JP5091096B2 - Charged particle generator - Google Patents

Charged particle generator Download PDF

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JP5091096B2
JP5091096B2 JP2008307514A JP2008307514A JP5091096B2 JP 5091096 B2 JP5091096 B2 JP 5091096B2 JP 2008307514 A JP2008307514 A JP 2008307514A JP 2008307514 A JP2008307514 A JP 2008307514A JP 5091096 B2 JP5091096 B2 JP 5091096B2
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正浩 有光
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Jeol Ltd
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Description

本発明は電子顕微鏡等の荷電粒子発生装置使用される電源に関する。   The present invention relates to a power source used for a charged particle generator such as an electron microscope.

荷電粒子源は熱電子放出させたり、電界放出させたりすることにより荷電粒子を発生させる。その発生した荷電粒子を加速させ、照射物に照射する機器は、電子顕微鏡、Ｘ線管、電子ビーム加熱装置、電子ビーム露光装置等多数あり、微少領域の観察、分析、加工、加熱、Ｘ線装置など幅広い分野で使われている。 The charged particle source generates charged particles by emitting thermoelectrons or emitting electric fields. There are many devices such as an electron microscope, an X-ray tube, an electron beam heating device, an electron beam exposure device, etc. that accelerate the generated charged particles and irradiate the irradiated object. Observation, analysis, processing, heating, X-rays of a minute region Used in a wide range of fields such as equipment.

この様な荷電粒子応用装置の構成例を図１に示す。図中１は基準電圧源１４からの基準電圧で制御される演算増幅器である。その演算増幅器１からの出力はスイッチング素子３，４によりスイッチングされ、昇圧トランス６の一次側巻き線に供給される。発振器２から出力されるパルスは、スイッチング素子３のスイッチング制御端子にそのまま入力し、また発振器２からの出力を極性反転器５で１８０度位相を変えてスイッチング素子４のスイッチング制御端子に入力する。それによりスイッチング素子３，４は交互にオンオフされ、演算増幅器１からの直流出力をスイッチングする事により交流化した電圧が昇圧トランス６の一次側に供給される。   A configuration example of such a charged particle application apparatus is shown in FIG. In the figure, reference numeral 1 denotes an operational amplifier controlled by a reference voltage from a reference voltage source 14. The output from the operational amplifier 1 is switched by the switching elements 3 and 4 and supplied to the primary winding of the step-up transformer 6. The pulse output from the oscillator 2 is input to the switching control terminal of the switching element 3 as it is, and the output from the oscillator 2 is input to the switching control terminal of the switching element 4 by changing the phase by 180 degrees with the polarity inverter 5. As a result, the switching elements 3 and 4 are alternately turned on and off, and a voltage converted into an alternating current by switching the direct current output from the operational amplifier 1 is supplied to the primary side of the step-up transformer 6.

７はダイオードとコンデンサから構成されるコッククロフト・ウォルトン回路である。昇圧トランス６の二次側交流出力電圧はコッククロフト・ウォルトン回路７により昇圧・整流される。   Reference numeral 7 denotes a Cockcroft-Walton circuit composed of a diode and a capacitor. The secondary side AC output voltage of the step-up transformer 6 is boosted and rectified by the Cockcroft-Walton circuit 7.

コッククロフト・ウォルトン回路７の出力は、出力抵抗８と出力コンデンサ９で構成されるフィルタ回路によりリップル分（変動分）が除去される。このリップルを除去した高電圧出力をフィラメント１０とターゲット１１間に印加する。このフィラメント１０とターゲット１１間に印加した高電圧を加速電圧ＡｃｃＶと言う。これにより、フィラメントから発生した電子は加速電圧により加速されターゲット１１に当たる。   Ripple (variation) is removed from the output of the Cockcroft-Walton circuit 7 by a filter circuit composed of an output resistor 8 and an output capacitor 9. A high voltage output from which the ripple has been removed is applied between the filament 10 and the target 11. A high voltage applied between the filament 10 and the target 11 is referred to as an acceleration voltage AccV. Thereby, the electrons generated from the filament are accelerated by the acceleration voltage and strike the target 11.

図中１２は加速電圧ＡｃｃＶに接続された帰還抵抗であり、１３は演算増幅器１の反転入力端子入力とアース間に接続された入力抵抗、１４は演算増幅器１の非反転入力端子とアース間に接続された加速電圧設定電圧源である。
帰還抵抗１２により演算増幅器１に負帰還がかかる。この様な負帰還回路により、加速電圧設定電源１４で設定された電圧を、入力抵抗１３と帰還抵抗１２で決まる増幅度倍した電圧が加速電圧ＡｃｃＶとなるように動作する。
フィラメント１０は加速電圧ＡｃｃＶ上の電位に位置する。そのため、フィラメント１０に電流を流し加熱するには、加速電圧ＡｃｃＶ上の電位に電力供給する必要がある。そのため、トランスにより加速電圧ＡｃｃＶを絶縁し電力供給を行う。このような加速電圧上への電力供給をパワー伝送と呼ぶ。
そのパワー伝送回路の説明をする。
まず、発振器２１から出力されるパルスをスイッチング素子１９の制御端子に入力し、また発振器２１からの出力を極性反転器２２で１８０度位相を変えてスイッチング素子２０の制御端子に入力する。それによりスイッチング素子１９，２０は交互にオンオフする。スイッチング素子１９、２０は、オンすると通電、オフすると遮断となる動作をする。２３、２４はコンデンサであり、１８はフィラメント加熱電流供給用直流電源である。今、発振器２１がＨＩを出力し、スイッチング素子１９オン、２０がオフすると、フィラメント電流設定直流電源１８からスイッチング素子１９、加速電圧絶縁トランス１５の一次側巻き線、コンデンサ２４、グランドと電流が流れる。次に、発振器２１がＬＯを出力し、スイッチング素子１９オフ、２０がオンすると、フィラメント電流設定直流電源１８からコンデンサ２３、加速電圧絶縁トランス１５の一次側巻き線、スイッチング素子２０、グランドと電流が流れる。よって、スイッチング素子１９オン、２０がオフする時と、スイッチング素子１９オフ、２０がオンする時では、加速電圧絶縁トランス１５の一次側巻き線に正方向と逆方向に電流が流れる。すると、加速電圧絶縁トランス１５の二次側に交流電圧が発生する。 In the figure, 12 is a feedback resistor connected to the acceleration voltage AccV, 13 is an input resistor connected between the inverting input terminal input of the operational amplifier 1 and ground, and 14 is between the non-inverting input terminal of the operational amplifier 1 and ground. It is a connected acceleration voltage setting voltage source.
Negative feedback is applied to the operational amplifier 1 by the feedback resistor 12. By such a negative feedback circuit, the voltage set by the acceleration voltage setting power supply 14 is operated so that a voltage obtained by multiplying the amplification factor determined by the input resistor 13 and the feedback resistor 12 becomes the acceleration voltage AccV.
The filament 10 is positioned at a potential on the acceleration voltage AccV. For this reason, in order to heat the filament 10 by passing a current, it is necessary to supply power to the potential above the acceleration voltage AccV. Therefore, power is supplied by insulating the acceleration voltage AccV with a transformer. Such power supply on the acceleration voltage is called power transmission.
The power transmission circuit will be described.
First, the pulse output from the oscillator 21 is input to the control terminal of the switching element 19, and the output from the oscillator 21 is input to the control terminal of the switching element 20 by changing the phase by 180 degrees with the polarity inverter 22. Thereby, the switching elements 19 and 20 are alternately turned on and off. The switching elements 19 and 20 operate to be energized when turned on and shut off when turned off. Reference numerals 23 and 24 denote capacitors, and 18 denotes a DC power supply for supplying filament heating current. When the oscillator 21 outputs HI and the switching element 19 is turned on and 20 is turned off, the current flows from the filament current setting DC power source 18 to the switching element 19, the primary winding of the acceleration voltage isolation transformer 15, the capacitor 24, and the ground. . Next, when the oscillator 21 outputs LO and the switching element 19 is turned off and the 20 is turned on, the primary current winding of the capacitor 23, the acceleration voltage isolation transformer 15, the switching element 20, the ground and the current are supplied from the filament current setting DC power source 18. Flowing. Therefore, when the switching elements 19 on and 20 are turned off and when the switching elements 19 off and 20 are turned on, a current flows in the primary winding of the acceleration voltage insulating transformer 15 in the direction opposite to the forward direction. Then, an AC voltage is generated on the secondary side of the acceleration voltage insulation transformer 15.

インダクタンス(誘導)成分とキャパシタンス(容量)成分を組み合わせると特周波数でインピーダンスにピークを持つ共振現象が起きる。このピークの周波数を共振周波数と呼ぶ。この共振現象は、加速電圧絶縁トランス１５の漏れ磁束による自己インダクタンスと、コンデンサ２３、２４のキャパシタンスによっても起きる。ここで、加速電圧絶縁トランス１５の自己インダクタンスと、コンデンサ２３、２４のキャパシタンスよって決まる共振周波数に、発振器２１の周波数を合わせ、スイッチング素子１９、２０を動作させる。するとトランス１５の自己インダクタンスと、コンデンサ２３、２４のキャパシタンスにより電流共振が起こり、これを利用する事により高効率、低ノイズで加速電圧絶縁トランス１５の二次側に供給できる。この様な回路をハーフブリッジ回路と言う。ハーフブリッジ回路によって、加速電圧絶縁トランス１５の一次側を動作させると、二次側に交流電圧が発生する。その発生した交流電圧を整流回路１６によって全波整流し、平滑用コンデンサ１７により、平滑化し、フィラメント１０の両端に印加する。そして、フィラメント電流設定電源１８の出力する電圧に基づいた電流をフィラメント１７に流し、フィラメント１７が加熱され、熱電子を放出する。   When an inductance (inductive) component and a capacitance (capacitance) component are combined, a resonance phenomenon having a peak in impedance at a special frequency occurs. This peak frequency is called a resonance frequency. This resonance phenomenon also occurs due to the self-inductance due to the leakage flux of the acceleration voltage isolation transformer 15 and the capacitances of the capacitors 23 and 24. Here, the switching elements 19 and 20 are operated by adjusting the frequency of the oscillator 21 to the resonance frequency determined by the self-inductance of the acceleration voltage isolation transformer 15 and the capacitances of the capacitors 23 and 24. Then, current resonance occurs due to the self-inductance of the transformer 15 and the capacitances of the capacitors 23 and 24, and by using this, the secondary voltage can be supplied to the secondary side of the acceleration voltage isolation transformer 15 with high efficiency and low noise. Such a circuit is called a half-bridge circuit. When the primary side of the acceleration voltage isolation transformer 15 is operated by the half bridge circuit, an AC voltage is generated on the secondary side. The generated AC voltage is full-wave rectified by the rectifier circuit 16, smoothed by the smoothing capacitor 17, and applied to both ends of the filament 10. Then, a current based on the voltage output from the filament current setting power supply 18 is supplied to the filament 17 so that the filament 17 is heated and emits thermoelectrons.

さて、電子顕微鏡等の荷電粒子ビーム装置で、荷電粒子ビームの加速する電圧は数ｋＶ以上の高電圧であり、時には１０００ｋＶ以上の場合もある。そのため、加速電圧絶縁トランス１５の一次側巻き線と二次側巻き線間の絶縁耐圧はそれに耐えるよう高くする必要がある。しかし、そのためには二次側巻き線と、その他のグランド電位の部分との沿面距離、空間距離を長く取る必要があり、加速電圧絶縁トランス自体が大型化する。その様なトランスを備えた荷電粒子線発生装置は大変大きなものとなってしまう。その結果、荷電粒子ビーム発生装置の小型化に大きな障害となるだけでなく、コストも莫大なものとなる。   Now, in a charged particle beam apparatus such as an electron microscope, the voltage at which the charged particle beam accelerates is a high voltage of several kV or more, and sometimes 1000 kV or more. Therefore, the withstand voltage between the primary side winding and the secondary side winding of the acceleration voltage isolation transformer 15 needs to be increased to withstand it. However, for this purpose, it is necessary to increase the creeping distance and the spatial distance between the secondary winding and the other ground potential portion, and the acceleration voltage isolation transformer itself is increased in size. A charged particle beam generator equipped with such a transformer would be very large. As a result, the charged particle beam generator is not only a major obstacle to downsizing, but also the cost is enormous.

そこで、図２に示す様な回路構成のものが提案されている。図２中、図１で使用した記号と同一記号のものは同一構成要素である。図１との相違点は、加速電圧絶縁トランスを複数個縦続接続したトランスに変えた点と、そのトランスのドライバ回路をプッシュプル型にした点である。
図２の回路の動作は、発振器２１から出力されるパルスをスイッチング素子１９に入力し、また発振器２１からの出力を極性反転器２２で１８０度位相を変えてスイッチング素子２０に入力する。それによりスイッチング素子１９，２０は交互にオンオフする。そして、一段目の（初段の）加速電圧絶縁トランス２５ａのセンタータップを接地した一次側巻き線Ａｎ１の両端に、交互に加熱電流設定電源１８からの電圧を与える。それにより、加速電圧絶縁トランス２５ａの二次側巻き線の両端に交流電圧が発生する。初段の加速電圧絶縁トランス２５ａの二次側巻き線Ａｎ２と、二段目の加速電圧絶縁トランス２５ｂの一次側巻き線Ｂｎ１とを接続する。また、二段目の加速電圧絶縁トランス２５ｂの二次側巻き線Ｂｎ２と三段目の加速電圧絶縁トランス２５ｃの一次側巻き線Ｃｎ１と接続する。そして、三段目の加速電圧絶縁トランス２５ｃの二次側巻き線Ｃｎ２と四段目の（最終段の）加速電圧絶縁トランス２５ｄの一次側巻き線Ｄｎ１とを接続し、最終段の加速電圧絶縁トランス２２ｄの二次側巻き線Ｄｎ２を整流器１６の入力端に接続する。それにより、前記プッシュブル型ドライブ回路とＡｃｃＶ上の整流ブリッジ１６との間に四個の加速電圧絶縁トランスを縦続接続した構成になる。 Accordingly, a circuit configuration as shown in FIG. 2 has been proposed. 2, the same symbols as those used in FIG. 1 are the same components. The difference from FIG. 1 is that a plurality of accelerating voltage isolation transformers are changed to cascaded transformers, and the driver circuit of the transformer is made a push-pull type.
In the operation of the circuit of FIG. 2, the pulse output from the oscillator 21 is input to the switching element 19, and the output from the oscillator 21 is input to the switching element 20 by changing the phase by 180 degrees with the polarity inverter 22. Thereby, the switching elements 19 and 20 are alternately turned on and off. Then, the voltage from the heating current setting power supply 18 is alternately applied to both ends of the primary winding An1 with the center tap of the first stage (first stage) acceleration voltage isolation transformer 25a grounded. As a result, an AC voltage is generated at both ends of the secondary winding of the acceleration voltage insulating transformer 25a. The secondary winding An2 of the first stage acceleration voltage isolation transformer 25a is connected to the primary winding Bn1 of the second stage acceleration voltage isolation transformer 25b. Further, the secondary winding Bn2 of the second stage acceleration voltage isolation transformer 25b is connected to the primary winding Cn1 of the third stage acceleration voltage isolation transformer 25c. Then, the secondary winding Cn2 of the third stage acceleration voltage isolation transformer 25c and the primary winding Dn1 of the fourth stage (final stage) acceleration voltage isolation transformer 25d are connected, and the final stage acceleration voltage isolation is achieved. The secondary winding Dn2 of the transformer 22d is connected to the input terminal of the rectifier 16. Thus, four acceleration voltage isolation transformers are cascaded between the push-bull drive circuit and the rectifier bridge 16 on AccV.

また、分割抵抗２６ｄ，２６ｃ，２６ｂ，２６ａを直列接続して加速電圧AｃｃVとグランド間に接続する。そして、分割抵抗２６ｄと２６ｃの接続点と、前記加速電圧絶縁トランス２５ｄの一次側巻き線Ｄｎ１と加速電圧絶縁トランス２５ｃの二次側巻き線Ｃｎ２との接続点に接続する。次に分割抵抗２６ｃと２６ｂの接続点と、前記加速電圧絶縁トランス２５ｃの一次側巻き線Ｃｎ１と加速電圧絶縁トランス２５ｂの二次側巻き線Ｂｎ２との接続点に接続する。同様に分割抵抗２６ｂと２６ａの接続点と前記加速電圧絶縁トランス２５ｂの一次側巻き線Ｂｎ１と加速電圧絶縁トランス２５ａの二次側巻き線Ａｎ２との接続点をそれぞれ接続する。これにより、加速電圧が前記分割抵抗で平等に分割され、各加速電圧絶縁トランス２５ｄ，２５ｃ，２５ｂ，２５ａの耐圧が１個の加速電圧絶縁トランスに比べ、四分の一程度で済む事になる。   Further, the division resistors 26d, 26c, 26b, and 26a are connected in series and connected between the acceleration voltage AccV and the ground. Then, a connection point between the division resistors 26d and 26c and a connection point between the primary winding Dn1 of the acceleration voltage isolation transformer 25d and the secondary winding Cn2 of the acceleration voltage isolation transformer 25c are connected. Next, the connection point between the division resistors 26c and 26b and the connection point between the primary winding Cn1 of the acceleration voltage isolation transformer 25c and the secondary winding Bn2 of the acceleration voltage isolation transformer 25b are connected. Similarly, the connection point between the dividing resistors 26b and 26a is connected to the connection point between the primary winding Bn1 of the acceleration voltage isolation transformer 25b and the secondary winding An2 of the acceleration voltage isolation transformer 25a. As a result, the acceleration voltage is equally divided by the dividing resistors, and the breakdown voltage of each of the acceleration voltage isolation transformers 25d, 25c, 25b, and 25a is about a quarter of that of a single acceleration voltage isolation transformer. .

この様に各加速電圧絶縁トランスの一次側巻き線と二次側巻き線の耐圧が著しく小さくて済むと、加速電圧絶縁トランスを構成する一次側巻き線、二次側巻き線、トランスコア間のそれぞれの絶縁に必要な沿面距離、空間距離を小さくする事が出来る。それにより、加速電圧絶縁トランスの数が複数個になっても、耐圧が著しく大きな１段の加速電圧絶縁トランスの場合に比べ、非常に小型になり、コストも大幅に低減出来る。   In this way, if the withstand voltage of the primary side winding and the secondary side winding of each acceleration voltage isolation transformer is extremely small, the primary side winding, the secondary side winding, and the transformer core constituting the acceleration voltage isolation transformer Creeping distance and clearance required for each insulation can be reduced. As a result, even when the number of acceleration voltage isolation transformers is plural, the size is significantly reduced and the cost can be significantly reduced as compared with the case of a single-stage acceleration voltage isolation transformer having a significantly large breakdown voltage.

特開平９−２３１９３５号公報JP-A-9-231935 特開２００４−２８１１７０号公報JP 2004-281170 A

さて、前記縦属接続させた各加速電圧絶縁トランスを含むプッシュプル回路を前記ハーフブリッジ回路に置き換え、高効率、低ノイズのフィラメント加熱電源を実現しようとした場合、次の様な問題が発生する。   When the push-pull circuit including the accelerating voltage isolation transformers connected in series is replaced with the half-bridge circuit to achieve a highly efficient and low-noise filament heating power supply, the following problems occur. .

前記図２の提案例の様に複数の加速電圧絶縁トランスを縦属接続した場合、初段加速電圧絶縁トランスの一次側から見たトランス全体の自己インダクタンスは縦属接続した個々の加速電圧絶縁トランスの自己インダクタンスを直列に接続したものと等価となる。それにより、加速電圧絶縁トランス１個の時に比べ、縦続接続された加速電圧絶縁トランスの自己インダクタンスは数倍に増加する。前述した様に、ハーフブリッジ回路は、加速電圧絶縁トランスの自己インダクタンスによって蓄積する電荷と、共振用コンデンサ２３、２４に蓄積する電荷を共振させる。しかし上記の様に、自己インダクタンスが大きくなりすぎると、蓄積する電荷量が増えすぎて共振させること自体が困難となる。従って、縦属接続させた加速電圧絶縁トランスを含むパワー伝送をハーフブリッジ回路で実現することは難しい。そのために、高効率、低ノイズのハーフブリッジ回路とコンパクトかつローコストの絶縁トランスの縦続接続を両立させ、加速電圧ＡｃｃＶ上にパワー伝送することができなかった。   When a plurality of acceleration voltage isolation transformers are cascade-connected as in the proposed example of FIG. 2, the self-inductance of the entire transformer viewed from the primary side of the first stage acceleration voltage isolation transformer is Equivalent to a self-inductance connected in series. As a result, the self-inductance of the cascaded accelerating voltage isolation transformer increases several times as compared with the case of a single acceleration voltage isolation transformer. As described above, the half bridge circuit resonates the charge accumulated by the self-inductance of the acceleration voltage isolation transformer and the charge accumulated in the resonance capacitors 23 and 24. However, as described above, if the self-inductance becomes too large, the amount of stored charge increases so that it is difficult to resonate. Therefore, it is difficult to realize power transmission including an accelerating voltage isolation transformer connected in cascade with a half-bridge circuit. For this reason, a high-efficiency, low-noise half-bridge circuit and a cascade connection of compact and low-cost insulating transformers are compatible, and power cannot be transmitted on the acceleration voltage AccV.

以上の説明においては、フィラメントから発生した熱電子を加速するためのパワー伝送を例に上げたが、電界放出型電子銃（ＦＥＧ）を搭載した荷電粒子ビーム装置にあっては、引き出し電極、サプレッサの電源にもパワー伝送が必要であり同様な問題がある。   In the above description, power transmission for accelerating thermionic electrons generated from the filament has been taken as an example. However, in a charged particle beam apparatus equipped with a field emission electron gun (FEG), an extraction electrode and a suppressor are used. The power source of this type also requires power transmission and has similar problems.

本発明はこの様な問題を解決するために成されたもので、高電圧上への新規なパワー伝送回路を提供する事を目的とする。   The present invention has been made to solve such a problem, and an object thereof is to provide a novel power transmission circuit on a high voltage.

本発明の荷電粒子線発生装置は、交流電圧を昇圧整流し荷電粒子を加速する加速電圧を発生する昇圧整流回路Ｃと、加速電圧が印加される荷電粒子源と、前記昇圧整流回路Ｃの出力と接地間に接続される直列接続された複数の抵抗からなる加速電圧分圧器と、前記荷電粒子源に接地電位から荷電粒子源に電力を供給するパワー伝送回路とを備え、
前記パワー伝送回路は、多段縦続接続された複数の絶縁トランス１５、１５ｂ、１５ｃ、１５ｄから構成されると共に、前記加速電圧分圧器の前記絶縁トランスそれぞれが電圧分担する電圧を均等にする電位点にそれぞれの前記絶縁トランスの縦続接続点を接続するようにした荷電粒子線発生装置において、
前記多段縦続接続された複数の絶縁トランス１５、１５ｂ、１５ｃ、１５ｄの各段間に、接地電位側絶縁トランスの二次巻き線からの交流電圧を直流電圧に変換する交流直流変換回路２７、２８，２９と、該交流直流変換回路からの直流電圧を交流電圧に変換して荷電粒子源側絶縁トランスの一次側巻き線へ供給する直流交流変換回路Ｂ２、Ｂ３、Ｂ４を配置した事を特徴とする。 The charged particle beam generator of the present invention includes a boost rectifier circuit C that generates an accelerating voltage that boosts and rectifies an alternating voltage to accelerate charged particles, a charged particle source to which the acceleration voltage is applied, and an output of the boost rectifier circuit C. An accelerating voltage divider consisting of a plurality of resistors connected in series connected between and ground, and a power transmission circuit for supplying power to the charged particle source from the ground potential to the charged particle source,
The power transmission circuit is composed of a plurality of cascaded isolation transformers 15, 15 b, 15 c, and 15 d, and at a potential point that equalizes the voltage shared by each of the isolation transformers of the acceleration voltage divider. In the charged particle beam generator configured to connect the cascade connection points of the respective insulation transformers,
AC / DC conversion circuits 27 and 28 for converting an AC voltage from the secondary winding of the ground potential side isolation transformer into a DC voltage between the stages of the plurality of cascaded isolation transformers 15, 15b, 15c and 15d. , 29, and DC / AC conversion circuits B2, B3, and B4 that convert the DC voltage from the AC / DC conversion circuit into an AC voltage and supply the AC voltage to the primary winding of the charged particle source-side insulating transformer. To do.

本発明によれば、荷電粒子発生装置の加速電圧上の電力供給を、加速電圧絶縁トランスを複数個用いて巻き線間の耐圧を下げ小型化しても、高効率、低ノイズで動作させ、かつ低コスト化できる効果がある。   According to the present invention, the power supply on the acceleration voltage of the charged particle generator can be operated with high efficiency and low noise even if a plurality of acceleration voltage insulation transformers are used to reduce the withstand voltage between the windings and reduce the size. There is an effect that the cost can be reduced.

以下、図面を参照して本発明の実施するための最良の形態を説明する。   The best mode for carrying out the present invention will be described below with reference to the drawings.

図３はこの様な原理に基づいて構成された荷電粒子発生装置の一概略例を示す。また、図１で使用した記号と同一記号としたものは同一構成要素である。
加速電圧発生回路Ｃは従来技術と同様であり、抵抗１２，１３で帰還のかかった演算増幅器１の出力を、スイッチング素子３，４でスイッチングし昇圧トランス６の一次側に交流電圧を供給する。昇圧トランス６の二次側巻き線の交流出力はコッククロフト・ウォルトン回路７に接続される。そして、コッククロフト・ウォルトン回路７により昇圧・整流する。そのコッククロフト・ウォルトン回路７出力を、出力抵抗８とフィルタコンデンサ９でリップルを除去し加速電圧ＡｃｃＶとして使用する。
次に、加速電圧上へ電力を供給するパワー伝送部分を説明する。
図中Ｂ１は発振器２１、スイッチング素子１９，２０、共振用コンデンサ２３，２４、加速電圧絶縁トランス１５で構成される１段目ハーフブリッジ回路である。この１段目ハーフブリッジ回路Ｂ１は、前記図１のハーフブリッジ回路と同じ動作をする。1段目ハーフブリッジ回路Ｂ１の加速電圧絶縁トランス１５の二次側出力は、ダイオードで構成される整流回路に並列接続した平滑コンデンサで構成された交直流変換回路２７によって直流電圧に変換される。その直流電圧が供給される２段目ハーフブリッジ回路Ｂ２は、１段目ハーフブリッジ回路Ｂ１と同じ動作をする回路である。そして２段目ハーフブリッジ回路Ｂ２は加速電圧絶縁トランス１５の二次側出力を交直流変換回路２７で直流化した電圧を電源として動作する。その２段目ハーフブリッジ回路Ｂ２の加速電圧絶縁トランス１５ｂの二次側出力は、交直流変換回路２８に接続され、直流化される。その直流化された出力を電源として、３段目ハーフブリッジ回路Ｂ３は動作する。同様に、加速電圧絶縁トランス１５ｃの二次側出力を直流化した出力を電源として４段目ハーフブリッジ回路Ｂ４は動作する。この様に加速電圧絶縁トランスの二次側出力を直流化し、直流化された出力を電源として動作するハーフブリッジ回路を接続する。つまり、縦続接続した加速電圧絶縁トランス毎に交直流変換回路とその直流化された出力を電源としたハーフブリッジ回路を挿入した物となる。
加速電圧絶縁トランス１５ｄの二次側出力はダイオードによって構成された整流回路１６に接続し、整流回路１６の出力は平滑コンデンサ１７によって直流化しフィラメント１０に電流を流す。それにより、フィラメント１７が加熱され、熱電子を放出する。
また、分割抵抗２６ｄ，２６ｃ，２６ｂ，２６ａを直列接続して加速電圧AｃｃVとグランド間に接続する。そして、分割抵抗２６ａと２６ｂの接続点と、ハーフブリッジＢ２の基準となる電圧である交直流変換回路のマイナス側出力Ｅを接続する。また、分割抵抗２６ｂと２６ｃの接続点と、ハーフブリッジＢ３の基準となる電圧である交直流変換回路２８のマイナス側出力Ｆを接続する。同様に、分割抵抗２６ｃと２６ｄの接続点と、ハーフブリッジＢ３の基準となる電圧である交直流変換回路２８のマイナス側出力Ｇを接続する。これにより、加速電圧が前記分割抵抗で平等に分割され、各加速電圧絶縁トランス２５ｄ，２５ｃ，２５ｂ，２５ａの一次側巻き線、二次側巻き線の耐圧は１個の加速電圧絶縁トランスに比べ、四分の一程度で済む事になる。
この様に、ハーフブリッジ回路のトランス二次側出力を直流化し、その直流化した出力を電源として動作するハーフブリッジ回路で作られた直交流変換回路を縦続接続させる事により、トランスのみを縦続接続した場合のようにトランスの自己インダクタンスが縦続接続した分だけ増加する事はなくなる。そのため、各ハーフブリッジ回路は、共振用コンデンサとトランスの自己インダクタンスで正常に電流共振し、プッシュプル回路に比べ著しく効率良く、また、低ノイズでパワー伝送が行う事ができる。
また、トランスの耐圧を複数個のトランスを用い分散させているため、高価で大型である耐圧の高い加速電圧絶縁トランスを使用せず、小型で安価な耐電圧の小さいトランスが使用できる。
さらに、設計上の理由もしくは製造上のばらつきによって、個々の加速電圧絶縁トランスの自己インダクタンスが異なる事がある。そのために、各段の共振周波数に違いが発生しても、ハーフブリッジ回路毎に発振器を持っているため、各ハーフブリッジのスイッチング周波数を最適な周波数に設定することができる。 FIG. 3 shows a schematic example of a charged particle generator constructed based on such a principle. Further, the same symbols as those used in FIG. 1 are the same components.
The acceleration voltage generation circuit C is the same as in the prior art, and the output of the operational amplifier 1 fed back by the resistors 12 and 13 is switched by the switching elements 3 and 4 to supply an AC voltage to the primary side of the step-up transformer 6. The AC output of the secondary winding of the step-up transformer 6 is connected to the Cockcroft-Walton circuit 7. Then, the voltage is boosted and rectified by the Cockcroft-Walton circuit 7. The output of the Cockcroft-Walton circuit 7 is used as the acceleration voltage AccV after the ripple is removed by the output resistor 8 and the filter capacitor 9.
Next, a power transmission part that supplies electric power to the acceleration voltage will be described.
In the figure, B1 is a first-stage half-bridge circuit including an oscillator 21, switching elements 19 and 20, resonance capacitors 23 and 24, and an acceleration voltage insulating transformer 15. The first half-bridge circuit B1 operates in the same manner as the half-bridge circuit shown in FIG. The secondary side output of the acceleration voltage isolation transformer 15 of the first-stage half-bridge circuit B1 is converted into a DC voltage by an AC / DC conversion circuit 27 formed of a smoothing capacitor connected in parallel to a rectifier circuit formed of a diode. The second-stage half-bridge circuit B2 to which the DC voltage is supplied is a circuit that performs the same operation as the first-stage half-bridge circuit B1. The second half bridge circuit B2 operates using a voltage obtained by converting the secondary output of the acceleration voltage isolation transformer 15 into a direct current by the AC / DC conversion circuit 27 as a power source. The secondary output of the acceleration voltage isolation transformer 15b of the second-stage half-bridge circuit B2 is connected to the AC / DC conversion circuit 28 and is converted to DC. The third half-bridge circuit B3 operates using the output converted to DC as a power source. Similarly, the fourth half-bridge circuit B4 operates with an output obtained by converting the secondary side output of the acceleration voltage isolation transformer 15c into a direct current as a power source. In this way, the secondary side output of the acceleration voltage isolation transformer is converted into a direct current, and a half bridge circuit that operates using the converted output as a power source is connected. In other words, an AC / DC converter circuit and a half bridge circuit using a DC output as a power source are inserted for each cascaded acceleration voltage insulating transformer.
The secondary output of the accelerating voltage isolation transformer 15d is connected to a rectifier circuit 16 constituted by a diode, and the output of the rectifier circuit 16 is converted into a direct current by a smoothing capacitor 17 so that a current flows through the filament 10. As a result, the filament 17 is heated and emits thermoelectrons.
Further, the division resistors 26d, 26c, 26b, and 26a are connected in series and connected between the acceleration voltage AccV and the ground. Then, the connection point between the division resistors 26a and 26b is connected to the negative output E of the AC / DC conversion circuit, which is a voltage serving as a reference for the half bridge B2. Further, the connection point between the dividing resistors 26b and 26c is connected to the minus side output F of the AC / DC conversion circuit 28, which is a reference voltage of the half bridge B3. Similarly, the connection point between the dividing resistors 26c and 26d is connected to the negative output G of the AC / DC conversion circuit 28, which is a reference voltage for the half bridge B3. As a result, the acceleration voltage is equally divided by the dividing resistor, and the withstand voltage of the primary side winding and the secondary side winding of each acceleration voltage isolation transformer 25d, 25c, 25b, 25a is higher than that of one acceleration voltage isolation transformer. That's about a quarter.
In this way, the transformer secondary side output of the half-bridge circuit is converted to direct current, and the orthogonal flow conversion circuit made of the half-bridge circuit that operates using the direct-current output as the power supply is connected in cascade, so that only the transformer is connected in cascade. In this case, the transformer self-inductance is not increased by the amount of cascade connection. Therefore, each half-bridge circuit normally resonates with the self-inductance of the resonance capacitor and the transformer, and can perform power transmission with much higher efficiency and lower noise than the push-pull circuit.
In addition, since the transformer withstand voltage is distributed by using a plurality of transformers, a small and inexpensive transformer with low withstand voltage can be used without using an expensive and large accelerating voltage insulating transformer with high withstand voltage.
Furthermore, the self-inductance of each accelerating voltage isolation transformer may differ due to design reasons or manufacturing variations. Therefore, even if a difference occurs in the resonance frequency of each stage, since each half bridge circuit has an oscillator, the switching frequency of each half bridge can be set to an optimum frequency.

なお、本実施の形態では、加速電圧ＡｃｃＶ上電位にあるフィラメントに電力供給する荷電粒子発生装置を例に上げたが、加速電圧上の荷電粒子源に電力供給するものであれば応用可能である（例えば、電界放出型電子銃を備えた荷電粒子ビーム装置における引き出し電極電源、或いはサプレッサ電極電源、荷電粒子源を制御する制御回路）。
なお、本実施の形態では、電子線発生装置を例に上げたが、加速電圧を逆電位(正の電位)に変えてイオン発生装置に応用できる事も言うまでも無い。 In the present embodiment, the charged particle generator for supplying power to the filament at the acceleration voltage AccV is taken as an example. However, the present invention is applicable as long as it supplies power to the charged particle source at the acceleration voltage. (For example, a control circuit for controlling an extraction electrode power source, a suppressor electrode power source, or a charged particle source in a charged particle beam apparatus including a field emission electron gun).
In the present embodiment, the electron beam generator is taken as an example, but it goes without saying that it can be applied to an ion generator by changing the acceleration voltage to a reverse potential (positive potential).

従来の荷電粒子発生装置の構成例を示している。The structural example of the conventional charged particle generator is shown. 提案された複数の加速電圧絶縁トランスを縦続接続した荷電粒子発生装置の構成例を示している。The example of a structure of the charged particle generator which cascade-connected several proposed acceleration voltage insulation transformers is shown. 本発明の荷電粒子発生装置の構成例を示している。The structural example of the charged particle generator of this invention is shown.

符号の説明Explanation of symbols

１…演算増幅器、２…発振器、３，４…スイッチング素子、５…極性反転器、６…昇圧トランス、７…コッククロフト・ウォルトン回路、８…出力抵抗、９…フィルタコンデンサ、１０…フィラメント、１１…ターゲット、１２…帰還抵抗、１３…入力抵抗、１４…加速電圧設定電源、１５…加速電圧絶縁トランス、１６…整流器、１７…平滑用コンデンサ、１８…直流電源、１９，２０…スイッチング素子、２１…発振器、２２…極性反転器、２３，２４…コンデンサ、２５ａ，２５ｂ．２５ｃ，２５ｄ…加速電圧絶縁トランス、２６ａ，２６ｂ．２６ｃ，２６ｄ…分割抵抗、２７，２８，２９…交直流変換回路、Ｂ１，Ｂ２，Ｂ３，Ｂ４…ハーフブリッジ回路、Ｃ…加速電圧発生回路   DESCRIPTION OF SYMBOLS 1 ... Operational amplifier, 2 ... Oscillator, 3, 4 ... Switching element, 5 ... Polarity inverter, 6 ... Boost transformer, 7 ... Cockcroft-Walton circuit, 8 ... Output resistance, 9 ... Filter capacitor, 10 ... Filament, 11 ... Target: 12 ... Feedback resistance, 13 ... Input resistance, 14 ... Acceleration voltage setting power supply, 15 ... Acceleration voltage isolation transformer, 16 ... Rectifier, 17 ... Smoothing capacitor, 18 ... DC power supply, 19, 20 ... Switching element, 21 ... Oscillator, 22 ... polarity inverter, 23, 24 ... capacitor, 25a, 25b. 25c, 25d ... acceleration voltage isolation transformer, 26a, 26b. 26c, 26d ... division resistance, 27, 28, 29 ... AC / DC conversion circuit, B1, B2, B3, B4 ... half bridge circuit, C ... acceleration voltage generation circuit

Claims (2)

交流電圧を昇圧整流し荷電粒子を加速する加速電圧を発生する昇圧整流回路と、
加速電圧が印加される荷電粒子源と、
前記昇圧整流回路の出力と接地間に接続される直列接続された複数の抵抗からなる加速電圧分圧器と、
前記荷電粒子源に接地電位から荷電粒子源に電力を供給するパワー伝送回路とを備え、
前記パワー伝送回路は、多段縦続接続された複数の絶縁トランスから構成されると共に、前記加速電圧分圧器の前記絶縁トランスそれぞれが電圧分担する電圧を均等にする電位点にそれぞれの前記絶縁トランスの縦続接続点を接続するようにした荷電粒子線発生装置において、
前記多段縦続接続された複数の絶縁トランスの各段間に、接地電位側絶縁トランスの二次巻き線からの交流電圧を直流電圧に変換する交直流変換回路と、
該交直流変換回路からの直流電圧を交流電圧に変換して荷電粒子源側絶縁トランスの一次側巻き線へ供給する直交流変換回路を配置した事を特徴とする荷電粒子線発生装置。 A step-up rectifier circuit that generates an accelerating voltage for stepping up an AC voltage to accelerate charged particles;
A charged particle source to which an acceleration voltage is applied;
An accelerating voltage divider comprising a plurality of resistors connected in series connected between the output of the boost rectifier circuit and ground;
A power transmission circuit that supplies power to the charged particle source from a ground potential to the charged particle source;
The power transmission circuit includes a plurality of cascaded isolation transformers, and cascades the isolation transformers at potential points that equalize the voltages shared by the isolation transformers of the acceleration voltage divider. In the charged particle beam generator configured to connect the connection points,
An AC / DC converter circuit that converts an AC voltage from a secondary winding of the ground potential side insulating transformer into a DC voltage between the stages of the plurality of cascaded insulating transformers, and
A charged particle beam generator comprising: a cross flow conversion circuit for converting a DC voltage from the AC / DC conversion circuit into an AC voltage and supplying the AC voltage to a primary winding of a charged particle source side insulating transformer. 前記、直交流変換回路はハーフブリッジ回路から成る請求項１記載の荷電粒子発生装置。 The charged particle generator according to claim 1, wherein the cross-flow conversion circuit is a half-bridge circuit.
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JPH0428200A (en) * 1990-05-22 1992-01-30 Rigaku Corp Power source device of x-ray generator
JP2004281170A (en) * 2003-03-14 2004-10-07 Origin Electric Co Ltd High voltage device for x-ray tube
JP4553701B2 (en) * 2004-11-30 2010-09-29 日本電子株式会社 High voltage generator for charged particle beam equipment
JP4818785B2 (en) * 2006-04-14 2011-11-16 オリジン電気株式会社 High stability power supply device and high voltage electron tube device using the same

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