product density in the electron beam radiation processing of the present invention.

Fig. 2 is a graph showing the relationship between the absorbed dose distribution of the product and the scan width under a certain beam energy in the electron beam radiation processing of the present invention.

Fig. 3 is a schematic diagram of placing the dose indicator of the present invention in a product for electron accelerator irradiation.

Fig. 4 is a schematic structural view of the belt-shaped dose indicator of the present invention.

Fig. 5 is a schematic diagram of different placement methods of the belt-shaped dose indicator of the present invention in the irradiated product box.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Embodiment one.

As shown in Figures 3, 4, and 5.

A method for measuring the effective range of electron beam radiation, comprising the following steps:

First, cut the plate glass into a long block structure as the dosimeter basic unit of the glass dose indicator D, and arrange the dosimeter basic unit on the surface of cardboard, plastic, wood or cloth and fix it to form a glass dosimeter. Dose indicator D, the dosimeter basic units can be closely connected or arranged at intervals to form a glass dose indicator matrix arrangement {m; n}, where m is the number of dosimeter basic units in the length direction, m≥3; n is the number of dosimeter basic units in the width direction, n≥1, where each dosimeter basic unit is recorded as D _{(m, n)} , and the matrix arrangement of glass dosimeters is called "dose indicator belt" and is recorded as D _{(m ×n)} ;

Secondly, place an incident dose indicator tape D _in for incident reference on the upper surface of the irradiated product, and place at least one depth dose indicator tape D _d obliquely inserted for measuring depth dose in the product irradiation box, and ensure that The glass dose indicator matrix arrangement m≥3, that is, the number of dosimeter basic units in the length direction is not less than three, and the length of the depth dose indicator belt _D should be greater than half of the actual depth of the irradiated product; the depth dose indicator The included angle between the upper surface of the meter belt D _d and the electron beam current is not less than 30 degrees; the incident dose indicator belt D _in for incident reference and the depth dose indicator belt D _in for measuring the depth dose should be misplaced to ensure the same An electron beam incident ray is different with the incident dose indicator with D _in and the depth dose indicator with D _d ; at the same time, prepare a non-irradiated glass dose indicator D as the background reference dose indicator with D ₀ ; the incident dose indicator The belt D _in and the depth dose indicator belt D _d can be placed in the same product box when the width of the product packaging box is greater than the width, otherwise they should be placed in separate boxes;

Third, place the above-mentioned products with various dose indicator belts on the electron accelerator conveying device for irradiation, as shown in Figure 3; determine whether to perform surface-changing irradiation according to the thickness of the product box and the product density; After all the irradiation operations are completed, take out all the dose indicator tapes for the following observations and determine the effective range:

1. Irradiation on both sides: Take a dose indicator from the incident and background reference dose indicators with D _in and D ₀ and superimpose them, denoted as A; from the depth dose indicator with D _d1(m×n) and depth The dosimeter belt D _d2(m×n) starts from the end m (assuming n=1), each takes a piece of dosimeter basic unit D _{d1(m, 1)} and D _{d2(m, 1)} to superimpose (denoted as B _m ) , compare the color difference between A and B _m , AB _m >0; for the second time, take a dosimeter basic unit D from the depth dose indicator tape D _{d1 (m×n)} and the depth dose indicator tape D _{d2 (m×n) d1(m-1, 1)} and D _{d2(m-1, 1)} are superimposed (denoted as B _m-1 ), compare the color difference AB _m-1 > 0...until the color difference AB _mi = 0; Take a piece of dosimeter basic unit D _{d1 (mi-1, 1) and} D _{d2 (mi- 1,1)} Superposition (denoted as B _mi-1 ), compare the color difference AB _mi-1 <0, and B _m-i+1 <B _mi <B _mi-1 , then the position of the mi-th dose indicator is approximately the electron beam Depth at half-incidence value for the test product;

Measure the distances R _d1 and R _d2 from the midpoint of the basic unit of the mi-th dosimeter to the upper and lower inner surfaces of the product box. For double-sided irradiation, the distance (R _d1 +R _d2 ) is the optimum effective thickness of the electron beam under this energy to irradiate the test product.

2. Irradiation on one side:

Take a piece of dose indicator from the incident reference dose indicator with D _in , and record it as A _in ; from the end of the depth dose indicator with D _{d1 (m×n)} (the depth dose indicator with D _{d2 (m×n)} is the same) Starting from m (assuming n=1), take a piece of dosimeter basic unit D _{d1(m, 1)} and record it as B _m , compare the color difference between A _in and B _m , A _in -B _m >0; the second time from the depth dose indication Take a piece of dosimeter basic unit D _{d1(m -1, 1) from meter belt D d1(m×n)} , record it as B _m-1 , compare the color difference A _in -B _m-1 >0...until Color difference A _in -B _mi ＝0; Take a dosimeter basic unit D _{d1(mi -1,1) from the depth dose indicator tape D d1} (m×n) for the ith time, record it as B _mi-1 , and compare the color difference A _in -B _mi-1 <0, and B _m-i+1 <B _mi <B _mi-1 , then the absorbed dose of the product at the mi-th tablet dose indicator is equal to the absorbed dose at the incident surface of the electron beam thickness of;

Measure the distance R _d1 from the far point of the lower edge of the basic unit of the mi-th dosimeter to the upper inner surface of the product box (or the lower inner surface, according to the placement position of the depth dose indicator belt D _{d (m×n)} ). When irradiating on one side, the distance R _d1 is the best effective thickness of the electron beam under this energy to irradiate the test product.

The principle of the invention is that the glass will turn into tea brown after being irradiated, and can be made into a glass indicating dosimeter. In view of this, the present invention uses glass material to make a strip-type dosimeter, as shown in Figure 4, as the irradiation depth increases, the color gradually fades. The color depth can intuitively determine the effective radiation range in electron beam radiation processing.

The details are as follows:

1. Manufacturing method of strip dose indicator (as shown in Figure 4)

1. The base material is ordinary glass plates such as flat glass, glass bottles and jars, and utensils.

2. Cut the above-mentioned glass plate into about 100mm ^long strips to make a glass dose indicator D (that is, the basic unit of the dosimeter, hereinafter referred to as the dose indicator). Arrange the dose indicators on the surface of attachable objects such as cardboard, plastic, wood, cloth, etc. and fix them, and they can be closely connected or spaced apart to form a matrix arrangement of dose indicators {m; n} (where m is the dose indicator in the longitudinal direction The number of meters, m≥3; n is the number of dose indicators in the width direction, n≥1. Each dose indicator is denoted as D _{(m, n)} and the matrix arrangement of dose indicators is called "dose indicator belt" D _(m×n) .

3. The total length of the dose indicator tape should be guaranteed: After irradiation treatment, at least one piece of dosimeter at the end of the belt is the background color. At least half thickness larger than the actual product.

2. How to use (as shown in Figure 3, 5)

1. Put the above-mentioned "dose indicator belt" in the product to be irradiated. In order to prevent the dose indicator belt from interfering with the dose distribution of the irradiated product, the following placement methods are adopted:

1) Incidence reference dose indicator with D _in : placed on the inner surface of the product.

2) Depth dose indicator belt D _d : Insert more than one dose indicator belt obliquely in the direction of the incident surface and the incident surface respectively, and the dose indicator surface forms an angle of more than 30 degrees with the electron beam current; The reference dosimeter tapes are staggered.

3) Background reference dose indicator D ₀ : no irradiation.

4) The incident reference dose indicator belt D _in and the depth dose indicator belt D _d can be placed in the same product box when the product box is wide enough (spacing > dose indicator bandwidth), otherwise they should be placed in separate boxes.

5) The number of dose indicators D in the incident reference dose indicator with D _in and the depth dose indicator with D _d should be as small as possible to meet the observation requirements. Its top view planes must not intersect.

2. Place the product on which the dose indicator belt has been placed on the electron accelerator conveying device to irradiate (as shown in Figure 3).

3. According to the thickness of the product box and the density of the product, determine whether to carry out surface-changing irradiation. After all irradiation operations are completed, take out the dose indicator belt for observation and determine the optimum irradiation depth.

3. Determination method of irradiation depth

1. Take a piece of dosimeter from the incident and background reference dosimeter bands _{D in} and D ₀ respectively _and superimpose it, which is recorded as A; ₎ from the end m, take a dose indicator D _{d1 (m, 1)} and D _{d2 (m, 1)} superimposed (denoted as B _m ), compare the color difference between A and B _m , AB _m >0; Depth dose indicator belt D _{d1 (m×n)} and belt D _{d2 (m×n)} each take a dose indicator D _{d1 (m-1, 1)} and D _{d2 (m-1, 1)} superimposed (denoted as B _m-1 ), compare the color difference AB _m-1 > 0... until the color difference AB _m-1 = 0; the ith time from the depth dose indicator with D _{d1 (m × n)} ] and with D _{d2 (m×n)} each take a dose indicator meter D _{d1 (mi-1, 1)} and D _{d2 (mi-1, 1)} superimposed (denoted as B _mi-1 ), compare the color difference AB _mi-1 <0, and If B _m-i+1 <B _mi <B _mi-1, the position of the mi-th dose indicator is approximately the half-incidence depth of the electron beam to the test product.

2. Measure the distances R _d1 and R _d2 from the midpoint of the dose indicator of the mi-th tablet to the upper and lower inner surfaces of the product box, which are the effective ranges of the electron beams with a specific energy to the test product.

3. The optimal thickness R _e =R _d1 +R _d2 of the product box under the surface-changing irradiation process is thus obtained.

4. In order to improve the observation accuracy and reduce the range error, the dose indicator sheet can be made as narrow as possible.

5. For low-dose irradiated products, thin dose indicator sheets can be used for irradiation and multi-layer superimposed observations, or high-dose irradiation can be used first to obtain the effective range of electron beams.

6. For complex products with uneven density, the depth dose indicator belt can be divided into several sections for irradiation, and the corresponding points can be superimposed and observed to obtain the effective range of the electron beam at each part of the product.

Application example 1.

The seasoning is irradiated on an electron accelerator with an energy of 10 Mev, the density is 0.7g/cm ³ , and the thickness of the test product box is 14cm. Put 3 dose indicator tapes in the product box: ① a length of 2cm incident reference dose indicator tape D _{in (2×1)} is placed on the upper surface of the product box, ② a length of 10cm (length: 14/2 ×1.414=9.9cm) depth dose indicator belt (plastic plate as carrier) D _{d1 (10×1)} obliquely inserted into the product from the incident surface about 45° direction, ③ a depth dose indicator with a length of 10cm D _{d2 (10 ×1)} It is obliquely inserted into the product from the direction of about 45° opposite the incident side. The front and back sides are irradiated, and the dose is about 10kGy. Take out the dose indicator and record the position of the dose indicator. Respectively for incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _d1(10,1) and D _d2(10,1) , depth dose indicators D _d1(9,1) and D _{d2 (9,1)} , depth dose indicators D _d1(8,1) and D _d2(8,1) are superimposed and observed to obtain colors A, B ₁₀ , B ₉ , and B ₈ . After colorimetry, the following conditions are met: AB ₉ = 0 and AB ₁₀ > 0, AB ₈ < 0, B ₁₀ < B ₉ < B ₈ , so the dose indicator D _{d1 (9, 1)} and D _{d2 (9, 1 )} midpoint is the effective range point of the seasoning, and the distance from this point to the upper and lower inner surfaces of the product box is measured to be 6.3cm and 6.3cm respectively, and the optimum thickness of food irradiation under the surface-changing irradiation process is obtained as R _e = 6.3 + 6.3 = 12.6 cm. Therefore, when the actual product is irradiated, the thickness of the product box should be controlled within 12.6cm to meet the minimum dose requirement.

Application example 2

The medical gloves are irradiated on an electron accelerator with an energy of 10 Mev, the density is 0.2g/cm ³ , and the thickness of the test product box is 45cm. Put 3 dose indicator tapes in the product box: ① one with a length of 2cm incident reference dose indicator tape D _{in (2×1)} placed on the upper surface of the product box, ② two with a length of 32cm (length: 45/2 ×1.414=31.8cm) The depth dose indicator belt (cardboard as the carrier) D _{d1 (32×1)} and D _{d2 (32×1)} are obliquely inserted into the product from the left and right directions of about 45° respectively from the incident surface. Use single-sided irradiation, the dose is about 20kGy, take out the dose indicator, and record the position of the dose indicator. Respectively for incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _d1(32,1) and D _d2(32,1) , depth dose indicators D _d1(31,1) and D _{d2 (31,1)} , depth dose indicators D _d1(30,1) and D _d2(30,1) are superimposed and observed to obtain colors A, B ₃₂ , B ₃₁ , and B ₃₀ . After colorimetry, the following conditions are met: AB ₃₁ = 0 and AB ₃₂ > 0, AB ₃₀ < 0, B ₃₂ < B ₃₁ < B ₃₀ , so the dose indicator D _{d1 (31, 1)} and D _{d2 (31, 1 )} midpoint is the effective range point of the medical product, the distance from this point to the upper surface of the product box is 20cm, and the optimal thickness of medical gloves under the surface-changing irradiation process is R _e =20×2 = 40cm. Therefore, when the actual product is subjected to surface-changing irradiation, the thickness of the product box should be controlled within 40cm to meet the minimum dose requirement.

Application example 3

Application example 3

The small packaged food is irradiated on an electron accelerator with an energy of 10 Mev, the density is 0.4g/cm ³ , and the thickness of the test product box is 15cm. Put 2 dose indicator belts in the product box: ① a length of 2cm incident reference dose indicator belt D _{in (1×1)} placed on the upper surface of the product box, ② a length of 24cm depth dose indicator belt ( The cloth tape is the carrier) D _{d1 (24×2)} is obliquely inserted into the product from the direction of about 30° from the incident surface. Use single-sided irradiation, the dose is about 10kGy, take out the dose indicator, and record the position of the dose indicator. Incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _d1(24,1) and D _d1(24,2) , depth dose indicators D _d1(23,1) and D _d1 respectively _{(23, 2)} , depth dose indicator D _{d1(22, 1)} and D _{d1(22, 2)} and depth dose indicator D _{d1(21, 1)} and D _{d1(21, 2)} are superimposed observations to obtain Color A, B ₂₄ , B ₂₃ , B ₂₂ , B ₂₁ . After colorimetry, the following conditions are met: AB ₂₂ = 0 and AB ₂₄ > 0, AB ₂₃ > 0, AB ₂₁ < 0, B ₂₃ < B ₂₂ < B ₂₁ , so the dose indicator D _{d1 (22×2)} midpoint is the effective range point of the small-packaged food, and the distance from this point to the inner surface of the product box is 10.8cm, and the optimal thickness of the small-packaged food under the surface-changing irradiation process is R _e =10.8×2= 21.6cm. Therefore, when the actual product is irradiated, the thickness of the product box should be controlled within 21.6cm to meet the minimum dose requirement.

Application example 4

The pharmaceutical excipients are irradiated on an electron accelerator with an energy of 1 Mev, the density is 0.053g/cm ³ , and the thickness of the test product box is 10cm. Put 2 dose indicator belts in the product box: ① a 2cm long incident reference dose indicator belt D _{in (1×1)} is placed on the upper surface of the product box, ② a 12cm long depth dose indicator belt ( The cloth tape is the carrier) D _{d1 (24×2)} is obliquely inserted into the product from the direction of about 30° from the incident surface. Use single-sided irradiation, the dose is about 15kGy, take out the dose indicator, and record the position of the dose indicator. Respectively for incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _d1(24,1) and D _d1(24,2) , depth dose indicators D _d1(23,1) and D _{d1 (23, 2)} , depth dose indicator D _{d1(22, 1)} and D _{d1(22, 2)} and depth dose indicator D _{d1(21, 1)} and D _{d1(21, 2)} are superimposed observations to obtain Color A, B ₂₄ , B ₂₃ , B ₂₂ , B ₂₁ . After colorimetry, the following conditions are met: AB ₂₂ = 0 and AB ₂₄ > 0, AB ₂₃ > 0, AB ₂₁ < 0, B ₂₃ < B ₂₂ < B ₂₁ , so the dose indicator D _{d1 (22×2)} midpoint is the effective range point of the pharmaceutical excipient, and the distance from this point to the upper inner surface of the product box is 5.4cm, and the optimal thickness of the irradiation of the pharmaceutical excipient under the surface-changing irradiation process is R _e =5.4×2= 10.8cm. Therefore, when the actual product is irradiated, the thickness of the product box should be controlled within 10.8cm to meet the minimum dose requirement.

Application example 5

The pet food is irradiated on an electron accelerator with an energy of 5 Mev, the density is 0.1 g/cm ³ , and the thickness of the test product box is 42 cm. Put 2 dose indicator belts in the product box: ① a 2cm long incident reference dose indicator belt D _{in (1×1)} placed on the upper surface of the product box, ② a 44cm long depth dose indicator belt ( The cloth tape is the carrier) D _{d1 (44×2)} is obliquely inserted into the product from the direction of about 30° from the incident surface. Single-sided irradiation, the dose is about 8kGy, take out the dose indicator, record the position of the dose indicator. Incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _d1(44,1) and D _d1(44,2) , depth dose indicators D _d1(43,1) and D _d1 respectively _(43,2) , depth dose indicators D _d1(42,1) and D _d1(42,2) and depth dose indicators D _d1(41,1) and D _d1(41,2) are superimposed observations to obtain Colors A, B ₄₄ , B ₄₃ , B ₄₂ , B ₄₁ . After colorimetry, the following conditions are met: AB ₄₂ = 0 and AB ₄₄ > 0, AB ₄₃ > 0, AB ₄₁ < 0, B ₄₃ < B ₄₂ < B ₄₁ , so the midpoint of the dose indicator D _{d1 (42×2)} is the effective range point of the pet food, the distance from this point to the upper inner surface of the product box is measured as 21cm, and the optimal thickness of the pet food irradiation under the surface-changing irradiation process is obtained as R _e =21×2=42cm. Therefore, when the actual product is irradiated, the thickness of the product box should be controlled within 42cm to meet the minimum dose requirement.

Application example 6

The mixed pet food was irradiated on an electron accelerator with an energy of 10 Mev. The density distribution of the product was uneven. The highest and lowest densities were 0.3g/cm ³ and 0.2g/cm ³ respectively. The density distribution and thickness of the two boxes of products taken are consistent. Place 6 dose indicator tapes in the two product boxes respectively: ① two 2cm incident reference dose indicator tapes D _{in (1×1)} are placed on the upper surface of product box 1 ^# and box 2 ^# , ② two Length 40cm depth dose indicator tape (cloth tape as the carrier) D _{d1 (40×1)} and D _{d2 (40×1)} are obliquely inserted into the product box 1 ^# from the left and right directions of about 30° from the incident surface respectively. ③Two lengths of 40cm depth dose indicator tapes (cloth tape as the carrier) D _{d3 (40×1)} and D _{d4 (40×1)} respectively from the other incident surface (opposite to the incident surface of product box 1 ^# ) Insert it obliquely into the product box 2 ^# in the left and right directions of about 30°. The product box 1 ^# is irradiated on the front side, and the product box 2 ^# is irradiated on the back side. The dose is about 12kGy. Take out the dose indicator and record the position of the dose indicator. Respectively compare the incident reference dose indicator D _in and background reference dose indicator D ₀ in deployment ①, and the similar color points of the corresponding dose indicator belts in deployment ② and ③ (the color is very light, which has been compared and eliminated first) ): depth dose indicator D _d1(40,1) and D _d3(30,1) , depth dose indicator D _d1(39,1) and D _d3(29,1) , depth dose indicator D _{d1(38 , 1)} and D _{d3 (28, 1)} and depth dose indicators D _{d2 (40, 1)} and D _{d4 (40, 1)} , depth dose indicators D _{d2 (39, 1)} and D _{d4 (29, 2 )} , the depth dose indicator D _{d3(38, 1)} and D _{d4(28, 2)} are superimposed and observed, and the result 1 is obtained: the superimposed color of D _d1(40×1) and D _d3(40×1) , A ¹ , B ¹ _40-30 , B ¹ _39-29 , B ¹ _38-28 , by color comparison, meet the following conditions: A ¹ -B ¹ _39-29 = 0 and A ¹ -B ¹ _40-30 >0, A ¹ -B ¹ _38-28 <0, B ¹ _40-30 <B ¹ _39-29 <B ¹ _38-28 , so the dose indicator D _d1(39×1) and D _d3(29×1) midpoint They are the effective range points of the mixed pet food, and the distances from this point to the inner surface of the product box are 19.25cm and 14.25cm.

Result 2 is also obtained: the superimposed color of D _{d2 (40×1)} and D _{d4 (40×1)} , A ² , B ² _40-30 , B ² _39-29 , B ² _38-28 , after colorimetry, conforms to The following conditions: A ² -B ² _39-29 = 0 and A ² -B ² _40-30 > 0, A ² -B ² _38-28 < 0, B ² _40-30 < B ² _39-29 < B ² _38-28 , so the midpoints of dose indicators D _{d2 (39×1)} and D _{d4 (29×1)} are the effective range points of the mixed pet food, and the distance from this point to the upper inner surface of the product box is also 19.25cm and 14.25cm.

Therefore, the product has a uniform density in the width direction, but an uneven density in the depth direction. Under the surface-changing irradiation process, the optimum irradiation thickness of the mixed pet food is R _e =19.25+14.25=33.5cm. Therefore, when the product is irradiated along the depth direction, the thickness of the product box should be controlled within 33.5 cm to meet the minimum dose requirement.

Application example 7

The dehydrated vegetables are irradiated on an electron accelerator with an energy of 3 Mev, the density is 0.1 g/cm ³ , and the thickness of the test product box is 15 cm. Put 3 dose indicator belts in the product box: ① a length of 2cm incident reference dose indicator belt D _{in (2×1)} placed on the upper surface of the product box, ② a length of 22cm depth dose indicator belt ( The cloth tape is the carrier) D _{d1 (22×1)} and D _{d2 (22×1)} are obliquely inserted into the product from the left and right directions of about 30° from the incident surface respectively. Single-sided irradiation, the dose is about 8kGy, take out the dose indicator, record the position of the dose indicator. Respectively for the incident reference dose indicator D _in , the depth dose indicators D _d1(22,1) and D _d2(22,1) , the depth dose indicators D _d1(21,1) and D _d2(21,1) , The depth dose indicators D _{d1(20, 1)} and D _{d2(20, 1)} are directly observed (without superimposed observation), and the colors A, B ¹ ₂₂ , B ² ₂₂ , B ¹ ₂₁ , B ² ₂₁ , B ¹ ₂₀ , B ² ₂₀ . After colorimetry, the following conditions are met: B ¹ ₂₂ ＝B ² ₂₂ ＜B ¹ ₂₁ ＝A＝B ² ₂₁ ＜B ¹ ₂₀ ＝B ² ₂₀ , so the dose indicator D _d1(21,1) and D _{d2(21 , 1)} is the best range point of the dehydrated vegetables at the far point of the edge, and the distance from this point to the upper surface of the product box is 10.5cm, and the best irradiation thickness of the dehydrated vegetables under the single-sided irradiation process is obtained as _Re = 10.5 cm. Therefore, when the actual product is irradiated on one side, the thickness of the product box should be controlled within 10.5cm to meet the minimum dose requirement.

Application example 8

The dehydrated vegetables are irradiated on an electron accelerator with an energy of 3 Mev, the density is 0.1 g/cm ³ , and the thickness of the test product box is 15 cm. Put 3 dose indicator belts in the product box: ① a length of 2cm incident reference dose indicator belt D _{in (2×1)} placed on the upper surface of the product box, ② a length of 26cm depth dose indicator belt ( The cloth tape is the carrier) D _{d1 (26×1)} and D _{d2 (26×1)} are obliquely inserted into the product from the left and right directions of about 30° from the incident surface respectively. Single-sided irradiation, the dose is about 8kGy, take out the dose indicator, record the position of the dose indicator. Respectively for incident and background reference dose indicators D _in and D ₀ , depth dose indicators D _{d1(26, 1)} and D _{d2(26, 1)} , depth dose indicators D _{d1(25, 1)} and D _{d2 (25,1)} , depth dose indicators D _d1(24,1) and D _d2(24,1) are superimposed and observed to obtain colors A, B ₂₆ , B ₂₅ , and B ₂₄ . After colorimetry, the following conditions are met: AB ₂₅ = 0 and AB ₂₆ > 0, AB ₂₄ < 0, B ₂₆ < B ₂₅ < B ₂₄ , so the dose indicator D _{d1 (25, 1)} and D _{d2 (25, 1 )} is the effective range point of the dehydrated vegetables, and the distance from this point to the upper surface of the product box is 12.25cm, and the optimal thickness of the dehydrated vegetables under the surface-changing irradiation process is R _e =12.25× 2 = 24.5 cm. Therefore, when the actual product is subjected to surface-changing irradiation, the thickness of the product box should be controlled within 24.5cm to meet the minimum dose requirement.

Embodiment two.

As shown in Figure 4.

A belt-shaped electronic radiation dose indicator, which is characterized in that it is composed of a glass sheet 1 and a flexible fixing belt 2 as the basic unit of the dosimeter, and each flexible fixing belt 2 is fixed with at least one row of no less than three pieces of glass slice 1. The glass sheets 1 can be fixed on the flexible fixing belt 2 at intervals or adjacent to each other, and the rows can be arranged at intervals or adjacent to each other. The glass sheet 1 should be colorless transparent glass or transparent glass with light background color. The glass sheet 1 can be ordinary glass plates such as flat glass, glass bottles and jars, and utensils. The flexible fixing belt 2 can be attachable objects such as cardboard, plastics, wood, cloth, etc., as shown in FIG. 4 .

The parts not involved in the present invention are the same as the prior art or can be realized by adopting the prior art.

Claims (10)

1. the assay method of an electron beam irradiation effective range is characterized in that it may further comprise the steps:

At first; Sheet glass is cut into the quantimeter elementary cell of rectangular block structure as vitrifying agent flow indicator D; And but described quantimeter elementary cell is arranged in cardboard, plastics, plank or dry goods attachment surface and the fixing vitrifying agent flow indicator D that forms; Can closely connect also between each quantimeter elementary cell and can be spaced, form vitrifying agent flow indicator arranged { m; N}, wherein m is the quantity of length direction quantimeter elementary cell, m>=3; N is the quantity of Width quantimeter elementary cell, n>=1, and wherein each quantimeter elementary cell note is made D _{(m, n)}, this vitrifying agent flow indicator arranged is called " dosage index gauge band " note and makes D _{(m * n)}

Secondly, place the referential incident dose index gauge of an incident band D at the upper surface of irradiation products _In, in the product irradiation box, place oblique cutting at least one be used to the to fathom depth dose index gauge band D of dosage _d, and m>=3 of assurance vitrifying agent flow indicator arranged, promptly the quantity of the quantimeter elementary cell of length direction is no less than three, depth dose index gauge band D _dLength should be greater than reality half the by the irradiation products degree of depth; Depth dose index gauge band D _dAngle between upper surface and the electron beam line is not less than 30 degree; The referential incident dose index gauge of incident band D _InDepth dose index gauge band D with the dosage that fathoms _dThe layout that should misplace guarantees not incident dose index gauge band D simultaneously of same electron beam incident line _InWith depth dose index gauge band D _dPrepare a vitrifying agent flow indicator D without irradiation simultaneously as background reference dose index strip D ₀Incident dose index gauge band D _InAnd depth dose index gauge band D _dCan place in the identical product case during at the width of product package, otherwise answer branch mailbox to place greater than bandwidth;

The 3rd, the above-mentioned product of having laid all kinds of dosage index gauge bands placed on the electron accelerator conveyer implement irradiation; According to beam energy, product box thickness and product density situation, determine whether to change face irradiation; After all the irradiation operation is accomplished, take out all dosage index gauge band and carry out following observation and definite effective range:

1. two-sided irradiation situation: from incident and background reference dose index gauge band D _InAnd D ₀Respectively get tablet amounts index gauge stack, be designated as A; From depth dose index gauge band D _{D1 (m * n)}With depth dose index gauge band D _{D2 (m * n)}Terminal m begins (supposing n=1), respectively gets a slice quantimeter elementary cell D _{D1 (m, 1)}And D _{D2 (m, 1)}Stack (is designated as B _m), compare A and B _mAberration, A-B _m＞0; The 2nd time from depth dose index gauge band D _{D1 (m * n)}With depth dose index gauge band D _{D2 (m * n)}Respectively get a slice quantimeter elementary cell D _{D1 (m-1,1)}And D _{D2 (m-1,1)}Stack (is designated as B _M-1), compare aberration A-B _M-1＞0...... is until aberration A-B _M-i=0; The i time from depth dose index gauge band D _{D1 (m * n)}With depth dose index gauge band D _{D2 (m * n)}Respectively get a slice quantimeter elementary cell D _{D1 (m-i-1,1)}And D _{D2 (m-i-1,1)}Stack (is designated as B _M-i-1), compare aberration A-B _M-i-1＜0, and B _M-i+1＜B _M-i＜B _M-i-1Then m-i tablet amounts index gauge place is about the half incident value degree of depth of electron beam to test products;

Measure m-i tablet amounts meter elementary cell mid point to the upper and lower inside surface distance R of product box _D1And R _D2During two-sided irradiation, distance (R _D1+ R _D2) be electron beam under this energy to the best net thickness of test products irradiation;

2. single face irradiation situation:

From incident reference dose index gauge band D _InGet a tablet amounts index gauge, be designated as A _InFrom depth dose index gauge band D _{D1 (m * n)}(depth dose index gauge band D _{D2 (m * n)}In like manner) terminal m begins (supposing n=1) and gets a slice quantimeter elementary cell D _{D1 (m, 1)}, be designated as B _m, compare A _InWith B _mAberration, A _In-B _m＞0; The 2nd time from depth dose index gauge band D _{D1 (m * n)}Get a slice quantimeter elementary cell D _{D1 (m-1,1)}, be designated as B _M-1, compare aberration A _In-B _M-1＞0...... is until aberration A _In-B _M-i=0; The i time from depth dose index gauge band D _{D1 (m * n)}Get a slice quantimeter elementary cell D _{D1 (m-i-1,1)}, be designated as B _M-i-1, compare aberration A _In-B _M-i-1＜0, and B _M-i+1＜B _M-i＜B _M-i-1, then m-i tablet amounts index gauge place equals and the pairing thickness of the absorbed dose of electron beam incident surface for the product absorbed dose;

(or following inside surface is according to depth dose index gauge band D to measure m-i tablet amounts meter elementary cell lower limb far point to product box upper inner surface _{D (m * n)}Riding position) distance R _D1During single face irradiation, distance R _D1Be electron beam under this energy to the best net thickness of test products irradiation;

2. the assay method of electron beam irradiation effective range according to claim 1, the length that it is characterized in that described vitrifying agent flow indicator are to treat half the 1.414 times of the irradiation products degree of depth.

3. the assay method of electron beam irradiation effective range according to claim 1 is characterized in that described depth dose index gauge band D _d: respectively at the plane of incidence and 1 above dosage index gauge band of incident opposite direction oblique cutting in product, its dosage index gauge face and electron beam line form the above angle of 30 degree; Open with incident reference dose index gauge tape error.

4. the assay method of electron beam irradiation effective range according to claim 1 is characterized in that product box is at the irradiation optimum thickness R that changes under the face irradiation technique _D1+ R _D2

5. the assay method of electron beam irradiation effective range according to claim 1 is characterized in that the length of quantimeter elementary cell should be greater than more than 3 times of its width in order to improve the observation degree of accuracy and to reduce range error.

6. the assay method of electron beam irradiation effective range according to claim 1 is characterized in that for the low dose irradiation product, and the dosage index gauge band that adopts thickness to make in the quantimeter elementary cell below 2 millimeters carries out irradiation, multilayer stack observation.

7. the assay method of electron beam irradiation effective range according to claim 1; It is characterized in that for the even complex product of density unevenness; Should depth dose index gauge band be divided into several sections and place irradiation, corresponding point stack observation is to obtain the electron beam effective range at each position of product.

8. the stripe electron beam irradiation dose index gauge that uses of the said method of a claim 1; It is characterized in that it is made up of glass sheet (1) and flexible fixed band (2) as the quantimeter elementary cell, be fixed with row on each flexible fixed band (2) at least and be no less than three glass sheet (1).

9. stripe electron beam irradiation dose index gauge according to claim 8 is characterized in that described glass sheet (1) is fixed on the flexible fixed band (2) by row interval or next-door neighbour, answers separation between row and the row.

10. stripe electron beam irradiation dose index gauge according to claim 8 is characterized in that described glass sheet (1) is colourless transparent glass or the transparent simple glass of shallow background color.

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