Thermoluminescence test heating accessory

Abstract

A thermoluminescence test heating accessory comprises a sample seat, a ceramic heating plate, a copper heat dissipation plate, a sample station and a temperature measuring thermocouple, the sample seat is installed on a rotating support capable of rotating by 360 degrees, a through hole is formed in the center of the sample seat, the sample station is located on the back face of the sample seat, and exciting light irradiates the sample station through the through hole; a ceramic heating plate is placed on the back surface of the sample station, and a thermocouple spring socket is arranged on the ceramic heating plate and is used for being connected with a temperature measuring thermocouple; and the back of the ceramic heating plate is a copper radiating plate. The sample seat is provided with 360-degree scales, so that the direction of scattered light is convenient to adjust; the copper radiating plate and the ceramic heating plate are contacted with the sample station, the heat capacity is small, the temperature control is accurate, and the operation is convenient.

Description

Technical Field

[0001] This utility model belongs to the field of fluorescence spectroscopy measurement technology, and in particular relates to a heating accessory for thermoluminescence testing. Background Technology

[0002] Thermoluminescence refers to the phenomenon where, when some substances are heated, electromagnetic radiation or other ionizing radiation that was originally absorbed and stored in crystal lattice defects is released as photons. Thermoluminescence technology has wide applications in radiation protection, environmental monitoring, and geological dating. For example, researchers at Guangdong Ocean University have developed a thulium-erbium-doped lithium magnesium phosphate material for detecting nuclear radiation intensity (CN202410694378).

[0003] On the other hand, thermoluminescence technology also plays an important role in the field of long afterglow materials. For example, the Changchun Institute of Optics, Fine Mechanics and Physics has utilized thermoluminescence technology to utilize Y3Al2Ga3O 12 Thermoluminescence spectroscopy of phosphors (CN202111512878). Thermoluminescence is also an important method for analyzing the defect energy level distribution in long-afterglow luminescent materials. Thermoluminescence spectroscopy can measure the change in luminescence intensity of a sample over time (temperature) under heating conditions at a fixed rate, and can analyze key information such as the location and concentration of defects in the sample material. With the widespread use of thermoluminescence technology in fluorescent material research, the demand for adding thermoluminescence testing accessories to fluorescence spectrometers, especially some older models, has increased significantly. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this utility model provides a universal heating accessory for thermoluminescence testing that can be matched with general commercial fluorescence spectrometers.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A thermoluminescence (TEL) testing heating accessory includes a sample holder, a ceramic heating plate, a copper heat sink, a sample station, and a temperature measuring thermocouple. The sample holder is mounted on a 360° rotatable support and has a through hole at its center. The sample station is located on the back of the sample holder, and excitation light is irradiated onto the sample station through the through hole. The ceramic heating plate is placed on the back of the sample station, and a thermocouple spring socket is provided on the ceramic heating plate for connection with the temperature measuring thermocouple. The back of the ceramic heating plate is a copper heat sink.

[0007] Furthermore, the sample holder and the copper heat sink are sandwiched between the sample station and the ceramic heating plate by long screws.

[0008] Furthermore, the sample station is a quartz cuvette, in which a liquid or solid powder sample is placed; or the sample station is a sheet-like solid sample.

[0009] Preferably, the quartz cuvette is made of high-temperature resistant, high-transmittance quartz, bonded together using a melting process, with a maximum temperature resistance of 800℃, making it suitable for high-temperature applications. The quartz cuvette measures 45mm in length, 12.5mm in width, and 3mm in thickness. Liquids or solid powders can be placed inside the cuvette. If the sample being measured is a sheet-like solid, such as a fluorescent film on a glass substrate, the fluorescent film can be placed directly in the location of the quartz cuvette without needing the cuvette itself.

[0010] Furthermore, the sample holder is an aluminum base connected by screws and a rotating bracket. The rotating bracket can rotate 360°, and the angle gauge has an accuracy of 5-10°, which is used to control the incident and reflection angles of monochromatic excitation light.

[0011] The ceramic heating plate is a sheet made of high-temperature resistant alumina wrapped with nickel, molybdenum and other thermal resistance wires. Its planar dimensions are rectangular, with a length of 3-5cm and a width of 2-3cm.

[0012] Two wires 301 are led out from the top of the ceramic heating plate. The rated voltage is 220V AC, and 24V DC is optional. The rated power is not less than 200W. The fastest heating rate is 10℃ / minute, and the maximum temperature is 600℃.

[0013] The temperature measuring thermocouple is either a soft thermocouple wire with a PTFE sheath or a 0.5mm diameter armored thermocouple, generally of type E, type K, and type T.

[0014] The front of the ceramic heating plate is coated with thermally conductive silicone grease to ensure good thermal contact with the sample station and to stabilize the position of the sample using its viscosity.

[0015] The copper heat sink has four stainless steel clips that fix the ceramic heating plate to the copper heat sink.

[0016] Thermal grease is applied between the copper heat sink and the ceramic heating plate for heat conduction. Stable thermal contact facilitates accurate and smooth control of sample temperature rise and fall.

[0017] The main advantages of this invention are: the sample holder uses an aluminum base, which ensures stable heat dissipation; the sample holder has 360° scale, which facilitates the adjustment of the direction of scattered light; the copper heat sink, ceramic heating plate and sample station are in contact, resulting in small heat capacity, precise temperature control and convenient operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the heating accessory for thermoluminescence testing;

[0019] Figure 2 This is a schematic diagram of thermoluminescence testing in a fluorescence spectrometer;

[0020] Figure 3 It is Ca 1-x Sr x Al2O4:Eu 2+ ,Dy 3+ Thermoluminescence curves of long-afterglow powders;

[0021] Figure 4 It is Ca 1-x Sr x Al2O4:Eu 2+ ,Dy 3+ Defect energy level analysis of long afterglow powder.

[0022] The components include: 1. Sample holder, 101. Rotating support, 102. Angle ruler, 103. Light transmission hole, 2. Cuvette, 3. Ceramic heating plate, 301. Resistance wire lead, 302. Thermocouple socket, 4. Temperature measuring thermocouple, 5. Copper heat sink, 501. Clamp, A. Continuous light source, B. Light source monochromator, C. Thermoluminescence testing heating accessory, D. Sample chamber, E. Fluorescence monochromator, F. Fluorescence photodetector, G. Temperature controller, and H. SCR. Detailed Implementation

[0023] The present invention will now be further described with reference to the accompanying drawings.

[0024] Reference Figures 1-4A thermoluminescence (TEL) testing heating accessory includes a sample holder 1, a ceramic heating plate 3, a copper heat sink 5, a sample station, and a temperature measuring thermocouple 4. The sample holder 1 is an aluminum base connected to a rotating bracket 101 via screws. The rotating bracket can rotate 360°, and the angle gauge 102 has an accuracy of 5-10°, which can control the incident and reflection angles of monochromatic excitation light. A through-hole 103 is located at the center of the sample holder, through which the excitation light irradiates the sample station. The sample station can be a quartz cuvette 2, made of high-temperature resistant, high-transmittance quartz, formed by a melting process, with a maximum temperature resistance of 800°C, suitable for high-temperature applications. The quartz cuvette 2 has dimensions of 45mm in length, 12.5mm in width, and 3mm in thickness. Liquids or solid powders can be placed inside the quartz cuvette 2. If the sample being measured is a sheet-like solid, such as a fluorescent film on a glass substrate, the fluorescent film can be placed directly at the location of the quartz cuvette 2 without the cuvette. A ceramic heating plate 3 is placed behind the sample station. The ceramic heating plate 3 is a sheet-like object made of high-temperature resistant alumina wrapped with nickel, molybdenum, or other resistance wires. Its planar dimensions are rectangular, 3-5 cm long and 2-3 cm wide. Two wires 301 extend from the top of the ceramic heating plate 3, with a rated voltage of 220V AC (24V DC optional), a rated power of not less than 200W, a maximum heating rate of 10℃ / minute, and a maximum temperature of 600℃. A thermocouple spring socket 302 is located on the ceramic heating plate 3 for connecting to a temperature-sensing thermocouple 4. The temperature-sensing thermocouple 4 is either a soft thermocouple wire with a PTFE sheath or a 0.5mm diameter armored thermocouple, typically of type E, K, or T. Thermal grease needs to be applied to the ceramic heating plate 3 to ensure good thermal contact with the quartz cuvette or sample, and to stabilize the sample's position using its adhesive properties. Behind the ceramic heating plate 3 is a copper heat sink 5, which has four stainless steel clips 501 that secure the ceramic heating plate 3 to it. Thermal grease can also be applied between the copper heat sink 5 and the ceramic heating plate 3 for heat conduction; stable thermal contact facilitates accurate and smooth control of sample temperature rise and fall.

[0025] The preferred fixing method is as follows: the sample holder 1 and the copper heat sink 5 are clamped in the middle by long screws between the sample station (quartz cuvette 2) and the ceramic heating plate 3.

[0026] like Figure 2As shown, the accessory of this invention is placed in the sample chamber D of a commercial fluorescence spectrometer for fluorescence spectrum measurement. Light source A illuminates the sample fixed by the thermoluminescence testing heating accessory C through a light source monochromator B. C is a top view of the thermoluminescence testing heating accessory. The sample emits fluorescence, which enters the fluorescence monochromator E on the right, is processed by a grating, and is received by the fluorescence photodetector. The temperature controller G is equipped with a 500-1000W power selectable SCR H and an RS485 communication module, and has a function for program-controlled heating and cooling processes. A computer connected to the temperature controller and the fluorescence spectrometer can simultaneously acquire temperature and fluorescence intensity signals, thereby obtaining the thermoluminescence fluorescence spectrum. Analysis of the thermoluminescence fluorescence spectrum data yields information about the sample's defect energy levels.

[0027] This embodiment of the invention uses a Fluoro Max-4 commercial fluorescence spectrometer to measure Ca. 1-x Sr x Al2O4:Eu 2+ ,Dy 3+ Thermoluminescence spectrum of long afterglow powder, structure as follows Figure 2 As shown, the heating accessory is as follows Figure 1 As shown.

[0028] First, the fluorescent powder is placed into a cuvette that is 45mm long, 12.5mm wide, and 3mm thick, bonded using a melt-bonding process. Figure 1 As shown, the copper heat sink and sample holder hold the alumina ceramic heating plate and cuvette in the middle. A suitable amount of thermal grease is applied between the copper heat sink, alumina ceramic heating plate, and cuvette. After being secured with screws, the sample holder is placed on a rotating support with an angular scale accuracy of 5°. Rotating the sample holder to a 60° position prevents the excitation light from being directly reflected into the fluorescence photodetector.

[0029] Before measurement, the sample was irradiated with a 450W xenon lamp for 5 minutes, then the light source was turned off and the sample was placed in the sample chamber for another 5 minutes to allow shallow traps in the sample to be cleared and to avoid affecting the pyroelectric spectroscopy measurement. Next, a commercial fluorescence spectrometer was used to measure the time evolution of the sample fluorescence intensity, i.e., real-time monitoring. An excitation light of 350 nm was selected, and the fluorescence peak position was chosen as 440 nm. After starting real-time monitoring of fluorescence intensity, the temperature control heating program was initiated at 30 seconds, using the start time of monitoring as zero. The sample was heated from room temperature (30℃) to 230℃ at a heating rate of 10℃ / minute. Heating automatically stopped when the temperature reached 230℃, and the sample was allowed to cool naturally. The temperature controller reading was observed, and fluorescence intensity monitoring was stopped when the target temperature of 230℃ was reached. By comparing the fluorescence intensity evolution data over time after 30 seconds with the temperature evolution data over time, the fluorescence intensity versus temperature curve could be obtained. The results are as follows: Figure 3As shown, this embodiment measured the pyroelectric spectra of four phosphors with different doping concentrations. The peak position of the curve corresponds to the center position of the defect energy level, while the area of ​​the curve corresponds to the density of the defect energy level. Based on the above theory, the defect energy level positions and densities of the four samples were analyzed, and the results are as follows. Figure 4 As shown, with increasing doping concentration, the defect energy level first becomes deeper and then shallower, while the concentration of the defect energy level first decreases and then increases. This indicates that rare earth element doping has a significant impact on the defect energy level of the phosphor.

Claims

1. A heating accessory for thermoluminescence testing, characterized in that, The accessories include a sample holder, a ceramic heating plate, a copper heat sink, a sample station, and a temperature measuring thermocouple. The sample holder is mounted on a rotating bracket that can rotate 360°. The sample holder has a through hole at its center. The sample station is located on the back of the sample holder, and the excitation light shines on the sample station through the through hole. The ceramic heating plate is placed on the back of the sample station, and there is a thermocouple spring socket on the ceramic heating plate for connecting to the temperature measuring thermocouple. The back of the ceramic heating plate is a copper heat sink.

2. The thermoluminescence testing heating accessory as described in claim 1, characterized in that: The sample holder and the copper heat sink are sandwiched between the sample station and the ceramic heating plate by long screws.

3. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The sample station is a quartz cuvette, in which a liquid or solid powder sample is placed; or the sample station is a sheet-like solid sample.

4. The thermoluminescence testing heating accessory as described in claim 3, characterized in that: The quartz cuvette is made of high-temperature resistant and high-transmittance quartz, which is bonded together by a melting process and has a maximum temperature resistance of 800℃. The dimensions of the quartz cuvette are 45mm in length, 12.5mm in width, and 3mm in thickness.

5. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The sample holder is an aluminum base connected by screws and a rotating bracket. The rotating bracket can rotate 360°, and the angle gauge has an accuracy of 5-10°, which is used to control the incident and reflection angles of monochromatic excitation light.

6. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The ceramic heating plate is a sheet-like material made of high-temperature resistant alumina wrapped with a thermal resistance wire. Its planar dimensions are rectangular, with a length of 3-5cm and a width of 2-3cm.

7. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: Two wires are led out from the top of the ceramic heating plate. The rated voltage is 220V AC or 24V DC, the rated power is not less than 200W, the fastest heating rate is 10℃ / minute, and the highest temperature is 600℃.

8. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The temperature measuring thermocouple is either a soft thermocouple wire with a PTFE sheath or a 0.5mm diameter armored thermocouple, using type E, type K, or type T.

9. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The front of the ceramic heating plate is coated with thermally conductive silicone grease to ensure good thermal contact with the sample station and to stabilize the position of the sample using its viscosity.

10. A thermoluminescence testing heating accessory as described in claim 1 or 2, characterized in that: The copper heat sink has four stainless steel clips that fix the ceramic heating plate to the copper heat sink; thermal grease is applied between the copper heat sink and the ceramic heating plate for heat conduction.

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