201138556 六、發明說明： 【發明所屬之技術領域】 本發明關於一種平坦輸出響應透射型X射線管，其 中，增加施加至該管的電壓時，在一些給定X射線能量 處量測X射線強度，來自透射型X射線管的輸出光譜沒 有改變。 【先前技術】 越來越多的需求在於使用X輻射同時量測樣品內各 種危險材料的濃度，以提供高速、低成本、和非常準確的 量測。例如在無基礎X輻射量測多種材料的濃度，有全 球性的問題。該X輻射和螢光量測相干涉。 現有的X射線管要求多種樣品暴露在不同的管電壓 和不同的濾光結構以提供此等量測，特別是當在RoHS要 件中，以同時量測鎘和其他有毒材料。 所需要的是：能以單一管和濾光器組態及單一量測， 同時提供高速、高準確度地量測多種元素。 【發明內容】 本發明揭露一種透射型X射線管。該透射型X射線 管包含：排空的殼體；陽極，設置在該殼體內，該陽極包 括在末端窗上之至少一薄箔的靶；陰極，設置在殻體內， 該陰極發射電子，該等電子沿著該殼體內的電子束路徑行 進，以撞擊在該陽極的一點（spot )內，並產生X射線束 -5- 201138556 ，該χ射線束經由該末端窗而離開該殻體；和電源’連 接至該陰極，該電源提供選定的電子能量，以產生不同光 子能量之χ射線光譜；其中，在至少一界定能量帶內之 韌致輻射光子的總數目不會隨著施加在該陽極和陰極之間 數千伏特之電壓的增加而明顯地增加。 較佳地，該薄箔的厚度在〇.〇5和2微米之間。 較佳地，選擇性地施加濾光器，以藉由按比例地吸收 在較低能量的更多X射線光子而改變X射線的該光譜’ 以產生來自該管的輸出光譜。 較佳地，該數千伏特是30 kVp。 較佳地，該數千電子伏特是40 kVp。 較佳地，該界定能量帶是10 keV或更少。 較佳地，該界定能量帶是20 keV或更少。 較佳地，在該增加的數千電子伏特中，在該界定能量 帶內之韌致輻射光子的該總數目，其離開平均數目的變化 不會超過5 %。 較佳地，在整個該增加的數千電子伏特中，在該界定 能量帶內之韌致輻射光子的該總數目，其離開該能量帶內 之平均數目的變化不會超過10%。 較佳地，該箔含有金屬元素，該金屬元素選自銃、鈦 、鉻、鐵、鎳、釔、鉬、铑、鈀、乱、餌、錶、鏡、鉅、 鎢、銶、鈾、金其中之一。 較佳地，該X射線管用於產生使用在X射線螢光分 析中的X射線。 -6 - 201138556 較佳地’該X射線管用於產生使用於roHS導向中相 關檢測元素的X射線。 較佳地，有產生X射線之材料的薄膜被沉積在該末 端窗的大氣側面上’且產生該沉積材料的低能量X射線 特徵。 【實施方式】 〇 開放的透射型管通常被使用於電子電路的成像和其他 高解析度的應用。封閉的管被密封具有真空，然而開放的 或「抽吸減壓（pump down)」的管具有持續地附接的真 空泵。當管經常被使用，而允許頻繁地更換在作業中可能 損壞的管零件時’該泵可抽吸成真空。爲了本發明的目的 ’除非另有聲明，否則透射型管包括開放的和封閉的透射 型管兩者。 圖1的透射型管包括排空的殼體6、和設置在殼體一 〇 端且一面暴露於大氣的陽極1°Χ射線靶箔2沉積在陽極 1之末端窗3 8上。例如冷的或電性加熱的陰極3發射電 子’該等電子被沿著電子束路徑4加速，並撞擊陽極靶而 產生X射線8。雖然此處顯示的是電性加熱的陰極，但是 可使用許多不同陰極組態其中任一者來取代。電源36連 接在陰極和陽極之間，以提供對電子束的加速力。所產生 的X射線穿過末端窗離開X射線管，該末端窗密封X射 線管隔離大氣。末端窗通常是由具有低原子數（Ζ )的材 料製成，例如鈹、銅、或鋁。選擇性的聚焦杯5將電子束 201138556 聚焦至靶上的一點（spot )上。取決於所要求的聚焦度數 ，可負性地、正性地、或中性地電偏壓聚焦杯。該點的最 大尺寸稱爲焦點尺寸或點尺寸。輸出的X射線含有靶材 料所獨有的韌致輻射（或制動輻射）和特徵線輻射兩者。 在本發明的較佳實施例中，選擇靶箔的厚度約小於2微米 。圖1是透射型中各元件所具有之功能的的簡單示意代表 圖，其並無意將該等功能之任一者的特定實施例限制於示 意圖。雖然爲了例示，所以圖1例示封閉的X射線管， 但是也可使用開放的或抽吸減壓的管。該封閉的X射線 管在生產中被密封。該開放的或抽吸減壓的管其管內側的 真空是在管的作業期間內以真空泵持續地排空。 圖2是供參考用且示意地代表反射型X射線管，其 包括排空的殼體。殼體內設置陰極9和陽極7。陽極7包 括沉積在基材上的X射線靶。當X射線撞擊陽極時，基 材移除所產生的熱。當陰極被加熱時，電子從陰極9發射 。電源3 6連接在陰極和陽極之間以提供電場。電場將來 自陰極的電子沿著電子束路徑10加速，並撞擊在陰極的 —點（spot )內，而產生X射線束8。然後，X射線穿過 側窗1 1離開管。反射型管從電子束撞擊之靶的相同側和 從X射線靶內所產生的X射線獲得所產生的X射線。 除非其他特別聲明的X射線管，否則以具有鎘締（ CdTe)感測器1毫米（mm)厚和10密爾（mil)的鈹（ Be)濾光器之AmptekModelXR-100取得光譜的資料。感 測器被放置在離X射線管1米（m)的距離處，且鎢視準 ** 8 - 201138556 儀具有設置在感測器前面之1 00微米（M m )直徑的視準 儀孔。管的電流固定在50微安培’且超過3分鐘的測試 期間蒐集資料。 爲了清晰，定義在本發明全文中會用到的一些術語是 有用的。「能（量）帶（energyband)」是任意定義的連 續帶，其是由X射線管產生的X射線能量’且以kev表 示。在給定能量帶中之「韌致輻射光子的總數」定義爲： 0 在給定能量帶中撞擊X射線光子感測器之不含有特徵輻 射的光子總數。該感測器例如CdTe、或ZCdTe、或類似 的感測器。藉由積分以光子數表示的強度對以keV表示的 X射線能量之曲線下方的面積來計算光子的總數。該X射 線能量是由X射線管所發射。圖1 3中，在曲線下變暗的 區域1 3例示在從20 keV至50 keV之能量帶內的「韌致 輻射光子總數」。在光子強度對X射線能量之曲線下方 的陰影區域13，提供本發明之透射型管在從20 keV至50 〇 keV之能量帶內的「韌致輻射光子總數」之曲線圖例示， 該透射管具有厚度0.75微米的鉬箔陽極靶和施加100 kVp 的加速電壓。此特殊的能量帶有總數爲44220的光子數。 在此能量帶中，鉅沒有產生重要的特徵線X輻射。雖然 此例示使用钽做爲靶材料’但是靶材料可爲許多適於用作 透射型X射線靶之不同材料其中任一者，該等材料包括 (但不限於）Sc、Ti、Cr、Fe、Ni、Y、Mo、Rh、Pd、 G d ' E r ' T m、Y b、T a、W、r e、P t、或 A u。 爲了供參考’圖4和5顯示當加速電壓逐漸增加時， ~ 9 - 201138556 反射型X射線管所產生之X射線的曲線代表圖。圖4是 使用反射型X射線管來量測，該管通常使用在電路板之 非破壞試驗（NDT )的X射線成像中。此管的靶材料是鎢 。1 4、1 5、1 6、1 7代表從光子感測器所產生且以數目表 示之X射線的強度’該強度爲所產生之X射線以keV表 示之能量的函數。14代表管的電壓爲30 kVp，15代表管 的電壓爲40 kVp，16代表管的電壓爲50 kVp，17代表管 的電壓爲60 kVp。可以看到，當增加管電壓時，韌致輻 射的峰値移動至較高的能量，大幅改變光譜。丨4至I 7例 示在許多增加管電壓中之每一者所進行的量測。圖5是當 電壓從50 kVp至150 kVp以20 kVp的增量增加時，典型 微聚焦反射型X射線管的輸出。注意到，當增加管電壓 時，在光譜中韌致輻射能量的峰値移動了。在1 3 0 k V p和 1 5 0 kVp時，通過用於蒐集光譜資料之儀器的鎢視準儀的 X射線’在60 keV以上，感測器讀値有可觀的扭曲變形 〇 對照之下，圖6是透射型管所產生之X射線的曲線 代表圖’該管具有4微米厚的鎢靶箔，使用在施加從40 kVp至80 kVp的低管電壓。透射型管的一般特色是韌致 輻射能量以keV表示的峰値不會隨著管電壓的增加而增加 〇 反射型X射線管顯示兩個特色，該等特色將反射型 管和本發明的X射線管清楚地分離。當增加施加的管電 壓時’韌致輻射的峰値移動至越來越高的能量。當施加的 -10- 201138556 電壓增加時，韌致輻射光子的總數在輸出χ射線能量 整個光譜都增加。這些特色限制使用該等X射線管來 決X射線螢光和X射線成像市場中的問題。 在本發明的較佳實施例中，當在透射型χ射線管 使用非常薄的靶箔時，施加高電壓跨越陽極和陰極，細 被活化以發射電子束撞撃靶，且增加施加的電壓。即使 幅增加施加於管的加速電壓，在明確定義之能量帶內的 ζ) 致輻射之光子總數也沒有實質地增加。圖7、8、9、1 〇 示本發明之透射型管此獨特的方面。圖7是從該管輸出 光譜’該管具有厚度2微米的箔靶，且管的電壓以 kVp的間隔從90 kVp至120 kVp變化。注意到，在約 至50 keV的較低X射線能量處，1〇〇、11〇、120 kVp 曲線光譜實質地相同。使用在100、110、120 kVp電壓 此管’顯現本發明的獨特技術。雖然選擇鉅當作靶材料 但是也可使用可被沉積在末端窗上呈非常薄之薄膜的任 〇 材料。 類似地’圖8顯示本發明之透射型管的輸出光譜， 管具有厚度1微米的鉬靶箔，且管的電壓以1〇 kVp的 隔從70 kVp變化至1〇〇 kVp。當電壓從80 kVp增加 100 kVp時’在約12 keV至40 keV的能量帶內，韌致 射光子的總數變化很少，再度顯示本發明透射型管的此 特方面。圖9進一步例示本發明使用厚度0.75微米之 箔陽極的X射線管’該管的電壓以1〇 kVp的間隔從 kVp變化至80 kVp。圖10例示本發明使用厚度〇·3微 之 解 中 絲 大 韌 例 的 10 12 的 的 » 何 該 間 至 輻 獨 鉬 40 米 -11 - 201138556 之鉬箔的X射線管，該管的電壓以10 kVp的間隔從40 kVp變化至70 kVp。雖然不包括厚度4微米之鉬靶箔的 資料，但是很明顯地，藉由增加管的電壓至約1 1 〇 kVp至 160 kVp的範圍，在從約12至40 keV的能量帶內，韌致 輻射光子的總數不會大幅地增加。 下文的表1是由四個不同的X射線管使用厚度0.3、 0.75、1、和2微米的钽靶箔所進行的量測摘要。該資料 的目的在於顯示本發明的一般顯著特色。在解釋此等資料 時’試驗誤差、和在X射線管結構及精度中的正常變化 ，必須全部考慮。使用Amptek Model XR-100以厚度1 毫米的CdTe感測器和1〇密爾（mil )的鈹濾光器取得該 等資料。感測器被放置在離X射線管1米（m )的距離處 ，且鎢視準儀具有設置在感測器前面之1 0 0微米直徑的視 準儀孔。管的電流保持恆定在50微安培，且管的電壓在 如上述的表1所示者變化。進行光譜量測，且量測和記錄 從13 keV至27 keV之曲線下的面積。任意選擇13-27 keV能量帶以大致例示本發明之管的輸出。可選擇較小或 較大的能量帶，而得不同的結果。一般而言，當增加靶箔 的厚度’管電壓（其代表韌致輻射的光子總數目不會因爲 管電壓之增加而大幅增加）通常移動至較高的電壓。0.3 微米的鉅靶管在40和70 kVp之間的光子平均數目爲 32851，且從平均數的最大變化爲1559個或4.7 %的最 大變化。0.75微米的鉅靶管在40和80 kVp之間的光子平 均數目爲3 44 12’且從平均數的最大變化爲578個或±1.6 -12- 201138556 %的最大變化。1微米的鉬靶管在8 0和1 0 0 kVp之間的 光子平均數目爲 74943個，且從平均數的最大變化爲 4163個或5.5%的最大變化。2微米的钽靶管在90和120 kVp之間的光子平均數目爲1 09784，且從平均數的最大 變化爲1631或1.4 %。 0.3微米钽(Ta) 0.75微米鉅 1微米鉬 2微米鉅 40kVp 31,680 34,096 50kVp 32,332 34,576 60kVp 32,982 34,384 70kVp 34,410 34,016 80kVp 34,990 70,780 90kVp 74,107 108,152 lOOkVp 76,560 110,238 llOkVp 78,326 110,394 120kVp 110,350BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a flat output responsive transmission type X-ray tube in which X-ray intensity is measured at a given X-ray energy when a voltage applied to the tube is increased. The output spectrum from the transmission type X-ray tube did not change. [Prior Art] An increasing demand is to simultaneously measure the concentration of various hazardous materials in a sample using X-radiation to provide high-speed, low-cost, and very accurate measurements. For example, in the absence of basic X-radiation measurements of the concentration of multiple materials, there is a global problem. The X-radiation and the fluorescence measurement interfere with each other. Existing X-ray tubes require multiple samples to be exposed to different tube voltages and different filter structures to provide such measurements, particularly when used in RoHS requirements to simultaneously measure cadmium and other toxic materials. What is needed is a single tube and filter configuration and a single measurement, while providing high speed, high accuracy measurement of multiple elements. SUMMARY OF THE INVENTION The present invention discloses a transmission type X-ray tube. The transmission type X-ray tube comprises: an evacuated housing; an anode disposed in the housing, the anode comprising at least one thin foil target on the end window; a cathode disposed in the housing, the cathode emitting electrons, the cathode Isoelectronics travel along the electron beam path within the housing to impinge on a spot in the anode and generate an X-ray beam -5 - 201138556 through which the xenon ray beam exits the housing; and a power source 'connected to the cathode, the power source providing selected electron energy to produce a x-ray spectrum of different photon energies; wherein the total number of bremsstrahlung photons in at least one defined energy band does not follow the anode applied The increase in voltage of several thousand volts between the cathode and the cathode is markedly increased. Preferably, the thin foil has a thickness between 〇. 5 and 2 microns. Preferably, a filter is selectively applied to vary the spectrum of X-rays by proportionally absorbing more X-ray photons at lower energies to produce an output spectrum from the tube. Preferably, the thousands of volts is 30 kVp. Preferably, the thousands of electron volts is 40 kVp. Preferably, the defined energy band is 10 keV or less. Preferably, the defined energy band is 20 keV or less. Preferably, in the increased number of thousands of electron volts, the total number of bremsstrahlung photons within the defined energy band will not vary by more than 5% from the average number. Preferably, throughout the increased number of thousands of electron volts, the total number of bremsstrahlung photons within the defined energy band will vary by no more than 10% from the average number of bands within the energy band. Preferably, the foil contains a metal element selected from the group consisting of niobium, titanium, chromium, iron, nickel, niobium, molybdenum, niobium, palladium, chaos, bait, watch, mirror, giant, tungsten, tantalum, uranium, gold. one of them. Preferably, the X-ray tube is used to generate X-rays for use in X-ray fluorescence analysis. -6 - 201138556 Preferably the X-ray tube is used to generate X-rays for the relevant detection elements in the ROHS guide. Preferably, a film having X-ray generating material is deposited on the atmospheric side of the end window' and produces low energy X-ray characteristics of the deposited material. [Embodiment] 〇 Open transmissive tubes are commonly used for imaging and other high-resolution applications of electronic circuits. The closed tube is sealed with a vacuum, whereas the open or "pump down" tube has a continuously attached vacuum pump. When the tube is often used, allowing frequent replacement of tube parts that may be damaged during operation, the pump can be pumped into a vacuum. For the purposes of the present invention 'Transmissive tubes include both open and closed transmission tubes unless otherwise stated. The transmissive tube of Fig. 1 includes an evacuated housing 6, and an anode 1° ray target foil 2 disposed at one end of the housing and exposed to the atmosphere on one side, deposited on the end window 38 of the anode 1. For example, the cold or electrically heated cathode 3 emits electrons which are accelerated along the electron beam path 4 and strike the anode target to produce X-rays 8. Although an electrically heated cathode is shown here, it can be replaced with any of a number of different cathode configurations. A power source 36 is connected between the cathode and the anode to provide an acceleration force to the electron beam. The generated X-rays exit the X-ray tube through the end window, which seals the X-ray tube to isolate the atmosphere. The end window is typically made of a material having a low atomic number (Ζ), such as tantalum, copper, or aluminum. The selective focus cup 5 focuses the electron beam 201138556 onto a spot on the target. The focus cup can be electrically biased negatively, positively, or neutrally depending on the desired degree of focus. The maximum size of this point is called the focus size or point size. The output X-rays contain both bremsstrahlung (or brake radiation) and characteristic line radiation that are unique to the target material. In a preferred embodiment of the invention, the thickness of the target foil is selected to be less than about 2 microns. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a simplified schematic representation of the function of the various components of the transmissive type, and is not intended to limit the particular embodiment of any of these functions to the drawings. Although illustrated in FIG. 1 for a closed X-ray tube, an open or suction reduced pressure tube may be used. The enclosed X-ray tube is sealed during production. The open or suction reduced pressure tube has a vacuum inside the tube that is continuously evacuated by a vacuum pump during operation of the tube. Figure 2 is a reference and schematically representative of a reflective X-ray tube comprising an evacuated housing. A cathode 9 and an anode 7 are disposed in the casing. The anode 7 includes an X-ray target deposited on a substrate. When the X-ray strikes the anode, the substrate removes the heat generated. When the cathode is heated, electrons are emitted from the cathode 9. A power source 36 is connected between the cathode and the anode to provide an electric field. The electric field in the future accelerates electrons from the cathode along the electron beam path 10 and impinges on the spot of the cathode to produce an X-ray beam 8. The X-rays then exit the tube through the side window 1 1 . The reflective tube obtains the generated X-rays from the same side of the target against which the electron beam strikes and from the X-rays generated within the X-ray target. Spectroscopic data were obtained with an Amptek Model XR-100 with a cadmium (Be) filter having a cadmium (CdTe) sensor of 1 mm (mm) thickness and 10 mils, unless otherwise specifically stated. The sensor is placed at a distance of 1 m (m) from the X-ray tube, and the tungsten collimator ** 8 - 201138556 has a collimator hole of 100 μm (M m ) diameter disposed in front of the sensor . The tube current was fixed at 50 microamperes and data was collected during the test period of more than 3 minutes. For clarity, some terms that are used throughout the present invention are defined to be useful. The "energy band" is an arbitrarily defined continuous band which is an X-ray energy generated by an X-ray tube and is expressed in kev. The "total number of bremsstrahlung photons" in a given energy band is defined as: 0 The total number of photons that do not contain characteristic radiation in the X-ray photon sensor in a given energy band. The sensor is for example a CdTe, or ZCdTe, or a similar sensor. The total number of photons is calculated by integrating the area indicated by the photon number to the area under the curve of the X-ray energy expressed in keV. The X-ray energy is emitted by the X-ray tube. In Fig. 13, the region 1 3 which is darkened under the curve exemplifies the "total number of bremsstrahlung photons" in the energy band from 20 keV to 50 keV. Providing a graph of the "total number of bremsstrahlung photons" of the transmission tube of the present invention in an energy band from 20 keV to 50 〇 keV in the shaded region 13 below the curve of photon intensity versus X-ray energy, the transmission tube A molybdenum foil anode target having a thickness of 0.75 μm and an accelerating voltage of 100 kVp were applied. This particular energy carries a total number of photons of 44220. In this energy band, giant does not produce important characteristic line X radiation. Although this example uses germanium as the target material 'but the target material may be any of a variety of different materials suitable for use as a transmission type X-ray target, including but not limited to Sc, Ti, Cr, Fe, Ni, Y, Mo, Rh, Pd, G d ' E r ' T m, Y b, T a, W, re, P t, or A u. For reference, Figures 4 and 5 show graphical representations of the X-rays produced by the ~9 - 201138556 reflective X-ray tube as the accelerating voltage is gradually increased. Figure 4 is a measurement using a reflective X-ray tube that is typically used in X-ray imaging of non-destructive testing (NDT) of circuit boards. The target material for this tube is tungsten. 1 4, 1 5, 16 and 17 represent the intensity of the X-rays produced by the photon sensor and expressed in number. This intensity is a function of the energy of the generated X-rays expressed in keV. 14 represents a tube voltage of 30 kVp, 15 represents a tube voltage of 40 kVp, 16 represents a tube voltage of 50 kVp, and 17 represents a tube voltage of 60 kVp. It can be seen that when the tube voltage is increased, the peak of the bremsstrahlung radiation moves to a higher energy, which greatly changes the spectrum.丨4 to I7 illustrate the measurements made by each of a number of increased tube voltages. Figure 5 shows the output of a typical microfocus reflective X-ray tube as the voltage increases from 50 kVp to 150 kVp in increments of 20 kVp. It is noted that when the tube voltage is increased, the peak of the bremsstrahlung energy in the spectrum shifts. At 1 3 0 k V p and 1 50 kVp, the X-ray of the tungsten collimator passed through the instrument for collecting spectral data is above 60 keV, and the sensor reading has considerable distortion. Figure 6 is a graph of the X-ray generated by the transmission tube. The tube has a 4 micron thick tungsten target foil used to apply a low tube voltage from 40 kVp to 80 kVp. The general characteristic of the transmissive tube is that the peak of the bremsstrahlung energy expressed in keV does not increase with the increase of the tube voltage. The reflective X-ray tube shows two features, which are the reflective tube and the X of the present invention. The tube is clearly separated. When the applied tube voltage is increased, the peak of the bremsstrahlung moves to an increasingly higher energy. When the applied voltage of -10- 201138556 increases, the total number of bremsstrahlung photons increases over the entire spectrum of the output x-ray energy. These features limit the use of these X-ray tubes to solve problems in the X-ray fluorescence and X-ray imaging markets. In a preferred embodiment of the invention, when a very thin target foil is used in a transmissive X-ray tube, a high voltage is applied across the anode and cathode, the fine is activated to emit an electron beam against the target, and the applied voltage is increased. Even if the amplitude increases the acceleration voltage applied to the tube, the total number of photons emitted in the well-defined energy band does not increase substantially. Figures 7, 8, 9, and 1 show this unique aspect of the transmissive tube of the present invention. Fig. 7 is a foil target having a thickness of 2 μm from the tube output spectrum, and the voltage of the tube was varied from 90 kVp to 120 kVp at intervals of kVp. It is noted that at the lower X-ray energies of about 50 keV, the 1 〇〇, 11 〇, 120 kVp curve spectra are substantially the same. The use of this tube at 100, 110, 120 kVp voltages demonstrates the unique technology of the present invention. Although giant is chosen as the target material, any material which can be deposited on the end window as a very thin film can also be used. Similarly, Fig. 8 shows the output spectrum of the transmission type tube of the present invention, the tube having a molybdenum target foil having a thickness of 1 μm, and the voltage of the tube varying from 70 kVp to 1 〇〇 kVp at intervals of 1 〇 kVp. When the voltage is increased by 100 kVp from 80 kVp, the total number of tough photons varies little in an energy band of about 12 keV to 40 keV, again showing this particular aspect of the transmissive tube of the present invention. Figure 9 further illustrates an X-ray tube of the present invention using a foil anode having a thickness of 0.75 microns. The voltage of the tube varies from kVp to 80 kVp at intervals of 1 〇 kVp. Figure 10 illustrates an X-ray tube of the molybdenum foil of the present invention using a thickness of 〇·3 micros of the solution of 10 12 in the toughness of the 40--11 - 201138556, the voltage of the tube is The 10 kVp interval varies from 40 kVp to 70 kVp. Although data for a 4 micron thick molybdenum target foil is not included, it is apparent that by increasing the tube voltage to a range of about 1 〇kVp to 160 kVp, in an energy band from about 12 to 40 keV, the toughness The total number of radiated photons does not increase significantly. Table 1 below is a summary of measurements made from four different X-ray tubes using ruthenium target foils with thicknesses of 0.3, 0.75, 1, and 2 microns. The purpose of this document is to show the general salient features of the present invention. In interpreting such information, the test error, and normal variations in the structure and accuracy of the X-ray tube, must all be considered. This information was obtained using a Amptek Model XR-100 with a 1 mm thick CdTe sensor and a 1 mil mil filter. The sensor was placed at a distance of 1 m (m) from the X-ray tube, and the tungsten collimator had a 100 mm diameter calibrator hole disposed in front of the sensor. The current of the tube was kept constant at 50 microamperes and the voltage of the tube was varied as shown in Table 1 above. Spectral measurements were taken and the area under the curve from 13 keV to 27 keV was measured and recorded. The 13-27 keV energy band is arbitrarily selected to roughly exemplify the output of the tube of the present invention. Smaller or larger energy bands can be chosen to give different results. In general, when the thickness of the target foil is increased, the tube voltage (which represents the total number of photons of bremsstrahlung does not increase substantially due to the increase in tube voltage) typically moves to a higher voltage. The average number of photons between the 40 micron giant target tube at 40 and 70 kVp is 32,851, and the maximum change from the mean is 1559 or 4.7%. The average photon number of the 0.75 micron giant target tube between 40 and 80 kVp is 3 44 12' and the maximum change from the mean is 578 or ±1.6 -12 to 201138556%. The average number of photons between a 0 micron molybdenum target tube between 80 and 100 kVp was 74,943, and the maximum change from the mean was a maximum change of 4163 or 5.5%. The average number of photons between the 90 and 120 kVp of the 2 micron target tube is 1 09784, and the maximum change from the mean is 1631 or 1.4%. 0.3 micron yttrium (Ta) 0.75 micron giant 1 micron molybdenum 2 micron giant 40kVp 31,680 34,096 50kVp 32,332 34,576 60kVp 32,982 34,384 70kVp 34,410 34,016 80kVp 34,990 70,780 90kVp 74,107 108,152 lOOkVp 76,560 110,238 llOkVp 78,326 110,394 120kVp 110,350
表2包括從非本發明之兩個附加管的總韌致輻射的量 測。相較於使用5 0微安培之管電流所作之上述表1的量 測，表2使用3 75微安培的管電流強度量測非破壞性測試 (NTD )反射型X射線管。第二管是具有4微米厚度之钽 靶箔的透射型X射線管。 -13- 201138556 NTD，反射型 4微米，鉬 30kVp 94,268 40kVp 147,078 33,911 50kVp 194,959 54,036 60kVp 267,187 73,587 70kVp 96,335 80kVp 138,005 表2 表1和表2的比較提供了清楚的差異，本發明的管在 從1 3至27 kVp之間給定的X射線能量帶提供相對不變 的總韌致輻射。此外，反射型管沒有顯示可和本發明之透 射型管比較的能量帶。 可從許多可能的元素的任一者選擇靶箔材料。在圖7 、8、9、和1 0中，選擇鉬作爲靶材料。如同熟知此項技 藝者所熟知，鉬具有高原子數，其依比例產生較高的X 射線強度。此外，在5 7.524和65.21 keV的X射線能量 ，鉬的Κ-α和K-冷特徵線造成輸出中的顯著峰値。在大 部分的應用中，在具有光子能量之平坦強度響應中的此等 峰値，並不是限制使用本發明之管的議題。但是，在一些 應用中，消除或限制此等特徵能量峰値是有利的。在本發 明的一較佳實施例中，選擇靶材料和濾光參數’使得在管 的平坦輸出響應中沒有特徵能量峰値。當在陽極靶中產生 X射線的箔含有低原子數的元素（例如銃、鉻、鎳、鐵、 和銅、及其他）時，特徵Κ線在約1 0 keV以下，且從輸 -14- 201138556 出光譜消除此等K線峰値。此通常以X射線輸出強度爲 代價而完成。 雖然選擇單一靶材料來顯現本發明的現象，但是層積 的靶材料和含有超過單一種元素的靶材料可取代使用。在 本發明的一較佳實施例中，在單一靶上可使用多種靶材料 ’且可移動電子束撞擊本發明所希望的靶區段。本發明可 使用各種靶材料中的任一者。呈現在本發明之靶箔內的可 〇 能金屬元素的局部清單，可選自銃、鉻、鈦、鐵、鎳 '釔 、鉬、錯、鈀、I、餌、鏡、錶、鉅、鎮、銶 '鉑（白金 )、金。 在本發明的一較佳實施例中，需要約1 0 keV以下的 軟X射線，特別是在X射線螢光的應用。因爲末端窗必 須足夠厚以密封真空管，所以末端窗過濾掉大部分想要的 低能量X射線。因此當需要低能量特徵X射線時，藉由 包括濺鍍之多種方法中的任一者，可將產生此等低能量特 〇 徵線的材料沉積在末端窗的大氣側面上。此材料的典型厚 度可薄如0.05微米，厚至約2或3微米。靶內產生約1〇 keV以上之高能量X射線，通過末端窗，從沉積在末端窗 相反於真空管之側面上的材料，激發出螢光特徵輻射。因 爲可將產生低能量的材料設置在非常靠近產生X射線的 點（spot )’所以可將能量高效率地傳輸至低能量特徵X 射線。末端窗的厚度可爲薄如約50微米至許多毫米的任 一者’因爲幾乎沒有高能量X輻射會被末端窗變弱。雖 然鈹經常是末端窗材料的選擇，但是可以任何數目之低原 -15- 201138556 子數（z)的兀素取代使用’該元素的例子如銘、銅、駄 、或其合金。藉由改變沉積材料的厚度和撞擊該祀之電子 的加速電壓及電流’可選擇低能量特徵線的亮度。 在本發明的一實施例中’使用濾光器以吸收來自本發 明之透射型管的低能量輻射。圖II是具有0.3微米鉬祀 箔之管的輸出的曲線代表圖，19是沒有濾光的輸出光譜 ’ 20是使用厚度200微米之銅濾光器的光譜，21使用厚 度400微米之銅濾光器的光譜。管的電壓是50 kVp，且 管的電流是5 0微安培。在一般的螢光應用中，由待檢測 之元素的X射線管所產生之背景X輻射雜訊是特別地重 要。使用適當的濾光結構，可將在待量測之Κ- α能量的 背景雜訊減至最小。使用已濾光之輸出21來量測在約20 至23 keV範圍內具有特徵Κ- α線發射的元素，藉由在線 發射能量上方能量帶5至1 0 keV的部分來決定背景雜訊 。本發明的管提供在該能量帶內的光譜，當管的電壓增加 時，光譜在整個該能量帶內基本上是恆定的。增加管的電 壓會增加較高能量的X射線光子，其能增加待檢測之元 素的κ-α響應，而不會增加雜訊位準。此特色使得本發 明的管在X射線螢光分析的領域中特別有用。 本發明的透射型管可使用各種濾光結構，以改善市面 上之管的有用性。在圖12所示之本發明的一較佳實施例 中，具有厚度0.75微米鉅靶箔、且在120 kVp和管電流 50微安培作業、及外部12毫米厚錦爐光器之管的輸出X 輻射，會在從約25 keV至約90 keV的整個能量帶內產生 -16 - 201138556 輸出光譜，該輸出光譜基本上是恆定的，除了钽箔靶在 5 7.52 keV處的特徵K線18以外。輸出光譜的曲線代表 圖被具有60 keV以上之能量的1毫米厚CdTe感測器之經 文件證明的降低響應、來自鎢視準儀的假（spurious )輻 射、感測器的拖尾效應、和其他的試驗瑕疵所扭曲。雖然 本實施例使用2毫米的鋁濾光器，但是可使用許多不同輸 出濾光器結構中任一者，以提供熟悉該項技藝者所熟知之 () 基本上平坦的輸出管。當光譜數據被使用於X射線成像 時，該輸出特別有用。對受檢查物體的X射線輸出，在 25和90 keV的能量之間，基本上是階梯函數。 在本發明的另一較佳實施例中’圖13、14提供使用 本發明之兩透射型管所取的能量光譜的曲線代表圖，該等 透射型管具有標準BCR-680 RoHS樣品，該樣品在離管的 末端5厘米（cm )的距離被量測。相較於反射型X射線 管，因爲透射型管提供非常廣的圓錐形角度（圖1中的8 〇 )，所以螢光樣品可被放置得更接近X射線管。1毫米 CdTe感測器放置在一條線上’該條線垂直於X射線的點 (spot)和BCR-680樣品的中心之間且鄰近於BCR-680 樣品容器之外側的一條線。歐洲R〇HS規格要求五種元素 同時螢光量測。該五種元素包括鎘 '鉛、汞、溴、和鉻。 使用具有厚度〇 . 3微米的鉬箔靶和〇 . 4毫米的銅濾光器之 透射型管而獲得圖13。19、20、21分別代表該管在管電 壓 50 kVp、60 kVp、70 kVp的X射線光譜。使用厚度 〇 · 7 5微米的钽箔靶和相同的濾光器而獲得圖1 4。2 2代表 -17- 201138556 鎘所產生的特徵X輻射。施加5〇 kVp、60 kVp、70 kVp (分別爲圖中的23、24、25 )的管電壓以獲得光譜。雖 然光譜顯示在鎘之Κ-α:能量的背景雜訊增加，但是該雜 訊是所使用之CdTe感測器的拖尾效應所產生的感測器雜 訊，且背景雜訊比所顯示者低很多。當管電壓增加時，信 號也增加許多。此結果的重大優點是允許使用較高的管電 壓和較低的管電流’以改善螢光量測的速率和準確性。在 此特別的例子中，將管電流減少至2 0微安培，允許減少 管加熱、減少點（spot )尺寸、和較長的細絲壽命，使用 本發明之X射線管於螢光分析之全部主要商業優點。因 爲X射線強度輸出隨著增加的管電壓而平坦，所以鄰近 鎘之K線的X射線管輸出之強度，不會隨著所施加的管 電壓之增加而增加，確保低背景輻射。濾光器的厚度和材 料是選自許多可能濾光器材料（包括但不限於鋁和銅）中 任一者，所以來自受檢樣品的Compton Scattering不會大 幅干涉樣品所產生之相關特徵線的量測。 【圖式簡單說明】 圖1是典型的透射型X射線管的示意圖。 圖2是典型的反射型X射線管的示意圖。 圖3來自X射線管之典型X射線光譜的示意圖’其 顯示20和50 keV之間的韌致輻射光子能量。圖3用於界 定在給定的能量帶內的總數目’陰影區域13代表在20 kev和50 keV能量之間，管所發射的光子總數目。此特 -18- 201138556 殊能量帶和測試條件有4 4 2 2 0個光子數。 圖4是顯示典型反射型χ射線管之光譜輸出的示意 圖。此是使用在非破壞試驗（NDT)成像中的典型反射型 X射線管。當電壓從30 kVp增加至60 kVp時，可看到韌 致輻射峰値移動至較高的能量。當增加管電壓時，大幅改 變光譜。管電流是5 0微安培’且使用1 〇 〇微米鎢視準儀 在1米處和3分鐘的測試期間量測光譜。 〇 圖5是反射型X射線管從50 kVp至150 kVp之施加 管電壓的光譜示意圖。當電壓從50 kVp至1 50 kVp且以 20 kVp的增量增加時的微聚焦反射型管。注意，當管電 壓增加時，韌致輻射能量的峰値在光譜中移動。 圖6是具有厚度4微米之钽（Ta)靶的透射型χ射 線管之輸出光譜示意圖。當電壓從40 kVp至80 kVp之 4Ta光譜。管電流50微安培。以keV表示之透射型管韌 致輻射能量峰値的特徵，不會隨著管電壓的增加而增加。 Ο 圖7是具有厚度2微米之钽靶的透射型X射線管之 輸出光譜示意圖。從90 kVp至120 kVp且以10 kVp爲間 隔之2Ta光譜。注意，1〇〇、110、120 kVp的光譜曲線實 質相同。因此，使用在100 kVp以上電壓的2Ta管顯示該 現象。 圖8是具有厚度1微米之鉬靶的透射型X射線管之 輸出光譜示意圖。管電壓從70 kVp至100 kVp且以10 kVp爲間隔之ITa管的光譜。注意，就2Ta靶而言，在 8 0 kVp或小於20 kVp，曲線開始重疊。就越來越厚的靶 -19- 201138556 材料而言’在特定光子能量之總能量處的電壓不會增加。 如同所預期的，X射線強度隨著靶厚度的減少而減少。 圖9是具有厚度0.75微米之鉅靶的透射型X射線管 之輸出光譜示意圖。（〇.75Ta，從40 kVp至80 kVp且以 10 kVp爲間隔，在50微安培管電流。） 圖1 〇是具有厚度0.3微米之鉬靶的透射型X射線管 之輸出光譜示意圖。（〇.3Ta，從40 kVp至80 kVp，在 5 〇微安培。）分析必須在X射線能量的能量帶寬度上進 行。 圖11是具有厚度0.3微米之鉬靶且使用兩個不同之 銅濾光器的透射型X射線管之輸出光譜示意圖。（〇. 3 Ta ，具有200和400微米之銅的銅濾光器，管電壓50 kVp ，管電流5 0微安培。） 圖12是具有厚度0.75微米之鉅靶且使用2毫米厚之 鋁濾光器的透射型X射線管之輸出光譜示意圖。（〇·7 5 Ta ，具有2毫米鋁，在120 kVp’ 50微安培）。隨著X射 線能量的增加，響應大致平坦，除了在5 7.524 keV處的 鉬 K - α。 圖13是具有厚度〇.75微米之钽靶的透射型X射線管 以量測RoHS元素之輸出光譜示意圖。（具有0.75Ta的 RoHS量測） 圖14是具有厚度〇·3微米之鉅靶的透射型X射線管 以量測RoHS元素之輸出光譜示意圖。（在50、6〇、70 kVp，0_3Ta 的 RoHS 量測） -20- 201138556 【主要元件符號說明】 1 :陽極 2 : ( X射線）靶箔 3 :陰極 4 :電子束路徑 5 :聚焦杯 ζ) 6 :殼體 7 :陽極 8 : X射線 9 :陰極 1 0 :電子束路徑 1 1 :側窗 1 3 :陰影區域 1 4〜1 7 : X射線的強度 〇 1 8 :特徵Κ線 19〜21 :光譜 22~25 :特徵X輻射 3 6 :電源 3 8 :末端窗 -21Table 2 includes measurements of total bremsstrahlung from two additional tubes other than the present invention. Table 2 measures the non-destructive test (NTD) reflective X-ray tube using a tube current intensity of 3 75 microamperes compared to the above Table 1 measurement using a tube current of 50 microamperes. The second tube was a transmission type X-ray tube having a target foil of 4 μm thickness. -13- 201138556 NTD, reflective 4 micron, molybdenum 30kVp 94,268 40kVp 147,078 33,911 50kVp 194,959 54,036 60kVp 267,187 73,587 70kVp 96,335 80kVp 138,005 Table 2 Comparison of Table 1 and Table 2 provides a clear difference, the tube of the present invention is from 1 3 A given X-ray energy band between 27 kVp provides relatively constant total bremsstrahlung. Furthermore, the reflective tube does not show an energy band comparable to the transmissive tube of the present invention. The target foil material can be selected from any of a number of possible elements. In Figures 7, 8, 9, and 10, molybdenum is selected as the target material. As is well known to those skilled in the art, molybdenum has a high atomic number which produces a relatively high X-ray intensity in proportion. In addition, at the X-ray energy of 5 7.524 and 65.21 keV, the Κ-α and K-cold characteristic lines of molybdenum caused significant peaks in the output. In most applications, such peaks in a flat intensity response with photon energy are not a limitation of the use of the tubes of the present invention. However, in some applications it may be advantageous to eliminate or limit these characteristic energy peaks. In a preferred embodiment of the invention, the target material and filter parameters are selected such that there is no characteristic energy peak in the flat output response of the tube. When the foil that produces X-rays in the anode target contains elements of low atomic number (such as ruthenium, chromium, nickel, iron, and copper, and others), the characteristic Κ line is below about 10 keV, and from the transmission -1438385 The spectrum eliminates these K-line peaks. This is usually done at the expense of X-ray output intensity. Although a single target material is selected to exhibit the phenomenon of the present invention, a laminated target material and a target material containing more than a single element may be used instead. In a preferred embodiment of the invention, a plurality of target materials' can be used on a single target and a movable electron beam impinges upon the desired target segment of the present invention. Any of a variety of target materials can be used in the present invention. A partial list of bismuth metal elements present in the target foil of the present invention may be selected from the group consisting of ruthenium, chromium, titanium, iron, nickel 'ruthenium, molybdenum, ruthenium, palladium, I, bait, mirror, watch, giant, town , 銶 'platinum (platinum), gold. In a preferred embodiment of the invention, soft X-rays below about 10 keV are required, particularly in X-ray fluorescence applications. Because the end window must be thick enough to seal the vacuum tube, the end window filters out most of the desired low energy X-rays. Thus, when low energy characteristic X-rays are desired, materials that produce such low energy characteristic lines can be deposited on the atmospheric side of the end window by any of a variety of methods including sputtering. Typical thicknesses of this material can be as thin as 0.05 microns and as thick as about 2 or 3 microns. High-energy X-rays of about 1 〇 keV or more are generated in the target, and the fluorescent characteristic radiation is excited from the material deposited on the side of the end window opposite to the vacuum tube through the end window. Since the material that produces low energy can be placed very close to the spot where the X-rays are generated, energy can be efficiently transmitted to the low-energy characteristic X-rays. The thickness of the end window can be as thin as about 50 microns to many millimeters 'because almost no high energy X radiation is weakened by the end window. Although it is often the choice of material for the end window, it can be replaced by any number of elements of the original -15-201138556 sub-number (z), such as the name, copper, tantalum, or alloy thereof. The brightness of the low energy feature line can be selected by varying the thickness of the deposited material and the accelerating voltage and current ' of the electrons striking the germanium. In an embodiment of the invention, a filter is used to absorb low energy radiation from the transmissive tube of the present invention. Figure II is a graphical representation of the output of a tube with a 0.3 micron molybdenum tantalum foil, 19 is an unfiltered output spectrum '20 is the spectrum of a copper filter using a thickness of 200 microns, and 21 is a copper filter using a thickness of 400 microns. The spectrum of the device. The tube voltage is 50 kVp and the tube current is 50 microamperes. In general fluorescent applications, background X-radiation noise generated by the X-ray tube of the element to be detected is particularly important. The background noise of the Κ-α energy to be measured can be minimized using an appropriate filter structure. The filtered output 21 is used to measure an element having a characteristic Κ-α line emission in the range of about 20 to 23 keV, and the background noise is determined by the portion of the energy band 5 to 10 keV above the line emission energy. The tube of the present invention provides a spectrum within the energy band that is substantially constant throughout the energy band as the tube voltage increases. Increasing the voltage of the tube increases the higher energy X-ray photons, which increase the κ-α response of the element to be detected without increasing the noise level. This feature makes the tube of the present invention particularly useful in the field of X-ray fluorescence analysis. The transmission tube of the present invention can use various filter structures to improve the usefulness of the tube on the market. In a preferred embodiment of the invention illustrated in Figure 12, the output X of a tube having a thickness of 0.75 micron giant target foil and operating at 120 kVp and tube current of 50 microamperes, and an outer 12 mm thick bristles Radiation, which produces a-16 - 201138556 output spectrum over the entire energy band from about 25 keV to about 90 keV, is substantially constant except for the characteristic K-line 18 of the 钽 foil target at 5 7.52 keV. The curve of the output spectrum represents a documented reduced response of a 1 mm thick CdTe sensor with energy above 60 keV, spurious radiation from a tungsten collimator, smearing effect of the sensor, and Other trials were distorted. While this embodiment uses a 2 mm aluminum filter, any of a number of different output filter configurations can be used to provide a substantially flat output tube that is well known to those skilled in the art. This output is particularly useful when spectral data is used for X-ray imaging. The X-ray output of the object under inspection, between 25 and 90 keV, is essentially a step function. In another preferred embodiment of the invention, Figures 13 and 14 provide graphical representations of the energy spectra taken using the two transmission tubes of the present invention having standard BCR-680 RoHS samples. The distance of 5 cm (cm) from the end of the tube was measured. Compared to a reflective X-ray tube, the fluorescent sample can be placed closer to the X-ray tube because the transmission tube provides a very wide conical angle (8 图 in Figure 1). A 1 mm CdTe sensor is placed on a line that is perpendicular to the line between the X-ray spot and the center of the BCR-680 sample and adjacent to the outside of the BCR-680 sample container. The European R〇HS specification requires five elements for simultaneous fluorescence measurement. The five elements include cadmium 'lead, mercury, bromine, and chromium. Figure 13 is obtained using a molybdenum foil target having a thickness of 3 μm and a transmission tube of a 4 mm copper filter. 19, 20, 21 represent the tube at a tube voltage of 50 kVp, 60 kVp, 70 kVp, respectively. X-ray spectrum. Figure 14 is obtained using a tantalum foil target with a thickness of 〇 · 5 5 μm and the same filter. 2 2 represents the characteristic X-radiation produced by cadmium -17- 201138556. A tube voltage of 5 〇 kVp, 60 kVp, 70 kVp (23, 24, 25 in the figure, respectively) was applied to obtain a spectrum. Although the spectrum shows an increase in the background noise of 镉-α: energy of cadmium, the noise is the sensor noise generated by the smearing effect of the CdTe sensor used, and the background noise ratio is displayed. A lot lower. As the tube voltage increases, the signal also increases a lot. A significant advantage of this result is that it allows for higher tube voltages and lower tube currents to improve the rate and accuracy of fluorescence measurements. In this particular example, the tube current is reduced to 20 microamperes, allowing for reduced tube heating, spot size, and longer filament life, using the X-ray tube of the present invention for fluorescence analysis. Major commercial advantages. Since the X-ray intensity output is flat with increasing tube voltage, the intensity of the X-ray tube output adjacent to the K-line of cadmium does not increase as the applied tube voltage increases, ensuring low background radiation. The thickness and material of the filter are selected from any of a number of possible filter materials, including but not limited to aluminum and copper, so Compton Scattering from the sample under test does not significantly interfere with the amount of associated feature lines produced by the sample. Measurement. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of a typical transmission type X-ray tube. Figure 2 is a schematic illustration of a typical reflective X-ray tube. Figure 3 is a schematic representation of a typical X-ray spectrum from an X-ray tube showing the bremsstrahlung photon energy between 20 and 50 keV. Figure 3 is used to define the total number within a given energy band. The shaded area 13 represents the total number of photons emitted by the tube between 20 kev and 50 keV. This special -18- 201138556 special energy band and test conditions have 4 4 2 2 photons. Fig. 4 is a schematic view showing the spectral output of a typical reflection type X-ray tube. This is a typical reflective X-ray tube used in non-destructive testing (NDT) imaging. When the voltage is increased from 30 kVp to 60 kVp, the tough radiation peak is seen to move to higher energy. When the tube voltage is increased, the spectrum is greatly changed. The tube current was 50 microamperes and the spectra were measured at 1 meter and 3 minutes using a 1 〇 〇 micron tungsten collimator. 〇 Figure 5 is a schematic diagram of the spectrum of the applied tube voltage from 50 kVp to 150 kVp for a reflective X-ray tube. A microfocus reflective tube when the voltage is increased from 50 kVp to 1 50 kVp and increased in increments of 20 kVp. Note that as the tube voltage increases, the peak of bremsstrahlung energy moves through the spectrum. Fig. 6 is a schematic view showing the output spectrum of a transmission type xenon tube having a tantalum (Ta) target having a thickness of 4 μm. When the voltage is from 40 kVp to 80 kVp, the 4Ta spectrum. The tube current is 50 microamperes. The characteristic of the radiant energy peak of the transmission tube expressed by keV does not increase as the tube voltage increases. Ο Figure 7 is a schematic diagram showing the output spectrum of a transmission type X-ray tube having a target of 2 μm thick. 2Ta spectrum from 90 kVp to 120 kVp with 10 kVp as the interval. Note that the spectral curves of 1〇〇, 110, and 120 kVp are essentially the same. Therefore, this phenomenon is shown using a 2Ta tube at a voltage of 100 kVp or more. Fig. 8 is a view showing the output spectrum of a transmission type X-ray tube having a molybdenum target having a thickness of 1 μm. The spectrum of the ITa tube with a tube voltage from 70 kVp to 100 kVp and separated by 10 kVp. Note that for the 2Ta target, at 80 kVp or less than 20 kVp, the curves begin to overlap. As for the increasingly thicker target -19-201138556 material, the voltage at the total energy of a particular photon energy does not increase. As expected, the X-ray intensity decreases as the target thickness decreases. Fig. 9 is a schematic view showing the output spectrum of a transmission type X-ray tube having a giant target having a thickness of 0.75 μm. (〇.75Ta, from 40 kVp to 80 kVp and at 10 kVp intervals, at 50 microamperes.) Figure 1 is a schematic representation of the output spectrum of a transmission X-ray tube with a 0.3 micron thickness of molybdenum target. (〇.3Ta, from 40 kVp to 80 kVp, at 5 〇 microamperes.) The analysis must be performed over the energy band width of the X-ray energy. Figure 11 is a schematic illustration of the output spectrum of a transmission type X-ray tube having a molybdenum target having a thickness of 0.3 microns and using two different copper filters. (〇. 3 Ta, copper filter with 200 and 400 micron copper, tube voltage 50 kVp, tube current 50 μA.) Figure 12 is a giant target with a thickness of 0.75 μm and a 2 mm thick aluminum filter. Schematic diagram of the output spectrum of a transmissive X-ray tube of an optical device. (〇·7 5 Ta, with 2 mm aluminum, at 120 kVp' 50 microamperes). As the X-ray energy increases, the response is roughly flat except for the molybdenum K - α at 5 7.524 keV. Figure 13 is a schematic view showing the output spectrum of a RoHS element by a transmission type X-ray tube having a 钽.75 μm thick target. (With a RoHS measurement of 0.75 Ta) Fig. 14 is a schematic diagram showing the output spectrum of a transmission type X-ray tube having a giant target having a thickness of 〇·3 μm to measure the RoHS element. (Root measurement at 50, 6〇, 70 kVp, 0_3Ta) -20- 201138556 [Explanation of main component symbols] 1 : Anode 2 : (X-ray) target foil 3 : Cathode 4 : Electron beam path 5 : Focus cup ζ 6 : Shell 7 : Anode 8 : X-ray 9 : Cathode 1 0 : Electron beam path 1 1 : Side window 1 3 : Shaded area 1 4 to 1 7 : X-ray intensity 〇 1 8 : Characteristic Κ line 19~ 21: Spectrum 22~25: Characteristic X-radiation 3 6 : Power supply 3 8 : End window-21