JP2003187729A - Rotating anode x-ray tube device - Google Patents
Rotating anode x-ray tube deviceInfo
- Publication number
- JP2003187729A JP2003187729A JP2001383925A JP2001383925A JP2003187729A JP 2003187729 A JP2003187729 A JP 2003187729A JP 2001383925 A JP2001383925 A JP 2001383925A JP 2001383925 A JP2001383925 A JP 2001383925A JP 2003187729 A JP2003187729 A JP 2003187729A
- Authority
- JP
- Japan
- Prior art keywords
- ray tube
- ray
- anode
- cathode
- tube
- 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.)
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- X-Ray Techniques (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ガラス製のＸ線管
外囲器を用いた回転陽極Ｘ線管を、管容器の絶縁油中に
封入した回転陽極Ｘ線管装置に係わり、特に、管容器の
構造に対する回転陽極Ｘ線管の電位分布の安定性と固有
ろ過に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary anode X-ray tube apparatus in which a rotary anode X-ray tube using a glass X-ray tube envelope is enclosed in insulating oil in a tube container, and more particularly, It relates to the stability and intrinsic filtration of the potential distribution of a rotating anode X-ray tube with respect to the structure of the tube container.
【０００２】[0002]
【従来の技術】図３は、従来の回転陽極Ｘ線管装置の構
造を示し、図４は、そのＸ線放射窓１６の部分を拡大表
示するものであり、（ａ）は管軸方向の断面図、（ｂ）
は側面方向の断面図である。ガラス製のＸ線管外囲器１
０を有したＸ線管１は、絶縁油１５が封入された管容器
１２内に設けられた陽極保持部７と陰極保持部６とに保
持されている。回転陽極１４は、タングステンの傘状の
ターゲット１４ａと回転子とが一体となり、陽極側の固
定部の軸受に支えられて高速回転する。陰極１３は、シ
リンダに保持されて、その位置は管軸より外れ、集束電
極とタングステンフィラメントから構成される。回転陽
極１４は、管容器１２内の陽極側に設けられたステータ
２のモータコイルの誘導回転磁界により高速で回転す
る。タングステンディスクのターゲット１４ａの電子衝
撃面積は回転することにより増大し、焦点の単位面積当
たりの入力は大きくなる。回転機構の軸受は多くはボー
ルベアリングが真空中で用いられ、ベアリングケースに
保持されて、鉛、銀などの薄い膜が潤滑剤として使われ
ている。Ｘ線管外囲器１０のガラスバルブは硬質ガラス
製のものが多く用いられ、内部を高真空にするために陰
極側のガラスのＸ線管外囲器１０の端面側からガラス製
の細いチップ管で真空排気され、排気終了後、このチッ
プ管は融着・封じ切られる。管容器１２の内側はＸ線の
漏洩を防ぐために防護鉛５が内張りされている。また、
Ｘ線管１の動作によって内部の温度が上昇し絶縁油１５
の体積が膨張するので、陰極側にベローズ８が設けられ
ている。2. Description of the Related Art FIG. 3 shows the structure of a conventional rotary anode X-ray tube device, and FIG. 4 is an enlarged view of an X-ray emission window 16 thereof. Sectional view, (b)
[FIG. 3] is a cross-sectional view in a side direction. Glass X-ray tube envelope 1
The X-ray tube 1 having 0 is held by the anode holding part 7 and the cathode holding part 6 provided in the tube container 12 in which the insulating oil 15 is sealed. The rotary anode 14 has a tungsten umbrella-shaped target 14a and a rotor integrated with each other, and is rotated at a high speed by being supported by a bearing of a fixed portion on the anode side. The cathode 13 is held by a cylinder, its position is off the tube axis, and is composed of a focusing electrode and a tungsten filament. The rotating anode 14 rotates at a high speed due to the induced rotating magnetic field of the motor coil of the stator 2 provided on the anode side in the tube container 12. The electron impact area of the tungsten disk target 14a is increased by rotation, and the input per unit area of the focus is increased. Ball bearings are often used in vacuum for the bearings of rotating mechanisms, held in a bearing case, and a thin film of lead, silver, or the like is used as a lubricant. The glass bulb of the X-ray tube envelope 10 is often made of hard glass, and a thin glass tip is made from the end face of the X-ray tube envelope 10 on the cathode side of the glass in order to create a high vacuum inside. The tube is evacuated and the tip tube is fused and sealed off after the evacuation is completed. The inside of the tube container 12 is lined with protective lead 5 to prevent leakage of X-rays. Also,
Due to the operation of the X-ray tube 1, the internal temperature rises and the insulating oil 15
The bellows 8 is provided on the cathode side because the volume of the bellows expands.
【０００３】Ｘ線管１は、絶縁油１５が封入された管容
器１２に収納され、動作時は管容器１２の円筒両側に設
けられたケーブルレセプタクル４から、負の高電圧及び
フィラメント電流が陰極１３に、正の高電圧が回転陽極
１４に、外部から供給される。そして、陰極１３のフィ
ラメントから放出する電子流が集束電極によって集束さ
れ、高速回転する回転陽極１４のタングステン面をもつ
傘状のターゲット１４ａ面に電子衝撃する。その時、衝
撃を受けたタングステン面からＸ線が放射し、Ｘ線管外
囲器１０のガラス壁と絶縁油１５を透過し、管容器１２
のＸ線放射口に、押え板３ａによって押えられアース電
位のマスク１７を備えた樹脂などの絶縁物からなるＸ線
放射窓１６から外部に放射する。The X-ray tube 1 is housed in a tube container 12 in which insulating oil 15 is sealed. During operation, a negative high voltage and a filament current are fed from a cable receptacle 4 provided on both sides of the cylinder of the tube container 12 to a cathode. At 13, a positive high voltage is externally supplied to the rotating anode 14. Then, the electron flow emitted from the filament of the cathode 13 is focused by the focusing electrode and bombarded with electrons on the umbrella-shaped target 14a surface having the tungsten surface of the rotating anode 14 which rotates at high speed. At that time, X-rays are radiated from the impacted tungsten surface, pass through the glass wall of the X-ray tube envelope 10 and the insulating oil 15, and the tube container 12
It is radiated to the outside from the X-ray radiation window 16 made of an insulating material such as resin and provided with the mask 17 of the ground potential, which is held by the holding plate 3a.
【０００４】[0004]
【発明が解決しようとする課題】従来の回転陽極Ｘ線管
装置は以上のように構成されているが、Ｘ線透視および
撮影を繰り返すと、電子流の陽極への衝突により発生し
たエネルギーは大部分が熱に変換されるため、回転陽極
１４のターゲット１４ａのタングステン面は高温度にな
る。その熱の一部は回転陽極１４の陽極保持部７側の方
向に伝導されるが、大部分の熱はタングステン面からの
輻射熱となって陰極１３の方向、Ｘ線管外囲器１０のガ
ラスバルブを通して管容器１２の絶縁油１５の方向、ス
テータ２の方向に伝わる。したがって陰極１３の集束電
極およびフィラメントは高温度になる。さらに、フィラ
メントから電子を回転陽極１４のターゲット１４ａに向
かって放出するために、フィラメントに電流を流して加
熱し、普通動作温度は２、５００°Ｋぐらいで寿命は、
１０、０００時間程度であるが、この温度での利用し得
る最大エミッションは０．５Ａ／ｃｍ２である。寿命は
タングステンの蒸発によって決まる。直径が最初の９０
％になると、それ以後は加速的に温度が上がり、さらに
蒸発速度を増して急速に溶断する。Ｘ線管１の真空度が
悪くて１０−５〜１０−４ｍｍＨｇ程度以下になると、
残留ガスの酸化作用およびイオン衝撃によってタングス
テンの蒸発が促進されて、寿命が低下する。蒸発したタ
ングステンは比較的温度の低いＸ線管外囲器１０のガラ
スバルブの内壁にＷ飛散膜として付着する。The conventional rotary anode X-ray tube device is constructed as described above, but when X-ray fluoroscopy and radiography are repeated, the energy generated by the collision of the electron stream with the anode is large. Since the part is converted into heat, the temperature of the tungsten surface of the target 14a of the rotary anode 14 becomes high. A part of the heat is conducted in the direction of the anode holding portion 7 side of the rotary anode 14, but most of the heat becomes radiant heat from the tungsten surface, the direction of the cathode 13, the glass of the X-ray envelope 10. It is transmitted to the direction of the insulating oil 15 of the tube container 12 and the direction of the stator 2 through the valve. Therefore, the focusing electrode and the filament of the cathode 13 have a high temperature. Further, in order to emit electrons from the filament toward the target 14a of the rotary anode 14, a current is applied to the filament to heat it, and the normal operating temperature is about 2,500 ° K.
Although it is about 10,000 hours, the maximum emission that can be used at this temperature is 0.5 A / cm 2 . The lifetime depends on the evaporation of tungsten. The first 90
When it reaches%, the temperature is accelerated thereafter, and the evaporation rate is further increased to rapidly melt. When the vacuum degree of the X-ray tube 1 is bad and becomes about 10 −5 to 10 −4 mmHg or less,
Oxidation of the residual gas and ion bombardment accelerate the evaporation of tungsten and shorten the life. The evaporated tungsten adheres to the inner wall of the glass bulb of the X-ray tube envelope 10 having a relatively low temperature as a W scattering film.
【０００５】一方、負の高電圧が供給され非対称形状を
したＸ線放射窓１６の近くに位置する陰極１３と、正の
高電圧が供給される回転陽極１４のターゲット１４ａ
と、アース電位を保ち防護鉛５が内張りされ、絶縁物の
樹脂からなるＸ線放射窓１６を備えた管容器１２との中
間に位置するＸ線管外囲器１０であるガラスバルブの内
外表面は、正及び負の電荷がチャージアップされる。電
荷が溜まり安定するまでに少なくとも、数ｍｓｅｃの時
間を要する。そして、絶縁物であるＸ線放射窓１６が近
くに存在するため、上記のＷ飛散膜が加わって、Ｘ線管
１のＸ線管外囲器１０におけるＸ線放射窓１６の周辺部
分のガラスバルブの内外表面は、非常に不安定な電位状
態になる。このように不安定な電位分布状態が存在する
と、ガラスバルブの内表面を介して陰極１３と回転陽極
１４のターゲット１４ａ間で放電したり、ガラスバルブ
を介してアース電位である管容器１２間で放電してガラ
スバルブを破壊したり、また、上記のＷ飛散膜が浮遊電
位となり、電荷を貯めて放電を誘発する。その誘発され
た放電によって、残留ガスのイオンがフィラメントの表
面をたたき、フィラメントからタングステンをさらに蒸
発させ、フィラメントの寿命をさらに低下させるという
問題がある。On the other hand, the cathode 14 located near the asymmetrical X-ray radiation window 16 supplied with a negative high voltage and the target 14a of the rotating anode 14 supplied with a positive high voltage.
And the inside and outside surfaces of the glass bulb, which is the X-ray tube envelope 10 positioned in the middle of the tube container 12 having the X-ray radiation window 16 made of resin of an insulator, which is lined with the protective lead 5 while keeping the earth potential. Are charged up with positive and negative charges. It takes at least several msec until the electric charge is accumulated and becomes stable. Since the X-ray radiation window 16 that is an insulator is present in the vicinity, the above-mentioned W scattering film is added, and the glass around the X-ray radiation window 16 in the X-ray tube envelope 10 of the X-ray tube 1 is added. The inner and outer surfaces of the bulb are in a very unstable potential state. When such an unstable potential distribution state exists, discharge occurs between the cathode 13 and the target 14a of the rotating anode 14 via the inner surface of the glass bulb, or between the tube containers 12 at the ground potential via the glass bulb. Discharge causes destruction of the glass bulb, and the W scattering film becomes a floating potential to accumulate electric charge and induce discharge. Due to the induced discharge, residual gas ions strike the surface of the filament, further evaporating tungsten from the filament, which further shortens the life of the filament.
【０００６】この問題を解決するために、Ｘ線放射窓１
６の内側にマスク１７を配置することが提案されてい
る。このマスク１７は導電性のもので、鉛やアルミニウ
ムが用いられ、アース電位とされる。しかし、マスク１
７とＸ線管外囲器１０との間には、絶縁のための隙間を
設けなければならない。通常この隙間には絶縁油が充填
されており、ターゲット１４ａから放射されるＸ線がこ
の部分で散乱・減衰する。即ち、固有ろ過値が大きくな
り、Ｘ線の有効利用という観点から、この隙間を小さく
し、且つＸ線放射窓１６、及びＸ線管外囲器１０のＸ線
放射窓１６近傍における電位分布を一様にして、安定し
て使用したいという課題がある。In order to solve this problem, the X-ray emission window 1
It has been proposed to place a mask 17 inside 6. The mask 17 is conductive, and is made of lead or aluminum and is set to the ground potential. But mask 1
A gap for insulation must be provided between 7 and the X-ray tube envelope 10. Normally, this gap is filled with insulating oil, and the X-rays emitted from the target 14a are scattered and attenuated at this portion. That is, from the viewpoint of effective use of X-rays by increasing the intrinsic filtration value, this gap is made small, and the potential distribution in the vicinity of the X-ray emission window 16 of the X-ray emission window 16 and the X-ray tube envelope 10 is reduced. There is a problem of uniform and stable use.
【０００７】本発明は、このような事情に鑑みてなされ
たものであって、管容器のＸ線放射窓の近傍に位置する
Ｘ線管ガラスバルブの電位分布を安定させ放電を抑制
し、且つ、放射Ｘ線に対する固有ろ過値を少なくした回
転陽極Ｘ線管装置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 stabilizes the electric potential distribution of the X-ray tube glass bulb located in the vicinity of the X-ray emission window of the tube container to suppress discharge, and An object of the present invention is to provide a rotating anode X-ray tube device having a reduced intrinsic filtration value for radiant X-rays.
【０００８】[0008]
【課題を解決するための手段】上記の目的を達成するた
め、本発明の回転陽極Ｘ線管装置は、管容器内部の絶縁
油中に陽極保持部と陰極保持部によって保持され、絶縁
物からなるＸ線管外囲器の高真空中に、高速回転する傘
状の陽極と、陰極とを対向配置した回転陽極Ｘ線管を備
え、この回転陽極Ｘ線管から放射するＸ線を、前記管容
器に設けられたＸ線放射窓から外部に照射する回転陽極
Ｘ線管装置において、前記Ｘ線放射窓の内側にアース電
位部材を配置し、前記Ｘ線放射窓に前記アース電位部材
よりＸ線管外囲器に近接して凹部を設けたものである。In order to achieve the above object, the rotary anode X-ray tube device of the present invention is held in an insulating oil inside a tube container by an anode holding part and a cathode holding part, and is made of an insulating material. In the high vacuum of the X-ray tube envelope, a rotating anode X-ray tube in which a high-speed rotating umbrella-shaped anode and a cathode are opposed to each other is provided, and X-rays emitted from the rotating anode X-ray tube are In a rotating anode X-ray tube device for irradiating an X-ray radiating window provided on a tube container to the outside, a ground potential member is arranged inside the X-ray radiating window, and the X-ray radiating window is connected to the X-ray radiating member from the ground potential member. A recess is provided near the envelope of the wire tube.
【０００９】そして、請求項２記載の回転陽極Ｘ線管
は、前記Ｘ線放射窓に設けられた凹部をＸ線管焦点幅方
向に曲面としたものである。Further, in the rotating anode X-ray tube according to the present invention, the concave portion provided in the X-ray emission window is a curved surface in the focal width direction of the X-ray tube.
【００１０】本発明の回転陽極Ｘ線管装置は上記のよう
に構成されており、回転陽極Ｘ線管から放射するＸ線
を、外部に照射するために管容器に設けられたＸ線放射
窓の内側に、アース電位部材を配置し、そのアース電位
部材よりＸ線管外囲器に近接して絶縁物のＸ線放射窓に
凹部を設けたものである。そして、Ｘ線放射窓に設けら
れた凹部をＸ線管焦点幅方向に曲面形状にしたものであ
る。それによって、Ｘ線管のＸ線管外囲器が、絶縁油を
介してＸ線放射窓近傍もアース電位にされ、管容器に一
様に覆われることになり、Ｘ線放射窓近傍のＸ線管外囲
器のガラスバルブ内外表面に、安定した電位分布を形成
することができる。そして、絶縁物のＸ線放射窓の凹部
が、Ｘ線管焦点幅方向に曲面を有し、アース電位部材よ
りＸ線管外囲器に一様に近接して設けられているので、
絶縁油によるＸ線の散乱・減衰が少なくなり、固有ろ過
値が小さくなって、Ｘ線を有効に外部に放射することが
できる。The rotary anode X-ray tube device of the present invention is constructed as described above, and the X-ray emission window provided in the tube container for irradiating the outside with the X-rays emitted from the rotary anode X-ray tube. A ground potential member is arranged inside the, and a recess is provided in the X-ray radiation window of the insulator, which is closer to the X-ray tube envelope than the ground potential member. Then, the concave portion provided in the X-ray radiation window is formed into a curved shape in the focal width direction of the X-ray tube. As a result, the X-ray tube envelope of the X-ray tube is set to the ground potential also in the vicinity of the X-ray emission window through the insulating oil, and is uniformly covered by the tube container. A stable potential distribution can be formed on the inner and outer surfaces of the glass bulb of the envelope of the wire tube. Since the concave portion of the X-ray radiation window of the insulator has a curved surface in the focal width direction of the X-ray tube and is provided evenly closer to the X-ray tube envelope than the ground potential member,
X-ray scattering / attenuation due to insulating oil is reduced, the intrinsic filtration value is reduced, and X-rays can be effectively radiated to the outside.
【００１１】[0011]
【発明の実施の形態】本発明の回転陽極Ｘ線管装置の実
施例を、図１および図２を参照しながら説明する。図１
は、本発明の回転陽極Ｘ線管装置の断面構造を示し、図
２は、Ｘ線放射窓３の部分を拡大表示したもので、
（ａ）はＸ線管１の管軸方向の断面を示し、（ｂ）は側
面方向の断面を示す図である。本回転陽極Ｘ線管装置
は、高真空に排気された硬質ガラスからなるＸ線管外囲
器１０と、そのＸ線管外囲器１０の一端に配置されステ
ータ２の回転磁界によって高速回転するターゲット１４
ａを有する回転陽極１４と、それに対向して配置された
フィラメントと集束電極によって電子を放出する陰極１
３と、Ｘ線管外囲器１０と回転陽極１４と陰極１３とか
ら構成されるＸ線管１を陽極保持部７と陰極保持部６と
によって保持し絶縁油１５中に封入され内壁に防護鉛５
を内張りした管容器１２と、回転陽極１４に正の高電圧
を供給し同時に陰極１３に負の高電圧とフィラメントに
電流を供給するためのケーブルレセプタクル４と、ター
ゲット１４ａに陰極１３からの電子が衝突しＸ線が放射
されそのＸ線を外部に照射するために管容器１２に押え
板３ａで取付けられ、内側にアース電位のマスク９を配
置し、Ｘ線管外囲器１０に近接しＸ線管焦点幅方向に曲
面を有した凹部１１が設けられた樹脂製のＸ線放射窓３
と、内部の温度上昇によって絶縁油１５が膨張したと
き、その容積を調節するベローズ８とから構成される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the rotary anode X-ray tube device of the present invention will be described with reference to FIGS. 1 and 2. Figure 1
Shows the cross-sectional structure of the rotating anode X-ray tube device of the present invention, and FIG. 2 is an enlarged view of the X-ray emission window 3.
(A) shows the cross section of the X-ray tube 1 in the tube axis direction, and (b) shows the side section. This rotating anode X-ray tube device is arranged at one end of the X-ray tube envelope 10 made of hard glass that has been evacuated to a high vacuum, and is rotated at high speed by the rotating magnetic field of the stator 2. Target 14
a rotating anode 14 having a, a cathode 1 which emits electrons by a filament and a focusing electrode arranged opposite to the rotating anode 14
3, an X-ray tube 1 composed of an X-ray tube envelope 10, a rotating anode 14 and a cathode 13 is held by an anode holding part 7 and a cathode holding part 6 and enclosed in insulating oil 15 to protect the inner wall. Lead 5
A tube container 12 lined with a cable receptacle 4 for supplying a positive high voltage to the rotating anode 14 and at the same time supplying a negative high voltage to the cathode 13 and a current to the filament, and electrons from the cathode 13 to the target 14a. The X-rays are radiated upon collision and are attached to the tube container 12 with the holding plate 3a to irradiate the X-rays to the outside. X-ray radiation window 3 made of resin provided with a concave portion 11 having a curved surface in the focal width direction of the tube.
And a bellows 8 that adjusts the volume of the insulating oil 15 when the insulating oil 15 expands due to a rise in internal temperature.
【００１２】Ｘ線管外囲器１０は、硬質ガラス製または
セラミックス製のものが用いられ、陰極側に設けられた
チップ管で内部を高真空に真空排気され、排気終了後こ
のチップ管は融着・封じ切られる。回転陽極１４は、正
の高電圧がケーブルレセプタクル４から印加され、絶縁
油１５中に設けられたステータ２のモータコイルの回転
磁界により高真空中で高速回転する。そのターゲット１
４ａには傘状のタングステンなどが使われ、回転機構の
軸受はボールベアリングが用いられる。陰極１３は、シ
リンダに保持されて、その位置は管軸より外れ、負の高
電圧がケーブルレセプタクル４から印加され同時にフィ
ラメントに電流が供給される。フィラメントにはタング
ステンが用いられ、モリブデンアンカによって支えられ
ており、インシュレータによって片側が絶縁され、一方
は集束電極に取付けられている。管容器１２は、内部に
絶縁油１５が封入され、内側に陽極保持部７と陰極保持
部６が設けられ、それにＸ線管１が保持される。そし
て、ステータ２に対応する位置に回転陽極１４の回転部
がセットされ、同時に、Ｘ線放射方向がＸ線放射窓３に
対応するようにセットされる。そして、ケーブルレセプ
タクル４からの導線が、回転陽極１４と陰極１３に接続
される。動作中に内部は温度が上昇し絶縁油１５の体積
が膨張するので、管容器１２の端面にベローズ８が備え
られている。The X-ray tube envelope 10 is made of hard glass or ceramics, and the inside thereof is evacuated to a high vacuum by a tip tube provided on the cathode side. After the evacuation is completed, the tip tube is melted. It is worn and sealed off. A positive high voltage is applied from the cable receptacle 4 to the rotating anode 14, and the rotating anode 14 rotates at high speed in a high vacuum due to the rotating magnetic field of the motor coil of the stator 2 provided in the insulating oil 15. Its target 1
An umbrella-shaped tungsten or the like is used for 4a, and a ball bearing is used for the bearing of the rotating mechanism. The cathode 13 is held by the cylinder, its position is deviated from the tube axis, and a negative high voltage is applied from the cable receptacle 4 and at the same time current is supplied to the filament. Tungsten is used for the filament, supported by a molybdenum anchor, insulated on one side by an insulator, and one attached to the focusing electrode. Insulating oil 15 is enclosed inside the tube container 12, the anode holding portion 7 and the cathode holding portion 6 are provided inside, and the X-ray tube 1 is held therein. Then, the rotating part of the rotary anode 14 is set at a position corresponding to the stator 2, and at the same time, the X-ray emission direction is set so as to correspond to the X-ray emission window 3. Then, the lead wire from the cable receptacle 4 is connected to the rotating anode 14 and the cathode 13. During operation, the temperature rises inside and the volume of the insulating oil 15 expands, so the bellows 8 is provided on the end surface of the pipe container 12.
【００１３】Ｘ線放射窓３は、Ｘ線を外部に照射するた
めに管容器１２に押え板３ａによって取付けられ、Ｘ線
に対して耐性を有し、Ｘ線透過性の良い樹脂製の窓であ
る。そして、本発明の回転陽極Ｘ線管装置のＸ線放射窓
３は、内側にアース電位の鉛製や導電塗料のマスク９を
配置し、Ｘ線管外囲器１０に近接して、Ｘ線管焦点幅方
向に曲面形状を有した凹部１１が設けられた樹脂製の窓
である。従来の図３に示す回転陽極Ｘ線管装置のＸ線管
外囲器１０は硬質ガラス製で、Ｘ線放射窓１６は耐Ｘ線
の良い樹脂で製作されており、これはＸ線をよく透過す
るとともに高電圧に耐え得るように絶縁性を持たせたも
のである。しかし、このような構成では、Ｘ線管１に高
電圧が印加された瞬間などにＸ線管外囲器１０の内面に
おける電位分布がきわめて不安定になりやすい。これ
は、Ｘ線管外囲器１０のみならずＸ線放射窓１６にも電
荷がたまり安定するまでに少なくとも数ｍｓｅｃの時間
を要するためである。このような流動的な電位分布は微
小放電につながり、さらにこれがトリガーとした大放電
を発生しやすくしている。このため、Ｘ線放射窓１６の
内側にマスク１７を配置している。このマスク１７は、
導電性のもので作られ、電位的にはアース電位とされ、
鉛、アルミニウム等が使われている。また、Ｘ線放射窓
１６自体はＸ線透過を考慮して樹脂製としている。しか
し、ターゲット１４ａから放射されるＸ線は、硬質ガラ
ス製のＸ線管外囲器１０の壁を透過し、絶縁油１５を透
過し、樹脂製のＸ線放射窓１６を透過して外部に照射さ
れる。これらの各部でＸ線は散乱・減衰して吸収され、
固有ろ過によってＸ線スペクトル特性が低エネルギー領
域で低下し、有効にＸ線を利用するということができな
い。そのため、この固有ろ過値をできるだけ小さくする
ために、本発明の回転陽極Ｘ線管装置のＸ線放射窓３
は、図２に示すように、Ｘ線管外囲器１０側に近接し
て、絶縁油１５の層を減らし、Ｘ線管１の幅方向に関し
ても周辺部分の絶縁油１５の層が厚くならないように、
Ｘ線管焦点幅方向に曲面形状を有した凹部１１が設けら
れている。これによりＸ線管外囲器１０とＸ線放射窓３
間の隙間（絶縁油１５）が小さくなり、固有ろ過値を小
さくすることができる。The X-ray radiating window 3 is attached to the tube container 12 by a holding plate 3a for irradiating X-rays to the outside, is made of resin having resistance to X-rays and good X-ray transparency. Is. The X-ray emission window 3 of the rotating anode X-ray tube device of the present invention has a mask 9 made of lead or conductive paint having a ground potential inside, and is placed in the vicinity of the X-ray tube envelope 10 for X-ray irradiation. This is a resin window provided with a concave portion 11 having a curved shape in the tube focal width direction. The X-ray tube envelope 10 of the conventional rotating anode X-ray tube apparatus shown in FIG. 3 is made of hard glass, and the X-ray radiation window 16 is made of a resin having good resistance to X-rays. It is transparent and has an insulating property so that it can withstand a high voltage. However, with such a configuration, the potential distribution on the inner surface of the X-ray tube envelope 10 is likely to be extremely unstable at the moment when a high voltage is applied to the X-ray tube 1. This is because it takes at least several msec until the electric charge accumulates not only in the X-ray tube envelope 10 but also in the X-ray emission window 16 and becomes stable. Such a fluid potential distribution leads to a minute discharge, which further facilitates the generation of a large discharge triggered. Therefore, the mask 17 is arranged inside the X-ray radiation window 16. This mask 17
It is made of conductive material and is electrically grounded.
Lead, aluminum, etc. are used. The X-ray radiation window 16 itself is made of resin in consideration of X-ray transmission. However, the X-rays emitted from the target 14a pass through the wall of the X-ray tube envelope 10 made of hard glass, the insulating oil 15, the resin X-ray emission window 16, and the outside. Is irradiated. X-rays are scattered and attenuated and absorbed in each of these parts,
Due to the inherent filtration, the X-ray spectrum characteristics are deteriorated in the low energy region, and it is impossible to effectively use the X-rays. Therefore, in order to make this intrinsic filtration value as small as possible, the X-ray emission window 3 of the rotating anode X-ray tube device of the present invention is used.
As shown in FIG. 2, the insulating oil 15 layer is reduced near the X-ray tube envelope 10 side, and the insulating oil 15 layer in the peripheral portion does not become thick in the width direction of the X-ray tube 1. like,
A concave portion 11 having a curved surface shape is provided in the focal width direction of the X-ray tube. Thereby, the X-ray tube envelope 10 and the X-ray emission window 3
The gap (insulating oil 15) between them is reduced, and the specific filtration value can be reduced.
【００１４】次に、回転陽極Ｘ線管装置の動作について
説明する。まず、ステータ２の電磁コイルに電流を流し
回転陽極１４を高速で回転させ、陰極１３のフィラメン
トに加熱電流を流す。そして、Ｘ線制御器から高電圧発
生装置を制御して、陰極１３に負の高電圧を、回転陽極
１４に正の高電圧を印加する。そのときＸ線管１の陰極
１３と回転陽極１４との間の静電容量、及び陰極１３と
アース電位の管容器１２との間、回転陽極１４と管容器
１２との間には、Ｘ線管外囲器１０のガラス絶縁物と絶
縁油１５が存在し、静電容量が存在するので、初期の電
圧立ち上がり時には高電圧が印加された瞬時に、その波
形は上記静電容量に相当するチャージ分によってなまっ
た波形になる。そして、陰極１３から熱電子が飛び出
し、回転陽極１４のターゲット１４ａに衝突すると、Ｘ
線を発生するが、それ以外に２次電子や反射電子も発生
する。その二次電子及び反射電子は再びターゲット１４
ａに衝突するものもあるが、一部はＸ線管外囲器１０の
内壁にチャージアップする。その電荷に対してＸ線管外
囲器１０の外面に、正の電荷をもったものが誘起され
る。本実施例ではＸ線放射窓３の内側に、アース電位を
形成するマスク９が設けられているので、Ｘ線管外囲器
１０の内壁にチャージアップする電荷は、安定して定在
する。従来のような樹脂製のＸ線放射窓１６のみであれ
ば、不安定な状態でＸ線管外囲器１０の内壁で電荷が浮
遊移動し、Ｘ線管外囲器１０の内壁にスパッタしたフィ
ラメントのタングステン飛散膜も加わって浮遊電位とな
り、電荷を貯めて放電を誘発する。その誘発された放電
によって、残留ガスのイオンがフィラメントの表面をた
たき、フィラメントからタングステンをさらに蒸発さ
せ、フィラメントの寿命をさらに低下させていた。ま
た、その周辺の電界強度が刻々と変化して、電荷の消滅
と発生が繰り返され、小さな放電が発生し、それによっ
て大放電を誘起しＸ線管１を故障させていた。本発明で
はＸ線管外囲器１０の内壁の電荷は、外部の一様なアー
ス電位によって定在するので、安定してＸ線管１を動作
させることができる。そして、Ｘ線放射窓３に、Ｘ線管
外囲器１０側に近接してＸ線管焦点幅方向に曲面形状を
有した凹部１１が設けられており、Ｘ線管外囲器１０と
Ｘ線放射窓３間の隙間（絶縁油１５）が小さくなり、Ｘ
線の散乱・減衰による固有ろ過値を小さくすることがで
き、低エネルギー領域の低減の少ないＸ線スペクトルを
外部に照射することができる。Next, the operation of the rotary anode X-ray tube device will be described. First, a current is passed through the electromagnetic coil of the stator 2 to rotate the rotating anode 14 at high speed, and a heating current is passed through the filament of the cathode 13. Then, the X-ray controller controls the high voltage generator to apply a negative high voltage to the cathode 13 and a positive high voltage to the rotating anode 14. At that time, the capacitance between the cathode 13 and the rotating anode 14 of the X-ray tube 1 and the X-rays between the cathode 13 and the tube container 12 at the ground potential and between the rotating anode 14 and the tube container 12 are considered. Since the glass insulator of the envelope 10 and the insulating oil 15 are present and the electrostatic capacity is present, the waveform thereof has a charge corresponding to the electrostatic capacity at the moment when the high voltage is applied at the initial voltage rise. The waveform becomes blunt depending on the minute. Then, when thermoelectrons fly out from the cathode 13 and collide with the target 14a of the rotating anode 14, X
Lines are generated, but secondary electrons and backscattered electrons are also generated. The secondary electrons and backscattered electrons are returned to the target 14 again.
Some of them collide with a, but some of them are charged up on the inner wall of the X-ray tube envelope 10. A charge having a positive charge is induced on the outer surface of the X-ray tube envelope 10 with respect to the charge. In the present embodiment, since the mask 9 that forms the ground potential is provided inside the X-ray radiation window 3, the electric charge that is charged up on the inner wall of the X-ray tube envelope 10 is stable and stable. If only the conventional X-ray radiation window 16 made of resin is used, the charges float and move on the inner wall of the X-ray tube envelope 10 in an unstable state and spatter on the inner wall of the X-ray tube envelope 10. The tungsten scattering film of the filament is also added to create a floating potential, which accumulates charges and induces discharge. The induced discharge caused the residual gas ions to strike the surface of the filament, further evaporating the tungsten from the filament, further reducing the life of the filament. In addition, the electric field strength around the periphery of the X-ray tube 1 changes every moment, and the disappearance and generation of electric charges are repeated, and a small discharge is generated, which induces a large discharge and damages the X-ray tube 1. In the present invention, the charges on the inner wall of the X-ray tube envelope 10 are settled by a uniform external ground potential, so that the X-ray tube 1 can be operated stably. The X-ray emission window 3 is provided with a concave portion 11 having a curved surface shape in the X-ray tube focal width direction in the vicinity of the X-ray tube envelope 10 side. The gap (insulating oil 15) between the line radiation windows 3 becomes smaller and X
The intrinsic filtration value due to the scattering / attenuation of rays can be reduced, and the X-ray spectrum with less reduction in the low energy region can be irradiated to the outside.
【００１５】[0015]
【発明の効果】本発明の回転陽極Ｘ線管装置は上記のよ
うに構成されており、回転陽極Ｘ線管の管容器に設けら
れたＸ線放射窓の内側に、アース電位部材を配置し、そ
のアース電位部材よりＸ線管外囲器に近接して絶縁物の
Ｘ線放射窓に、Ｘ線管焦点幅方向に曲面形状の凹部を設
けているので、Ｘ線放射窓近傍もアース電位になり、Ｘ
線管外囲器のガラスバルブ内外表面に安定した電位分布
が形成され、微小放電、さらには大放電の発生を抑制す
ることができ、Ｘ線管の寿命を延ばすことができる。そ
して、絶縁物のＸ線放射窓の凹部が、Ｘ線管外囲器に一
様により近接して設けられているので、絶縁油によるＸ
線の散乱・減衰が少なくなり、固有ろ過値が小さくな
り、低エネルギー領域のＸ線スペクトルも有効に利用す
ることができる。The rotary anode X-ray tube device of the present invention is constructed as described above, and the ground potential member is arranged inside the X-ray radiation window provided in the tube container of the rotary anode X-ray tube. Since a curved concave portion is provided in the X-ray emission window of the insulator in the vicinity of the X-ray tube envelope from the earth potential member, a curved surface-shaped recess is provided in the X-ray tube focal width direction. Becomes X
A stable potential distribution is formed on the inner and outer surfaces of the glass bulb of the envelope of the X-ray tube, and it is possible to suppress the generation of minute discharges and even large discharges, and it is possible to extend the life of the X-ray tube. Since the recess of the X-ray radiation window of the insulator is provided even closer to the X-ray tube envelope, the X-ray emission of the insulating oil
X-ray spectra in the low energy region can be effectively used because the scattering / attenuation of rays is reduced, the intrinsic filtration value is reduced.
【図１】 本発明の回転陽極Ｘ線管装置の一実施例を示
す図である。FIG. 1 is a diagram showing an embodiment of a rotary anode X-ray tube device of the present invention.
【図２】 本発明の回転陽極Ｘ線管装置のＸ線放射窓部
の断面構造を示す図である。FIG. 2 is a diagram showing a cross-sectional structure of an X-ray emission window portion of the rotary anode X-ray tube device of the present invention.
【図３】 従来の回転陽極Ｘ線管装置を示す図である。FIG. 3 is a view showing a conventional rotary anode X-ray tube device.
【図４】 従来の回転陽極Ｘ線管装置のＸ線放射窓部の
断面構造を示す図である。FIG. 4 is a view showing a cross-sectional structure of an X-ray emission window portion of a conventional rotary anode X-ray tube device.
１…Ｘ線管 ２…ステータ ３、１６…Ｘ線放射窓 ３ａ…押え板 ４…ケーブルレセプタクル ５…防護鉛 ６…陰極保持部 ７…陽極保持部 ８…ベローズ ９、１７…マスク １０…Ｘ線管外囲器 １１…凹部 １２…管容器 １３…陰極 １４…回転陽極 １４ａ…ターゲット １５…絶縁油 1 ... X-ray tube 2 ... Stator 3, 16 ... X-ray radiation window 3a ... Holding plate 4 ... Cable receptacle 5 ... Protective lead 6 ... Cathode holding part 7 ... Anode holder 8 ... Bellows 9, 17 ... Mask 10 ... X-ray tube envelope 11 ... Recess 12 ... Tube container 13 ... Cathode 14 ... Rotating anode 14a ... target 15 ... Insulating oil
───────────────────────────────────────────────────── フロントページの続き (72)発明者 原野 稔 京都市中京区西ノ京桑原町１番地 株式会 社島津製作所内 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Minoru Harano 1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association Inside the Shimadzu factory
Claims (2)
保持部によって保持され、絶縁物からなるＸ線管外囲器
の高真空中に、高速回転する傘状の陽極と、陰極とを対
向配置した回転陽極Ｘ線管を備え、この回転陽極Ｘ線管
から放射するＸ線を、前記管容器に設けられたＸ線放射
窓から外部に照射する回転陽極Ｘ線管装置において、前
記Ｘ線放射窓の内側にアース電位部材を配置し、前記Ｘ
線放射窓に前記アース電位部材よりＸ線管外囲器に近接
して凹部を設けたことを特徴とする回転陽極Ｘ線管装
置。1. An umbrella-shaped anode, which is held in an insulating oil inside a tube container by an anode holding part and a cathode holding part and rotates at a high speed in a high vacuum of an X-ray tube envelope made of an insulating material, and a cathode. In a rotary anode X-ray tube device comprising: a rotary anode X-ray tube in which and are opposed to each other, and irradiating X-rays emitted from the rotary anode X-ray tube to the outside from an X-ray emission window provided in the tube container. A ground potential member is arranged inside the X-ray radiation window,
A rotary anode X-ray tube device, wherein a recess is provided in the radiation window nearer to the X-ray tube envelope than the ground potential member.
焦点幅方向に曲面としたことを特徴とする請求項１記載
の回転陽極Ｘ線管装置。2. The rotary anode X-ray tube device according to claim 1, wherein the recess provided in the X-ray emission window is a curved surface in the focal width direction of the X-ray tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001383925A JP3760858B2 (en) | 2001-12-18 | 2001-12-18 | Rotating anode X-ray tube device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001383925A JP3760858B2 (en) | 2001-12-18 | 2001-12-18 | Rotating anode X-ray tube device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003187729A true JP2003187729A (en) | 2003-07-04 |
| JP3760858B2 JP3760858B2 (en) | 2006-03-29 |
Family
ID=27593793
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001383925A Expired - Fee Related JP3760858B2 (en) | 2001-12-18 | 2001-12-18 | Rotating anode X-ray tube device |
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| Country | Link |
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| JP (1) | JP3760858B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008536284A (en) * | 2005-04-19 | 2008-09-04 | スンチェ・ハイテック・カンパニー・リミテッド | Flexible soft X-ray ionizer |
| JP2014143089A (en) * | 2013-01-24 | 2014-08-07 | Jobu:Kk | X-ray generator |
-
2001
- 2001-12-18 JP JP2001383925A patent/JP3760858B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008536284A (en) * | 2005-04-19 | 2008-09-04 | スンチェ・ハイテック・カンパニー・リミテッド | Flexible soft X-ray ionizer |
| JP2014143089A (en) * | 2013-01-24 | 2014-08-07 | Jobu:Kk | X-ray generator |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3760858B2 (en) | 2006-03-29 |
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