JPH027512B2 - - Google Patents
Info
- Publication number
- JPH027512B2 JPH027512B2 JP58180150A JP18015083A JPH027512B2 JP H027512 B2 JPH027512 B2 JP H027512B2 JP 58180150 A JP58180150 A JP 58180150A JP 18015083 A JP18015083 A JP 18015083A JP H027512 B2 JPH027512 B2 JP H027512B2
- Authority
- JP
- Japan
- Prior art keywords
- window member
- ray
- radiation
- radiation detector
- cfrp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005855 radiation Effects 0.000 claims description 27
- 229920005989 resin Polymers 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 7
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 6
- 239000004917 carbon fiber Substances 0.000 claims description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 6
- 239000004020 conductor Substances 0.000 claims description 2
- 239000004918 carbon fiber reinforced polymer Substances 0.000 description 13
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 12
- 229910052782 aluminium Inorganic materials 0.000 description 12
- 239000011888 foil Substances 0.000 description 12
- 238000001514 detection method Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000003014 reinforcing effect Effects 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
- 238000000862 absorption spectrum Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000007872 degassing Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 238000003325 tomography Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 238000002083 X-ray spectrum Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- -1 epoxy resin) Chemical compound 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
- H01J47/001—Details
- H01J47/002—Vessels or containers
- H01J47/004—Windows permeable to X-rays, gamma-rays, or particles
Landscapes
- Measurement Of Radiation (AREA)
- Apparatus For Radiation Diagnosis (AREA)
- Electron Tubes For Measurement (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は放射線検出器に係り、特にＸ線入射窓
部材を改良した放射線検出器に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a radiation detector, and particularly to a radiation detector with an improved X-ray entrance window member.
放射線断層撮影装置、例えば、コンピユータ・
トモグラフイ（以下単に「CT装置」と略称する）
は、第１図に示すように、放射線発生手段１より
曝射されたＸ線フアンビーム（FX）が被検体３
を透過後に放射線検出器２に入射するようになつ
ている。しかして、この放射線検出器２は、被検
体透過後のＸ線エネルギを電離電流として検出
し、これをＸ線吸収データとして出力するもので
あり、その性能は、CT装置における最終的な再
構成画像の良否に大きく影響する。そこで、優れ
たCT装置を得るためには、感度，密度分解等の
優れた放射線検出器を具備しなければならない。
Radiation tomography equipment, e.g.
Tomography (hereinafter simply referred to as "CT device")
As shown in FIG. 1, the X-ray fan beam (FX) emitted from the radiation generating means 1
After passing through the radiation, the radiation enters the radiation detector 2. This radiation detector 2 detects the X-ray energy after passing through the subject as an ionizing current and outputs this as X-ray absorption data, and its performance depends on the final reconstruction in the CT device. This greatly affects the quality of the image. Therefore, in order to obtain an excellent CT device, it is necessary to have a radiation detector with excellent sensitivity, density resolution, etc.
ところで、従来の放射線検出器の材質には、第
２図に示すＸ線入射窓部材４ａも含めて、Ｘ線透
過の比較的良効なアルミニウム等が適用されてい
た。 Incidentally, the material of conventional radiation detectors, including the X-ray entrance window member 4a shown in FIG. 2, has been made of aluminum or the like, which has relatively good X-ray transmission properties.
しかしながら、アルミニウム等のＸ線入射窓部
材４ａの影響により、被検体透過Ｘ線の低エネル
ギーフオトンが減衰する傾向にあり、従来より以
下に述べるような問題が生じていた。 However, due to the influence of the X-ray entrance window member 4a made of aluminum or the like, low-energy photons of the X-rays transmitted through the subject tend to be attenuated, which has conventionally caused problems as described below.
すなわち、放射線検出器の密度分解能は、第３
図に示すＸ線入射窓４ａを透過して検出素子群６
に到達する低エネルギフオトンに比例するが、こ
の低エネルギフオトンは、検出素子に到達する前
に、Ｘ線入射窓部材４ａ（アルミニウム）によつ
て吸収されてしまう。この結果、密度分解能の悪
い放射線検出器となつてしまうのである。 In other words, the density resolution of the radiation detector is
The detection element group 6 passes through the X-ray entrance window 4a shown in the figure.
However, the low-energy photons are absorbed by the X-ray entrance window member 4a (aluminum) before reaching the detection element. This results in a radiation detector with poor density resolution.
本発明は前記事情に鑑みてなされたもので、被
写体透過Ｘ線エネルギの低エネルギフオトンを十
分に検出素子に到達させることによつて、密度分
解能の優れた放射線検出器を提供することを目的
とする。
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radiation detector with excellent density resolution by sufficiently allowing low-energy photons of the X-ray energy transmitted through the object to reach the detection element. shall be.
前記目的を達成するための本発明の概要は、少
なくとも放射線の入射する窓部材が、炭素繊維強
化樹脂と、該炭素繊維強化樹脂に積層される導電
体箔とを有することを特徴とするものである。
The outline of the present invention for achieving the above object is characterized in that at least a window member through which radiation enters has a carbon fiber reinforced resin and a conductive foil laminated on the carbon fiber reinforced resin. be.
以下、本発明の一実施例について図面を参照し
ながら説明する。
An embodiment of the present invention will be described below with reference to the drawings.
第４図は本発明に係る放射線検出器を示す断面
斜視図である。同図７は、Ｘ線入射方向（矢印Ｘ
―ray）に切欠部（Ｘ線入射窓）を有し、かつ、
プレート８によつて閉塞されるケースである。こ
のケース７の切欠部に、窓部材４ａが、例えば接
着剤によつて接着されるとともに、例えば第５図
に示すように、額縁形状の補強部材１０及びビス
１１によつて補強されている。 FIG. 4 is a cross-sectional perspective view showing a radiation detector according to the present invention. 7 shows the X-ray incident direction (arrow
-ray) has a notch (X-ray entrance window), and
This is a case where the plate 8 is used to close the case. A window member 4a is bonded to the notch of the case 7 with, for example, an adhesive, and is reinforced with a frame-shaped reinforcing member 10 and screws 11, as shown in FIG. 5, for example.
次に前記窓部材４ａの構成について説明する。
この窓部材４ａは、第６図に示すように、たとえ
ば15〜25μm厚のシート状に形成された炭素繊維
強化樹脂（Carbon Fiber Reinforced
Plastics；以下CFRPと略称する）のシート１６
を10枚程度積層し、所望の厚さ（t2.0〜2.5mm）を
得、かつ窓部材内壁（検出素子群６側）に導電体
箔（t25〜50μm）、例えばアルミニウム箔１７が
貼り付けられて成る。 Next, the structure of the window member 4a will be explained.
As shown in FIG. 6, this window member 4a is made of carbon fiber reinforced resin formed into a sheet shape with a thickness of 15 to 25 μm, for example.
Plastics (hereinafter abbreviated as CFRP) sheet 16
About 10 sheets are laminated to obtain the desired thickness (t2.0 to 2.5 mm), and a conductive foil (t25 to 50 μm), such as aluminum foil 17, is pasted on the inner wall of the window member (detection element group 6 side). It is made up of
ここで、前記シート状に形成されたCFRP（こ
れを「プリプレグ」と称する）１６の積層は、例
えばオートクレーブで特定時間加熱することによ
り容易に実現できる。また、Ｘ線入射窓部材に
CFRPを用いるのは次の理由による。 Here, the lamination of the sheet-shaped CFRP (referred to as "prepreg") 16 can be easily realized, for example, by heating in an autoclave for a specific period of time. In addition, the X-ray entrance window member
The reason for using CFRP is as follows.
すなわち、従来のＸ線入射窓部材たるアルミニ
ウムは、エネルギ60kevでＸ線吸収係数μ＝0.27
cm-1であるのに対し、CFRPのＸ線透過率は、エ
ネルギ60kev〜100kevにおいてAl当量（アルミ当
量）で1/10と、極めて優れている。したがつて、
CFRPを用いれば低エネルギフオトンの透過率が
向上し、密度分解能の向上が図れるのである。さ
らに、前記CFRPの検出素子群６側にアルミニウ
ム箔１７を貼り付けるのは次の理由による。 In other words, aluminum, which is the conventional X-ray entrance window material, has an X-ray absorption coefficient μ = 0.27 at an energy of 60 keV.
cm -1 , whereas the X-ray transmittance of CFRP is extremely excellent at 1/10 of Al equivalent (aluminum equivalent) at energy of 60kev to 100kev. Therefore,
Using CFRP improves the transmittance of low-energy photons and improves density resolution. Furthermore, the reason why the aluminum foil 17 is attached to the detection element group 6 side of the CFRP is as follows.
すなわち、CFRPはカーボン繊維とレジン（主
にエポキシ樹脂）から構成されており、使用中熱
を受けると、第８図に示すように、レジンから例
えばH2O，CO，NH3等のガスが発生し、このガ
スが、検出器内において放射線により電離された
Xe+、e-と結合し、検出器特性に悪影響を与える
虞れがある。また、窓部材内壁を絶縁物質にする
と（すなわち、窓部材がCFRPのみであると）、
第９図に示すように、Ｘ線により電離されたXe+
が検出素子に収集されず、前記窓部材内壁に付着
し、検出器特性に悪影響を与える虞れがある。そ
こで、CFRP９の検出素子群６側（窓部材内壁）
にアルミニウム箔１７を貼り付けることにより、
脱ガス防止及び帯電防止を図るとともに、均一電
界分布を得るのである。 In other words, CFRP is composed of carbon fiber and resin (mainly epoxy resin), and when it is heated during use, gases such as H 2 O, CO, and NH 3 are released from the resin, as shown in Figure 8. This gas is ionized by radiation in the detector.
There is a risk that it will combine with Xe + and e - and adversely affect the detector characteristics. Also, if the inner wall of the window member is made of an insulating material (i.e., if the window member is made only of CFRP),
As shown in Figure 9, Xe + ionized by X-rays
is not collected by the detection element and may adhere to the inner wall of the window member, which may adversely affect the characteristics of the detector. Therefore, the detection element group 6 side of CFRP9 (window member inner wall)
By pasting aluminum foil 17 on
This prevents degassing and charging, and also provides a uniform electric field distribution.
このように構成される放射線検出器のシミユレ
ーシヨン結果を第１０図に示す。同図ａはＸ線入
射窓４ａの前面におけるＸ線スペクトルを示し、
また、ｂ，ｃはそれぞれ本発明に係る窓部材（ア
ルミニウム箔を貼り付けたCFRP），従来の窓部
材（アルミニウム）の場合であつて、それぞれ同
じ厚さに形成した際の検出素子群６でのＸ線吸収
スペクトルを示している。同図から明らかなよう
に、本発明に係る窓部材の場合のＸ線吸収スペク
トルは、従来のそれに比べ15〜20％向上すること
が分かる。 FIG. 10 shows simulation results of the radiation detector constructed in this manner. Figure a shows the X-ray spectrum in front of the X-ray entrance window 4a,
Furthermore, b and c are the cases of the window member according to the present invention (CFRP pasted with aluminum foil) and the conventional window member (aluminum), respectively, and the detection element group 6 when formed to the same thickness. The X-ray absorption spectrum of As is clear from the figure, the X-ray absorption spectrum of the window member according to the present invention is improved by 15 to 20% compared to the conventional one.
尚、本発明は前記実施例によつて限定されるも
のではなく、本発明の要旨の範囲内で適宜に変形
実施が可能であるのはいうまでもない。 It goes without saying that the present invention is not limited to the embodiments described above, and that modifications can be made as appropriate within the scope of the gist of the present invention.
例えば、窓部材４ａの補強を第１１図及び第１
２図に示すように、窓部材４ａの周囲を穿設せず
して、補強部材１３及びビス１４によつて、前記
窓部材４ａを補強することも可能である。 For example, the reinforcement of the window member 4a is shown in FIGS.
As shown in FIG. 2, it is also possible to reinforce the window member 4a with reinforcing members 13 and screws 14 without drilling around the window member 4a.
また、前記実施例では、導電体箔をアルミニウ
ム箔としたが、これに限定されず例えば、銅箔，
ニツケル箔，鉄箔等でも良い。 Further, in the above embodiments, the conductive foil is aluminum foil, but is not limited to this, and for example, copper foil,
Nickel foil, iron foil, etc. may also be used.
さらに、CFRPに導電体箔を積層させる方法と
しては、抵抗加熱，電子ビーム等による蒸着法、
あるいは、スパツタ法による蒸着法を用いても良
い。 Furthermore, methods for laminating conductive foil on CFRP include resistance heating, vapor deposition using an electron beam, etc.
Alternatively, a sputtering vapor deposition method may be used.
以上説明したように本発明によれば、検出素子
における放射線の低エネルギ側の吸収が増加する
ので、密度分解能が向上し、臨床的に有効なデー
タの収集が可能となるとともに、Ｘ線入射窓のＸ
線透過率が増大し、Ｓ／Ｎが向上する。また、
CFRP導電体箔を積層することにより、CFRPか
らの脱ガス防止，帯電防止が図られるとともに、
均一電界分布が得られる等、優れた効果を奏する
放射線検出器を提供することができる。
As explained above, according to the present invention, the absorption of radiation on the low energy side in the detection element is increased, so the density resolution is improved, it becomes possible to collect clinically effective data, and the X-ray incidence window X of
The linear transmittance increases and the S/N ratio improves. Also,
By laminating CFRP conductive foil, it is possible to prevent degassing from CFRP and prevent static electricity.
It is possible to provide a radiation detector that exhibits excellent effects such as obtaining a uniform electric field distribution.
第１図はCT装置を示す概略説明図、第２図は
放射線検出器の概略斜視図、第３図は第２図に示
す放射検出器の断面図、第４図は本発明に係る放
射線検出器を示す断面図、第５図は第４図に示す
放射線検出器の窓部材の補強を説明するための説
明図、第６図及び第７図は第４図に示す放射線検
出器の窓部材の詳細な構成を説明するための説明
図、第８図及び第９図は放射線検出器の窓部材を
第６図及び第７図に示す構成とする理由を説明す
るための説明図、第１０図は第４図に示す放射線
検出器の特性を示す特性図、第１１図及び第１２
図は第５図に示す窓部材の補強の変形例を説明す
るための説明図である。
４ａ…窓部材、９…炭素繊維強度樹脂
（CFRP）、１７…アルミニウム箔（導電体箔）。
Fig. 1 is a schematic explanatory diagram showing a CT device, Fig. 2 is a schematic perspective view of a radiation detector, Fig. 3 is a sectional view of the radiation detector shown in Fig. 2, and Fig. 4 is a radiation detection according to the present invention. 5 is an explanatory diagram for explaining the reinforcement of the window member of the radiation detector shown in FIG. 4, and FIGS. 6 and 7 are the window members of the radiation detector shown in FIG. 4. 8 and 9 are explanatory diagrams for explaining the reason why the window member of the radiation detector has the configuration shown in FIGS. 6 and 7. The figures are characteristic diagrams showing the characteristics of the radiation detector shown in Figure 4, Figures 11 and 12.
This figure is an explanatory view for explaining a modification of reinforcing the window member shown in FIG. 5. 4a... Window member, 9... Carbon fiber reinforced resin (CFRP), 17... Aluminum foil (conductor foil).
Claims (1)
する容器と、この容器の放射線を受ける面に設け
られ、前記放射線を受ける面を炭素繊維強化樹脂
からなる第１の層、及び前記気体に接する面を導
電体からなる第２の層によつて形成した窓部とを
有することを特徴とする放射線検出器。1. A container that encloses a gas that ionizes when it receives radiation from the outside; a first layer that is provided on the radiation-receiving surface of this container, and that the radiation-receiving surface is covered with a first layer made of carbon fiber reinforced resin; and a window formed by a second layer made of a conductor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58180150A JPS6074253A (en) | 1983-09-30 | 1983-09-30 | Radioactive ray detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58180150A JPS6074253A (en) | 1983-09-30 | 1983-09-30 | Radioactive ray detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6074253A JPS6074253A (en) | 1985-04-26 |
| JPH027512B2 true JPH027512B2 (en) | 1990-02-19 |
Family
ID=16078270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58180150A Granted JPS6074253A (en) | 1983-09-30 | 1983-09-30 | Radioactive ray detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6074253A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9076628B2 (en) | 2011-05-16 | 2015-07-07 | Brigham Young University | Variable radius taper x-ray window support structure |
| US8989354B2 (en) * | 2011-05-16 | 2015-03-24 | Brigham Young University | Carbon composite support structure |
| US9502206B2 (en) | 2012-06-05 | 2016-11-22 | Brigham Young University | Corrosion-resistant, strong x-ray window |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5749879A (en) * | 1980-09-10 | 1982-03-24 | Toshiba Corp | Detector for radiation |
-
1983
- 1983-09-30 JP JP58180150A patent/JPS6074253A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5749879A (en) * | 1980-09-10 | 1982-03-24 | Toshiba Corp | Detector for radiation |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6074253A (en) | 1985-04-26 |
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