JP2012036230A - Phosphor and electromagnetic radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor which emits a red light when an electromagnetic radiation such as an X-ray passes.SOLUTION: The phosphor (4), in which a guest substance that converts the energy of an electron of an excited host substance into luminescence is added to the host substance excited when an electromagnetic wave (2a) passes, includes the host substance that contains at least sulfur, barium, and gallium, and the guest substance that contains at least samarium and converts the energy of the electron into red luminescence.

Description

  The present invention relates to a phosphor and an electromagnetic wave detection device.

2. Description of the Related Art Configurations using electromagnetic waves such as X-rays are widely adopted in medical diagnostic devices, non-destructive inspection devices, security inspection devices in airports, and the like. As scintillators used for visualizing and detecting invisible electromagnetic waves such as X-rays, techniques described in the following Patent Documents 1 and 2 are known.
Japanese Patent Application Laid-Open No. 2007-248283 as Patent Document 1 discloses a typical Gd ₂ O ₂ S: Tb (commonly referred to as “GOS”, Tb-doped gadolinium oxalide as an example of a material for visualizing electromagnetic waves such as X-rays. ) And CaWO ₄ (commonly called “CWO”).
Japanese Patent Application Laid-Open No. 2001-59899 as Patent Document 2 describes a scintillator material (CsI: Tl) in which thallium (Tl) is added (doped) to cesium iodide (CsI) as a scintillator material. .

JP 2007-248283 A (“0030”) JP 2001-59899 A (Claim 4)

(Problems of conventional technology)
In the scintillator materials described in Patent Documents 1 and 2, when X-rays pass, GOS is green (peak emission wavelength is about 550 nm), CWO is blue (peak emission wavelength is about 425 nm), and CsI: Tl is yellow The emission is green (peak emission wavelength is 570 nm).
On the other hand, in CCDs (Charge Coupled Devices) and the like that are widely used as photodetectors, Si is used for the detection section, and the light receiving peak is 700 nm to 800 nm, so that red light is not affected. The light sensitivity is high. That is, the scintillator material that has been widely used conventionally has a problem in that there is a shift in sensitivity characteristics when a semiconductor detector is used, and there is a limit to high sensitivity. Further, when trying to use a detector suitable for each wavelength, it is necessary to make a special order (optimization) of the detector, and there is a problem that the cost increases.

  An object of the present invention is to provide a phosphor that emits red light when electromagnetic waves such as X-rays pass through.

In order to solve the technical problem, the phosphor according to claim 1 comprises:
A phosphor in which a guest substance that converts the energy of electrons in the excited host substance into light emission is added to the host substance that is excited when electromagnetic waves pass through it.
The host material comprising at least sulfur, barium and gallium;
The guest material containing at least samarium and converting the energy of the electrons into red light emission; and
It is provided with.

In order to solve the technical problem, the electromagnetic wave detector of the invention according to claim 2,
A scintillator comprising the phosphor according to claim 1;
A semiconductor detector for detecting red light emission from the scintillator;
It is provided with.

  According to the first and second aspects of the invention, it is possible to provide a phosphor that emits red light that is visible light when an electromagnetic wave such as X-rays is irradiated.

FIG. 1 is a schematic explanatory diagram of the X-ray inspection apparatus according to the first embodiment. FIG. 2 is an explanatory diagram of a method for producing a scintillator material. FIG. 3 is an explanatory diagram showing the compositions of the experimental example and the comparative example, and is a table showing the element amounts of the host materials of the experimental example and the comparative example. FIG. 4 is an explanatory diagram of the measurement result of the absorption coefficient of the experimental example, and is a graph in which the horizontal axis represents wavelength and the vertical axis represents transmittance. FIG. 5 is an explanatory diagram of the dependency of the absorption coefficient at a wavelength of 960 nm on the samarium concentration. The horizontal axis represents the samarium concentration and the vertical axis represents the absorption coefficient. FIG. 6 is a schematic explanatory diagram of the apparatus used in the PL measurement experiment. FIG. 7 is an explanatory diagram of the PL emission measurement results of the experimental example and the comparative example, and is a semilogarithmic graph in which a sample is taken on the horizontal axis and the intensity of PL emission is taken on the vertical axis. FIG. 8 is an explanatory diagram of a PL spectrum measurement result when the experimental example 1 is irradiated with excitation light having a wavelength of 405 nm, and is a graph in which the horizontal axis indicates the wavelength and the vertical axis indicates the intensity. FIG. 9 is an explanatory diagram of an X-ray excitation luminescence measuring apparatus according to the first embodiment. FIG. 10 is an explanatory diagram of the measurement result of X-ray excitation luminescence of Experimental Example 1, and is a graph in which the horizontal axis represents wavelength and the vertical axis represents XL intensity. FIG. 11 is an explanatory diagram of an image taken by the X-ray excited luminescence high sensitivity camera of Experimental Example 1. 12 is an explanatory diagram of a photograph of the X-ray excitation light emission of Experimental Example 1 taken with a camera, FIG. 12A is a photograph of the entire state irradiated with X-rays, FIG. 12B is a photograph of the phosphor portion in FIG. 12A, FIG. 12C is a photograph of the phosphor portion in a state where X-ray irradiation is not performed. FIG. 13 is an X-ray diffraction diagram of Experimental Example 1, which is a graph with the diffraction angle 2θ on the horizontal axis and the intensity on the vertical axis.

Next, examples which are specific examples of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is a schematic explanatory diagram of the X-ray inspection apparatus according to the first embodiment.
In FIG. 1, the X-ray inspection apparatus 1 of Example 1 as an example of the electromagnetic wave detector of this invention has the X-ray source 2 which irradiates X-ray 2a as an example of an electromagnetic wave source. The X-ray 2a from the X-ray source 2 is irradiated to the inspection object 3 which is an object to be inspected, and the X-ray transmitted through the inspection object 3 reaches a scintillator 4 as an example of a phosphor. Visible light 4a generated in the scintillator 4 by the X-rays 2a reaching the scintillator 4 is imaged by a CCD camera 6 using Si as an example of an imaging device and an example of a semiconductor detector. A computer 7 as an example of an image processing apparatus is connected to the CCD camera 6, an image captured by the CCD camera 6 is processed by the computer 7, and the captured image is displayed as an example of a display. 7a.

(Description of scintillator)
The scintillator 4 of Example 1 is composed of a material obtained by adding a host substance that is excited when X-rays pass to a guest substance that converts the electron energy of the excited host substance into light emission. The substance includes at least sulfur (S), barium (Ba), and gallium (Ga), and the guest substance includes at least samarium (Sm) that emits red light. As an example of the material of such a scintillator 4, in Example 1, the chemical formula: Ga ₂ S ₃ —BaS: Sm ₂ S ₃ , that is, a gallium sulfide-barium sulfide polycrystal added with (doped) samarium sulfide Can be suitably used.

(Operation of Example 1)
In the X-ray inspection apparatus 1 according to the first embodiment having the above-described configuration, red light is emitted when X-rays that have passed through the inspection object 3 pass through the scintillator 4. Therefore, compared with a scintillator that emits blue or green light with respect to X-rays, the sensitivity characteristics of the CCD camera 6 which is a semiconductor detector having high sensitivity to red light are well matched, and high sensitivity can be achieved. become. Therefore, X-rays can be detected with high sensitivity, and sensitivity can be improved by using a relatively inexpensive CCD camera 6.

(Experimental example)
Next, an experiment for verifying the function of the scintillator 4 of the present invention was performed.

(How to make scintillator materials)
FIG. 2 is an explanatory diagram of a method for producing a scintillator material.
In FIG. 2, a quartz glass ampoule 11 having an inner diameter of 10 mm was used when preparing samples of the scintillator material of the experimental example and the comparative example.
In the experimental example, sulfur (S) was used, and the sample containing sulfur as a main component was likely to burst during the temperature rise, so that the quartz glass ampoule 11 was coated with carbon. That is, by pouring acetone into the ampule 11 and heating at a high temperature, a very thin silicon carbide film is formed in the ampule 11. By applying the carbon coat, it is possible to increase the strength of the ampoule 11 and avoid rupture. Note that the amount of carbon remaining in the ampoule 11 is small and does not react with chalcogen elements (S, Se, Te, etc.), so that it is considered that there is no effect on the sample (scintillator material) to be produced.

In the experimental example, the quartz glass ampoule 11 was cleaned with an organic solvent and hydrogen fluoride before the carbon coating was performed on the ampoule 11. Then, the raw material is weighed into the carbon-coated ampule 11 after washing, and the ampule 11 is vacuum-sealed in order to prevent the raw material from being oxidized during melting. In the experimental example, the sample (scintillator material) to be manufactured was weighed so as to be 4 [g].
In FIG. 2, the ampoule 11 in which the raw material is sealed is suspended by a connecting wire 14 with a weight 13 in a hollow cylindrical rotary electric furnace 12. In the embodiment, a nichrome wire is used as the connection line 14, but the present invention is not limited to this, and any available connection line can be used.
The rotary electric furnace 12 is manually controlled at a rate of temperature increase from 100 ° C./min to 200 ° C./min to increase the temperature to 790 ° C., and is 1000 ° C. at 0.6 ° C./min to 0.7 ° C./min. Raise to about 10 minutes and hold at 1000 ° C. for 12 hours. The rotary electric furnace 12 of Example 1 is initially kept in a horizontal state, kept for 3 hours near the melting point of sulfur (112.8 ° C.) so that the raw materials are uniformly mixed, and stirred once every 30 minutes. . And even after it became 1000 degreeC, after stirring once for 30 minutes, after 12 hours passed, it put in the water 16 and quenched in water, and produced the bulk glass.

Experimental Examples 1 and 2 and Comparative Examples 1 to 12 were produced by the method for producing the scintillator material.
(Comparative Examples 1-6, 8)
Comparative Examples 1 to 6 and 8 are samples obtained by adding samarium (Sm) as a guest material to germanium (Ge), sulfur (S), and gallium (Ga) as a host material, and satisfy the following chemical formulas To do.
(Ge _x S _y Ga _100-xy ) _99.5 Sm _0.5
Note that x = 14 to 40 and y = 60 to 80.
That is, the guest material has atomic% concentration (at%), Ge is x [at%], S is y [at%], and Ga is 100-xy [at%]. The composition is such that 0.5 [at%] Sm is added to 5 [at%]. As for Sm, PL is emitted when Sm is in the range of about 0.1 [at%] to 3 [at%] from the experimental results of other rare earth photo-excited emission (PL emission), and X-ray excitation emission ( The experiment was conducted using 0.5 [at%] as a typical value in consideration of the experience of the present inventor that the (XL emission) is also comparable.
In each of the following comparative examples and experimental examples, S and Ga, Ge having a purity of 99.9999% and Sm ₂ S ₃ having a purity of 99.9% were weighed and used in the ampule 11 so as to satisfy each chemical formula. Is housed in.

(Comparative Example 7)
In Comparative Example 7, sulfur (S) was replaced with selenium (Se) for comparison of chalcogen elements in Comparative Examples 1-6. Specifically, the Oite, x = 28.2, and y = 65.8 _{to (Ge x Se y Ga 100-} xy) 99.5 Sm 0.5. In Comparative Example 7, unlike Comparative Examples 1 to 6 and 8, Se having a purity of 99.999% and Sm ₃ Se ₄ were used as raw materials.
(Comparative Examples 9 and 10)
In Comparative Examples 9 and 10, samples obtained by adding cesium iodide (CsI) as an example of a heavy element having an atomic number of 50 or more as a guest material to the host materials of Comparative Examples 1 to 7 were used. In Comparative Examples 9 and 10, CsI having a purity of 99.9% was used as a raw material.
(Comparative Examples 11 and 12)
In Comparative Examples 11 and 12, in the guest material not containing germanium, barium (Ba) as an example of a heavy element was added as a guest material. In Comparative Examples 11 and 12, BaS having a purity of 99.9% was used as a raw material, and the holding time at 1000 ° C. was 6 hours in the manufacturing process.
(Experimental example 1)
In Experimental Example 1 and Experimental Example 2, in the guest material not containing germanium, barium (Ba) as an example of a heavy element was added as a guest material. In Experimental Example 1, BaS having a purity of 99.9% was used as a raw material. In the experimental example, the time for holding at 1000 ° C. in the manufacturing process was 12 hours in Experimental Example 1 and 2 hours in Experimental Example 2.

FIG. 3 is an explanatory diagram showing the compositions of the experimental example and the comparative example, and is a table showing the element amounts of the host materials of the experimental example and the comparative example.
In FIG. 3, therefore, Comparative Examples 1 to 12 and Experimental Examples 1 and 2 have the following compositions.
Comparative Example 1: (Ge _20.8 S _64.2 Ga ₁₅ ) _99.5 Sm _0.5
Comparative Example 2: (Ge ₁₉ S ₇₅ Ga ₆ ) _99.5 Sm _0.5
Comparative Example 3: (Ge ₂₉ S ₆₅ Ga ₆ ) _99.5 Sm _0.5
Comparative Example 4: (Ge ₁₄ S ₈₀ Ga ₆ ) _99.5 Sm _0.5
Comparative Example 5: (Ge _19.4 S _77.6 Ga ₃ ) _99.5 Sm _0.5
Comparative Example 6: (Ge _23.5 S _70.5 Ga ₆ ) _99.5 Sm _0.5
Comparative Example 7: (Ge _28.2 Se _65.8 Ga ₆ ) _99.5 Sm _0.5
Comparative Example 8: (Ge ₄₀ S ₆₀ ) _99.5 Sm _0.5
Comparative Example 9: (Ge _2.8 S _33.6 Ga _27.6 Cs ₁₈ I ₁₈ ) _99.5 Sm _0.5
Comparative Example 10: (Ge _5.7 S _37.1 Ga _25.2 Cs ₁₆ I ₁₆ ) _99.5 Sm _0.5
Comparative Example 11: (S ₅₃ Ga ₁₂ Ba ₃₅ ) _99.5 Sm _0.5 1000 ° C. 6 hours Comparative Example 12: (S _52.5 Ga ₁₀ Ba _37.5 ) _99.5 Sm _0.5 1000 ° C. 6 hours Experimental Example 1: (S _53.5 Ga ₁₄ Ba _32.5 ) _99.5 Sm _0.5 1000 ° C for 12 hours Experimental example 2: (S ₅₄ Ga ₁₆ Ba ₃₀ ) _99.5 Sm _0.5 1000 ° C for 2 hours

For the samples prepared in Experimental Example 1 and Comparative Examples 1 to 10, whether each sample became crystalline (glass ceramic) or amorphous (amorphous) was determined by XRD (X-ray Diffraction: X-ray diffraction). ) Measured with a measuring device.
In the experimental example, RINT2000 manufactured by Rigaku Corporation was used as an XRD measuring device, and the powdered sample was fixed on a glass plate with grease and measured. Measurement conditions are as follows.
X-ray generated: CuK _α 1
Diffractometer and scintillation counter tube voltage: 40 kV
Tube current: 200 mA
Scanning axis: 2θ / θ
Scan speed: 2 deg / min
Sampling width: 0.01 deg
Scan range: 20-60deg
Divergence slit: 2deg
Scattering slit: 2 deg
Receiving slit: 0.6mm

  When the samples of Comparative Examples 1 to 10 and Experimental Example 1 were measured using the XRD measurement apparatus, in Comparative Examples 1 to 8, the spectrum was broad (gradual) and was determined to be amorphous. On the other hand, in Comparative Examples 9, 10, 11, and 12, the spectrum had a sharp (pointed) peak, and it was determined that the crystal was the main component. On the other hand, in Experimental Example 1, since an amorphous component and a crystalline component were observed, it was determined that the glass ceramic was a mixture of both phases.

FIG. 4 is an explanatory diagram of the measurement result of the absorption coefficient of the experimental example, and is a graph in which the horizontal axis represents wavelength and the vertical axis represents transmittance.
FIG. 5 is an explanatory diagram of the dependency of the absorption coefficient at a wavelength of 960 nm on the samarium concentration. The horizontal axis represents the samarium concentration and the vertical axis represents the absorption coefficient.
The absorption coefficient was measured to confirm that samarium was dispersed in the glass. In the experiment, the host material Ge ₄₀ S ₆₀ of Comparative Example 8 was used as a base material, and Sm was 0 [at%], 0.5 [at%], 1 [at%], 4 [at%], 8 [At%] The absorption coefficient of the added one was measured. The experimental results are shown in FIGS.
In FIG. 4, an absorption band peculiar to samarium is observed at 900 to 1600 [nm], and it was found that samarium (Sm) is dispersed in the glass. In FIG. 5, from the experimental results at a wavelength of 960 nm, the absorption coefficient increased in proportion to the increase in samarium, and it was confirmed that the solubility of samarium in the base material was high.

(Measurement of photoluminescence (PL emission))
Since measurement of X-ray excited luminescence is difficult to handle X-rays, PL luminescence that can be measured more easily than measurement of X-ray excited luminescence was first measured. This is because a material that does not emit light by PL (Photoluminescence) may not emit light with strong intensity even with X-ray excitation because rare earth (Sm in the experimental examples and comparative examples) may not be optically active. For Comparative Examples 11 and 12 and Experimental Example 2, the measurement of PL emission was omitted.

(Description of PL measuring device)
FIG. 6 is a schematic explanatory diagram of the apparatus used in the PL measurement experiment.
In FIG. 6, the experimental apparatus 21 for PL measurement has a light source 22. Light 22a from the light source 22 is collected by a condenser lens 23 as an example of an optical system, and reflected by a reflecting mirror 24 toward a sample 25 to be irradiated with light. The light excitation light emission 26 by the light 22 a irradiated on the sample 25 is condensed by a condensing lens 27 as an example of an optical system and introduced into a measuring device 28. The measuring device 28 includes a filter 28a that cuts a part of the wavelength, a spectroscope 28b that splits the light-excited light emission 26 that has passed through the filter 28a, and a detector 28c that detects the light split by the spectroscope 28b. The detector 28c is connected to a personal computer 30 as an example of a data processing device via a cable 29. Data processing of detection data detected by the detector 28c in the personal computer 30 and display of processing results are displayed. Is done.

In the PL measurement experimental apparatus 21 of Example 1, as the light source 22, (1) a semiconductor laser with a wavelength of 405 nm (output: 23.8 [mW]), (2) an ion laser with a wavelength of 488 nm (output: 27.27). 1 [mW]), (3) A semiconductor laser having a wavelength of 532 nm (output: 21.5 [mW]) was used.
Further, as the measuring device 28, (1) Spectrometer 28b: CT-10 manufactured by JASCO Corporation (Grating: 900 [lines / mm]), Detector 28c: Photomaru R446 manufactured by Hamamatsu Photonics Co., Ltd. (2) JOBIN TRIAX 320 (grating 1200 [lines / mm]) manufactured by YVON was used. In the experiment, the measuring instrument (1) was used for measuring the PL intensity, and the measuring instrument (2) was used for measuring the PL spectrum.
Further, as a filter 28c, in order to cut off the light 22a from the light source 22 having high intensity, a high-pass filter O430 (transmits a wavelength of 430 nm or more) and Y530 (transmits a wavelength of 530 nm or more) according to each laser used as the light source 22. ), R617 (transmitting wavelength 617 nm or more).

(Measurement result of PL emission)
FIG. 7 is an explanatory diagram of the PL emission measurement results of the experimental example and the comparative example, and is a semilogarithmic graph in which a sample is taken on the horizontal axis and the intensity of PL emission is taken on the vertical axis.
Experiments were performed on Comparative Examples 1 to 10 and Experimental Example 1 using the experimental apparatus 21 for PL light emission measurement. The experimental results are shown in FIG.
In FIG. 7, in Comparative Examples 1 to 7, it was confirmed that the intensity of PL light emission increased as the wavelength of the irradiated light became shorter (energy increased). In Comparative Examples 1 to 7, the intensity of the sample of Comparative Example 5 was increased with respect to photoexcitation at a wavelength of 405 nm. This indicates that the comparative example 5 has less Ga than the other comparative examples, and the Ga ratio affects the PL strength.
In Comparative Example 8, the spectrum of PL emission was not measured and the intensity was not obtained. The reason why the Se-based material used as the host material of Comparative Example 8 has lower strength than the S-based glasses of Comparative Examples 1 to 7 is not because the Se-based material absorbs light in the glass. It is thought.

In Comparative Example 10 and Experimental Example 1, the intensity of PL light emission was very strong, and light was emitted so that it could be confirmed with the naked eye. With respect to the PL emission intensity of Comparative Example 5, Comparative Example 10 and Experimental Example 1 were 0.72 times and 1100 times, respectively.
Next, when the dependency of the excitation source, that is, the light source 22, was examined, it was confirmed that the intensity of the 405 nm excitation source was 10 times or more in Comparative Example 5 compared to the other two excitation sources. This Sm absorption band at 400nm (energy level ⁶ H _5/2 - ⁶ P _5/2) considered or has not the intensity of the PL emission as the excitation source close to the 400nm becomes strong .

FIG. 8 is an explanatory diagram of a PL spectrum measurement result when the experimental example 1 is irradiated with excitation light having a wavelength of 405 nm, and is a graph in which the horizontal axis indicates the wavelength and the vertical axis indicates the intensity.
8, to the sample of Example 1, at room temperature in the spectrum when irradiated with an excitation light having a wavelength 405nm at (300K), peak 563nm band (energy level ⁴ G _5/2 - ⁶ H _5/2 ), 598 nm band (energy level _{^{4 G 5/2 - 6 H 7/2)}} , 645nm band (energy level _{^{4 G 5/2 - 6 H 9/2)}} , 707nm band (energy level ⁴ G _{5 / 2} - ⁶ H _11/2) and it has been identified.
Therefore, the transition from the energy level ⁴ G _5/2 specific to samarium to ⁶ H _7/2 was confirmed, and Sm emission was confirmed.
In addition, the subscript of 1, 2, such as a1, a2, b1, b2, c1, c2, d1, d2 in FIG. 8 is a transition from the ⁴ G _5/2 level was Stark division can be seen. As a result, samarium emission was confirmed.

(Measurement of X-ray excitation luminescence)
FIG. 9 is an explanatory diagram of an X-ray excitation luminescence measuring apparatus according to the first embodiment.
In FIG. 9, the X-ray excited luminescence measuring device 31 of Example 1 has an X-ray protective shield 32 surrounding the periphery in order to prevent X-rays from leaking to the outside. In the X-ray protective shield 32, an X-ray source 33 that irradiates an X-ray 33a is disposed as an example of an electromagnetic wave source. This X-ray is a CuKα ray and is output at 40 mA, 50-200 kV. In the X-ray protective seal 32, a sample 34 is disposed at a position where the X-ray 33a from the X-ray source 33 is irradiated.
The light emitted from the sample 34 is split by a transmission grating 37 as an example of a spectroscope disposed outside the lead glass 36 of the X-ray protective shield 32. The split light is detected by a digital camera 38 as an example of a detector disposed in the vicinity of the transmission type grating 37. In Example 1, a blazed diffraction grating of 600 lines / mm is used as the transmissive grating 37, and a digital camera having a focal length of 35 mm and an F value of 3.5 is used as the digital camera 38 for 15 seconds. A low-resolution spectrum was taken through lead glass.
A conventionally known personal computer 39 as an example of an information processing apparatus is connected to the digital camera 38, and the personal computer 39 performs data processing of detection data in the digital camera 38 and display of processing results. In the X-ray excitation luminescence measuring apparatus 31 of Example 1, the spectrum intensity was measured by the digital camera 38 and the personal computer 39.

FIG. 10 is an explanatory diagram of the measurement result of the X-ray excitation light emission of Experimental Example 1, and is a graph in which the horizontal axis represents wavelength and the vertical axis represents intensity.
Using the X-ray excited luminescence measuring device 31, X-ray excited luminescence (XL luminescence: X-ray Luminescence) of the samples of Comparative Examples 1 to 12 and Experimental Examples 1 and 2 was confirmed. The experimental results are shown in FIG.
In FIG. 10, when Experimental Example 1 was used as the sample 34, light emission peculiar to Sm at 560 nm, 600 nm, and 640 nm similar to that obtained by PL measurement was confirmed. Thereby, it was confirmed that Sm emitted light by X-ray irradiation. Similar results were obtained in Experimental Example 2. In Comparative Examples 1 to 12, no light emission was confirmed.

FIG. 11 is an explanatory diagram of an image taken by the X-ray excited luminescence high sensitivity camera of Experimental Example 1.
12 is an explanatory view of a photograph of the X-ray excitation light emission of Experimental Example 1 taken with a camera, FIG. 12A is a photograph of the entire state irradiated with X-rays, FIG. 12B is a photograph of the light emitter portion in FIG. FIG. 12C is a photograph of the light emitter portion in a state where X-ray irradiation is not performed.
In FIG. 11, when the sample 34 of Experimental Example 1 was photographed with a high-sensitivity CCD camera, it was confirmed that light was emitted at the center as shown in the image of FIG.
In addition, the sample of Experimental Example 1 was observed not only with a highly sensitive CCD camera but also with the naked eye in the dark. The photograph is shown in FIG. The photo is flashed. As shown in FIG. 12, it can be seen that the X-ray excitation light emission part is shining red, and it is assumed that the light emission is considerably strong.

(Identification of crystal)
FIG. 13 is an X-ray diffraction diagram of Experimental Example 1, which is a graph with the diffraction angle 2θ on the horizontal axis and the intensity on the vertical axis.
Next, with respect to the sample of Experimental Example 1 that emitted X-ray excitation light, an attempt was made to identify the crystal phase using an XRD measurement apparatus. An X-ray diffraction pattern as an experimental result is shown in FIG.
In FIG. 13, the result of Experimental Example 1 coincides with the PDF card 00-049-1599 of ICDD (International Center for Diffraction Data), and it can be identified that Ba ₄ Ga ₂ S ₇ is the main component. Signals from the raw material BaS and Ga ₂ S ₃ were not observed, and it was also confirmed that no unreacted raw material remained.
Therefore, it was confirmed that red light emission excited by X-rays can be captured from a Ga-S chalcogenide glass ceramic containing barium added with samarium. In addition, the sample of Example 1 is easy and easy to manufacture because the manufacturing method is not complicated and easy compared to the manufacturing method of manufacturing a single crystal, and even a polycrystal emits light, and the manufacturing cost is also reduced. it can.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is made in the range of the summary of this invention described in the claim. Is possible. Modification examples (H01) to (H04) of the present invention are exemplified below.
(H01) In the above-described embodiments, the illustrated measuring apparatus, measurement conditions, and the like are not limited to the illustrated numerical values, and can be changed as appropriate.
(H02) The X-ray examination apparatus in the above embodiment can be used as an X-ray examination apparatus for use in diagnosing or diagnosing a disease or an affected part when the inspected body 3 is a human body. Further, when the object to be inspected is a user or a baggage, it can be used as a security inspection device in an airport or a port for performing a safety inspection of dangerous goods and prohibited items. Further, when the object to be inspected 3 is a building, a work of art, a cultural property, etc., it can be used as a nondestructive inspection device that nondestructively inspects damage, past repair status, and internal structure.

(H03) In the above embodiment, X-rays are exemplified as an example of electromagnetic waves. However, the present invention is not limited to this, and application to the conversion (visualization) of ultraviolet rays and radiation such as gamma rays into red light can be expected.
(H04) In the above embodiment, X-rays can be observed with red light, which is visible light, and can be seen with the eyes. For example, conventionally known green phosphors and blue phosphors are also used in combination. By doing so, it is also possible to obtain an X-ray pseudo color image using light emission of the three primary colors of R, G, and B.

1 ... Electromagnetic wave detector,
2a ... electromagnetic waves,
4 ... phosphor, scintillator,
6 ... Semiconductor detector.

Claims (2)

A phosphor in which a guest substance that converts the energy of electrons in the excited host substance into light emission is added to the host substance that is excited when electromagnetic waves pass through it.
The host material comprising at least sulfur, barium and gallium;
The guest material containing at least samarium and converting the energy of the electrons into red light emission; and
The phosphor described above. A scintillator comprising the phosphor according to claim 1;
A semiconductor detector for detecting red light emission from the scintillator;
An electromagnetic wave detection apparatus comprising: