Photomultiplier tube single photoelectron response calibration method, device and detector

Abstract

The present disclosure provides a method, device, equipment, medium and detector for calibrating the single photoelectron response of a photomultiplier tube. The method includes: acquiring the charge spectrum of the output signal of the photomultiplier tube at m light intensities respectively to obtain m charge spectra; determining the number of photoelectron events falling within the target charge interval in the m charge spectra respectively to obtain m first event numbers; obtaining the probability of the single photoelectron response function within the target charge interval based on the m first event numbers and the probability distribution model of the photoelectron event number; updating the target charge interval with the first interval width as the step length, and repeatedly performing the operation of obtaining the probability of the single photoelectron response function within the target charge interval until all charge values ​​in the charge spectrum are traversed with the first interval width, thereby obtaining the charge response distribution function of the single photoelectron, and determining the single photoelectron response information for the photomultiplier tube based on the charge response distribution function of the single photoelectron.

Description

Technical Field

[0001] The present disclosure relates to the field of photoelectric detection technology, and in particular to a method, device, electronic device, storage medium, computer program product and a detector for calibrating the single photoelectron response of a photomultiplier tube. Background Art

[0002] Photomultiplier tube (PMT) refers to a vacuum electronic device that converts weak light signals into electrical signals. Photomultiplier tubes are usually used in weak light environments and can measure extremely weak radiation power in low-energy photometry and spectroscopy, and have a wide range of applications. Among them, if the single photoelectron response information of the photomultiplier tube can be accurately obtained in the application, such as the average number of photoelectrons, the average value, variance and higher-order moments of the single photoelectron response distribution, it is crucial for calibrating the working gain, energy resolution and other parameters of the detector.

[0003] In order to obtain the single photoelectron response information of the photomultiplier tube, the related art usually first assumes that the single photoelectron response function of the photomultiplier tube conforms to a mathematical analytical model. Then, the single photoelectron response function of the photomultiplier tube to the photoelectron spectrum is obtained by convolving the background noise and the photoelectron number distribution function, and the photoelectron spectrum is fitted using this function to obtain the parameters describing the single photoelectron response. However, the single photoelectron response function of the photomultiplier tube obtained by the above method depends on the pre-assumed mathematical analytical model of the single photoelectron response function, and cannot accurately describe the actual single photoelectron response function, resulting in inaccurate measurement results. Summary of the invention

[0004] In view of this, the present disclosure provides a method, device, electronic device, storage medium, computer program product and a detector for calibrating single photoelectron response of a photomultiplier tube, in order to at least partially solve the above-mentioned technical problems.

[0005] According to one aspect of the present disclosure, a method for calibrating a single photoelectron response of a photomultiplier tube is provided, comprising: obtaining charge spectra of output signals of a photomultiplier tube respectively under m light intensities to obtain m charge spectra; m is an integer greater than 3; determining the number of photoelectron events in the m charge spectra that fall within a target charge interval to obtain m first event numbers; the target charge interval has a first interval width; obtaining the probability of a single photoelectron response function being within the target charge interval based on the m first event numbers and a probability distribution model for the number of photoelectron events; the probability distribution model for the number of photoelectron events characterizes the probability of the single photoelectron response function in different charge spectra. The probability distribution of the number of photoelectron events falling within the first interval width; updating the target charge interval with the first interval width as the step size, and repeatedly performing the operation of obtaining the probability of a single photoelectron response function within the target charge interval, until all charge values ​​in the charge spectrum are traversed with the first interval width, and the probability of multiple single photoelectron response functions within the target charge interval is obtained; based on the probabilities of multiple single photoelectron response functions within the target charge interval, a charge response distribution function of a single photoelectron is obtained; and based on the charge response distribution function of a single photoelectron, single photoelectron response information for a photomultiplier tube is determined.

[0006] According to an embodiment of the present disclosure, the m charge spectra include a charge spectrum obtained under a light-free measurement condition and a charge spectrum obtained under (m-1) different light-exposed measurement conditions; the above method also includes: determining the average number of photoelectrons obtained under the first light-exposed measurement condition; and applying the average number of photoelectrons to a pre-constructed photoelectron event number probability distribution optimization model to obtain a photoelectron event number probability distribution model.

[0007] According to an embodiment of the present disclosure, the method further includes: acquiring the amplitude spectrum of the photomultiplier tube output signal under the light-free measurement condition and the first light measurement condition, respectively, to obtain the amplitude spectrum under the light-free measurement condition and the amplitude spectrum under the first light measurement condition.

[0008] According to an embodiment of the present disclosure, determining the average number of photoelectrons obtained under the first light measurement condition includes: respectively determining the number of cases in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the number of cases in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition; and determining the average number of photoelectrons obtained under the first light measurement condition based on the number of cases in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the number of cases in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition.

[0009] According to an embodiment of the present disclosure, the probability distribution model of the number of photoelectron events satisfies:

[0010]

[0011] Among them, f(x) represents the probability distribution model of the number of photoelectron events, λ1 represents the average number of photoelectrons obtained under the first light measurement condition, p0 represents the probability of the number of photoelectron events with zero photoelectron event charge falling within the first interval width, p1 represents the probability of the number of photoelectron events with a single photoelectron event charge falling within the first interval width, p2 represents the probability of the number of photoelectron events with two photoelectron event charges falling within the first interval width, and x represents the proportional coefficient of the average number of photoelectrons obtained under other light measurement conditions relative to the average number of photoelectrons obtained under the first light measurement condition.

[0012] According to an embodiment of the present disclosure, the average number of photoelectrons is calculated using the following formula:

[0013]

[0014] Among them, λ 1 represents the average number of photoelectrons obtained under the first light measurement condition, N 1_amp Indicates the number of cases where the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition, N 0_amp Represents the number of events whose amplitude is lower than the amplitude threshold in the amplitude spectrum under no-light measurement conditions.

[0015] According to another aspect of the present disclosure, a method and device for calibrating a single photoelectron response of a photomultiplier tube is provided, comprising: an acquisition module, for respectively acquiring the charge spectrum of the output signal of the photomultiplier tube under m light intensities, to obtain m charge spectra; m is an integer greater than 3; a first determination module, for respectively determining the number of photoelectron events falling within a target charge interval in the m charge spectra, to obtain m first event numbers; the target charge interval has a first interval width; a calculation module, for obtaining the probability of a single photoelectron response function being within the target charge interval based on the m first event numbers and a probability distribution model for the number of photoelectron events; the probability distribution model for the number of photoelectron events characterizes the probability of the single photoelectron response function falling within the target charge interval in different charge spectra. The probability distribution of the number of photoelectron events falling within the first interval width; a second determination module, used to update the target charge interval with the first interval width as a step size, and repeatedly execute the operation of obtaining the probability of the single photoelectron response function within the target charge interval, until all charge values ​​in the charge spectrum are traversed with the first interval width to obtain the probability of multiple single photoelectron response functions within the target charge interval; a third determination module, used to obtain the charge response distribution function of the single photoelectron based on the probability of multiple single photoelectron response functions within the target charge interval; and a fourth determination module, used to determine the single photoelectron response information for the photomultiplier tube based on the charge response distribution function of the single photoelectron.

[0016] According to another aspect of the present disclosure, an electronic device is provided, including: a processor and a memory, wherein at least one instruction is stored in the memory, and when the instruction is executed by the processor, the above method is implemented.

[0017] According to another aspect of the present disclosure, a computer-readable storage medium is provided, in which at least one instruction is stored, and when the instruction is executed by a processor, the above method is implemented.

[0018] According to another aspect of the present disclosure, a computer program product is provided, including a computer program, which implements the above method when executed by a processor.

[0019] According to another aspect of the present disclosure, a detector is provided, comprising the electronic device according to an embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0021] Figure 1 is a flow chart of a method for calibrating a single photoelectron response of a photomultiplier tube according to an embodiment of the present disclosure;

[0022] Figure 2 is a flow chart of a method for determining a probability distribution model of photoelectron event count according to an embodiment of the present disclosure;

[0023] Figure 3A It is the charge spectrum of the photomultiplier tube output signal obtained under the no-light measurement condition and the first light measurement condition;

[0024] Figure 3B is the amplitude spectrum of the photomultiplier tube output signal obtained under the no-light measurement condition and the first light measurement condition;

[0025] Figure 4 is a flow chart of a method for determining the average number of photoelectrons obtained under the first light measurement condition according to an embodiment of the present disclosure;

[0026] Figure 5A is a schematic diagram of a charge response distribution function of a single photoelectron of a first photomultiplier tube according to an embodiment of the present disclosure;

[0027] Figure 5B is a schematic diagram of a charge response distribution function of a single photoelectron of a second photomultiplier tube according to an embodiment of the present disclosure;

[0028] Figure 6 is a block diagram of a photomultiplier tube single photoelectron response calibration device according to an embodiment of the present disclosure;

[0029] Figure 7 It is a block diagram of an electronic device used to implement the method for calibrating the single photoelectron response of a photomultiplier tube according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0032] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0033] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0034] In the technical solution disclosed herein, the acquisition, collection, storage, use, processing, transmission, provision, disclosure and application of data all comply with the provisions of relevant laws and regulations, take necessary confidentiality measures, and do not violate public order and good morals.

[0035] Photomultiplier tubes are vacuum electronic devices that can convert weak light signals into electrical signals. Photomultiplier tubes are usually used in weak light environments and can measure extremely weak radiation power in low-energy photometry and spectroscopy, and have a wide range of applications. If the single photoelectron response information of the photomultiplier tube can be accurately obtained in the application, such as the average number of photoelectrons, the average value, variance, and higher-order moments of the single photoelectron response distribution, it is crucial for calibrating the working gain, energy resolution and other parameters of the detector.

[0036] In the process of realizing the concept of the present disclosure, the inventors found that in order to obtain the single photoelectron response information of the photomultiplier tube, the single photoelectron response function of the photomultiplier tube is usually assumed in the related art. Then, the single photoelectron response function of the photomultiplier tube to the photoelectron spectrum is obtained by convolving the background noise and the photoelectron number distribution function, and the photoelectron spectrum is fitted with the function to obtain the parameters describing the single photoelectron response. For example, in one related technology, it is assumed that the response of the photomultiplier tube to a single photoelectron is a Gaussian function. However, in actual use, the response of the photomultiplier tube to a single photoelectron often deviates from the Gaussian function, that is, in addition to the Gaussian distribution formed by normal photoelectron multiplication and amplification, there are also related proportions of insufficiently amplified signals. In order to describe these insufficiently amplified small signals, another related technology assumes that the response of the photomultiplier tube to a single photoelectron is a Gaussian function + exponential function, where the exponential part is used to describe the insufficiently amplified component. However, since the charge of the component that is not fully amplified (described by the exponential function) is small, it is often superimposed on the electronic noise in the photoelectron spectrum and is difficult to distinguish. In addition, the shape of this signal distribution may vary with the model of the photomultiplier tube, the type of dynode, the working gain of the photomultiplier tube, and the individual differences of the photomultiplier tube, resulting in inaccurate measurement results.

[0037] Figure 1 The figure is a flow chart of a method for calibrating a single photoelectron response of a photomultiplier tube according to an embodiment of the present disclosure.

[0038] like Figure 1 As shown, the photomultiplier tube single photoelectron response calibration method includes operations S110 to S160.

[0039] In operation S110 , charge spectra of output signals of the photomultiplier tubes are respectively acquired under m light intensities to obtain m charge spectra.

[0040] According to the embodiment of the present disclosure, the magnitudes of the m light intensities are respectively denoted as I 0 ,I 1 ,I 2 ,…,I m-1 , where I 0 =0,I 1 to I m-1Therefore, the measurement under m light intensities includes one measurement without light (i.e., measurement under the condition of zero light intensity) and (m-1) measurements with light (i.e., measurement under the condition of non-zero light intensity).

[0041] For each of the m light intensities, at that light intensity, light source N is triggered trig times, and record the waveform of the output signal of the photomultiplier tube each time it is triggered. By analyzing each waveform, the integrated charge of the output signal of the photomultiplier tube triggered this time can be obtained, thereby obtaining the charge spectrum of the output signal of the photomultiplier tube under this light intensity. 0 ,I 1 ,I 2 ,…,I m-1 The charge spectra of the photomultiplier tube output signal are obtained under these m light intensities, and m charge spectra are obtained, which are recorded as B, S 1 , S 2 ,…,S m-1 It can be understood that the m charge spectra include the charge spectra obtained under the condition of no light measurement (i.e., under zero light intensity I 0 The charge spectrum B) and the charge spectrum obtained under (m-1) different light measurement conditions (i.e., under light intensity I 1 to I m-1 The charge spectrum S obtained under 1 To S m-1 ).

[0042] In order to improve the measurement accuracy, in some embodiments, m may be greater than 3, for example. The specific value may depend on the actual situation and is not limited here.

[0043] In operation S120, the number of photoelectron events in the m charge spectra that fall within the target charge interval is determined respectively to obtain m first event numbers.

[0044] According to the embodiment of the present disclosure, for m charge spectra, a target charge interval (denoted as [q 1 , q 2 ]), the target charge interval has a first interval width, and the first interval width is recorded as (q 2 -q 1 ). For each of the m charge spectra, the number of charge spectra falling within the target charge interval [q 1 , q 2 ], thereby obtaining m first event numbers. For example, the charge spectra B, S 1 , S 2 ,…,S m-1 falls in the target charge interval [q 1 , q 2], and the number of photoelectron events in the first case N is obtained. 0 、N 1 、N 2 ,…,N m-1 .

[0045] According to an embodiment of the present disclosure, the first interval width can be set according to actual conditions, without specific limitation. In one example, the first interval width can be determined according to the gain of the photomultiplier tube. For example, assuming that the gain of the photomultiplier tube is G and the energy resolution is 33.3% (for example only), the average value of the charge amplified by a single photoelectron is Ge, where e is the unit charge. The interval charge interval [0, 2Ge] can be divided into 100 equal parts, and the width of each first interval can be determined to be 0.02Ge.

[0046] In operation S130 , the probability of a single photoelectron response function being within a target charge interval is obtained according to the m first event numbers and a photoelectron event number probability distribution model.

[0047] According to an embodiment of the present disclosure, m first case numbers N are obtained. 0 、N 1 、N 2 ,…,N m-1 Afterwards, the single photoelectron response function in the target charge interval [q 1 , q 2 ] is the probability within .

[0048] In the embodiment of the present disclosure, the probability distribution model of the number of photoelectron events characterizes the number of photoelectron events falling within the first interval width (q 2 -q 1 The method of determining the probability distribution model of the number of photoelectron events will be introduced later.

[0049] In operation S140, the target charge interval is updated with the first interval width as a step size, and the operation of obtaining the probability of a single photoelectron response function being within the target charge interval is repeatedly performed until all charge values ​​in the charge spectrum are traversed with the first interval width to obtain the probability of multiple single photoelectron response functions being within the target charge interval.

[0050] According to an embodiment of the present disclosure, the first interval width (q 2 -q 1 ) is the step size, and the target charge interval is updated to obtain an updated target charge interval. For example, the updated target charge interval [q 2 , q 2 +(q 2 -q 1)]. Then, operations S120 and S130 are repeatedly performed to obtain the single photoelectron response function in the updated target charge interval [q 2 , q 2 +(q 2 -q 1 The above operation of obtaining the probability of a single photoelectron response function being within the target charge interval is repeated until all charge values ​​in the charge spectrum are traversed with the first interval width, thereby obtaining the probability of multiple single photoelectron response functions being within the target charge interval.

[0051] In operation S150 , a charge response distribution function of a single photoelectron is obtained according to the probability that the plurality of single photoelectron response functions are within the target charge interval.

[0052] According to the embodiments of the present disclosure, a single photoelectron charge response distribution function can be obtained based on the probability of multiple single photoelectron response functions in the target charge interval. The single photoelectron charge response distribution function describes the probability distribution of the single photoelectron response as the charge changes in the entire charge interval.

[0053] In operation S160 , single photoelectron response information for a photomultiplier tube is determined according to a charge response distribution function of the single photoelectron.

[0054] According to an embodiment of the present disclosure, the single photoelectron response information of the photomultiplier tube may include, for example, but is not limited to, parameters such as the average number of photoelectrons, the average value, standard deviation, and higher-order moments of the single photoelectron response distribution, as well as parameters such as the gain of the photomultiplier tube and the single photoelectron energy resolution. For example, the gain of the photomultiplier tube may be determined to be u / e, and the single photoelectron energy resolution may be determined to be σ / u. Wherein, σ and u are the average value and standard deviation of the response distribution function of the single photoelectron, respectively, and e is the unit charge.

[0055] According to an embodiment of the present disclosure, by measuring the charge spectrum of the photomultiplier tube output signal under multiple light intensities, and determining the number of photoelectron events falling within the target charge interval in the charge spectrum under multiple light intensities, the probability of a single photoelectron response function within the target charge interval is obtained. Then, the interval width is kept unchanged, and all charge values ​​in the charge spectrum are traversed to obtain the charge response distribution function of the single photoelectron, and the single photoelectron response information for the photomultiplier tube. Compared to the method of first assuming the single photoelectron response function of the photomultiplier tube, and then obtaining the single photoelectron response function of the photomultiplier tube to the photoelectron spectrum by convolving the background noise and the photoelectron number distribution function, the present disclosure proposes a non-model-dependent calibration method for the single photoelectron response of the photomultiplier tube, which can obtain the single photoelectron response information of the photomultiplier tube in a simple and efficient manner, thereby improving the accuracy of the single photoelectron response calibration.

[0056] Reference below Figure 2 The method for determining the probability distribution model of the number of photoelectron events is explained.

[0057] Figure 2 The present invention is a flowchart of a method for determining a probability distribution model of photoelectron event count according to an embodiment of the present disclosure.

[0058] like Figure 2 As shown, the method for determining the probability distribution model of the number of photoelectron events includes operations S210 to S220.

[0059] In operation S210, an average number of photoelectrons obtained under a first light measurement condition is determined.

[0060] Assume that the light intensity is I 1 The following measurement is the first light measurement. Correspondingly, the charge spectrum obtained under the first light measurement condition is S 1 The average number of photoelectrons obtained under the first light measurement condition is recorded as λ 1 .

[0061] The following will refer to Figure 3A , Figure 3B and Figure 4 A method for determining the average number of photoelectrons obtained under the first light measurement condition is described in detail.

[0062] Figure 3A is the charge spectrum of the photomultiplier tube output signal obtained under the no-light measurement condition and the first light measurement condition, Figure 3B It is the amplitude spectrum of the photomultiplier tube output signal obtained under the condition of no light measurement and the condition of the first light measurement.

[0063] like Figure 3A As shown, in the charge spectra of the photomultiplier tube output signals obtained under the no-light measurement condition and the first light measurement condition, the difference between the distribution curve A of the event obtained under the first light measurement condition and the distribution curve B of the no-light event obtained under the no-light measurement condition corresponds to the contribution of the light signal in the charge spectrum. Figure 3A It can be seen that, for example, in the charge interval [0.05×20pc, 0.2×20pc], the difference between the distribution curve A of the light event and the distribution curve B of the dark event is not all zero; in other words, the steps of the charge spectrum still contain some contributions from the light signal.

[0064] like Figure 3BAs shown in the figure, in the amplitude spectrum of the photomultiplier tube output signal obtained under the no-light measurement condition and the first light measurement condition, for example, in the amplitude interval [0, 0.005V], the distribution curve C of the event obtained under the first light measurement condition and the distribution curve D of the no-light event obtained under the no-light measurement condition basically overlap, and the steps of the amplitude spectrum are almost entirely contributed by the no-light event. Therefore, compared with the integrated charge, it is easier to distinguish whether an event is a no-light event by using the signal amplitude.

[0065] In the embodiment of the present disclosure, in order to more accurately determine the average number of photoelectrons obtained under the first light measurement condition, the average number of photoelectrons obtained under the first light measurement condition can be calculated based on the amplitude spectrum of the photomultiplier tube output signal obtained under the light-free measurement condition and the first light measurement condition.

[0066] Figure 4 It is a flow chart of a method for determining the average number of photoelectrons obtained under the first light measurement condition according to an embodiment of the present disclosure.

[0067] like Figure 4 As shown, the method for determining the average number of photoelectrons obtained under the first light measurement condition includes operations S411 to S413.

[0068] In operation S411, the amplitude spectrum of the photomultiplier tube output signal is acquired under the no-light measurement condition and the first light measurement condition, respectively, to obtain the amplitude spectrum under the no-light measurement condition and the amplitude spectrum under the first light measurement condition.

[0069] According to an embodiment of the present disclosure, the light intensities corresponding to the no-light measurement condition and the first light measurement condition are I and 0 and I 1 , where I 0 = 0. The process of obtaining the amplitude spectrum of the photomultiplier tube output signal under the no-light measurement condition is similar to the process of obtaining the amplitude spectrum of the photomultiplier tube output signal under the first light measurement condition. 0 ) is used as an example to illustrate the process of obtaining the amplitude spectrum of the photomultiplier tube output signal.

[0070] Intensity I 0 Next, trigger light source N trig times, and record the waveform of the output signal of the photomultiplier tube each time it is triggered. By analyzing each waveform, the signal amplitude of the output signal of the photomultiplier tube triggered this time can be obtained. Thus, the amplitude spectrum of the output signal of the photomultiplier tube under the light intensity can be obtained. Similarly, the amplitude spectrum under the first light measurement condition can be obtained by the above method.

[0071] In operation S412, the number of instances in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the number of instances in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition are determined respectively.

[0072] According to an embodiment of the present disclosure, an amplitude threshold (referred to as th_amp) may be set so that in the amplitude spectrum under the no-light measurement condition and the amplitude spectrum under the first light measurement condition, the cases with amplitudes lower than the amplitude threshold are almost all no-light cases. That is, in the amplitude interval [-∞, th_amp], the number of light cases is approximately zero. In one example, the amplitude threshold th_amp may be set so that the number of cases with amplitudes lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition accounts for 90% of the total number of cases, thereby determining the amplitude threshold.

[0073] Based on the above mechanism, the average number of photoelectrons obtained under the first light measurement condition can be determined by the number of events in the amplitude spectrum under the light-free measurement condition where the amplitude is lower than the amplitude threshold and the number of events in the amplitude spectrum under the light-free measurement condition where the amplitude is lower than the amplitude threshold.

[0074] According to an embodiment of the present disclosure, under a certain light intensity, the number X of photoelectrons collected by the first dynode of the photomultiplier tube conforms to the Poisson distribution:

[0075] (1)

[0076] In formula (1), represents the average number of photoelectrons, n represents the number of photoelectrons collected by the first dynode of the photomultiplier tube in a certain triggering, represents the probability of collecting n photoelectrons.

[0077] Based on formula (1), we can obtain the number of cases N that fall within the amplitude interval [-∞, th_amp]: _amp Among them, N _amp It is equal to the sum of the contributions of zero photoelectron events, single photoelectron events, and multiple photoelectron events.

[0078] (2)

[0079] In formula (2), P 0_amp represents the probability that the amplitude of a zero photoelectron event falls within the amplitude interval [-∞, th_amp], P 1_amp represents the probability that the amplitude of a single photoelectron event falls within the amplitude interval [-∞, th_amp], P 2_amp represents the probability that the amplitudes of two photoelectron events fall within the amplitude interval [-∞, th_amp], N trig Indicates the number of times the light source is triggered when measuring at each light intensity, N _amprepresents the number of events falling within the amplitude interval [-∞, th_amp], P(X=0) represents the probability of collecting zero photoelectrons, P(X=1) represents the probability of collecting a single photoelectron, and P(X=2) represents the probability of collecting two photoelectrons.

[0080] Since the probability of three or more photoelectron events falling within the amplitude interval [-∞, th_amp] is small, the three-photoelectron and more photoelectron pairs N can be ignored. _amp Therefore, according to formula (1) and formula (2), N _amp It is expressed as shown in formula (3).

[0081] (3)

[0082] According to formula (3), the number of cases N with amplitudes below the amplitude threshold in the amplitude spectrum under the no-light measurement condition can be determined: 0_amp And the number of cases N with amplitudes below the amplitude threshold in the amplitude spectrum under the first light measurement condition 1_amp .

[0083] (4)

[0084] (5)

[0085] In formula (4) and formula (5), λ 1 It represents the average number of photoelectrons obtained under the first light measurement conditions.

[0086] Since in the amplitude spectrum under the no-light measurement condition and the amplitude spectrum under the first light measurement condition, the cases with amplitudes below the amplitude threshold are almost all no-light cases, therefore, in formula (5), P 1_amp and P 2 _ amp can be approximated to zero, then the number of cases N with amplitudes below the amplitude threshold in the amplitude spectrum under the first light measurement condition is 1_amp It can be expressed as shown in formula (6).

[0087] (6)

[0088] In operation S413, the average number of photoelectrons obtained under the first light measurement condition is determined according to the number of occurrences in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the number of occurrences in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition.

[0089] According to formula (4) and formula (6), the average number of photoelectrons λ obtained under the first light measurement condition can be calculated: 1 .

[0090] (7)

[0091] In some embodiments, the average number of photoelectrons obtained under the first light measurement condition λ can also be determined. 1 The following is the average number of photoelectrons λ obtained under the first light measurement condition. 1 The calculation process of the expectation and variance is explained in detail.

[0092] Since almost all the cases where the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the amplitude spectrum under the first light measurement condition are no-light cases, the probability P that the amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition is N0_amp =P 0_amp , the probability P that the amplitude in the amplitude spectrum under the first light measurement condition is lower than the amplitude threshold N1_amp = Therefore, the average number of photoelectrons obtained under the first light measurement condition is 1 It can also be expressed as shown in formula (8).

[0093] (8)

[0094] For a certain event, its amplitude can be lower than the amplitude threshold or higher than the amplitude threshold. Therefore, the number of events N whose amplitude is lower than the amplitude threshold in the amplitude spectrum under the no-light measurement condition is 0_amp Satisfies binomial distribution. Among them, the probability of binomial distribution P N0_amp The obedience parameters are , Beta distribution, P N0_amp The expectation and variance of can be calculated using formula (9) and formula (10) respectively.

[0095] (9)

[0096] (10)

[0097] In formula (9) and formula (10), E(P N0_amp ) indicates P N0_amp expectations, Indicates P N0_amp The variance of .

[0098] Similarly, the number of events N in the amplitude spectrum under the first light measurement condition where the amplitude is below the amplitude threshold is 1_amp Satisfies the binomial distribution. From this, we can get the probability P of the binomial distribution N1_amp The expected E(P N1_amp ) and variance .

[0099] (11)

[0100] (12)

[0101] P N0_amp and P N1_amp Determined by two amplitude spectra, they are independent of each other. Using the error transfer formula, in the first-order approximation, we have:

[0102] (13)

[0103] Therefore, the average number of photoelectrons obtained under the first light measurement condition is 1 The expectation E(λ 1 ) and variance It can be expressed as:

[0104] (14)

[0105] (15)

[0106] In some embodiments, if the probability P of the binomial distribution is N0_amp Estimated Then, using the variance formula and error propagation formula of binomial distribution, we can also get the average number of photoelectrons λ obtained under the first light measurement condition. 1 The expectation E(λ 1 ) and variance Expected E(λ 1 ) and variance The calculations are performed using the following formulas (16) and (17) respectively.

[0107] (16)

[0108] (17)

[0109] In some embodiments, when N 0_amp 、N 1_amp When it is large, the variance calculated by using formula (15) and formula (17) is It tends to be consistent.

[0110] In some embodiments, if , , then the average number of photoelectrons obtained under the first light measurement condition is 1 Variance It can be calculated using formula (18).

[0111] (18)

[0112] According to formula (18), the average number of photoelectrons λ obtained under the first light measurement condition can be calculated: 1 The relative error of .

[0113] (19)

[0114] In formula (19), Indicates the average number of photoelectrons obtained under the first light measurement condition λ 1 The relative error of .

[0115] In the actual measurement process, the step position of the amplitude spectrum may change over time, causing the entire amplitude spectrum to shift. N0_amp and P N1_amp In addition to the statistical error, the error also includes the error caused by translation.

[0116] The error caused by translation in the amplitude spectrum obtained under no-light measurement conditions satisfies the relationship in the following formula (20).

[0117] (20)

[0118] In formula (20), represents the square of the error caused by translation, W represents the degree of deviation of the amplitude spectrum under the condition of no light measurement, and h 0 represents the number of events at the amplitude threshold in the amplitude spectrum under no-light measurement conditions, B w Indicates the Bin width of the histogram.

[0119] According to formula (20), the relative error caused by translation in the amplitude spectrum obtained under light-free measurement conditions can be determined, which satisfies the following relationship.

[0120] (twenty one)

[0121] With N trig The increase of h 0 and N 0_amp will increase in the same proportion, so the misalignment error will not decrease with the increase of statistics; at the same time, as the amplitude threshold becomes smaller, N 0_amp The smaller the error caused by translation, the larger the error caused by translation. It can be seen that the error caused by translation and the statistical error are independent. Therefore, after considering the error caused by translation, P N0_amp The variance of is expressed as shown in the following formula (22).

[0122] (twenty two)

[0123] Similarly, for the amplitude spectrum obtained under the first light measurement condition, after considering the error caused by translation, P N1_amp The variance of is expressed as shown in the following formula (23).

[0124] (twenty three)

[0125] In formula (23), h 1 Represents the number of events at the amplitude threshold in the amplitude spectrum obtained under the first light measurement condition.

[0126] Therefore, considering the statistical error and the error caused by translation, the average number of photoelectrons λ obtained under the first light measurement condition can be obtained: 1 The variance of satisfies the following relationship:

[0127] (twenty four)

[0128] In the embodiment of the present disclosure, the amplitude spectrum obtained under the no-light measurement condition can be obtained by multiple measurements under the same conditions. Then the variance S of the mean of the amplitude spectrum obtained under the no-light measurement condition is observed, thereby obtaining the degree of deviation W of the amplitude spectrum under the no-light measurement condition, where If W is close to the variance of the mean of the amplitude spectra obtained under these light-free measurement conditions, it means that the average number of photoelectrons obtained under the first light measurement condition is 1 It is relatively accurate, and the error caused by translation can be ignored at this time. If it is assumed that the average number of photoelectrons obtained under the first light measurement condition is λ 1 The variance is caused by translation. At this time, translation correction can be performed to eliminate the error caused by translation.

[0129] Return to reference Figure 2 In operation S220, the average number of photoelectrons is applied to a pre-constructed photoelectron event number probability distribution optimization model to obtain a photoelectron event number probability distribution model.

[0130] The process of constructing the probability distribution optimization model of the number of photoelectron events will be described in detail below in conjunction with specific embodiments.

[0131] As mentioned above, under a certain light intensity, the number of photoelectrons X collected by the first dynode of the photomultiplier tube conforms to the Poisson distribution. Therefore, it can be determined that the charge spectrum measured under this light intensity falls within the target charge interval [q 1 , q 2 ] (denoted as N). Where N is equal to the sum of the contributions of zero photoelectron events, single photoelectron events, and multiple photoelectron events in the charge spectrum, which satisfies the following relationship.

[0132] (25)

[0133] In formula (25), P n Indicates that the charge of n (n=0, 1, 2,…) photoelectron events falls within the target charge interval [q 1 , q 2 ], N trig Indicates the number of times the light source is triggered when measuring at this light intensity.

[0134] Since three or more photoelectron events fall within the target charge interval [q 1 , q 2 ] is small, so the contribution of three photoelectrons and more photoelectrons to N can be ignored. Therefore, according to formula (1) and formula (25), N can be expressed in the form shown in formula (26).

[0135] (26)

[0136] Since the expected difference between the charge spectrum obtained under the condition of light measurement (i.e., the light intensity is not zero) and the charge spectrum obtained under the condition of no light measurement (i.e., the light intensity is zero) is equal to the average photoelectron number Therefore, the average number of photoelectrons λ obtained under the first light measurement condition can be used 1 To represent the average number of photoelectrons obtained under other light measurement conditions λ i , which satisfies the following relationship.

[0137] (27)

[0138] In formula (27), a i represents a constant, S 1 represents the charge spectrum obtained under the first light measurement condition, E(S 1 ) represents the expectation of the charge spectrum obtained under the first light measurement condition, S i represents the charge spectrum of the photomultiplier tube output signal obtained under the i-th (i=1,2, …, m-1) light measurement condition, E(S i ) represents the expectation of the charge spectrum obtained under the i-th measurement condition with light, B represents the charge spectrum obtained under the measurement condition without light, and E(B) represents the expectation of the charge spectrum obtained under the measurement condition without light.

[0139] According to formula (26) and formula (27), the charge spectra measured under m different light intensities falling within the target charge interval [q 1 , q 2 ], which satisfies:

[0140] (28)

[0141] (29)

[0142] (30)

[0143] …

[0144] (31)

[0145] In formula (28) to formula (31), N 0 Indicates that the charge spectrum under the condition of no light measurement falls into the target charge interval [q 1 , q 2 ], N i Indicates that the charge spectrum under the i-th (i=1, 2,…, m-1) light measurement condition falls within the target charge interval [q 1 , q 2 ], the number of photoelectron events in i represents the average number of photoelectrons obtained under the condition of light measurement for the i-th time i The average number of photoelectrons obtained under the first light measurement condition is 1 The ratio between .

[0146] Based on formulas (28) to (31), the charge spectra measured under different light intensities can fall into the target charge interval [q 1 , q 2 The percentage of the number of photoelectron events in ] to the total number of events is expressed as shown in the following formula (32), thereby obtaining the above-mentioned photoelectron event number probability distribution optimization model.

[0147] (32)

[0148] In formula (32), f(x) represents the probability distribution model of the number of photoelectron events, and x represents the average number of photoelectrons λ obtained under other light measurement conditions. i Relative to the average number of photoelectrons obtained under the first light measurement condition λ 1 The proportionality factor.

[0149] In the above formula (32), p 0 、p 1 、p 2 and λ 1 The average number of photoelectrons λ obtained under the first light measurement condition can be determined according to operations S411 to S413. 1 Then, λ 1Substituting into formula (32), we can obtain the probability distribution model of the number of photoelectron events.

[0150] In the embodiment of the present disclosure, according to the above process of constructing the photoelectron event number probability distribution optimization model and formula (28) to formula (32), it can be known that the function corresponding to the photoelectron event number probability distribution model passes through the following m data points: (0, N 0 / N trig )、(1, N 1 / N trig )、(a 2 , N 2 / N trig )、…、(a m-1 , N m-1 / N trig ). Therefore, in determining the m charge spectra that fall within the target charge interval [q 1 , q 2 ], that is, m first event numbers are obtained. The single photoelectron response function in the target charge interval [q 1 , q 2 ] probability. Among them, the target charge interval [q 1 , q 2 ] has a first interval width (q 2 -q 1 ). Next, the target charge interval can be updated with the first interval width as a step size, and the operation of obtaining the probability of a single photoelectron response function being within the target charge interval can be repeatedly performed until all charge values ​​in the charge spectrum are traversed with the first interval width, and the probability of multiple single photoelectron response functions being within the target charge interval is obtained. Then, based on the probabilities of multiple single photoelectron response functions being within the target charge interval, the charge response distribution function of the single photoelectron is obtained.

[0151] In order to enable those skilled in the art to more clearly understand the technical solution of the present disclosure, the advantages of the present disclosure will be explained below in conjunction with specific embodiments.

[0152] In the embodiment of the present disclosure, the first photomultiplier tube is measured under six different light intensities (one of which is zero and the other five are not zero) to obtain six charge spectra. According to the method described above, the average number of photoelectrons under five light measurements can be obtained, which are 0.283, 0.695, 1.549, 2.406 and 3.440 respectively.

[0153] According to the photomultiplier tube single photoelectron response calibration method disclosed in the present invention, based on the six charge spectra obtained above, a charge response distribution function of the single photoelectron response for describing the single photoelectron response of the first photomultiplier tube can be obtained.

[0154] Figure 5A is a schematic diagram of a charge response distribution function of a single photoelectron of a first photomultiplier tube according to an embodiment of the present disclosure, Figure 5B is a schematic diagram of the charge response distribution function of a single photoelectron of the second photomultiplier tube according to an embodiment of the present disclosure.

[0155] like Figure 5A As shown, in the charge response distribution curve of the single photoelectron of the first photomultiplier tube, it can be seen that there are indeed a certain number of small signals that have not been fully amplified, and the positions where the small signals are concentrated just overlap with the steps, making the small signals difficult to observe.

[0156] In order to better understand the shape of the small signal part, the second photomultiplier tube of the same model was measured under the same light intensity and gain conditions, and the charge response distribution function of the single photoelectron response used to describe the single photoelectron response of the second photomultiplier tube was obtained.

[0157] like Figure 5B As shown, in the charge response distribution curve of the single photoelectron of the second photomultiplier tube, there are also a certain number of small signals that are not fully amplified. Moreover, the shape of the small signal of the second photomultiplier tube is different from that of the first photomultiplier tube. The small signal of the first photomultiplier tube is closer to a Gaussian function, while the small signal of the second photomultiplier tube is closer to an exponential function. It can be seen that based on the method disclosed in the present invention, not only can the shape of the small signal that is not fully amplified in the photoelectron spectrum be accurately described, but also the shapes of the small signal distributions of different photomultiplier tubes can be distinguished, thereby improving the accuracy of the measurement results.

[0158] Based on the above-mentioned photomultiplier tube single photoelectron response calibration method, the present disclosure also provides a photomultiplier tube single photoelectron response calibration device. Figure 6 The device is described in detail.

[0159] Figure 6 It is a structural block diagram of a photomultiplier tube single photoelectron response calibration device according to an embodiment of the present disclosure.

[0160] like Figure 6 As shown, the photomultiplier tube single photoelectron response calibration device 600 includes an acquisition module 610 , a first determination module 620 , a calculation module 630 , a second determination module 640 , a third determination module 650 and a fourth determination module 660 .

[0161] The acquisition module 610 is used to respectively acquire the charge spectra of the output signals of the photomultiplier tubes under m light intensities, and obtain m charge spectra; m is an integer greater than 3.

[0162] The first determination module 620 is used to respectively determine the number of photoelectron events in the m charge spectra that fall within the target charge interval to obtain m first event numbers; the target charge interval has a first interval width.

[0163] The calculation module 630 is used to obtain the probability of a single photoelectron response function within a target charge interval based on the m first event numbers and the photoelectron event number probability distribution model; the photoelectron event number probability distribution model characterizes the probability distribution of the number of photoelectron events falling within the first interval width in different charge spectra.

[0164] The second determination module 640 is used to update the target charge interval with the first interval width as the step size, and repeatedly perform the operation of obtaining the probability of the single photoelectron response function being within the target charge interval until all charge values ​​in the charge spectrum are traversed with the first interval width to obtain the probability of multiple single photoelectron response functions being within the target charge interval.

[0165] The third determination module 650 is used to obtain the charge response distribution function of the single photoelectron according to the probability of multiple single photoelectron response functions being within the target charge interval.

[0166] The fourth determination module 660 is used to determine the single photoelectron response information for the photomultiplier tube according to the charge response distribution function of the single photoelectron.

[0167] According to an embodiment of the present disclosure, any multiple modules of the acquisition module 610, the first determination module 620, the calculation module 630, the second determination module 640, the third determination module 650 and the fourth determination module 660 can be combined in one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the acquisition module 610, the first determination module 620, the calculation module 630, the second determination module 640, the third determination module 650 and the fourth determination module 660 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of the acquisition module 610, the first determination module 620, the calculation module 630, the second determination module 640, the third determination module 650 and the fourth determination module 660 can be at least partially implemented as a computer program module, and when the computer program module is executed, the corresponding function can be performed.

[0168] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium, a computer program product, and a detector.

[0169] According to an embodiment of the present disclosure, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method as described above.

[0170] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to cause a computer to execute the method as described above.

[0171] According to an embodiment of the present disclosure, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0172] According to an embodiment of the present disclosure, a detector is provided. The detector may include the electronic device of any of the above embodiments.

[0173] Figure 7A block diagram of an electronic device suitable for implementing a method for calibrating a single photoelectron response of a photomultiplier tube according to an embodiment of the present disclosure is schematically shown.

[0174] like Figure 7 As shown, the electronic device 700 according to an embodiment of the present disclosure includes a processor 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 702 or a program loaded from a storage part 708 to a random access memory (RAM) 703. The processor 701 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 701 may also include an onboard memory for caching purposes. The processor 701 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0175] In RAM 703, various programs and data required for the operation of electronic device 700 are stored. Processor 701, ROM 702 and RAM 703 are connected to each other via bus 704. Processor 701 performs various operations of the method flow according to the embodiment of the present disclosure by executing the program in ROM 702 and / or RAM 703. It should be noted that the program can also be stored in one or more memories other than ROM 702 and RAM 703. Processor 701 can also perform various operations of the method flow according to the embodiment of the present disclosure by executing the program stored in the one or more memories.

[0176] According to an embodiment of the present disclosure, the electronic device 700 may further include an input / output (I / O) interface 705, which is also connected to the bus 704. The electronic device 700 may further include one or more of the following components connected to the I / O interface 705: an input portion 706 including a keyboard, a mouse, etc.; an output portion 707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 708 including a hard disk, etc.; and a communication portion 709 including a network interface card such as a LAN card, a modem, etc. The communication portion 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 710 as needed, so that a computer program read therefrom is installed into the storage portion 708 as needed.

[0177] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present disclosure is implemented.

[0178] According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present disclosure, the computer-readable storage medium may include the ROM 702 and / or RAM 703 described above and / or one or more memories other than ROM 702 and RAM 703.

[0179] The embodiment of the present disclosure also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the photomultiplier tube single photoelectron response calibration method provided in the embodiment of the present disclosure.

[0180] The above functions defined in the system / device of the embodiment of the present disclosure are performed when the computer program is executed by the processor 701. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0181] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 709, and / or installed from the removable medium 711. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0182] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 709, and / or installed from the removable medium 711. When the computer program is executed by the processor 701, the above functions defined in the system of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0183] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0184] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0185] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0186] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for calibrating the single photoelectron response of a photomultiplier tube, It is characterized in that include: Under m light intensities, the charge spectra of the photomultiplier tube output signals are respectively acquired to obtain m charge spectra; m is an integer greater than 3; Determine the number of photoelectron events in the m charge spectra that fall within the target charge interval, and obtain m first event numbers; the target charge interval has a first interval width; According to the m first event numbers and the photoelectron event number probability distribution model, the probability of a single photoelectron response function being within the target charge interval is obtained; the photoelectron event number probability distribution model characterizes the probability distribution of the number of photoelectron events falling within the first interval width in different charge spectra; The target charge interval is updated with the first interval width as a step length, and the operation of obtaining the probability of a single photoelectron response function being within the target charge interval is repeatedly performed until all charge values ​​in the charge spectrum are traversed with the first interval width to obtain the probability of multiple single photoelectron response functions being within the target charge interval; Obtaining a charge response distribution function of a single photoelectron according to the probability of the plurality of single photoelectron response functions being within the target charge interval; and Determining single photoelectron response information for the photomultiplier tube according to the charge response distribution function of the single photoelectron; The m charge spectra include a charge spectrum obtained under a light-free measurement condition and (m-1) different charge spectra obtained under light-exposed measurement conditions; the method further includes: Determine the average number of photoelectrons obtained under the first light measurement conditions; as well as The average number of photoelectrons is applied to a pre-constructed photoelectron event number probability distribution optimization model to obtain the photoelectron event number probability distribution model.

2. The method according to claim 1, It is characterized in that The method further comprises: The amplitude spectrum of the photomultiplier tube output signal is obtained under the no-light measurement condition and the first light measurement condition respectively, to obtain the amplitude spectrum under the no-light measurement condition and the amplitude spectrum under the first light measurement condition.

3. The method according to claim 2, It is characterized in that Determining the average number of photoelectrons obtained under the first light measurement condition comprises: Determine the number of instances in which the amplitude is below the amplitude threshold in the amplitude spectrum under the no-light measurement condition and the number of instances in which the amplitude is below the amplitude threshold in the amplitude spectrum under the first light measurement condition; and The average number of photoelectrons obtained under the first light measurement condition is determined based on the number of instances in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the light-free measurement condition and the number of instances in which the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition.

4. The method according to any one of claims 1 to 3, It is characterized in that The probability distribution model of the number of photoelectron events satisfies: Among them, f(x) represents the probability distribution model of the number of photoelectron events, λ1 represents the average number of photoelectrons obtained under the first light measurement condition, p0 represents the probability of the number of photoelectron events with zero photoelectron event charge falling within the first interval width, p1 represents the probability of the number of photoelectron events with a single photoelectron event charge falling within the first interval width, p2 represents the probability of the number of photoelectron events with two photoelectron event charges falling within the first interval width, and x represents the proportional coefficient of the average number of photoelectrons obtained under other light measurement conditions relative to the average number of photoelectrons obtained under the first light measurement condition.

5. The method according to claim 3, It is characterized in that The average photoelectron number is calculated using the following formula: Among them, λ 1 represents the average number of photoelectrons obtained under the first light measurement condition, N 1_amp Indicates the number of cases where the amplitude is lower than the amplitude threshold in the amplitude spectrum under the first light measurement condition, N 0_amp Represents the number of events whose amplitude is lower than the amplitude threshold in the amplitude spectrum under no-light measurement conditions.

6. A photomultiplier tube single photoelectron response calibration device, It is characterized in that include: An acquisition module is used to respectively acquire the charge spectra of the output signals of the photomultiplier tubes under m light intensities to obtain m charge spectra; m is an integer greater than 3; A first determination module is used to respectively determine the number of photoelectron events in the m charge spectra that fall within the target charge interval to obtain m first event numbers; the target charge interval has a first interval width; A calculation module, for obtaining the probability of a single photoelectron response function being within the target charge interval according to the m first event numbers and a photoelectron event number probability distribution model; the photoelectron event number probability distribution model characterizes the probability distribution of the number of photoelectron events falling within the first interval width in different charge spectra; A second determination module is used to update the target charge interval with the first interval width as a step size, and repeatedly perform the operation of obtaining the probability of a single photoelectron response function being within the target charge interval, until all charge values ​​in the charge spectrum are traversed with the first interval width, and the probability of multiple single photoelectron response functions being within the target charge interval is obtained; A third determination module is used to obtain a charge response distribution function of a single photoelectron according to the probability that the plurality of single photoelectron response functions are within the target charge interval; and The fourth determination module is used to determine the single photoelectron response information for the photomultiplier tube according to the charge response distribution function of the single photoelectron.

7. An electronic device, include: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors execute the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, causes the processor to execute the method according to any one of claims 1 to 5.

9. A detector, It is characterized in that Comprising the electronic device as claimed in claim 7.

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