Preparation method of standard quartz sample for calibration of luminescence dating instrument

Abstract

The invention discloses a preparation method of a standard quartz sample for calibration of a luminescence dating instrument, and relates to the technical field of luminescence dating, and the preparation method comprises the following steps: preparing a quartz glass front wall, a quartz glass rear wall and an annular pad; placing an annular pad between the quartz glass front wall and the quartz glass rear wall, and placing a quartz sample in a central hole of the annular pad to obtain a loading appliance which completes loading; wrapping the loading device with an aluminum foil, placing the loading device on a special support, and placing the loading device at the measurement point of the reference radiation field; measuring the air kerma at the measuring point; calculating a conversion coefficient from air kerma energy to quartz absorbed dose; calculating the absorbed dose of the quartz sample; evaluating the uniformity of the quartz sample by using a luminescence dating instrument and adopting a single-factor variance analysis method; and evaluating the stability of the quartz absorbed dose by adopting a mode of taking out at different times after irradiation and respectively measuring and reading. According to the invention, the loading of the standard quartz sample is more convenient, and the obtained dosage is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescence dating, and in particular to a method for preparing a standard quartz sample for calibrating a luminescence dating instrument. Background Art

[0002] After being buried, minerals receive ionizing radiation generated by the decay of radioactive substances such as uranium, thorium, and potassium in the environment, and accumulate luminescence signals. When mineral particles are heated or irradiated with light beams in the laboratory, the natural luminescence signals accumulated during the burial period can be stimulated. Since the natural luminescence signal of a mineral is positively correlated with the radiation energy (dose) it receives, the functional relationship between the luminescence signal and the radiation dose can be established, and the equivalent dose can be obtained using the measured natural luminescence signal. The equivalent dose is then divided by the environmental dose rate to obtain the age of the mineral burial. This process is called luminescence dating.

[0003] The method to establish the functional relationship between the luminescence signal and the radiation dose is to use the built-in β radiation source in the luminescence dating instrument to irradiate the sample with a determined dose multiple times and measure the corresponding luminescence signal. The method of multiple irradiation is to control the specific irradiation time (generally in seconds) of the built-in β radiation source of the sample luminescence dating instrument through the instrument; because the radioactivity and dose rate of the radiation source gradually decrease over time, it is necessary to use a quartz sample (i.e., standard quartz) that has been independently irradiated with a known equivalent dose (absorbed dose) for dose calibration, so as to obtain the accurate dose rate of the built-in radiation source of the instrument.

[0004] For traditional multi-grain (single-piece) luminescence dating, the calibration of the laboratory radiation source dose rate is based on multi-grain standard quartz. In recent years, with the advancement of dating technology, the single-grain luminescence dating method of quartz and potassium feldspar has been gradually improved. This method can determine the degree of fading before sample deposition and the mixing of mineral particles in different deposition processes. In principle, each mineral particle can obtain a deposition age. The testing efficiency of this method is much higher than that of single-piece luminescence dating. Therefore, this method has been used more and more widely, especially for solving the age problem of samples in complex sedimentary environments (such as archaeological site deposits, cave sediments, glacial sediments, ancient lake banks and river terraces, etc.). The calibration of the built-in β radiation source dose rate of the luminescence dating instrument of the single-grain method also needs to be carried out through single-grain testing of standard quartz, which puts forward more stringent requirements on the consistency of dose between standard quartz particles.

[0005] At present, the standard quartz samples used for luminescence dating calibration mainly come from Denmark. There is no scientific research institution in China that has developed standard quartz, but the latest research shows that the dose of standard quartz produced before October 2019 is underestimated by about 8% (Autzen et al., 2022). This result has caused serious trouble for all luminescence dating laboratories. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a standard quartz sample for calibrating a luminescence dating instrument, so as to solve the problems existing in the above-mentioned related technologies, facilitate the loading of samples, and make the dosage of standard quartz more accurate.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention discloses a method for preparing a standard quartz sample for calibrating a luminescence dating instrument, comprising the following steps:

[0009] Step 1, preparation of a loading device: prepare a quartz glass front wall and a quartz glass rear wall, both of which are flat plates and are used to sandwich the granular quartz sample in the middle, and the quartz glass front wall is closer to the radiation source than the quartz glass rear wall; prepare an annular pad, which is used to be placed between the quartz glass front wall and the quartz glass rear wall, and the central hole of the annular pad is used to place the quartz sample;

[0010] Step 2, quartz loading: place the annular pad on the front side of the rear wall of the quartz glass, place the quartz sample in the center hole of the annular pad, and place the front wall of the quartz glass on the front side of the annular pad;

[0011] Step 3: Irradiation of quartz: Wrap the loading device with aluminum foil, place the loading device on a special bracket, and place it at the measurement point of the reference radiation field for irradiation;

[0012] Step 4: Parameter evaluation: measure the air kerma rate at the measuring point;

[0013] Step 5: Calculate the conversion factor from air kerma to quartz absorbed dose;

[0014] Step 6: Calculate the absorbed dose of the quartz sample according to the air kerma rate, conversion coefficient and irradiation time;

[0015] Step 7: After the prepared quartz samples are grouped, they are measured using a luminescence dating instrument; a one-way analysis of variance method is used to calculate the ratio of the between-group variance to the within-group variance to evaluate the uniformity of the quartz samples;

[0016] Step 8. Place the irradiated quartz sample in a shielding box, take it out at different times after irradiation, and measure it respectively; use linear regression fitting to calculate the slope of the linear fitting equation and its standard deviation, and evaluate the stability of the quartz absorbed dose by the difference between the slope and 0.

[0017] Preferably, in step 1, if the radiation source is Cs-137 and the energy is 662keV, the thickness of the quartz glass front wall is at least 0.55mm; if the radiation source is Co-60 and the energy is 1.25MeV, the thickness of the quartz glass front wall is at least 2mm, and the thickness of the quartz glass rear wall is at least 0.5mm.

[0018] Preferably, the thickness of the annular gasket is no greater than 1 mm, so that the loading thickness of the quartz sample does not exceed 1 mm.

[0019] Preferably, the central hole of the annular pad is a square hole or a circular hole.

[0020] Preferably, the lower end of the loading device is fixed on a dedicated bracket or the upper end is hoisted on a dedicated bracket.

[0021] Optionally, the special bracket includes a pair of first vertical plates parallel to each other and a pair of second vertical plates parallel to each other; a first upper slot is set at the upper end of the first vertical plate, and two first lower slots are set at the lower end of the first vertical plate; two second upper slots are set at the upper end of the second vertical plate; the first vertical plate and the second vertical plate are perpendicular to each other; the two first lower slots of the first vertical plate are respectively inserted into the second upper slots of the two second vertical plates, and the lower end of the loading tool is inserted into the first upper slot to fix the lower end of the loading tool on the special bracket.

[0022] Optionally, the special bracket includes a pair of first vertical plates parallel to each other, a pair of second vertical plates parallel to each other and a third vertical plate; a first upper slot is set at the upper end of the first vertical plate, and two first lower slots are set at the lower end of the first vertical plate; two second upper slots are set at the upper end of the second vertical plate; the first vertical plate and the second vertical plate are perpendicular to each other; the two first lower slots of the first vertical plate are respectively inserted into the second upper slots of the two second vertical plates; the two ends of the third vertical plate are respectively inserted into the first upper slots of the two first vertical plates, and the upper end of the loading device is connected to the third vertical plate by a hanging line to hang the upper end of the loading device on the special bracket.

[0023] Preferably, in step five, a corresponding model is established using Monte Carlo software, a standard quartz integration area or detector is placed in the corresponding area, and the conversion coefficient of air kerma to absorbed dose under monoenergetic photons is simulated and obtained, and then the energy spectrum of the irradiated radiation mass is integrated through the fluence spectrum and the conversion coefficient of the monoenergetic photons to obtain the energy spectrum average value of the conversion coefficient.

[0024] Preferably, in step five, a corresponding model is established using Monte Carlo software, actual energy spectrum data at the radiation field measurement point is input, the air kerma and the absorbed dose of quartz are calculated respectively, and the conversion coefficient from air kerma to absorbed dose under the radiation quality is directly obtained.

[0025] Preferably, in step seven, the quartz sample is divided into different samples; a portion is taken out from each sample, and the samples are divided into 10 aluminum plates in the luminescence dating instrument for measurement using the luminescence dating instrument; a one-way analysis of variance method is used to determine whether there is a systematic deviation between the measurements of each group by comparing the between-group variance and the within-group variance; if the ratio of the between-group variance to the within-group variance is less than the critical value of the statistical test, the quartz sample is considered to be uniform.

[0026] Compared with the related art, the present invention has achieved the following technical effects:

[0027] The present invention uses two flat quartz glasses to sandwich the quartz sample in the middle, so that the quartz sample is distributed in a flat plate shape, reducing mutual shielding of the quartz samples, thereby improving the consistency of the absorbed dose of the quartz sample.

[0028] The present invention sets requirements for the thickness of quartz. If the radiation source is Cs-137 with an energy of 662keV, the thickness of the front wall of the quartz glass is at least 0.55mm; if the radiation source is Co-60 with an energy of 1.25MeV, the thickness of the front wall of the quartz glass is at least 2mm, and the thickness of the rear wall of the quartz glass is at least 0.5mm, so as to facilitate irradiation of the quartz sample in a state of charged particle equilibrium, ensure that the scattered particles in the back area of ​​the quartz sample can be compensated when the quartz sample is irradiated, and facilitate stable evaluation of the absorbed dose of the quartz sample.

[0029] The present invention designs two layers of quartz glass plates with an annular pad in the middle, and quartz particles are spread flat in the central hole of the annular pad, so that the quartz glass front wall and the quartz glass rear wall are respectively attached to the annular pad from both sides, so as to facilitate the uniform spreading and removal of granular quartz samples.

[0030] The present invention adopts quartz glass having a smaller mass-energy absorption coefficient difference with the quartz sample as the loading device material, which can better ensure that the radiation fluence spectrum changes less when the radiation passes through the irradiation device and the quartz sample, and the evaluation value is more accurate and reliable.

[0031] The present invention adopts a light-shielding method of wrapping the loading device with aluminum foil. The aluminum foil has a better light-shielding effect, and the composition is known, so its influence on the absorbed dose of the quartz sample can be accurately evaluated, so that the quartz absorbed dose value is accurate.

[0032] In the preferred embodiment of the present invention, the quartz sample and the loading device can be placed naked in the radiation field for irradiation by fixing the lower end or hanging the upper end, so as to ensure that the quartz sample is not affected by backscattering, so that the measurement result is more accurate and reliable.

[0033] In the preferred embodiment of the present invention, when calculating the conversion coefficient, a variety of calculation methods can be selected, which has high flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of a method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of an assembly method of a special bracket and a loading device;

[0037] Figure 3 This is the relationship between unit dose and depth under Cs-137 irradiation conditions;

[0038] Figure 4 This is the relationship between unit dose and depth under Co-60 irradiation conditions.

[0039] In the figure: 1- loading device; 2- special bracket; 3- hanging wire; 21- first vertical board; 22- second vertical board; 23- third vertical board. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide a method for preparing a standard quartz sample for calibrating a luminescence dating instrument, so as to solve the problems existing in the above-mentioned related technologies and make the dosage of the standard quartz more accurate.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figure 1 to Figure 4 This embodiment provides a method for preparing a standard quartz sample for calibrating a luminescence dating instrument, comprising the following steps:

[0044] Step 1, preparation of loading device 1: prepare a quartz glass front wall and a quartz glass rear wall, the quartz glass front wall and the quartz glass rear wall are both flat-plate-shaped and used to sandwich the granular quartz sample in the middle, and the quartz glass front wall is closer to the radiation source than the quartz glass rear wall; prepare an annular pad, the annular pad is flat-plate-shaped and used to be placed between the quartz glass front wall and the quartz glass rear wall, and the central hole of the annular pad is used to place the quartz sample;

[0045] Step 2, quartz loading: place the annular pad on the front side of the rear wall of the quartz glass, place the quartz sample in the center hole of the annular pad, and place the front wall of the quartz glass on the front side of the annular pad;

[0046] Step 3, irradiation of quartz: Wrap the loading device 1 with aluminum foil, place the loading device 1 on the special bracket 2, and place it at the measurement point of the reference radiation field for irradiation;

[0047] Step 4: Parameter evaluation: measure the air kerma rate at the measuring point;

[0048] Step 5: Calculate the conversion factor from air kerma to quartz absorbed dose;

[0049] Step 6: Calculate the absorbed dose of the quartz sample according to the air kerma rate, conversion coefficient and irradiation time;

[0050] Step 7: After the prepared quartz samples are grouped, they are measured using a luminescence dating instrument; a one-way analysis of variance method is used to calculate the ratio of the between-group variance to the within-group variance to evaluate the uniformity of the quartz samples;

[0051] Step 8. Place the irradiated quartz sample in a shielding box (such as a lead can), take it out at different times after irradiation, and measure it respectively; use linear regression fitting to calculate the slope of the linear fitting equation and its standard deviation, and evaluate the stability of the quartz absorbed dose by the difference between the slope and 0.

[0052] The working principle of the method for preparing the standard quartz sample for calibrating the luminescence dating instrument in this embodiment is as follows:

[0053] In the prior art, the loading device 1 is usually in a hollow cylindrical shape, which results in inconsistent absorbed doses of quartz samples at different radial positions. In this embodiment, two flat pieces of quartz glass are used to sandwich the quartz sample in the middle, so that the quartz sample is distributed in a flat shape, reducing mutual shielding of the quartz samples, thereby improving the consistency of the absorbed dose of the quartz sample.

[0054] The diameter of quartz particles is relatively small (about 250nm). If the above-mentioned flat-plate distribution method is used, it is difficult to load and remove the quartz sample through a narrow and long slit. Therefore, this embodiment designs two layers of quartz glass plates with a ring pad in the middle. The quartz particles are spread flat in the center hole of the ring pad, and the front wall and the rear wall of the quartz glass are respectively attached to the ring pad from both sides, so as to facilitate the uniform spreading and removal of the granular quartz sample.

[0055] In the prior art, the material of the loading device 1 is usually soda glass, polyethylene, etc., while the present embodiment uses quartz glass having a mass-energy absorption coefficient less different from that of the quartz sample as the material of the loading device 1, which can better ensure that the radiation fluence spectrum changes less when the radiation passes through the irradiation device and when it passes through the quartz sample, and the evaluation value is more accurate and reliable.

[0056] In the prior art, a light-shielding method of wrapping the loading device 1 with black tape is usually used. However, the composition of the black tape is unknown, and the effect of the black tape on the absorbed dose of the quartz sample cannot be ensured. This embodiment uses an aluminum foil to wrap the loading device 1 for light-shielding. The aluminum foil has a better light-shielding effect, and the composition is known, so its effect on the absorbed dose of the quartz sample can be accurately evaluated, so that the quartz absorbed dose value is accurate.

[0057] After the above improvements, the preparation method of this embodiment can make the dosage of standard quartz more accurate, but there may still be some standard quartz whose dosage does not meet the requirements. These samples are rejected according to the corresponding standards after step seven and step eight.

[0058] As a possible example, in step 1, if the radiation source is Cs-137, the thickness of the quartz glass front wall is at least 0.55 mm; if the radiation source is Co-60, the thickness of the quartz glass front wall is at least 2 mm, and the thickness of the quartz glass rear wall is at least 0.5 mm.

[0059] It should be noted that the function of the quartz glass front wall is to ensure that the quartz sample is irradiated in a state of charged particle equilibrium when the quartz sample is irradiated. The function of the quartz glass rear wall is to ensure that the scattered particles in the back area can be compensated when the quartz sample is irradiated. After calculation, if the radiation source is Cs-137 (energy 662keV), the thickness of the quartz glass front wall is at least 0.55mm. The experimental results are shown in Figure 3 If the radiation source is Co-60 (energy 1.25 MeV), the thickness of the front wall of the quartz glass is at least 2 mm, and the thickness of the rear wall of the quartz glass is at least 0.5 mm. The experimental results are shown in Figure 4 .

[0060] Figure 3The figure shows the relationship between the depth of the quartz particles (depth refers to the distance from the rear surface of the quartz glass front wall) and the unit fluence dose under Cs-137 irradiation conditions. It can be seen that at a depth of 0.55 mm, the unit fluence absorbed dose is equal to the unit fluence kerma, indicating that the charged particles are balanced.

[0061] Figure 4 The figure shows the relationship between the depth of the quartz particles and the unit fluence dose under Co-60 irradiation conditions. It can be seen that at a depth of 2 mm, the unit fluence absorbed dose is equal to the unit fluence kerma, indicating that the charged particles are balanced.

[0062] As a possible example, the thickness of the annular pad is not greater than 1 mm, so that the loading thickness of the quartz sample does not exceed 1 mm. Exemplarily, the thickness of the annular pad is preferably 1 mm.

[0063] As a possible example, the central hole of the annular pad is a square hole or a round hole.

[0064] Exemplarily, the outer contours of the quartz glass front wall, the quartz glass rear wall and the annular gasket are of the same size, and the distance between the inner contour and the outer contour of the annular gasket is 1 cm.

[0065] As a possible example, the lower end of the loading device 1 is fixed on the dedicated bracket 2 or the upper end is hoisted on the dedicated bracket 2 .

[0066] In the prior art, the loading device 1 is usually fixed on organic glass, and the backscattering of organic glass needs to be considered when calculating the absorbed dose of quartz. In this embodiment, the quartz sample and the loading device 1 can be placed naked in the radiation field for irradiation by fixing the lower end or hanging the upper end, so as to ensure that the quartz sample is not affected by the backscattering, so that the measurement result is more accurate and reliable.

[0067] Reference Figure 2 When the upper end hoisting method is adopted, the special bracket 2 includes a pair of mutually parallel first vertical plates 21 and a pair of mutually parallel second vertical plates 22 and a third vertical plate 23. A first upper slot is set at the upper end of the first vertical plate 21, and two first lower slots are set at the lower end of the first vertical plate 21. Two second upper slots are set at the upper end of the second vertical plate 22. The first vertical plate 21 and the second vertical plate 22 are perpendicular to each other. The two first lower slots of the first vertical plate 21 are respectively inserted into the second upper slots of the two second vertical plates 22. The two ends of the third vertical plate 23 are respectively inserted into the first upper slots of the two first vertical plates 21, and the upper end of the loading device 1 is connected to the third vertical plate 23 through the hanging wire 3, so that the upper end of the loading device 1 is hoisted on the special bracket 2.

[0068] When the lower end is fixed, the special bracket 2 includes a pair of mutually parallel first vertical plates 21 and a pair of mutually parallel second vertical plates 22. A first upper slot is provided at the upper end of the first vertical plate 21, and two first lower slots are provided at the lower end of the first vertical plate 21. Two second upper slots are provided at the upper end of the second vertical plate 22. The first vertical plate 21 and the second vertical plate 22 are perpendicular to each other. The two first lower slots of the first vertical plate 21 are respectively inserted into the second upper slots of the two second vertical plates 22, and the lower end of the loading device 1 is inserted into the first upper slot, so that the lower end of the loading device 1 is inserted and fixed to the special bracket 2.

[0069] By adopting the special bracket 2 with the plug-in structure, it is convenient to disassemble when not in use to reduce the storage space.

[0070] Exemplarily, the sum of the depths of the first lower slot and the second upper slot is equal to the height of the second vertical plate 22 , so that the lower end of the first vertical plate 21 is flush with the lower end of the second vertical plate 22 , thereby improving the stability of the dedicated bracket 2 .

[0071] Exemplarily, the number of the second upper slots at the upper end of the second vertical plate 22 is greater than two, so as to adjust the position of the first vertical plate 21 .

[0072] In step 5, there are multiple ways to calculate the conversion coefficient, and those skilled in the art can flexibly choose.

[0073] Exemplarily, when calculating the conversion coefficient, a corresponding model can be established using Monte Carlo software, and a standard quartz integration area or detector can be placed in the corresponding area to simulate the conversion coefficient of air kerma to absorbed dose under monoenergetic photons. Then, the energy spectrum of the irradiated radiation mass is integrated through the fluence spectrum and the conversion coefficient of the monoenergetic photons to obtain the energy spectrum average value of the conversion coefficient.

[0074] For example, when calculating the conversion coefficient, the corresponding model can be established using Monte Carlo software, the actual energy spectrum data at the radiation field measurement point is input, the air kerma and the absorbed dose of quartz are calculated respectively, and the conversion coefficient from air kerma to absorbed dose under the radiation quality is directly obtained.

[0075] As a possible example, in step 7, the quartz sample is divided into different samples. A portion is taken from each sample and placed on aluminum plates in 10 luminescence dating instruments for measurement using a luminescence dating instrument. The one-way analysis of variance method is used to compare the variance between groups to determine whether there is a systematic deviation between the measurements of each group. If the ratio of the variance between groups to the variance within groups (F value) is less than the critical value of the statistical test, the quartz sample is considered to be uniform. This critical value can be flexibly set by the preparation personnel according to the preparation standard.

[0076] It is understandable that when performing the one-way ANOVA method in step seven, the above parameters can be adjusted to meet actual needs.

[0077] As a possible example, in step eight, a portion of the quartz sample is randomly taken out after irradiation and immediately measured using a luminescence dating instrument, and the remaining quartz sample is placed in a shielding box for one month before a portion of the quartz sample is taken out for the second time. The time interval between two consecutive quartz sample taking outs is not less than one month.

[0078] Exemplarily, in step eight, the quartz sample can be taken out 13 times, namely, when the quartz sample is just placed in the shielding box, one month, two months, three months, four months to twelve months.

[0079] As a possible example, the absorbed dose of the quartz sample is not limited to the 5Gy mentioned in the scheme, but can actually be wider and can be selected according to needs and actual conditions; the radiation type can be X-rays, gamma rays, beta rays, or electrons and other radiation particles; it is not limited to 662keV (Cs-137) and 1.25MeV (Co-60), but can be selected according to needs and actual conditions.

[0080] As a possible example, in step 4, in a gamma-ray standard radiation field, a standard ionization chamber traceable to a gamma-ray air kerma benchmark (such as National Basic Certificate

[2019] No. 145) is used to accurately measure the air kerma rate at the location where the reference radiation field is intended to be used to irradiate quartz.

[0081] As a possible example, the calculation formula for step six is ​​as follows:

[0082]

[0083] in The kerma of air at the position where the reference radiation field is to be used to irradiate the quartz for the standard ionization chamber; Calibration factor for ionization chamber traceability to a reference; is the ionization current of the ionization chamber; k tp is the temperature and pressure correction of the ambient air; h K,D is the conversion coefficient from air kerma to standard quartz absorbed dose; t is the irradiation time.

[0084] The calculation formula for step eight is as follows:

[0085]

[0086] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a standard quartz sample for calibrating a luminescence dating instrument, characterized in that: The following steps are involved: Step 1, preparation of a loading device: prepare a quartz glass front wall and a quartz glass rear wall, both of which are flat plates and are used to sandwich the granular quartz sample in the middle, and the quartz glass front wall is closer to the radiation source than the quartz glass rear wall; prepare an annular pad, which is used to be placed between the quartz glass front wall and the quartz glass rear wall, and the central hole of the annular pad is used to place the quartz sample; Step 2, quartz loading: place the annular pad on the front side of the rear wall of the quartz glass, place the quartz sample in the center hole of the annular pad, and place the front wall of the quartz glass on the front side of the annular pad; Step 3: Irradiation of quartz: Wrap the loading device with aluminum foil, place the loading device on a special bracket, and place it at the measurement point of the reference radiation field for irradiation; Step 4: Parameter evaluation: measure the air kerma rate at the measuring point; Step 5: Calculate the conversion factor from air kerma to quartz absorbed dose; Step 6: Calculate the absorbed dose of the quartz sample according to the air kerma rate, conversion coefficient and irradiation time; Step 7: After the prepared quartz samples are grouped, they are measured using a luminescence dating instrument; a one-way analysis of variance method is used to calculate the ratio of the between-group variance to the within-group variance to evaluate the uniformity of the quartz samples; Step 8. Place the irradiated quartz sample in a shielding box, take it out at different times after irradiation, and measure it respectively; use linear regression fitting to calculate the slope of the linear fitting equation and its standard deviation, and evaluate the stability of the quartz absorbed dose by the difference between the slope and 0.

2. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: In step 1, if the radiation source is Cs-137 and the energy is 662keV, the thickness of the quartz glass front wall is at least 0.55mm; if the radiation source is Co-60 and the energy is 1.25MeV, the thickness of the quartz glass front wall is at least 2mm, and the thickness of the quartz glass rear wall is at least 0.5mm.

3. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: The thickness of the ring gasket should not be greater than 1 mm so that the loading thickness of the quartz sample does not exceed 1 mm.

4. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: The center hole of the annular gasket is a round hole or a square hole.

5. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: The lower end of the loading device is fixed on a special bracket or the upper end is hoisted on a special bracket.

6. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 5, characterized in that: The special bracket includes a pair of first vertical plates parallel to each other and a pair of second vertical plates parallel to each other; a first upper slot is set at the upper end of the first vertical plate, and two first lower slots are set at the lower end of the first vertical plate; two second upper slots are set at the upper end of the second vertical plate; the first vertical plate and the second vertical plate are perpendicular to each other; the two first lower slots of the first vertical plate are respectively inserted into the second upper slots of the two second vertical plates, and the lower end of the loading tool is inserted into the first upper slot, so that the lower end of the loading tool is inserted and fixed on the special bracket.

7. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 5, characterized in that: The special bracket includes a pair of first vertical plates parallel to each other, a pair of second vertical plates parallel to each other and a third vertical plate; a first upper slot is arranged at the upper end of the first vertical plate, and two first lower slots are arranged at the lower end of the first vertical plate; two second upper slots are arranged at the upper end of the second vertical plate; the first vertical plate and the second vertical plate are perpendicular to each other; the two first lower slots of the first vertical plate are respectively inserted into the second upper slots of the two second vertical plates; the two ends of the third vertical plate are respectively inserted into the first upper slots of the two first vertical plates, and the upper end of the loading device is connected to the third vertical plate by a hanging line so that the upper end of the loading device can be hoisted on the special bracket.

8. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: In step five, the corresponding model is established using Monte Carlo software, and a standard quartz integration area or detector is placed in the corresponding area to simulate the conversion coefficient of air kerma to absorbed dose under monoenergetic photons. Then, the energy spectrum of the irradiated radiation mass is integrated through the fluence spectrum and the conversion coefficient of the monoenergetic photons to obtain the energy spectrum average value of the conversion coefficient.

9. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: In step five, the corresponding model is established using Monte Carlo software, the actual energy spectrum data at the radiation field measurement point is input, the air kerma and the absorbed dose of quartz are calculated respectively, and the conversion coefficient from air kerma to absorbed dose under the radiation quality is directly obtained.

10. The method for preparing a standard quartz sample for calibrating a luminescence dating instrument according to claim 1, characterized in that: In step seven, the irradiated quartz samples are divided into different samples; a portion is taken out from each sample and packed on aluminum plates in 10 luminescence dating instruments for measurement using a luminescence dating instrument; a one-way analysis of variance method is used to determine whether there is a systematic deviation between the measurements of each group by comparing the between-group variance and the within-group variance. If the ratio of the between-group variance to the within-group variance is less than the critical value of the statistical test, the quartz sample is considered to be uniform.

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