Control circuit for rapid gain adjustment of photomultiplier tube, photomultiplier device and wafer defect detection system

Abstract

This invention belongs to the field of electrical component technology, specifically relating to a control circuit for rapid gain adjustment of a photomultiplier tube, a photomultiplier device, and a wafer defect detection system. The control circuit for rapid gain adjustment of a photomultiplier tube includes: a photomultiplier tube, a first constant current circuit, a second constant current circuit, and a driving unit. The driving unit is configured to output a changing voltage to the first and second constant current circuits, causing a change in the voltage of each multiplier electrode in the first and second multiplier electrode groups. This invention can output a high-speed changing voltage with a period as low as 10ns, causing the voltage of the corresponding multiplier electrode in the first and second constant current circuits to change rapidly, i.e., a voltage difference change occurs between adjacent multiplier electrodes in the first and second multiplier electrode groups, thereby changing the amplification factor and achieving a rapid gain change at the 10ns level.

Description

Technical Field

[0001] This utility model belongs to the field of electrical component technology, specifically relating to semiconductor lasers, and more particularly to a control circuit for rapid gain adjustment of a photomultiplier tube, a photomultiplier device, and a wafer defect detection system. Background Technology

[0002] Currently, the voltage divider circuits used in photomultiplier tubes include resistor voltage divider circuits, RC bias circuits, and transistor current amplification circuits. Traditionally, to change the gain, the high voltage of the photomultiplier tube is changed only by analog signals, or the current of the voltage divider circuit is changed. This results in slow gain adjustment speed, with adjustment time in the millisecond range, which is not suitable for applications with rapid gain changes.

[0003] Therefore, there is an urgent need to develop a new control circuit for rapid gain adjustment of photomultiplier tubes, a photomultiplier device, and a wafer defect detection system to solve the technical problem of slow gain adjustment speed caused by the use of traditional voltage divider circuits in photomultiplier tubes.

[0004] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Utility Model Content

[0005] This disclosure provides at least one control circuit for rapid gain adjustment of a photomultiplier tube, a photomultiplier device, and a wafer defect detection system.

[0006] In a first aspect, embodiments of this disclosure provide a control circuit for rapid gain adjustment of a photomultiplier tube, comprising: a photomultiplier tube, a first constant current circuit, a second constant current circuit, and a driving unit; wherein the first constant current circuit is electrically connected to each corresponding dynode of a first dynode group in the photomultiplier tube, the second constant current circuit is electrically connected to each corresponding dynode of a second dynode group in the photomultiplier tube, and the first constant current circuit and the second constant current circuit are respectively electrically connected to the driving unit; the driving unit is configured to output a variable voltage to the first constant current circuit to cause a change in the voltage of each corresponding dynode in the first dynode group; and the driving unit is configured to output a variable voltage to the second constant current circuit to cause a change in the voltage of each corresponding dynode in the second dynode group.

[0007] In one optional embodiment, the first constant current circuit includes: a plurality of resistors, a plurality of capacitors, and a first constant current source; each of the resistors is connected in series between the driving unit and the first constant current source, and each of the capacitors is connected in parallel with the corresponding resistor; the two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplying electrode in the first multiplying electrode group, the two ends of the last resistor are electrically connected to the corresponding multiplying electrode in the first multiplying electrode group and the first constant current source, and the two ends of the remaining resistors are electrically connected to the two corresponding multiplying electrodes in the first multiplying electrode group.

[0008] In one optional embodiment, the second constant current circuit includes: a plurality of resistors, a plurality of capacitors, and a second constant current source; each of the resistors is connected in series between the driving unit and the second constant current source, and each of the capacitors is connected in parallel with the corresponding resistor; the two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplier electrode in the second multiplier electrode group, the two ends of the last resistor are electrically connected to the corresponding multiplier electrode in the second multiplier electrode group and the second constant current source, and the two ends of the remaining resistors are electrically connected to the two corresponding multiplier electrodes in the second multiplier electrode group.

[0009] In one optional implementation, the driving unit includes: a first operational amplifier; the first operational amplifier is electrically connected to a first constant current circuit and a second constant current circuit to output a variable voltage to the first constant current circuit and the second constant current circuit.

[0010] In one optional embodiment, the driving unit includes: a first operational amplifier and a second operational amplifier; the first operational amplifier is electrically connected to a first constant current circuit to output a variable voltage to the first constant current circuit; the second operational amplifier is electrically connected to a second constant current circuit to output a variable voltage to the second constant current circuit.

[0011] In one optional embodiment, the photomultiplier electrodes in the photomultiplier tube are numbered sequentially, with odd-numbered electrodes located on one side of the photomultiplier tube and forming the first group of photomultiplier electrodes; and even-numbered electrodes located on the other side of the photomultiplier tube and forming the second group of photomultiplier electrodes.

[0012] In one optional implementation, the total number of multiplying electrodes in the first multiplying electrode group is greater than the total number of multiplying electrodes in the second multiplying electrode group, and the extra multiplying electrode in the first multiplying electrode group is electrically connected to a fixed voltage source.

[0013] In one optional embodiment, the number of dynamometer electrodes in the first dynamometer electrode group is 5, and the number of dynamometer electrodes in the second dynamometer electrode group is 4; or the number of dynamometer electrodes in the first dynamometer electrode group is 5, and the number of dynamometer electrodes in the second dynamometer electrode group is 5; or the number of dynamometer electrodes in the first dynamometer electrode group is 6, and the number of dynamometer electrodes in the second dynamometer electrode group is 5; or the number of dynamometer electrodes in the first dynamometer electrode group is 6, and the number of dynamometer electrodes in the second dynamometer electrode group is 6.

[0014] Secondly, embodiments of this disclosure also provide a photomultiplier device, which includes: a control circuit for rapid gain adjustment of a photomultiplier tube as described above.

[0015] Thirdly, embodiments of this disclosure also provide a wafer defect detection system, which includes: a control circuit for rapid adjustment of photomultiplier tube gain as described above.

[0016] The beneficial effect of this utility model is that, through the driving unit, it can output high-speed changing voltages with periods as low as 10ns to the first constant current circuit and the second constant current circuit respectively, so that the voltage of the corresponding multiplication electrode in the first constant current circuit and the second constant current circuit changes rapidly, that is, the voltage difference between adjacent multiplication electrodes in the first multiplication electrode group and the second multiplication electrode group changes, thereby changing the amplification factor accordingly, thus achieving a rapid change in gain at the 10ns level.

[0017] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A circuit diagram of a control circuit for rapid gain adjustment of a photomultiplier tube provided in an embodiment of this disclosure;

[0021] Figure 2A circuit diagram of another control circuit for rapid gain adjustment of a photomultiplier tube provided in an embodiment of this disclosure.

[0022] In the picture:

[0023] I1, First constant current source; I2, Second constant current source;

[0024] U1, First operational amplifier; U2, Second operational amplifier; U3, Photomultiplier tube. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0027] In this document, when an element or layer is referred to as “located,” “joined to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly located, joined, connected, attached to, or coupled to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as “directly on another element or layer,” “directly joined to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items.

[0028] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0029] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0030] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] The following detailed description, with reference to the accompanying drawings, describes some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] like Figures 1 to 2 As shown, at least one embodiment provides a control circuit for rapid gain adjustment of a photomultiplier tube, comprising: a photomultiplier tube U3, a first constant current circuit, a second constant current circuit, and a driving unit; wherein the first constant current circuit is electrically connected to each corresponding dynode of the first dynode group in the photomultiplier tube U3, the second constant current circuit is electrically connected to each corresponding dynode of the second dynode group in the photomultiplier tube U3, and the first constant current circuit and the second constant current circuit are respectively electrically connected to the driving unit; the driving unit is configured to output a variable voltage to the first constant current circuit to change the voltage of each corresponding dynode in the first dynode group; and the driving unit is configured to output a variable voltage to the second constant current circuit to change the voltage of each corresponding dynode in the second dynode group.

[0034] Specifically, the photomultiplier electrode, also known as the photomultiplier plate, is an electron-sensitive plate that emits a large number (at least twice) of secondary electrons after being struck by high-energy electrons such as photoelectrons, thereby causing a cascade amplification effect. Furthermore, the gain of the photomultiplier tube U3 changes exponentially with the voltage between the photomultiplier electrodes.

[0035] In at least one embodiment, the driving unit can output a high-speed changing voltage with a period as low as 10ns to the first constant current circuit and the second constant current circuit respectively, so that the voltage of the corresponding multiplication electrode in the first constant current circuit and the second constant current circuit changes rapidly, that is, the voltage difference between adjacent multiplication electrodes in the first multiplication electrode group and the second multiplication electrode group changes, thereby changing the amplification factor accordingly, thereby achieving a rapid change in gain at the 10ns level.

[0036] In at least one embodiment, please refer to Figure 1 , Figure 2 The first constant current circuit includes: several resistors, several capacitors, and a first constant current source I1; each resistor is connected in series between the driving unit and the first constant current source I1, and each capacitor is connected in parallel with its corresponding resistor; the two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplier electrode in the first multiplier electrode group, the two ends of the last resistor are electrically connected to the corresponding multiplier electrode in the first multiplier electrode group and the first constant current source I1, and the two ends of the remaining resistors are electrically connected to the two corresponding multiplier electrodes in the first multiplier electrode group.

[0037] Specifically, when the number of multiplication electrodes in photomultiplier tube U3 is 9, please refer to [link to relevant documentation]. Figure 1 The first constant current circuit includes: resistors R11, R1, R3, R5, and R7 connected in series, with R7 as the first resistor and R11 as the last resistor. The two ends of resistor R7 are electrically connected to the driving unit and the multiplier electrode DY7, respectively. The two ends of resistor R5 are electrically connected to the multiplier electrodes DY7 and DY5, respectively. The two ends of resistor R3 are electrically connected to the multiplier electrodes DY5 and DY3, respectively. The two ends of resistor R1 are electrically connected to the multiplier electrodes DY3 and DY1, respectively. The two ends of resistor R11 are electrically connected to the multiplier electrode DY1 and the first constant current source I1, forming an independent first constant current circuit. The first constant current circuit is driven by the driving unit, and the multiplier electrode DY9 in the photomultiplier tube U3 is connected to a fixed voltage separately.

[0038] Specifically, please refer to Figure 1 Capacitor C11 is connected in parallel with resistor R11, capacitor C1 is connected in parallel with resistor R1, capacitor C3 is connected in parallel with resistor R3, capacitor C5 is connected in parallel with resistor R5, and capacitor C7 is connected in parallel with resistor R7.

[0039] Specifically, when the number of multiplication electrodes in the photomultiplier tube U3 is odd, the circuit structure of the first constant current circuit and each multiplication electrode in the first multiplication electrode group is the same as... Figure 1 similar.

[0040] Specifically, when the number of multiplication electrodes in photomultiplier tube U3 is 10, please refer to [link to relevant documentation]. Figure 2 The first constant current circuit includes: resistors R11, R1, R3, R5, R7, and R9 connected in series, with R9 as the first resistor and R11 as the last resistor. The two ends of resistor R9 are electrically connected to the driving unit and the multiplier electrode DY9, respectively. The two ends of resistor R7 are electrically connected to the multiplier electrodes DY9 and DY7, respectively. The two ends of resistor R5 are electrically connected to the multiplier electrodes DY7 and DY5, respectively. The two ends of resistor R3 are electrically connected to the multiplier electrodes DY5 and DY3, respectively. The two ends of resistor R1 are electrically connected to the multiplier electrodes DY3 and DY1, respectively. The two ends of resistor R11 are electrically connected to the multiplier electrode DY1 and the first constant current source I1, respectively, forming an independent first constant current circuit, which is driven by the driving unit.

[0041] Specifically, please refer to Figure 2 Capacitor C11 is connected in parallel with resistor R11, capacitor C1 is connected in parallel with resistor R1, capacitor C3 is connected in parallel with resistor R3, capacitor C5 is connected in parallel with resistor R5, capacitor C7 is connected in parallel with resistor R7, and capacitor C9 is connected in parallel with resistor R9.

[0042] Specifically, when the number of multiplication electrodes in the photomultiplier tube U3 is even, the circuit structure of the first constant current circuit and each multiplication electrode in the first multiplication electrode group is the same as... Figure 2 similar.

[0043] In at least one embodiment, please refer to Figure 1 , Figure 2 The second constant current circuit includes: several resistors, several capacitors, and a second constant current source I2; each resistor is connected in series between the driving unit and the second constant current source I2, and each capacitor is connected in parallel with its corresponding resistor; the two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplier electrode in the second multiplier electrode group, the two ends of the last resistor are electrically connected to the corresponding multiplier electrode in the second multiplier electrode group and the second constant current source I2, and the two ends of the remaining resistors are electrically connected to the two corresponding multiplier electrodes in the second multiplier electrode group.

[0044] Specifically, when the number of multiplication electrodes in photomultiplier tube U3 is 9, please refer to [link to relevant documentation]. Figure 1The second constant current circuit includes resistors R12, R2, R3, R4, and R5 connected in series, with resistor R8 as the first resistor and resistor R12 as the last resistor. The two ends of resistor R8 are electrically connected to the driving unit and the multiplier electrode DY8, respectively. The two ends of resistor R6 are electrically connected to the multiplier electrodes DY8 and DY6, respectively. The two ends of resistor R4 are electrically connected to the multiplier electrodes DY6 and DY4, respectively. The two ends of resistor R2 are electrically connected to the multiplier electrodes DY4 and DY2, respectively. The two ends of resistor R12 are electrically connected to the multiplier electrode DY2 and the second constant current source I2, respectively, forming an independent second constant current circuit, which is driven by the driving unit.

[0045] Specifically, please refer to Figure 1 Capacitor C12 is connected in parallel with resistor R12, capacitor C2 is connected in parallel with resistor R2, capacitor C3 is connected in parallel with resistor R3, capacitor C6 is connected in parallel with resistor R6, and capacitor C8 is connected in parallel with resistor R8.

[0046] Specifically, when the number of multiplication electrodes in the photomultiplier tube U3 is odd, the circuit structure of the second constant current circuit and each multiplication electrode in the second multiplication electrode group is the same as... Figure 1 similar.

[0047] Specifically, when the number of multiplication electrodes in photomultiplier tube U3 is 10, please refer to [link to relevant documentation]. Figure 2 The second constant current circuit includes resistors R12, R2, R4, R6, R8, and R10 connected in series, with R10 as the first resistor and R12 as the last resistor. The two ends of resistor R10 are electrically connected to the driving unit and the multiplier electrode DY10, respectively. The two ends of resistor R8 are electrically connected to the multiplier electrodes DY10 and DY8, respectively. The two ends of resistor R6 are electrically connected to the multiplier electrodes DY8 and DY6, respectively. The two ends of resistor R4 are electrically connected to the multiplier electrodes DY6 and DY4, respectively. The two ends of resistor R2 are electrically connected to the multiplier electrodes DY4 and DY2, respectively. The two ends of resistor R12 are electrically connected to the multiplier electrode DY2 and the second constant current source I2, respectively, forming an independent second constant current circuit, which is driven by the driving unit.

[0048] Specifically, please refer to Figure 2 Capacitor C12 is connected in parallel with resistor R12, capacitor C2 is connected in parallel with resistor R2, capacitor C4 is connected in parallel with resistor R4, capacitor C6 is connected in parallel with resistor R6, capacitor C8 is connected in parallel with resistor R8, and capacitor C10 is connected in parallel with resistor R10.

[0049] Specifically, when the number of multiplication electrodes in photomultiplier tube U3 is even, the circuit structure of the second constant current circuit and each multiplication electrode in the second multiplication electrode group is the same as... Figure 2 similar.

[0050] Specifically, Figure 1 , Figure 2 Each resistor in the middle is a voltage divider resistor. Figure 1 , Figure 2 Each capacitor in the middle serves to rapidly pass alternating current.

[0051] In at least one embodiment, please refer to Figure 1 , Figure 2 The driving unit includes: a first operational amplifier U1; the first operational amplifier U1 is electrically connected to a first constant current circuit and a second constant current circuit to output a changing voltage to the first constant current circuit and the second constant current circuit.

[0052] Specifically, the first operational amplifier U1 can be configured to simultaneously drive the first constant current circuit and the second constant current circuit.

[0053] Specifically, the first operational amplifier U1 can be directly driven for output, and the first operational amplifier U1 can also be driven for output through an optocoupler.

[0054] In at least one embodiment, please refer to Figure 1 , Figure 2 The driving unit includes: a first operational amplifier U1 and a second operational amplifier U2; the first operational amplifier U1 is electrically connected to a first constant current circuit to output a variable voltage to the first constant current circuit; the second operational amplifier U2 is electrically connected to a second constant current circuit to output a variable voltage to the second constant current circuit.

[0055] Specifically, the first operational amplifier U1 and the second operational amplifier U2 can be configured to drive the first constant current circuit and the second constant current circuit, respectively.

[0056] Specifically, the first operational amplifier U1 and the second operational amplifier U2 can be directly driven for output, and at the same time, the first operational amplifier U1 and the second operational amplifier U2 can also be driven for output through an optocoupler.

[0057] Specifically, please refer to Figure 1 The voltage between adjacent multiplier electrodes is determined by I1, I2, V1 (output voltage of U1), and V2 (output voltage of U2). Therefore, the voltage of the first multiplier electrode group is V. dy1 =I1*(R1+R3+R5+R7)+V1, where V is the voltage of the second multiplication electrode group. dy2=I2*(R2+R4+R6+R8)+V2, where I1, I2, R1, R2, R3, R4, R5, R6, R7, and R8 are fixed parameters, and V... dy1 V dy2 It changes constantly due to the rapid changes in V1 and V2.

[0058] In at least one embodiment, please refer to Figure 1 , Figure 2 The photomultiplier electrodes in the photomultiplier tube U3 are numbered sequentially. The odd-numbered photomultiplier electrodes are located on one side of the photomultiplier tube U3 and form the first photomultiplier electrode group; the even-numbered photomultiplier electrodes are located on the other side of the photomultiplier tube U3 and form the second photomultiplier electrode group.

[0059] Specifically, please refer to Figure 1 The odd-numbered multiplication electrodes are DY1, DY3, DY5, DY7, and DY9, and are located on one side of the photomultiplier tube U3; the even-numbered multiplication electrodes are DY2, DY4, DY6, and DY8, and are located on the other side of the photomultiplier tube U3.

[0060] Specifically, please refer to Figure 2 The odd-numbered multiplication electrodes are DY1, DY3, DY5, DY7, and DY9, and are located on one side of the photomultiplier tube U3; the even-numbered multiplication electrodes are DY2, DY4, DY6, DY8, and DY10, and are located on the other side of the photomultiplier tube U3.

[0061] Specifically, please refer to Figure 1 , Figure 2 I_PMT is the current of photomultiplier tube U3, and the K and A terminals of photomultiplier tube U3 are connected in the circuit.

[0062] Specifically, the photomultiplier tube U3 can be equipped with 9 to 12 multiplication electrodes.

[0063] In at least one embodiment, please refer to Figure 1 , Figure 2 The total number of multiplying electrodes in the first multiplying electrode group is greater than the total number of multiplying electrodes in the second multiplying electrode group, and the extra multiplying electrode in the first multiplying electrode group is electrically connected to a fixed voltage source.

[0064] Specifically, please refer to Figure 1When the total number of multiplication electrodes in photomultiplier tube U3 is 9, the total number of multiplication electrodes in the first multiplication electrode group is 5, that is, the total number of multiplication electrodes in the first multiplication electrode group is 4. At this time, the extra multiplication electrode DY9 in the first multiplication electrode group is connected to the fixed voltage source V4.

[0065] In at least one embodiment, please refer to Figure 1 , Figure 2 The first dynamometer electrode group has 5 dynamometer electrodes, and the second dynamometer electrode group has 4 dynamometer electrodes; or the first dynamometer electrode group has 5 dynamometer electrodes, and the second dynamometer electrode group has 5 dynamometer electrodes; or the first dynamometer electrode group has 6 dynamometer electrodes, and the second dynamometer electrode group has 5 dynamometer electrodes; or the first dynamometer electrode group has 6 dynamometer electrodes, and the second dynamometer electrode group has 6 dynamometer electrodes.

[0066] Based on the same technical concept, at least one embodiment also provides a photomultiplier device, which includes: a control circuit for rapid adjustment of the gain of the photomultiplier tube as described above.

[0067] Based on the same technical concept, at least one embodiment also provides a wafer defect detection system, which includes: a control circuit for rapid adjustment of photomultiplier tube gain as described above.

[0068] Specifically, the control circuit for rapid gain adjustment of photomultiplier tube can realize rapid adjustment of the gain of photomultiplier tube U3, which can be applied to wafer defect detection.

[0069] In summary, this invention can output high-speed changing voltages with periods as low as 10ns to the first constant current circuit and the second constant current circuit through the driving unit, so that the voltages of the corresponding multiplication electrodes in the first constant current circuit and the second constant current circuit change rapidly, that is, the voltage difference between adjacent multiplication electrodes in the first multiplication electrode group and the second multiplication electrode group changes, thereby changing the amplification factor accordingly, thus achieving a rapid gain change at the 10ns level.

[0070] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0071] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as the second element, component, region, layer, or segment.

[0072] Spatially relative terms, such as “inside,” “outside,” “below,” “below,” “down,” “above,” “up,” etc., may be used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. In addition to the orientations depicted in the figures, spatially relative terms may be intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “below” other elements or features would be oriented as “above” other elements or features. Thus, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0073] In the above discussion, unless otherwise stated, when used to describe numerical values, the terms “about,” “approximately,” “basically,” etc., indicate a change of + / - 10% in that value.

[0074] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A control circuit for rapid gain adjustment of a photomultiplier tube, characterized in that, include: Photomultiplier tube (U3), first constant current circuit, second constant current circuit and drive unit; in The first constant current circuit is electrically connected to each corresponding multiplication electrode of the first multiplication electrode group in the photomultiplier tube (U3), and the second constant current circuit is electrically connected to each corresponding multiplication electrode of the second multiplication electrode group in the photomultiplier tube (U3). The first constant current circuit and the second constant current circuit are electrically connected to the driving unit respectively. The driving unit is configured to output a variable voltage to the first constant current circuit so that the voltage of each corresponding multiplier electrode in the first multiplier electrode group changes. as well as The driving unit is also configured to output a variable voltage to the second constant current circuit so that the voltage of each corresponding multiplier electrode in the second multiplier electrode group changes.

2. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 1, characterized in that, The first constant current circuit includes: several resistors, several capacitors, and a first constant current source (I1); Each of the resistors is connected in series and then connected between the driving unit and the first constant current source (I1), and each of the capacitors is connected in parallel with the corresponding resistor. The two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplier electrode in the first multiplier electrode group, respectively. The two ends of the last resistor are electrically connected to the corresponding multiplier electrode in the first multiplier electrode group and the first constant current source (I1), respectively. The two ends of the remaining resistors are electrically connected to the two corresponding multiplier electrodes in the first multiplier electrode group, respectively.

3. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 1, characterized in that, The second constant current circuit includes: several resistors, several capacitors, and a second constant current source (I2); Each of the resistors is connected in series and then connected between the driving unit and the second constant current source (I2), and each of the capacitors is connected in parallel with the corresponding resistor; The two ends of the first resistor are electrically connected to the driving unit and the corresponding multiplier electrode in the second multiplier electrode group, respectively. The two ends of the last resistor are electrically connected to the corresponding multiplier electrode in the second multiplier electrode group and the second constant current source (I2), respectively. The two ends of the remaining resistors are electrically connected to the two corresponding multiplier electrodes in the second multiplier electrode group, respectively.

4. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 1, characterized in that, The driving unit includes: a first operational amplifier (U1); The first operational amplifier (U1) is electrically connected to the first constant current circuit and the second constant current circuit to output a variable voltage to the first constant current circuit and the second constant current circuit.

5. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 1, characterized in that, The driving unit includes: a first operational amplifier (U1) and a second operational amplifier (U2); The first operational amplifier (U1) is electrically connected to the first constant current circuit to output a variable voltage to the first constant current circuit; The second operational amplifier (U2) is electrically connected to the second constant current circuit to output a variable voltage to the second constant current circuit.

6. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 1, characterized in that, The photomultiplier tube (U3) has its multiplier electrodes numbered sequentially. The odd-numbered multiplier electrodes are located on one side of the photomultiplier tube (U3) and are the first multiplier electrode group. Each of the even-numbered multiplication electrodes is located on the other side of the photomultiplier tube (U3) and is the second multiplication electrode group.

7. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 6, characterized in that, The total number of multiplying electrodes in the first multiplying electrode group is greater than the total number of multiplying electrodes in the second multiplying electrode group, and the extra multiplying electrode in the first multiplying electrode group is electrically connected to a fixed voltage source.

8. The control circuit for rapid gain adjustment of a photomultiplier tube as described in claim 6, characterized in that, The first dynamometer electrode group has 5 dynamometer electrodes, and the second dynamometer electrode group has 4 dynamometer electrodes. Alternatively, the number of multiplying electrodes in the first multiplying electrode group is 5, and the number of multiplying electrodes in the second multiplying electrode group is 5; Alternatively, the number of multiplying electrodes in the first multiplying electrode group is 6, and the number of multiplying electrodes in the second multiplying electrode group is 5; Alternatively, the number of multiplying electrodes in the first multiplying electrode group is 6, and the number of multiplying electrodes in the second multiplying electrode group is 6.

9. A photomultiplier device, characterized in that, include: The control circuit for rapid gain adjustment of a photomultiplier tube as described in any one of claims 1-8.

10. A wafer defect detection system, characterized in that, include: The control circuit for rapid gain adjustment of a photomultiplier tube as described in any one of claims 1-8.

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