JP2009192313A - Beam detection member and beam detector using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a beam detection member and a beam detector using it, capable of exciting visible light more efficiently from a radiation light beam, a soft X-ray beam or the like in the range from high energy to low energy, and detecting its position or an intensity distribution highly accurately and stably for a long period, and manufacturable at lower cost than a conventional detection device. <P>SOLUTION: In the beam detection member 2 for detecting the position or the intensity of a beam 7, a beam irradiation part 6 for irradiating the beam 7 comprises a polycrystal diamond film 4 containing boron (B) averagely 10-150 ppm, and the boron (B) concentration in the polycrystal diamond 4 has an uneven concentration distribution in the film thickness direction of the polycrystal diamond film 4. The beam detector 1 is constituted of such a beam detection member 2 and excitation light observation means 3, 3a for observing excited excitation light 8, 8a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention uses a beam detection member for detecting the position and intensity of the beam light by irradiating the beam irradiation unit with a beam such as high-energy radiation generated in a synchrotron radiation facility or the like, and the same. The present invention relates to a beam detector.

  In recent years, synchrotron radiation facilities that generate beam-like ultraviolet rays to X-rays have been widely used in research and development in the fields of medicine, materials, electronics, and the like. Although it is important to accurately grasp the position and intensity of such an invisible beam, it is not easy. Furthermore, since the energy of the radiated light is high, there is a risk that a non-irradiated object or an experimenter will be accidentally irradiated with high energy light, or that a large amount of X-rays may be irradiated indirectly while the experimenter is not aware. There is sex.

  Therefore, there is a need for a beam detector and a beam detection method that simply measure the position and intensity of the emitted light beam. Fluorescent screens generally used for grasping the positions of ultraviolet rays and X-ray beams cannot be used for this purpose because the fluorescent screen itself is damaged when the energy of the radiated light beam increases.

  As a conventional beam detector or beam detection method for grasping the position of an ultraviolet ray or an X-ray beam, an X-ray beam is applied to a monitor plate on which a photoelectric film is formed on the front half and the back half. A method in which electrons (photoelectrons) are emitted from a photoelectric film and the amount of electrons emitted from each surface is measured with a secondary electron multiplier (see Patent Document 1), or a disk in which metal electrodes are arranged on both surfaces and have a perforation in the center Photoelectrons are emitted when radiated light is irradiated onto a gas-phase synthetic diamond plate, a method for estimating the center position of a radiated light beam by monitoring the photoelectron current (see Patent Document 2), etc. has been proposed. ing.

  However, in the beam detector and detection method according to the conventional example, the former cannot determine the two-dimensional beam position (y coordinate), and the latter does not know the position of the emitted light beam in advance unless the position of the emitted light beam is known in advance. I had a self-contradiction that I couldn't monitor.

In response to such problems, the present inventors have already applied polycrystalline diamond having excellent X-ray transparency, thermal conductivity, and heat resistance to the beam position detection member, and the position and intensity of the synchrotron radiation X-ray beam. Proposed a beam detection member capable of measuring the above and a beam detector using the same (see Patent Document 3). This proposal is an excellent invention that can easily measure the position and intensity of a synchrotron X-ray beam, which was impossible before, but there is room for improvement in terms of more efficient visible light excitation in the beam detection member. There is.
Japanese Patent Laid-Open No. 7-318657 JP-A-8-279624 JP 2007-262381 A

  In view of such problems, the present invention has been made by continuing research and development, and as a result, has gained new knowledge, including a synchrotron radiation beam ranging from high energy to low energy, and soft X A beam detection member capable of exciting a line beam or the like more efficiently with visible light and detecting its position and intensity distribution stably with high accuracy for a long period of time, and can be manufactured at a lower cost than a conventional detection device, and the same It is to provide a beam detector using the.

  In order to achieve the above object, the means employed by the beam detection member according to claim 1 of the present invention is a beam detection member for detecting the position and intensity of the beam, and a beam irradiation unit to which the beam is irradiated Is composed of a polycrystalline diamond film containing an average of 10 to 150 ppm of boron (B), and the boron concentration in the polycrystalline diamond has a non-uniform concentration distribution in the film thickness direction of the polycrystalline diamond. Is.

  The means employed by the beam detection member according to claim 2 of the present invention is characterized in that the boron (B) concentration in the polycrystalline diamond has a portion of 150 ppm or more and a portion of 10 ppm or less in the film thickness direction. Is.

  The means adopted by the beam detecting member according to claim 3 of the present invention is the beam detecting member according to claim 2, wherein the boron (B) concentration in the polycrystalline diamond is 150 ppm or more and 10 ppm or less. The volume ratio of the polycrystalline diamond in the film thickness direction is 33% or more and 66% or less.

  According to a fourth aspect of the present invention, there is provided the beam detecting member employed in the beam detecting member according to any one of the first to third aspects, wherein at least a part of the diamond film is held by the substrate. In addition, the polycrystalline diamond has a thickness of 3 to 30 μm.

  The means employed by the beam detection member according to claim 5 of the present invention is the beam detection member according to any one of claims 1 to 4, wherein the average particle of the diamond particles forming the polycrystalline diamond film is The diameter is 10 μm or less.

  The means employed by the beam detector according to claim 6 of the present invention is a beam detector provided with a beam detection member for detecting the position and intensity of the beam, according to any one of claims 1 to 5. And the excitation light observing means for observing the excitation light when the beam irradiating part is irradiated with the beam. The excitation observed by the excitation light observing means The position and intensity of the beam are detected by light.

  According to the beam detection member according to claim 1 of the present invention, the beam detection member for detecting the position and intensity of the beam, wherein the beam irradiation unit irradiated with the beam has an average of 10 to 10 boron (B). It consists of a polycrystalline diamond film containing 150 ppm, and the boron (B) concentration in the polycrystalline diamond has a non-uniform concentration distribution in the film thickness direction of the polycrystalline diamond, so that excitation excited when the beam is irradiated Light can be extracted outside as high-intensity excitation light without being absorbed inside.

  In addition, in the crystal lattice of polycrystalline diamond, when boron having a smaller atomic radius than carbon substitutes for carbon, the internal stress of the diamond film is reduced. The distribution is more prominent than the uniform case.

  Furthermore, according to the beam detection member according to claim 2 of the present invention, the boron (B) concentration in the polycrystalline diamond has a portion of 150 ppm or more and a portion of 10 ppm or less in the film thickness direction. Visible light excited with high efficiency in the above portion can be efficiently transmitted through the portion having a boron concentration of 10 ppm or less and extracted outside the diamond film.

  Furthermore, according to the beam detection member of claim 3 of the present invention, the volume of the portion of the polycrystalline diamond in which the boron (B) concentration is 150 ppm or more and 10 ppm or less in the film thickness direction of the polycrystalline diamond. Since the ratio is 33% or more and 66% or less, the intensity of excitation light that is excited when the beam is irradiated is further increased.

  According to the beam detection member of claim 4 of the present invention, since at least a part of the diamond film is held by the substrate, the polycrystalline diamond has a self-supporting film structure, and the synchrotron radiation beam is applied to the self-supporting film portion. Because it is irradiated, it will not break even for high-intensity beams. In particular, when the substrate is silicon, not only is it excellent in heat conduction, but it is easy to process, and it is easy to ensure the flatness of the substrate and the perpendicularity to the radiation beam 7. At the same time, since the polycrystalline diamond has a film thickness of 3 to 30 μm, the radiated light beam can be transmitted without causing scattering or diffraction.

  According to the beam detection member of claim 5 of the present invention, since the average particle diameter of the diamond particles forming the polycrystalline diamond film is 10 μm or less, a light emitting region of an appropriate size and a high emission luminance having an appropriate light emission luminance. A quality transmitted radiation beam is obtained.

  On the other hand, according to the beam detector according to claim 6 of the present invention, in the beam detector provided with the beam detection member for detecting the position and intensity of the beam, any one of claims 1 to 5 is provided. And the excitation light observing means for observing the excitation light when the beam irradiating part is irradiated with the beam. The excitation observed by the excitation light observing means Since the position and intensity of the beam are detected by light, a radiation beam is directly applied to the polycrystalline diamond film, and the emission position from the polycrystalline diamond film and its intensity distribution are monitored by the excitation light observation means. The beam position and intensity distribution can be determined.

  First, a beam detection member and a beam detector using the same according to Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic perspective view schematically showing the surface of a beam detection member according to Embodiment 1 of the present invention, and FIG. 2 schematically shows the back surface of the beam detection member according to Embodiment 1 of the present invention. It is a typical perspective view. FIG. 3 is a schematic cross-sectional view schematically showing the overall configuration of the beam detector using the beam detection member according to Embodiment 1 of the present invention.

  As shown in FIGS. 1 and 2, the beam detection member 2 according to Embodiment 1 of the present invention has a polycrystalline diamond (C) film 4 formed on the back surface of a substrate 5, and the substrate 5 has only its peripheral portion. It is configured as a ring-shaped frame. The beam irradiating section 6 which is made of the polycrystalline diamond film (hereinafter also simply referred to as diamond film or polycrystalline diamond) 4 and irradiated with at least the beam 7 is doped with 10 to 150 ppm of boron (B) on average. It is preferable. The boron concentration in the polycrystalline diamond 4 in the beam irradiation section 6 preferably has a non-uniform concentration distribution in the film thickness direction of the polycrystalline diamond 4.

  In the beam detecting member 2, the substrate in the region of the beam irradiating portion 6 that passes when the radiated light beam 7 is irradiated is removed, and the polycrystalline diamond film 4 has a self-standing structure as shown in FIG. ing. Such a structure can be formed by using silicon as the substrate 5, for example, masking the silicon substrate with an acid-resistant material while leaving a region to be removed, and etching it with a hydrofluoric acid solution.

  It is preferable that the polycrystalline diamond film 4 has a thin film thickness, for example, on the beam irradiation unit 6 and a thick film on the other substrate 5. Such a film thickness distribution of the polycrystalline diamond film 4 can be realized by applying a selective growth technique of the diamond film 4. As described above, the reason why the thickness of the diamond film 4 is thin in the beam irradiation unit 6 and the others are thick is to suppress the temperature rise of the beam irradiation unit 6.

  Since the beam detection member 2 according to the present invention has a simple configuration as shown in FIGS. 1 and 2, the beam detection that requires the complicated manufacturing process presented in Patent Documents 1 and 2 according to the conventional example. Compared with the member, the manufacturing cost can be greatly reduced.

  Then, by incorporating boron (B) atoms into the polycrystalline diamond film 4, visible light having sufficient intensity from the irradiation spot 7a when irradiated with the radiation beam 7 as will be described later with reference to FIG. (There is an intensity peak in the wavelength range of 500 to 600 nm) is excited and emitted as excitation light 8 and 8a.

  The reason why the average boron concentration in the polycrystalline diamond film 4 in the beam irradiation section 6 is preferably in the range of 10 to 150 ppm will be described in detail later, but qualitatively, if the boron concentration is less than 10 ppm, visible light is visible. The excitation light intensity observed due to the low density of boron that emits becomes insufficient. On the other hand, when the boron concentration exceeds 150 ppm, the absorption of excitation light in the diamond 4 becomes remarkable, and the excitation light extracted outside This is because it becomes weaker.

  Further, the boron concentration in the diamond film 4 has a non-uniform distribution in the film thickness direction, and has a portion of 150 ppm or more and a portion of 10 ppm or less, and furthermore, such a portion is in the film thickness direction. The occupying ratio is preferably 33% or more and 66% or less. It is important mainly for the following two reasons that the boron contained in the polycrystalline diamond film 4 has a non-uniform concentration distribution in the film thickness direction as described above.

(1) First, the first reason is that highly efficient photoexcitation can be obtained. That is, when diamond 4 partially containing boron at a concentration of 150 ppm or more coexists with a portion containing boron at a concentration of 10 ppm or less, visible light excited with high efficiency in the former part efficiently transmits the latter part. Can be taken out of the diamond.

(2) The second reason is that the film stress can be improved. That is, in the crystal lattice of polycrystalline diamond 4, when boron having a smaller atomic radius than carbon is substituted for carbon, the internal stress of diamond 4 is reduced. However, such an action is more prominent when the distribution is present than when the boron is uniform in the diamond 4. If the beam detection member 2 is curved or irregularly deformed, the position of the beam irradiation unit 6 becomes unstable, which causes a large measurement error of the detected beam position. is important.

  The inventors made various samples by changing the diborane flow rate and the substrate temperature at the time of film formation of the polycrystalline diamond 4 used for the beam detection member 2, and compared the excitation light intensity when the beam was irradiated under the same conditions. did. As a result, it is important that the volume ratio in the film thickness direction of the polycrystalline diamond 4 in the portion where the boron concentration in the polycrystalline diamond 4 is 150 ppm or more and 10 ppm or less is 33% or more and 66% or less. I found it.

  The portion where the boron concentration distribution is 150 ppm or more and the portion where the boron concentration is 10 ppm or less are not limited to one place in the film thickness direction of the diamond film 4, and may be any number. Further, it is preferable that either one of the front surface and the back surface of the diamond film 4 has a low boron concentration of 10 ppm or less from the viewpoint of light transmission. Further, both of the front and back surfaces of the diamond film 4 have a low boron concentration of 10 ppm or less. Visible light excited inside the diamond film 4 is reflected by the both surfaces and confined inside. Therefore, it is more preferable.

  The diamond film 4 may have a portion having no boron locally. This is because the portion without boron does not contribute to excitation of visible light, but transmits visible light. On the other hand, in the film thickness direction of the diamond film 4, the maximum allowable concentration of boron in the above-mentioned “portion where the boron concentration distribution is 150 ppm or more” is 1000 ppm, preferably 800 ppm, more preferably 600 ppm. If boron exceeds 1000 ppm, the diamond is degenerated (semi-metallized) and the visible light transmittance is greatly reduced, so that it is difficult to extract the excitation light excited inside the diamond film 4. .

  The surface of the polycrystalline diamond film 4 can be flattened by polishing. Such polishing methods include a chemical mechanical polishing method in which the surface is polished while being dipped in a polishing liquid in which abrasive grains such as alumina, silica, and titania are dispersed in water, and the diamond 4 is scraped. In a vacuum chamber in which the internal temperature can be controlled, there is a method of polishing the diamond 4 while reducing a metal oxide of iron, nickel, cobalt, or copper with carbon in the diamond surface layer. The surface flatness can be easily measured with a stylus profilometer or a microscope utilizing interference / phase difference of laser light.

  The average particle diameter of the diamond particles forming the polycrystalline diamond film 4 is as small as possible, and is preferably at least 10 μm or less. With such a diamond particle diameter, an appropriately sized light emission region, appropriate light emission luminance, and a high quality transmitted radiation beam can be obtained. Visible light excited inside the diamond film 4 is taken out of the film while being scattered by fine crystal grain boundaries existing inside the polycrystalline diamond film 4.

  If the polycrystalline diamond 4 has a large particle size, the detected beam irradiation spot 7a expands beyond the true beam diameter, so that the accuracy of position detection decreases. Therefore, the diamond particles forming the polycrystalline diamond film 4 preferably have a fine average particle size of at least 10 μm. The average particle diameter here is obtained as an average interval (average distance) of grain boundaries appearing at the interface between particles in an image obtained by photographing the surface of the polycrystalline diamond film 4 with an electron microscope.

  Thus, since the beam detection member 2 according to the present invention is configured using the diamond film 4 that is durable to radiation, in addition to the emitted light, a high-energy beam such as an electron beam or acceleration radiation particles is used. It can also be applied to the measurement. When used for a high-intensity synchrotron radiation beam, the polycrystalline diamond film 4 and the substrate 5 other than the beam irradiation unit 6 are coated with a metal film such as aluminum having high thermal conductivity and excellent workability. In addition, this portion can be joined with a water cooling jig to prevent a local temperature rise and deformation caused by the diamond film 4.

  In the beam detection member 2 of the present invention, it is preferable that a part of the diamond 4 is held by the substrate 5 as shown in FIG. Since the polycrystalline diamond 4 has a self-supporting film structure, and the synchrotron radiation beam 7 is applied to the self-supporting film portion, the high-intensity beam 7 is not damaged. In particular, when the substrate 5 is silicon, not only is it excellent in heat conduction, but it is easy to process, and it is easy to ensure the flatness of the substrate 5 and the perpendicularity to the emitted light beam 7. Further, the film thickness of the polycrystalline diamond 4 is preferably 3 to 30 μm from the viewpoint of beam transmittance, and when the average roughness of the film surface is 30 to 100 nm, the beam irradiation spot 7a is irradiated. The radiation beam 7 is transmitted without being scattered or diffracted.

  The radiation detector 1 according to the embodiment of the present invention is arranged on the irradiation side of the beam detection member 2 according to the embodiment of the present invention as described above and the radiation beam 7 as shown in FIG. The excitation light observation means 3 is provided. When the polycrystalline diamond film 4 constituting the beam irradiating part 6 of the beam detecting member 2 is irradiated with the radiated light beam 7, the visible light is excited, and the excited light 8a is uniformly emitted from the beam irradiated spot 7a in all directions. To do.

  Therefore, for example, by observing the excitation light 8a to the back side of the beam detection member 2 with the excitation light observation means 3, the position and intensity of the irradiation spot 7a of the beam light 7 can be detected. As the excitation light observation means 3, a normal optical camera, digital camera, ultraviolet CCD camera, video camera, or the like can be used.

  Since the beam detection member 2 according to the present invention is configured using diamond having high thermal conductivity, there is no local overheating of the radiation beam spot 7a. Further, since diamond is composed of carbon having a small atomic number (that is, having a small number of electrons), the interaction with the emitted light 7 is small and there is almost no absorption. Therefore, it is also possible to measure the position and intensity change of the radiation light beam 7 by installing the beam detection member 2 according to the present invention on the incident side and transmission side of the radiation light beam 7 of the sample.

  In addition, since the beam detection member 2 according to the present invention is configured using the diamond film 4 that is resistant to radiation, measurement of high energy beams such as electron beams and accelerated radiation particles in addition to the radiation light. It can also be applied to. In particular, when the polycrystalline diamond film 4 has a self-supporting film structure, it can be used as a detection unit that is not damaged even by a high-current electron beam.

  1 and 2 show typical embodiments of the beam detecting member 2 according to the present invention. However, in the present invention, in principle, the polycrystalline diamond film 4 is irradiated with the radiation beam 7 and excited. The polycrystalline diamond film 4 is not necessarily required to have a self-supporting film structure as long as the emitted light emission (visible light or ultraviolet light) phenomenon occurs. In addition to the silicon substrate, the substrate 5 may be made of a refractory metal or ceramics, or may be a silicon dioxide thin film interposed between a substrate such as a silicon substrate and a polycrystalline diamond film. Such modifications are within the scope of the present invention.

<Experimental example>
The beam detection member 2 formed with the polycrystalline diamond film 4 as shown in FIGS. 1 to 3 and the beam detector 1 using the same were manufactured by the following procedure. First, the surface of the silicon substrate 5 was carbonized by exposing the silicon substrate 5 having a diameter of 25 mm to a mixed plasma of 5 volume% methane and 95 volume% hydrogen at a substrate temperature of about 800 ° C. for 20 minutes. Next, a −150 V bias voltage was applied to the substrate 5 for 20 minutes to form diamond nuclei on the entire surface of the substrate 5.

Thereafter, the application of the bias voltage was stopped, and then 0.1 to 50 ppm of diborane (B ₂ H ₆ ) gas was added to a mixed gas of 2% by volume methane and 98% by volume hydrogen, and diamond was formed by microwave plasma CVD. A polycrystalline diamond 4 having a film thickness of 35 to 40 μm was obtained on the entire surface of the silicon substrate 5. It was confirmed by secondary ion mass spectrometry that the diamond film 4 was doped with 0.2 to 1100 ppm of boron on average depending on the amount of diborane gas added.

  The surface of the diamond 4 was polished and flattened by chemical mechanical polishing, and the polycrystalline diamond film 4 was cleaned in aqua regia at about 120 ° C. Thereafter, the back surface of the silicon substrate 5 was protected with a polyimide film that was hardly dissolved in hydrofluoric acid, and immersed in hydrofluoric acid, the silicon in the beam irradiation part (approximately 10 mm diameter) 6 through which the radiation beam was transmitted was removed by etching. The produced beam detection member 2 was placed on a holding stand, and the beam detector 1 was configured using a color CCD camera as the excitation light observation means 3 and 3a.

  When the beam irradiation part 6 of the beam detecting member 2 is irradiated with a radiated light beam 7 having an energy of 5 to 60 keV, clear blue-green excitation lights 8 and 8a are observed at an irradiation spot 7a through which the radiated light beam 7 is transmitted. It was done. When the measurement was performed by changing the acceleration voltage and beam current of the emitted light 7, the intensity of the excitation light 8 and 8a changed in proportion to the energy of the emitted light 7. At the same time, the intensity of the observed excitation lights 8 and 8a has a dependence as shown in FIG. 4 with respect to the average boron concentration in the diamond film 4, and the diamond film 4 of the beam detection member 2 contains 10 to 150 ppm of boron. It has been found preferable to include.

  FIG. 4 is a diagram showing the measurement result of the excitation light intensity with respect to the average boron concentration in the diamond film. Here, the boron concentration is measured using secondary ion mass spectrometry, and the average boron concentration is an arithmetic average value of each boron concentration obtained by measuring along the thickness direction of the diamond film 4. It is what I have sought. The excitation light intensity was measured using a silicon photodiode.

<Example 1>
A diamond film 4 doped with boron was formed on the substrate 2 in the same procedure as in the above experimental example, and the beam detection member 2 and the beam detector 1 using the same were manufactured. In order to dope boron into the polycrystalline diamond 1, diborane or trimethylboron (B (CH ₃ ) ₃ ) diluted with hydrogen is added to the source gas, the thickness is 10 to 25 μm, and the average particle size of the diamond particles is A polycrystalline diamond 4 of 10 μm or less was obtained. At this time, the flow rate of the gas containing boron and the temperature of the substrate 2 are changed in the range of 700 to 850 ° C., so that the boron concentration in the diamond film 4 is not uniform as in the experimental example but in the film thickness direction. It was made with various distributions.

  FIG. 5 shows the result of measuring the boron concentration distribution with respect to the film depth of the diamond 4 by secondary ion mass spectrometry. In this sample, 50 ppm of boron was taken in on average, but it was not uniform in the depth direction and had a distribution in the range of 0.1 to 800 ppm. Further, the surface side of the diamond film 4 was set to a low concentration with a boron concentration of 10 ppm or less. A part of the silicon substrate 5 was etched from such a boron-doped diamond sample in the same manner as in the above experimental example to obtain a beam detection member 2.

  When such a beam detection member 2 was irradiated with an X-ray beam having an energy of 15 keV, blue-green excitation lights 8 and 8a were observed from the polycrystalline diamond film 4 region of the irradiation spot 7a. Further, when the intensity of the irradiated X-ray beam was changed and observed, the luminance of the irradiation spot 7a was changed in proportion to the intensity. However, when compared with a diamond film having an average boron concentration of 50 ppm and a constant concentration in the film produced in the experimental example, four times the excitation light intensity was observed.

  That is, when the boron concentration distribution with respect to the film depth of the diamond 4 is non-uniform and a portion containing boron at a concentration of 150 ppm or more and a portion containing a concentration of 10 ppm or less coexist in the film thickness direction, high efficiency is achieved in the former portion. The visible light excited by the

<Example 2>
Next, based on the results of Example 1, the boron concentration distribution in the polycrystalline diamond 4 was changed to produce the beam detection member 2, and the excitation light intensities thereof were compared. First, an aqueous solution containing fine diamond having an average particle diameter of 5 to 50 nm was applied to a silicon substrate 5 of 20 mm × 20 mm, and then dried and subjected to diamond nucleus formation promoting treatment.

The substrate 5 is placed in a plasma CVD apparatus, and 0.1 to 50 ppm of diborane (B ₂ H ₆ ) gas is added to a mixed gas of 5% by volume methane, 5% by volume hydrogen, and 90% by volume argon to form a diamond composition. A polycrystalline diamond 4 having a film thickness of 35 to 40 μm and an average particle diameter of diamond particles of 10 μm or less was obtained on the entire surface of the substrate 5. In the film formation process, the flow rate of diborane gas was changed to control the boron concentration distribution in the film thickness direction.

  The obtained diamond 4 was composed of an aggregate of fine crystal grains that were difficult to measure, the surface thereof was flat, and a separate polishing step was omitted. The surface of this microcrystalline diamond 4 was washed in aqua regia at about 120 ° C. Thereafter, the back surface of the silicon substrate 5 was protected with a polyimide film that is difficult to dissolve in hydrofluoric acid, and immersed in hydrofluoric acid, the silicon in the beam irradiation portion (approximately 10 mm diameter) 6 was removed by etching.

  The produced beam detection member 2 was placed on a holding stand, and the beam detector 1 was configured using a color CCD camera as the excitation light observation means 3 and 3a. When the beam detecting member 2 was irradiated with a radiated light beam 7 having an energy of 5 to 60 keV, clear blue-green excitation light 8a was observed at an irradiation spot 7a through which the radiated light beam 7 was transmitted. The measurement was performed by changing the acceleration voltage and the beam current of the emitted light 7, but the intensity of the excitation light 8a changed in proportion to the energy of the emitted light 7.

  At the same time, the observed excitation light intensity depends on the volume ratio in the film pressure direction of the diamond 4 in the portion where the boron concentration in the microcrystalline diamond 4 is 150 ppm or more and 10 ppm or less as shown in FIG. Therefore, it was found that the microcrystalline diamond 4 of the beam detection member 2 preferably contains 33 to 66% by volume of a boron concentration of 150 ppm or more and 10 ppm or less from the viewpoint of excitation light intensity.

  Since the beam detection member according to the present invention is composed of a diamond film having excellent radiation resistance and a substrate such as a silicon substrate, the performance does not deteriorate in a short time unlike other materials. In addition, by controlling and doping boron atoms in the polycrystalline diamond film, excitation light having sufficient intensity is observed from the irradiated spot of the synchrotron radiation beam, and the beam is emitted using an excitation light observation means such as a normal video camera. A detector can be configured to capture a clear spot image.

  As described above, the beam detection member according to the present invention and the beam detector using the same can improve the excitation efficiency of visible light in the beam detection member. Therefore, even if the polycrystalline diamond constituting the detection member has a small film thickness, it is possible to ensure sufficient excitation light intensity for detection by the visible light detector. And since the boron concentration in the polycrystalline diamond film of the beam detection member is specified, not only the transmission of the synchrotron radiation X-ray beam is improved, but the thermal load of the detection member is reduced accordingly, The range of application is expanded to high-intensity (high energy density) beams. Taking a synchrotron radiation facility as an example, this means that it can cope with beam detection on the upstream side (side near the light source) and the next generation synchrotron radiation beam (free electron X-ray laser beam).

It is the typical perspective view which showed typically the surface of the beam detection member which concerns on Embodiment 1 of this invention. It is the typical perspective view which showed typically the back surface of the beam detection member which concerns on Embodiment 1 of this invention. It is the typical sectional view showing typically the whole beam detector composition using the beam detection member concerning Embodiment 1 of the present invention. It is a figure which shows the measurement result of the excitation light intensity with respect to the Example of this invention with respect to the average boron density | concentration in a diamond film. It is a figure which concerns on the Example of this invention and shows the measurement result of the boron concentration distribution with respect to the film depth of a diamond film. It is a figure which concerns on the Example of this invention and is a figure which shows the measurement result of the excitation light intensity with respect to the volume ratio to which the boron concentration in a diamond film occupies 150 ppm or more and 10 ppm or less in the film | membrane pressure direction of the said diamond 4.

Explanation of symbols

1 ... Beam detector, 2 ... Beam detection member,
3, 3a ... excitation light observation means,
4 ... (polycrystalline) diamond film, 5 ... substrate, 6 ... beam irradiation part,
7 ... synchrotron radiation beam, 7a ... (beam) irradiation spot,
8, 8a ... Excitation light

Claims (6)

  A beam detection member for detecting the position and intensity of a beam, and a beam irradiation portion irradiated with the beam is formed of a polycrystalline diamond film containing 10 to 150 ppm of boron (B) on average. The boron (B) concentration has a non-uniform concentration distribution in the film thickness direction of the polycrystalline diamond.   2. The beam detection member according to claim 1, wherein a concentration of boron (B) in the polycrystalline diamond has a portion of 150 ppm or more and a portion of 10 ppm or less in the film thickness direction.   The volume ratio of the portion of the polycrystalline diamond in which the boron (B) concentration is 150 ppm or more and 10 ppm or less in the film thickness direction of the polycrystalline diamond is 33% or more and 66% or less. 3. The beam detection member according to 2.   4. The beam according to claim 1, wherein at least a part of the diamond film is held by a substrate, and the thickness of the polycrystalline diamond is 3 to 30 μm. 5. Detection member.   The beam detection member according to any one of claims 1 to 4, wherein an average particle diameter of diamond particles forming the polycrystalline diamond film is 10 µm or less.   6. A beam detector comprising a beam detection member for detecting the position and intensity of a beam, wherein the beam is irradiated to the beam detection member according to claim 1 and the beam irradiation unit. And the excitation light observation means for observing the excitation light, and detecting the position and intensity of the beam by the excitation light observed by the excitation light observation means. Beam detector.

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