阅读说明：本技术 一种用于对微光探测器的光电倍增管进行快速开关的方法及系统 (Method and system for rapidly switching photomultiplier of micro-light detector ) 是由 王晶 杨永东 张晓春 于 2019-12-24 设计创作，主要内容包括：本发明公开了一种用于对微光探测器的光电倍增管进行快速开关的方法及系统,其中方法包括：对微光探测器的分压电路增加门控电路；当激光器关闭时,将脉冲低电平信号输入门控电路输入端,通过所述微光探测器的高压电源为所述分压电路的第一倍增级、第二倍增级和第三倍增级之间形成电势差,光电倍增管PMT开启；当激光器开启时,将脉冲高电平信号输入门控电路输入端,切断所述微光探测器的高压电源供电,所述分压电路的第一倍增级、第二倍增级和第三倍增级之间形成电势差为0,光电倍增管PMT关闭。(The invention discloses a method and a system for quickly switching on and off a photomultiplier of a micro-light detector, wherein the method comprises the following steps: a gate control circuit is added to a voltage division circuit of the low-light detector; when the laser is closed, a pulse low-level signal is input into the input end of the gate control circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and the photomultiplier tube PMT is opened; when the laser is started, a pulse high-level signal is input to the input end of the gate control circuit, the power supply of a high-voltage power supply of the micro-light detector is cut off, potential difference formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit is 0, and the photomultiplier PMT is closed.)

1. A method for fast switching of a photomultiplier tube of a micro-light detector, the method comprising:

a gate control circuit is added to a voltage division circuit of the low-light detector;

when the laser is closed, a pulse low-level signal is input into the input end of the gate control circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and the photomultiplier tube PMT is opened;

when the laser is started, a pulse high-level signal is input to the input end of the gate control circuit, the power supply of a high-voltage power supply of the micro-light detector is cut off, potential difference formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit is 0, and the photomultiplier PMT is closed.

2. The method of claim 1, wherein when the laser is off, a pulsed low level signal is input to the gating circuit input, a potential difference is formed between the first multiplier stage, the second multiplier stage, and the third multiplier stage, and the photomultiplier tube PMT is turned on, further comprising:

when the laser is turned off, a pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

3. The method of claim 1, wherein the photomultiplier tube PMT is turned off by inputting a pulsed high level signal to the input of the gating circuit to create a potential difference of 0 between the first multiplier stage, the second multiplier stage, and the third multiplier stage when the laser is on, and further comprising:

when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, the quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplier stage, the second multiplier stage and the third multiplier stage.

4. The method of claim 1, the adding a gating circuit to a voltage divider circuit of a micro-light detector, comprising:

and a gate control circuit is added by leading out pins of the voltage division circuit.

5. The method of claim 1, wherein the pulsed low level signal is a TTL pulsed low level signal.

6. A system for fast switching of a photomultiplier tube of a micro-light detector, the system comprising:

the initial unit is used for adding a gate control circuit to a voltage division circuit of the low-light detector;

the starting unit is used for inputting a pulse low-level signal into the input end of the gate control circuit when the laser is closed, forming potential differences among the first multiplier stage, the second multiplier stage and the third multiplier stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and starting the photomultiplier tube PMT;

and the closing unit is used for inputting a pulse high-level signal into the input end of the gate control circuit when the laser is started, cutting off the power supply of a high-voltage power supply of the micro-light detector, forming a potential difference of 0 among a first multiplying stage, a second multiplying stage and a third multiplying stage of the voltage division circuit, and closing the PMT.

7. The system of claim 6, the activation unit to: when the laser is closed, a pulse low-level signal is input into the input end of the gating circuit, potential differences are formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier tube PMT is started and is also used for:

when the laser is turned off, a pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

8. The system of claim 6, the shutdown unit to: when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, a potential difference of 0 is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier tube PMT is closed and is also used for:

when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, the quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplier stage, the second multiplier stage and the third multiplier stage.

9. The system of claim 6, the addition of a gating circuit to a voltage divider circuit of a micro-light detector, comprising:

and a gate control circuit is added by leading out pins of the voltage division circuit.

10. The system of claim 6, wherein the pulsed low level signal is a TTL pulsed low level signal.

Technical Field

The invention relates to the technical field of micro light detection, in particular to a method and a system for quickly switching on and off a photomultiplier of a micro light detector.

Background

In tests such as a laser spectroscopy test, a fluorescence test, raman spectroscopy, a biological DL test, and a boltzmann electron temperature test, a signal as a test object is very weak, and therefore a highly sensitive photomultiplier tube is generally used as a detection means. However, the intensity of light used as the excitation source is often very strong, which easily leads to saturation of the output current of the photomultiplier anode and even irreversible damage. Therefore, the photomultiplier needs to be closed to avoid damage when the exciting light acts; and when the signal light needs to be detected, the photomultiplier is started again for detection.

The peripheral circuit of the photomultiplier consists of a high-voltage power supply, a voltage division circuit, an amplification discrimination circuit and a shaping circuit. The high-voltage power supply and the voltage division circuit are used for providing potential difference for each dynode of the photomultiplier, so that the photomultiplier can normally work.

PMT: all known as a PhotoMultiplier Tube, i.e., a PhotoMultiplier Tube. It is a vacuum electronic device capable of converting weak optical signals into electrical signals. A detector for converting incident photons into photoelectric signals using the external photoelectric effect. The photomultiplier consists of an incidence window, a photocathode surface, a multiplication system, an anode and the like. Under the excitation of photons, the photocathode surface emits electrons into vacuum (external photoelectric effect), and under the action of an electric field, the electrons are collected to the first dynode through the focusing electrode, and the impact multiplied electrons can release more electrons. Then, the mixture sequentially passes through the dynodes to perform secondary electron multiplication. And finally, the secondary electrons emitted by the final dynode are output through the anode.

DL: is called Delay Luminescence in its entirety. The organism is subjected to external excitation, for example by a laser beam. At the end of the re-excitation, the organism will also emit photons in this broad band and gradually decay. And the energy distribution is uniform in the 400-800nm band. This longer time (in the order of ms to s) after excitation photon emission is called delayed luminescence.

Disclosure of Invention

The technical scheme of the invention provides a method and a system for quickly switching a photomultiplier of a micro-light detector, so as to solve the problem of how to quickly switch the photomultiplier of the micro-light detector.

In order to solve the above problems, the present invention provides a method for rapidly switching a photomultiplier of a micro light detector, the method comprising:

a gate control circuit is added to a voltage division circuit of the low-light detector;

when the laser is closed, a pulse low-level signal is input into the input end of the gate control circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and the photomultiplier tube PMT is opened;

when the laser is started, a pulse high-level signal is input to the input end of the gate control circuit, the power supply of a high-voltage power supply of the micro-light detector is cut off, potential difference formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit is 0, and the photomultiplier PMT is closed.

Preferably, when the laser is turned off, a pulse low-level signal is input to the input end of the gating circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on, further comprising:

when the laser is turned off, a pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

Preferably, when the laser is turned on, by inputting a pulse high level signal to the input end of the gating circuit, a potential difference of 0 is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned off, further comprising:

when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, the quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplier stage, the second multiplier stage and the third multiplier stage.

Preferably, the adding of the gate control circuit to the voltage division circuit of the micro light detector comprises:

and a gate control circuit is added by leading out pins of the voltage division circuit.

Preferably, the pulse low level signal is a TTL pulse low level signal.

According to another aspect of the present invention, there is provided a system for fast switching of a photomultiplier tube of a micro-light detector, the system comprising:

the initial unit is used for adding a gate control circuit to a voltage division circuit of the low-light detector;

the starting unit is used for inputting a pulse low-level signal into the input end of the gate control circuit when the laser is closed, forming potential differences among the first multiplier stage, the second multiplier stage and the third multiplier stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and starting the photomultiplier tube PMT;

and the closing unit is used for inputting a pulse high-level signal into the input end of the gate control circuit when the laser is started, cutting off the power supply of a high-voltage power supply of the micro-light detector, forming a potential difference of 0 among a first multiplying stage, a second multiplying stage and a third multiplying stage of the voltage division circuit, and closing the PMT.

Preferably, the opening unit is configured to: when the laser is closed, a pulse low-level signal is input into the input end of the gating circuit, potential differences are formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier tube PMT is started and is also used for:

when the laser is turned off, a pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

Preferably, the closing unit is configured to: when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, a potential difference of 0 is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier tube PMT is closed and is also used for:

when the laser is started, a pulse high-level signal is input into the input end of the gate control circuit, the quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplier stage, the second multiplier stage and the third multiplier stage.

Preferably, the adding of the gate control circuit to the voltage division circuit of the micro light detector comprises:

and a gate control circuit is added by leading out pins of the voltage division circuit.

Preferably, the pulse low level signal is a TTL pulse low level signal.

The technical scheme of the invention provides a method and a system for quickly switching on and off a photomultiplier of a micro-light detector, wherein the method comprises the following steps: a gate control circuit is added to a voltage division circuit of the low-light detector; when the laser is closed, TTL pulse low-level signals are input into the input end of the gate control circuit, potential differences are formed among a first multiplying stage, a second multiplying stage and a third multiplying stage of the voltage division circuit through a high-voltage power supply of the micro-light detector, and a photomultiplier tube (PMT) is started; when the laser is started, a TTL pulse high-level signal is input into the input end of the gate control circuit, the power supply of a high-voltage power supply of the micro-light detector is cut off, potential difference of 0 is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit, and the PMT is closed. The technical scheme of the invention provides a gate control circuit applied to a photomultiplier tube, and a method for controlling a first dynode, a second dynode and a third dynode of the photomultiplier tube is provided. The experimental results show that the PMT has the response time of 40ns when being closed and 10uS when being opened. The quick response time meets the requirements of experiments, and the device is low in price and easy to install.

Drawings

A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:

FIG. 1 is a flow chart of a method for rapidly switching a photomultiplier tube of a micro-light detector in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a stage for rapidly switching a photomultiplier tube of a micro-light detector in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a gating circuit according to a preferred embodiment of the present invention;

FIG. 4 is a diagram illustrating the pulse at terminal C and the voltage DY3 when the gating signal at terminal C is low according to the preferred embodiment of the present invention;

FIG. 5 is a diagram illustrating the pulse at terminal C and the voltage DY3 when the gating signal at terminal C is high according to the preferred embodiment of the present invention; and

fig. 6 is a block diagram of a system for rapidly switching a photomultiplier tube of a micro-light detector according to a preferred embodiment of the present invention.

Detailed Description

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

FIG. 1 is a flow chart of a method for rapidly switching a photomultiplier tube of a micro-light detector according to a preferred embodiment of the present invention. According to the embodiment of the application, under the condition that an original circuit is not damaged, only the corresponding multiplication pin is led out, and the gate control circuit is additionally arranged on the voltage division and voltage division circuit, so that the gate control function of the detector can be realized. The gate control circuit controls the potential difference of the front three multiplication stages of the PMT through the external TTL pulse, further controls the enabling and disabling of the PMT, and has the advantages of high response speed, high extinction ratio and flexible operation. The gate control circuit is designed based on a CR110 PMT, and is controlled by a method for controlling a first dynode, a second dynode and a third dynode of the photomultiplier. The experimental results show that the PMT off response time is 40ns and the on response time is 10 uS. The quick response time meets the requirements of experiments, and the device is low in price and easy to install. As shown in fig. 1, the present application provides a method for fast switching of a photomultiplier tube of a micro-light detector, the method comprising:

preferably, in step 101: a gate control circuit is added to a voltage division circuit of the low-light detector. Preferably, a gate control circuit is added to the voltage dividing circuit of the micro light detector, and the gate control circuit comprises: and a gate control circuit is added by leading out pins of the voltage division circuit. The application can lead out corresponding multiplication pin and install gate control circuit on the voltage division and voltage division circuit under the condition of not destroying the original circuit, thus the detector can realize the gate control function.

Preferably, at step 102: when the laser is closed, a TTL pulse low-level signal is input into the input end of the gate control circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit by a high-voltage power supply of the micro-light detector, and the photomultiplier PMT is started.

Preferably, when the laser is turned off, a TTL pulse low level signal is input to the input terminal of the gating circuit, a potential difference is formed between the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on, further comprising: when the laser is turned off, a TTL pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

What contributes to the photomultiplier tube PMT gating operation in this application is the gating design in the voltage divider circuit, as shown in fig. 3. + HV is the high voltage power input end, DY1, DY2 and DY3 … DYn are the multiplication stages of the voltage divider, and R1, R2 and R3 … Rn are divider resistors. The voltage division circuit of the photomultiplier PMT is formed. The triode Q1, the diode D1, the accelerating capacitor C1, the resistor R6 and the resistor R7 jointly form a gate control circuit. The emitting electrode and the collecting electrode of the triode Q1 are respectively connected with the photocathode plane P and the third tripling electrode DY3, and the C end is the input end of a gating signal.

When the gating signal at the end C is at a low level, the triode Q1 is cut off, and the potential difference among the photocathode surfaces P, DY1, DY2 and DY3 is normal. Electrons generated by the photocathode surface are accelerated and multiplied under the action of an electric field, and the PMT is turned on. The PMT has a response time of about 10uS, and as shown in FIG. 4, A1 is a C terminal pulse, and A2 is a voltage value at DY 3. The application is convenient for observation, and the C-terminal signal is reversely displayed.

The gate control circuit controls the potential difference of the front three multiplication stages of the photomultiplier PMT through the external TTL pulse, further controls the enabling and disabling of the photomultiplier PMT, and has the advantages of high response speed, high extinction ratio and flexible operation.

Preferably, in step 103: when the laser is started, a TTL pulse high-level signal is input into the input end of the gate control circuit, the power supply of a high-voltage power supply of the micro-light detector is cut off, potential difference of 0 is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit, and the PMT is closed.

Preferably, when the laser is turned on, by inputting a TTL pulse high level signal to the input end of the gating circuit, a potential difference of 0 is formed between the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned off, further comprising: when the laser is started, a TTL pulse high-level signal is input into the input end of the gate control circuit, a quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage.

When the gating signal of the end C is at a high level, the triode Q1 is conducted, the potential difference among the photocathode surfaces P, DY1, DY2 and DY3 is zero, electrons generated by the photocathode surfaces cannot be accelerated, and therefore the purpose of turning off the PMT is achieved. The response time of the photomultiplier tube PMT is about 40nS, as shown in FIG. 5, B1 is a C-terminal pulse, and B2 is a voltage value at DY 3. The application is convenient for observation, and the C-terminal signal is reversely displayed.

The potential difference changes between the multiplier stages of the present application are shown in the following table:

fig. 6 is a block diagram of a system for rapidly switching a photomultiplier tube of a micro-light detector according to a preferred embodiment of the present invention. As shown in fig. 6, the present application provides a system for fast switching of a photomultiplier tube of a micro-light detector, the system comprising:

the initial unit 601 is used for adding a gate control circuit to a voltage division circuit of the micro light detector. Preferably, a gate control circuit is added to the voltage dividing circuit of the micro light detector, and the gate control circuit comprises: and a gate control circuit is added by leading out pins of the voltage division circuit. The application can lead out corresponding multiplication pin and install gate control circuit on the voltage division and voltage division circuit under the condition of not destroying the original circuit, thus the detector can realize the gate control function.

And the starting unit 602 is used for inputting a TTL pulse low-level signal into the input end of the gate control circuit when the laser is closed, forming potential differences among the first multiplier stage, the second multiplier stage and the third multiplier stage of the voltage division circuit by using a high-voltage power supply of the micro-light detector, and starting the photomultiplier tube PMT.

Preferably, the opening unit 602 is configured to: when the laser is closed, the TTL pulse low level signal is input into the input end of the gate control circuit, a potential difference is formed among the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier tube PMT is started and is also used for: when the laser is turned off, a TTL pulse low-level signal is input into an input end C of the gate control circuit, a quick response triode Q1 of the gate control circuit is cut off, potential differences are formed between a photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage, and the photomultiplier PMT is turned on.

What contributes to the photomultiplier tube PMT gating operation in this application is the gating design in the voltage divider circuit, as shown in fig. 3. + HV is the high voltage power input end, DY1, DY2 and DY3 … DYn are the multiplication stages of the voltage divider, and R1, R2 and R3 … Rn are divider resistors. The voltage division circuit of the photomultiplier PMT is formed. The triode Q1, the diode D1, the accelerating capacitor C1, the resistor R6 and the resistor R7 jointly form a gate control circuit. The emitting electrode and the collecting electrode of the triode Q1 are respectively connected with the photocathode plane P and the third tripling electrode DY3, and the C end is the input end of a gating signal.

When the gating signal at the end C is at a low level, the triode Q1 is cut off, and the potential difference among the photocathode surfaces P, DY1, DY2 and DY3 is normal. Electrons generated by the photocathode surface are accelerated and multiplied under the action of an electric field, and the PMT is turned on. The PMT has a response time of about 10uS, and as shown in FIG. 4, A1 is a C terminal pulse, and A2 is a voltage value at DY 3. The application is convenient for observation, and the C-terminal signal is reversely displayed.

The gate control circuit controls the potential difference of the front three multiplication stages of the photomultiplier PMT through the external TTL pulse, further controls the enabling and disabling of the photomultiplier PMT, and has the advantages of high response speed, high extinction ratio and flexible operation.

And the closing unit 603 is used for inputting a TTL pulse high-level signal into the input end of the gate control circuit when the laser is started, cutting off the power supply of a high-voltage power supply of the micro-light detector, forming a potential difference of 0 among the first multiplying stage, the second multiplying stage and the third multiplying stage of the voltage division circuit, and closing the PMT.

Preferably, a closing unit 603 for: when the laser opens, through with TTL pulse high level signal input gate-controlled circuit input, it is 0 to form the potential difference between first multiplier stage, second multiplier stage and the third multiplier stage, and photomultiplier PMT closes, still is used for:

when the laser is started, a TTL pulse high-level signal is input into the input end of the gate control circuit, a quick response triode Q1 of the gate control circuit is conducted, and potential difference of 0 is formed between the photocathode plane P and the first multiplying stage, the second multiplying stage and the third multiplying stage.

When the gating signal of the end C is at a high level, the triode Q1 is conducted, the potential difference among the photocathode surfaces P, DY1, DY2 and DY3 is zero, electrons generated by the photocathode surfaces cannot be accelerated, and therefore the purpose of turning off the PMT is achieved. The response time of the photomultiplier tube PMT is about 40nS, as shown in FIG. 5, B1 is a C-terminal pulse, and B2 is a voltage value at DY 3. The application is convenient for observation, and the C-terminal signal is reversely displayed.

The potential difference changes between the multiplier stages of the present application are shown in the following table:

the invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.