Indium-based chloride scintillation crystal and preparation method thereof

Abstract

The invention relates to the technical field of scintillation crystal preparation, in particular to an indium-based chloride scintillation crystal and a preparation method thereof. According to the method, the quartz crucible with the necking seed crystal tube is used for preparing the indium-based chloride scintillation crystal by adopting a Bridgman-Stockbarger method, the non-uniform melting characteristic of raw materials can be overcome by adjusting process parameters, the defects caused by phase change are improved, regulation and control can be carried out according to the required performance, and the method is suitable for industrial production. And finally, the indium-based chloride scintillation crystal Cs2LiIn1-xCexCl6 which is good in crystallization performance, large in size and good in optical performance is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of scintillation crystal preparation, and in particular to an indium-based chloride scintillation crystal and a preparation method thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In recent years, with the widespread use of radioactive materials, thermal neutron-gamma dual readout detectors that can simultaneously detect and effectively identify thermal neutrons and gamma rays are becoming increasingly important in preventing nuclear proliferation, nuclear leakage, security inspections, and nuclear radiation environmental protection. The widely used thermal neutron-gamma dual readout detectors generally contain two types of detectors. One is the thermal neutron detector, such as 3 He gas tube; the other is a gamma ray detector, such as NaI:Tl crystal detector; the two detectors work together to detect thermal neutrons and gamma rays at the same time. Thermal neutron detection mainly uses neutrons and thermal neutrons to detect specific isotopes in the material (such as 3 He, 6 Li and 10 B) reaction, releasing alpha particles, and then indirectly detecting neutrons; gamma ray detection mainly uses gamma rays to activate scintillation crystals to emit light, and then detects through energy analysis. There are many types of scintillation crystals that can be used to detect gamma rays, which is also the main content of scintillation crystal research; thermal neutron detection requires materials containing 3 He, 6 Li or 10 B and other specific isotopes, so the material types are much fewer and the development is slow. Traditional thermal neutron detectors are 3 He proportional counter, but in recent years, 3 He resources are close to exhaustion and existing resources can no longer meet the needs.

[0004] At present, Cs2LiYCl6 (CLYC) crystal has excellent performance in the detection field. It can achieve 7% energy resolution at 662KeV and can effectively distinguish thermal neutrons and gamma rays. However, its application is limited by its difficult preparation, easy deliquesce, high price and size. Yb:YAG has a fast response time for neutron detection, but the performance of the crystal material is degraded due to irradiation in the mixed field of thermal neutrons and gamma rays. The best alpha particle light output to gamma ray light output ratio of Li6Gd(BO3)3 single crystal is only 0.16, which cannot effectively distinguish particles in the mixed field.

[0005] Therefore, there is an urgent need to develop large-sized, radiation-resistant neutron detectors with strong thermal neutron and gamma-ray discrimination capabilities. Summary of the invention

[0006] In order to overcome the above problems, the present invention provides an indium chloride scintillation crystal and a preparation method thereof. In the absence of water and oxygen, a bulk indium chloride scintillation crystal Cs2LiIn with large size, good crystallinity, easy operation and good optical performance is grown. 1-x Ce x Cl6.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] In a first aspect of the present invention, an indium-based chloride scintillation crystal is provided, wherein the chemical formula of the indium-based chloride scintillation crystal is: Cs2LiIn 1-x Ce x Cl6, where the value range of x is 0.0001≤x≤0.015.

[0009] The cerium ions that play a luminescent role in the indium-based chloride scintillation crystal exist in the form of +3 valence, and the cerium ions randomly occupy the In 3+ The ionic lattice forms a luminescent center.

[0010] The second aspect of the present invention provides a method for preparing the indium-based chloride scintillation crystal according to the first aspect, comprising the following steps:

[0011] (1) According to the chemical formula of indium chloride scintillator crystal Cs2LiIn 1-x Ce x Cl6 weigh each raw material;

[0012] (2) Under an inert gas atmosphere, grinding each raw material into powder, and mixing all the raw material powders uniformly;

[0013] (3) placing the mixed raw material powder in a specified quartz crucible, evacuating the quartz crucible into a vacuum state, and then sealing the quartz crucible;

[0014] (4) Place the sealed quartz crucible into the crucible descending furnace, heat the temperature to 700-750°C, maintain the temperature for 3-4 hours, then cool it down to 380-400°C, maintain the temperature for 3-4 hours; repeat the heating and cooling process 3-4 times, and then cool it down to room temperature to form Cs2LiIn 1-x Ce x Cl6 polycrystalline material;

[0015] (5) Containing Cs2LiIn 1-x Ce xThe quartz crucible of Cl6 polycrystalline material is placed vertically in a vertically arranged crucible descending furnace, and the temperature is raised to 610-650°C and kept warm for 9.5-12 hours; a descending program is set so that the quartz crucible passes through a temperature gradient zone of 16-25°C / cm at a descending rate of 0.25-0.4 mm / h to complete melt crystallization;

[0016] (6) Annealing the crystal to obtain the indium-based chloride scintillation crystal.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention relates to the technical field of scintillation crystal preparation, and specifically to an indium-based chloride scintillation crystal and a preparation method thereof. The present invention uses a quartz crucible with a necked seed crystal tube to prepare an indium-based chloride scintillation crystal by a crucible descent method. By adjusting the process parameters, the non-uniform melting characteristics of the raw materials can be overcome, the defects caused by phase change can be improved, and the process can be regulated according to the required performance, and finally an indium-based chloride scintillation crystal Cs2LiIn with good crystallization performance, large size and good optical performance is prepared. 1-x Ce x Cl6.

[0019] (2) Indium-based chloride scintillating crystal Cs2LiIn prepared by the present invention 1-x Ce x Cl6 has a hexagonal crystal system and has broad development prospects in the fields of radiation detection and ultraviolet photoelectricity.

[0020] (3) The raw materials in the present invention include CsCl, LiCl, InCl3 and CeCl3. Due to their non-uniform melting characteristics, excess LiCl is used to improve the crystallinity of the crystal.

[0021] (4) The special structure of the quartz crucible with a necked seed crystal tube can eliminate the crystal nucleus and prevent spontaneous nucleation from generating seed crystals of poor quality and undesirable growth and crystallization direction, which in turn leads to more subsequent defects and cracking of crystal growth.

[0022] (5) The experiment found that the setting of the temperature gradient zone will affect the quality of the crystal. Specifically, a temperature gradient that is too large, such as greater than 25°C / cm, will cause serious crystal cracking and reduce the crystal quality; a temperature gradient that is too small, such as less than 16°C / cm, will make the crystal have poor crystallinity and cannot be crystallized.

[0023] At the same time, the setting of the cooling rate will also affect the quality of the crystal. If the cooling rate is too fast, such as a cooling rate greater than 10℃ / h, the thermal stress will be released quickly, leading to cracking; if the cooling rate is too slow, such as a cooling rate less than 5℃ / h, it will be in a high temperature state for a long time, and the gas pressure in the quartz crucible will be high, which may easily cause the quartz crucible to burst. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 The figure is a physical picture of a quartz crucible with a necked seed crystal tube;

[0026] Figure 2 It is a schematic diagram of the structure of a quartz crucible with a necked seed crystal tube;

[0027] Figure 3 The specific dimensions of the quartz crucible with the necked seed crystal tube used in Example 2 and Comparative Examples 2-3;

[0028] Figure 4 The actual picture of the crystal, wherein (a) is the indium chloride scintillating crystal Cs2LiIn prepared in Example 2 1- x Ce x (b) is a physical picture of the crystal prepared in Comparative Example 1, (c) is a physical picture of the crystal prepared in Comparative Example 2; (d) is a physical picture of the crystal prepared in Comparative Example 3;

[0029] Figure 5 The indium chloride scintillating crystal Cs2LiIn prepared in Example 2 1-x Ce x XRD pattern of Cl6;

[0030] Figure 6 The indium chloride scintillating crystal Cs2LiIn prepared in Example 2 1-x Ce x UV-Vis test spectrum of Cl6;

[0031] Figure 7 The indium chloride scintillating crystal Cs2LiIn prepared in Example 2 1-x Ce x Photoluminescence spectrum test results of Cl6;

[0032] Figure 8 This is a physical picture of the quartz crucible with only a seed crystal tube structure used in Comparative Example 1. DETAILED DESCRIPTION

[0033] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] A first typical embodiment of the present invention provides an indium-based chloride scintillation crystal, wherein the chemical formula of the indium-based chloride scintillation crystal is: Cs2LiIn 1-x Ce x Cl6, where the value range of x is 0.0001≤x≤0.015.

[0036] The cerium ions that play a luminescent role in the indium-based chloride scintillation crystal exist in the form of +3 valence, and the cerium ions randomly occupy the In 3+ The ionic lattice forms a luminescent center.

[0037] A second typical embodiment of the present invention provides a method for preparing the indium-based chloride scintillation crystal according to the first aspect, comprising the following steps:

[0038] (1) According to the chemical formula of indium chloride scintillator crystal Cs2LiIn 1-x Ce x Cl6 weigh each raw material;

[0039] (2) Under an inert gas atmosphere, grinding each raw material into powder, and mixing all the raw material powders uniformly;

[0040] (3) placing the mixed raw material powder in a specified quartz crucible, evacuating the quartz crucible into a vacuum state, and then sealing the quartz crucible;

[0041] (4) Place the sealed quartz crucible into the crucible descending furnace, heat the temperature to 700-750°C, maintain the temperature for 3-4 hours, then cool it down to 380-400°C, maintain the temperature for 3-4 hours; repeat the heating and cooling process 3-4 times, and then cool it down to room temperature to form Cs2LiIn 1-x Ce x Cl6 polycrystalline material;

[0042] (5) Containing Cs2LiIn 1-x Ce x The quartz crucible of Cl6 polycrystalline material is placed vertically in a vertically arranged crucible descending furnace, and the temperature is raised to 610-650°C and kept warm for 9.5-12 hours; a descending program is set so that the quartz crucible passes through a temperature gradient zone of 16-25°C / cm at a descending rate of 0.25-0.4 mm / h to complete melt crystallization;

[0043] (6) Annealing the crystal to obtain the indium-based chloride scintillation crystal.

[0044] In one or more embodiments, in step (1), the raw materials include CsCl, LiCl, InCl3 and CeCl3, wherein the molar ratio of CsCl, LiCl, InCl3 and CeCl3 is 2:(1-1.05):(1-x):x, wherein the value range of x is 0.0001≤x≤0.015. Using excess LiCl can improve the crystallinity of the crystal.

[0045] In one or more embodiments, in step (3), the defined quartz crucible is a quartz crucible with a necked seed crystal tube, the quartz crucible with a necked seed crystal tube comprises a quartz crucible body and a necked seed crystal tube connected in sequence, the necked seed crystal tube comprises a necking region and a seed crystal region connected in sequence;

[0046] The seed crystal region includes a first seed crystal region, a diameter-changing region and a second seed crystal region which are connected in sequence;

[0047] The quartz crucible body and the necked seed crystal tube are integrally formed.

[0048] Preferably, the inner diameter of the quartz crucible body is larger than the seed crystal zone; the inner diameter of the end of the necking zone connected to the quartz crucible body is the same as that of the quartz crucible body; the inner diameter of the end of the necking zone connected to the seed crystal zone is the same as that of the seed crystal zone; the inner diameter of the necking zone gradually decreases from the end connected to the quartz crucible body to the end connected to the seed crystal zone.

[0049] Preferably, the ratio of the lengths of the quartz crucible body, the necking region and the seed crystal region is (15.5-16.5):3:6, preferably 16:3:6.

[0050] Preferably, the length ratio of the first seed crystal region, the diameter-changing region and the second seed crystal region is 4:(0.8-1.2):10, preferably 4:1:10.

[0051] Preferably, the inner diameters of the first seed crystal region and the second seed crystal region are the same; the ratio of the inner diameter of the quartz crucible body to the inner diameter of the first seed crystal region is (2.4-2.6):1, preferably 2.5:1.

[0052] Preferably, the inner diameter of the diameter-changing zone is smaller than the inner diameters of the first seed crystal zone and the second seed crystal zone; and the inner diameter of the diameter-changing zone has a smooth transition.

[0053] Further preferably, the ratio of the inner diameter of the diameter-changing zone to the inner diameter of the first seed crystal zone is 2:(0.8-1.2), preferably 2:1.

[0054] In one or more embodiments, in step (4), the heating rate during the heating process is 85 to 95° C. / h, preferably 90° C. / h.

[0055] In one or more embodiments, in step (4), during the process of cooling the temperature to 380-400° C., the cooling rate is 55-65° C. / h, preferably 60° C. / h.

[0056] In one or more embodiments, in step (4), during the process of cooling to room temperature, the cooling rate is 18-22°C / h, preferably 20°C / h.

[0057] In one or more embodiments, in step (5), when the temperature is raised to 610-650°C, the rate of heating is 58-65°C / h, preferably 60°C / h.

[0058] In one or more embodiments, in step (6), the annealing process includes: cooling the upper temperature zone to 445-455°C; heating the lower temperature zone to 445-455°C; in the process of adjusting the temperatures of the upper and lower temperature zones, the temperature of the middle temperature zone is maintained at 350-360°C; then the upper and lower temperature zones are simultaneously cooled to 395-405°C, and after the middle temperature zone is heated to 395-405°C, the three temperature zones are simultaneously kept warm for 1.5-2.5h, and then cooled to room temperature to obtain the indium chloride scintillation crystal.

[0059] Preferably, during the annealing process, the heating or cooling rates of the three temperature zones are the same, which is 5 to 8° C. / h, preferably 5° C. / h.

[0060] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0061] Example 1

[0062] According to the characteristics of spontaneous nucleation of crystals, in order to obtain better quality seed crystals, a quartz crucible with a necked seed crystal tube structure is designed and customized. The necking is intended to eliminate excess crystal nuclei in the growth direction. Figure 1 This is a physical picture of a quartz crucible with a necked seed crystal tube. Figure 2 It is a schematic diagram of the structure of a quartz crucible with a necked seed crystal tube.

[0063] like Figure 2 As shown, a quartz crucible with a necked seed crystal tube, the quartz crucible with a necked seed crystal tube comprises a quartz crucible body 1 and a necked seed crystal tube connected in sequence, the necked seed crystal tube comprises a necking area 2 and a seed crystal area connected in sequence;

[0064] The seed crystal area includes a first seed crystal area 3, a diameter-changing area 4 and a second seed crystal area 5 which are connected in sequence;

[0065] The quartz crucible body 1 and the necked seed crystal tube are integrally formed.

[0066] Among them, the inner diameter of the quartz crucible body 1 is larger than the seed crystal area; the inner diameter of the end of the necking area 2 connected to the quartz crucible body 1 is the same as that of the quartz crucible body 1; the inner diameter of the end of the necking area 2 connected to the seed crystal area is the same as that of the seed crystal area; the inner diameter of the necking area 2 gradually decreases from the end connected to the quartz crucible body 1 to the end connected to the seed crystal area.

[0067] The length ratio of the quartz crucible body 1 , the necking area 2 and the seed crystal area is (15.5-16.5):3:6, preferably 16:3:6.

[0068] The length ratio of the first seed crystal region 3 , the diameter-changing region 4 and the second seed crystal region 5 is 4:(0.8-1.2):10, preferably 4:1:10.

[0069] The inner diameters of the first seed crystal region 3 and the second seed crystal region 5 are the same; the ratio of the inner diameter of the quartz crucible body 1 to the inner diameter of the first seed crystal region 3 is (2.4-2.6):1, preferably 2.5:1.

[0070] The inner diameter of the diameter-changing zone 4 is smaller than the inner diameters of the first seed crystal zone 3 and the second seed crystal zone 5, and the inner diameter of the diameter-changing zone 4 is smoothly transitioned. The ratio of the inner diameter of the diameter-changing zone 4 to the inner diameter of the first seed crystal zone 3 is 2:(0.8-1.2), preferably 2:1.

[0071] The specific dimensions of the quartz crucible with a necked seed crystal tube used in the following Example 2 and Comparative Examples 2 to 3 are as follows: Figure 3 shown.

[0072] Example 2

[0073] Indium chloride scintillator crystal Cs2LiIn 1-x Ce x Preparation of Cl6:

[0074] (1) Pretreatment of quartz crucible with necked seed tube:

[0075] Use deionized water to wash and remove the debris and stains attached to the surface, and then use ultrasonic cleaning. Specifically: inject deionized water into the quartz crucible and place it on the filter screen in the water bath ultrasonic cleaning instrument to avoid direct contact between the seed crystal tube and the instrument during ultrasonic cleaning to prevent the impact of ultrasonic vibration on the quartz crucible. The power of ultrasonic cleaning is 180w and the time is 30min. Repeat the above cleaning process twice.

[0076] Inject anhydrous ethanol into the inner cavity of the quartz crucible that has been washed with deionized water and seal it with plastic wrap to prevent external dust from contacting the lumen. Perform ultrasonic cleaning in a water bath ultrasonic cleaner with a power of 180w for 30min. Repeat the above cleaning process twice.

[0077] Transfer the quartz crucible washed with anhydrous ethanol to a drying oven and dry it at 60°C for 24 hours to ensure that the liquid on the tube wall evaporates without residue, and set it aside for use.

[0078] (2) Raw material pretreatment:

[0079] In a glove box filled with inert gas, the chemical formula of indium chloride scintillating crystals is Cs2LiIn 1-x Ce x Cl6, weigh CsCl, LiCl, InCl3, and 1.5% mol CeCl3 with a purity greater than 99.99%. Due to its non-uniform melting characteristics, 5% mol excess LiCl was selected in the raw material selection, and the remaining raw materials were all stoichiometric ratios. Grind each raw material into powder, and mix all the raw material powders evenly. Put the mixed raw material powders into the quartz crucible of step (1). In order to remove moisture and oxygen in the raw materials and the quartz crucible, place it at 150°C and evacuate it to a vacuum degree of less than 6×10 -3 Pa. Then, the sealing is performed using an oxyhydrogen torch in a continuous ionization vacuum state and a rotation state of 20 r / min.

[0080] (3) Place the sealed quartz crucible in step (2) into a crucible descending furnace, and heat the temperature to 700°C at a heating rate of 90°C / h to ensure that the raw material is completely melted. After maintaining for 3 hours, cool the temperature to 400°C at a cooling rate of 60°C / h until the polycrystalline material is completely solidified, and maintain for 3 hours. Repeat the heating and cooling process 3 times to complete the aging of the polycrystalline material, and cool the temperature to room temperature at a cooling rate of 20°C / h to form Cs2LiIn 1-x Ce x Cl6 polycrystalline material.

[0081] (4) Containing Cs2LiIn 1-x Ce x The quartz crucible of Cl6 polycrystalline material is placed vertically in a vertically set crucible descending furnace, and the temperature is raised to 620℃ at a rate of 60℃ / h, and kept warm for 10 hours to ensure that the polycrystalline material can be completely melted. The descending program is set to make the quartz crucible pass through the 16℃ / cm temperature gradient zone at a descending rate of 0.4mm / h. This descending rate and the temperature gradient match the ion migration rate in the phase change until the material length in the cavity has completely passed the position of the solidification point in the temperature gradient zone, and then the descent stops automatically and enters the next step.

[0082] (5) After the temperature in step (4) stops decreasing, the program automatically enters the cooling process. The upper temperature zone decreases from 627°C to 450°C at a cooling rate of 5°C / h; the lower temperature zone increases from 335°C to 450°C at a heating rate of 5°C / h. During this period, the temperature of the middle temperature zone is maintained at 356°C. After preliminary testing, this annealing process can ensure that the grown single crystal will not be remelted a second time. Subsequently, the upper and lower temperature zones are simultaneously decreased to 400°C, and the middle temperature zone is increased to 400°C. The three temperature zones are kept warm for 2 hours at the same cooling rate of 5°C / h to obtain the indium chloride scintillation crystal Cs2LiIn 1-x Ce x Cl6.

[0083] The indium chloride scintillation crystal Cs2LiIn prepared in this example 1-x Ce x The physical picture of Cl6 is as follows Figure 4 As shown in (a).

[0084] The indium chloride scintillator crystal Cs2LiIn prepared in this example 1-x Ce x Take a uniform block of good quality from the first seed crystal area, necking area, and quartz crucible body area of ​​Cl6, grind it thoroughly, and perform XRD test. The test results are as follows: Figure 5 As shown, the structural formula of the indium chloride scintillator crystal prepared in this embodiment is finally determined to be Cs2LiIn 0.99 Ce 0.01 Cl6.

[0085] The indium chloride scintillator crystal prepared in this example was subjected to transmittance test and UV-Vis test. The transparent area block with equal diameter was cut, ground and polished to form a 7mm×5mm×2mm rectangular ingot. The polished ingot was placed in a UV spectrophotometer. The test results are shown in Figure 2. Figure 6 As shown. The scintillation crystal can achieve a high transmittance. The 260-325nm band is Ce 3+ The characteristic absorption peak of Ce 3+ Successfully doped into Cs2LiInCl6 crystals.

[0086] The indium chloride scintillator crystal prepared in this example was subjected to a photoluminescence spectrum test. The transparent area in the crucible body was cut, ground and polished to form a 7mm×5mm×2mm rectangular ingot. The polished ingot was placed in a fluorescence spectrometer. The test results are shown in Figure 2. Figure 7 As shown. Under 340nm excitation, the crystal shows a double peak emission at 375nm and 410nm, which belongs to Ce 3+ 5d-4f transition.

[0087] Comparative Example 1

[0088] Compared with Example 2, the quartz crucible in this comparative example is changed to a quartz crucible having only a seed crystal tube structure, and its structure is as follows Figure 8 As shown, other conditions remain unchanged.

[0089] The crystals prepared in this comparative example are as follows Figure 4 As shown in (b), the quartz crucible with a necked seed crystal tube was not used, and spontaneous nucleation generated seed crystals of poor quality and unsatisfactory growth crystallization direction, resulting in more subsequent defects and more serious cracking during crystal growth.

[0090] Comparative Example 2

[0091] Compared with Example 2, this comparative example does not add excessive LiCl, and only uses the chemical formula of the scintillation crystal Cs2LiIn 1-x Ce x Cl6 weigh each raw material, keeping other conditions unchanged.

[0092] The crystals prepared in this comparative example are as follows Figure 4 As shown in (c), in a non-uniform melting system, according to the stoichiometric ratio, the desired solid phase precipitated from the liquid phase will become less due to the difference in Li content, and the crystallization quality is poor.

[0093] Comparative Example 3

[0094] Compared with Example 2, this comparative example changes the temperature gradient and the descent rate in the crucible descent method, and other conditions remain unchanged. Specifically, the quartz crucible is made to pass through the temperature gradient zone of 25°C / cm at a descent rate of 0.25 mm / h until the material length in the cavity has completely passed the position of the solidification point in the temperature gradient zone, and then the descent automatically stops and proceeds to the next step.

[0095] The crystals prepared in this comparative example are as follows Figure 4 As shown in (d), the temperature gradient and the drop rate are too small, which makes it impossible to match the ion migration rate during the phase change, resulting in poor crystallinity, opacity and poor performance of the crystal.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An indium chloride scintillation crystal, characterized in that: The chemical formula of the indium chloride scintillating crystal is: Cs2LiIn 1-x Ce x Cl6, where the value range of x is 0.0001≤x≤0.

015.

2. The method for preparing the indium chloride scintillation crystal according to claim 1, characterized in that: The following steps are involved: (1) According to the chemical formula of indium chloride scintillator crystal Cs2LiIn 1-x Ce x Cl6 weigh each raw material; (2) Under an inert gas atmosphere, grinding each raw material into powder, and mixing all the raw material powders uniformly; (3) placing the mixed raw material powder in a specified quartz crucible, evacuating the quartz crucible into a vacuum state, and then sealing the quartz crucible; (4) Place the sealed quartz crucible into the crucible descending furnace, heat the temperature to 700-750°C, maintain the temperature for 3-4 hours, then cool it down to 380-400°C, maintain the temperature for 3-4 hours; repeat the heating and cooling process 3-4 times, and then cool it down to room temperature to form Cs2LiIn 1-x Ce x Cl6 polycrystalline material; (5) Containing Cs2LiIn 1-x Ce x The quartz crucible of Cl6 polycrystalline material is placed vertically in a vertically arranged crucible descending furnace, and the temperature is raised to 610-650°C and kept warm for 9.5-12 hours; a descending program is set so that the quartz crucible passes through a temperature gradient zone of 16-25°C / cm at a descending rate of 0.25-0.4 mm / h to complete melt crystallization; (6) Annealing the crystal to obtain the indium-based chloride scintillation crystal.

3. The preparation method according to claim 2, characterized in that: In step (1), the raw materials include CsCl, LiCl, InCl3 and CeCl3, wherein the molar ratio of CsCl, LiCl, InCl3 and CeCl3 is 2:(1-1.05):(1-x):x, wherein the value range of x is 0.0001≤x≤0.

015.

4. The preparation method according to claim 2, characterized in that: In step (3), the quartz crucible defined is a quartz crucible with a necked seed crystal tube, the quartz crucible with a necked seed crystal tube comprises a quartz crucible body and a necked seed crystal tube connected in sequence, the necked seed crystal tube comprises a necking region and a seed crystal region connected in sequence; The seed crystal area includes a first seed crystal area, a diameter-changing area and a second seed crystal area which are connected in sequence; The quartz crucible body and the necked seed crystal tube are integrally formed.

5. The preparation method according to claim 4, characterized in that: The inner diameter of the quartz crucible body is larger than the seed crystal area; the inner diameter of the end of the necking area connected to the quartz crucible body is the same as that of the quartz crucible body; the inner diameter of the end of the necking area connected to the seed crystal area is the same as that of the seed crystal area; the inner diameter of the necking area gradually decreases from the end connected to the quartz crucible body to the end connected to the seed crystal area; Or, the length ratio of the quartz crucible body, the necking area and the seed crystal area is (15.5-16.5):3:6, preferably 16:3:

6.

6. The preparation method according to claim 4, characterized in that: The length ratio of the first seed crystal region, the diameter-changing region and the second seed crystal region is 4:(0.8-1.2):10, preferably 4:1:10; Or, the inner diameters of the first seed crystal region and the second seed crystal region are the same; the ratio of the inner diameter of the quartz crucible body to the inner diameter of the first seed crystal region is (2.4-2.6):1, preferably 2.5:1; Or, the inner diameter of the diameter-changing zone is smaller than the inner diameters of the first seed crystal zone and the second seed crystal zone; and the inner diameter of the diameter-changing zone has a smooth transition; preferably, the ratio of the inner diameter of the diameter-changing zone to the inner diameter of the first seed crystal zone is 2:(0.8-1.2), preferably 2:

1.

7. The preparation method according to claim 3, characterized in that: In step (4), the heating rate during the heating process is 85 to 95°C / h, preferably 90°C / h.

8. The preparation method according to claim 3, characterized in that: In step (4), the cooling rate during the cooling process to 380-400°C is 55-65°C / h, preferably 60°C / h.

9. The preparation method according to claim 3, characterized in that: In step (4), during the process of cooling to room temperature, the cooling rate is 18 to 22°C / h, preferably 20°C / h; Alternatively, in step (5), when the temperature is raised to 610-650°C, the rate of heating is 58-65°C / h, preferably 60°C / h.

10. The preparation method according to claim 3, characterized in that: In step (6), the annealing process includes: cooling the upper temperature zone to 445-455° C.; heating the lower temperature zone to 445-455° C.; in the process of adjusting the temperature of the upper temperature zone and the lower temperature zone, the temperature of the middle temperature zone is maintained at 350-360° C.; then the upper and lower temperature zones are simultaneously cooled to 395-405° C., after the middle temperature zone is heated to 395-405° C., the three temperature zones are simultaneously kept warm for 1.5-2.5 hours, and then cooled to room temperature to obtain the indium chloride scintillation crystal; Preferably, during the annealing process, the heating or cooling rates of the three temperature zones are the same, which is 5 to 8° C. / h, preferably 5° C. / h.

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