WO2022191152A1 - 電子顕微鏡、電子-光子相関測定装置、及び電子-光子相関測定方法 - Google Patents
電子顕微鏡、電子-光子相関測定装置、及び電子-光子相関測定方法 Download PDFInfo
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- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
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- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
- G01N23/2251—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion using incident electron beams, e.g. scanning electron microscopy [SEM]
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- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
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- H01J37/02—Details
- H01J37/22—Optical or photographic arrangements associated with the tube
- H01J37/222—Image processing arrangements associated with the tube
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- H01J37/244—Detectors; Associated components or circuits therefor
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- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/244—Detection characterized by the detecting means
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- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/245—Detection characterised by the variable being measured
- H01J2237/24571—Measurements of non-electric or non-magnetic variables
- H01J2237/24585—Other variables, e.g. energy, mass, velocity, time, temperature
Definitions
- the present invention relates to an electron microscope, an electron-photon correlation measurement device, and an electron-photon correlation measurement method.
- Fluorescence lifetime microscopes which measure the fluorescence lifetime of substances and living organisms in an excited state, can visualize substances and living organisms microscopically. It is a useful tool. However, fluorescence lifetime microscopy cannot obtain information below 100 nm, which is particularly important in elucidating the internal structures and functions of substances, living organisms, and the like, due to the diffraction limit of irradiated light.
- the computing unit has a storage unit storing parameter values indicating characteristics of the electron-photon time correlation previously measured for one or more known substances or living organisms
- the discriminating unit stores the calculated Calculate the degree of matching between the parameter value of the electron-photon time correlation of the sample and the parameter value of the electron-photon time correlation of a known substance or living body, and find the parameter value where the degree of matching exceeds a predetermined threshold and is the maximum. It is preferable to discriminate a known substance or organism having a sample as indicative of the substance or organism of the sample.
- the electron detector includes a light emitter that reacts with the electrons irradiated to the sample and emits photons, and a photon detector that detects the photons emitted from the light emitter and outputs a detection signal to the calculator. It is preferable to have a part and a.
- the photon detector is also used as a photon detection part of the electron detector, detects photons emitted from the sample and photons emitted from the light emitter, and outputs a detection signal to the calculator. is preferred.
- FIG. 1 is a diagram schematically showing the configuration of an electron microscope and an electron-photon correlation measurement apparatus according to the first embodiment.
- FIG. 2A is a diagram schematically showing the electron-photon time correlation calculated by the electron microscope of the first embodiment.
- FIG. 2B is a diagram showing an example of electron-photon time correlation obtained by actual measurement using the electron microscope of the first embodiment.
- FIG. 3 is a diagram schematically showing the photon-photon time correlation calculated by the electron microscope of the first embodiment.
- FIG. 4 is a flow chart schematically showing the electron-photon correlation measurement method of the first embodiment.
- FIG. 5 is a diagram schematically showing the configuration of an electron microscope and an electron-photon correlation measurement apparatus according to the second embodiment.
- this electron microscope distinguishes a sample based on the electron-photon time correlation, which includes information such as the fluorescence lifetime of substances and living organisms in an excited state.
- information such as the temperature of the environment of the sample.
- this passive detection system can also be provided as an electron-photon correlation measurement device, which is an attachment added to an existing electron microscope.
- FIG. 1 is a diagram schematically showing the configuration of an electron microscope 1 and an electron-photon correlation measuring device 7 of the first embodiment.
- An electron microscope 1 includes an electron gun 2 , an electron detector 3 , a photon detector 4 and a calculator 5 .
- the electron microscope 1 is also realized by adding an electron-photon correlation measuring device 7 as a passive detection system to an existing electron microscope main body 8 having an electron gun 2 and a chamber.
- the electron gun 2 and the sample 6 are placed in an evacuated chamber of the electron microscope main body 8, as shown in FIG. placed.
- the electron detector 3 is arranged on the opposite side of the sample 6 from the electron gun 2 and arranged so as to be able to detect electrons 30 that have passed through the sample 6 .
- the photon detector 4 is arranged such that photons 40 emitted from the sample 6 can be detected through a photon detection window 82 provided in the wall of the chamber.
- the calculator 5 is communicatively connected to at least the electron detector 3 and the photon detector 4 by wire or wirelessly.
- the electron gun 2 irradiates the sample 6 with electrons 20 .
- the electron gun 2 is not a pulsed electron beam in which a large number of electrons 20 are temporally compressed, but a continuous electron beam spontaneously emitted from the electron source at random intervals.
- a sample 6 is irradiated one by one.
- An FE electron gun, a thermal electron gun, a Schottky electron gun, or the like can be used as the electron gun 2 for irradiating such a continuous electron beam, but it is preferable to use an FE electron gun, which has excellent spatial resolution.
- the electron detector 3 detects electrons 30 that have passed through the sample 6 among the electrons 20 emitted from the electron gun 2 .
- the electron detector 3 has a time resolution capable of detecting electrons 30 that have passed through the sample 6 one by one.
- the electron detector 3 having such a high temporal resolution is configured using a light emitter 31 and a photon detector 32, as shown in FIG. 1, for example.
- the light emitter 31 is a scintillator that emits photons 33 by reacting with the electrons 30 transmitted through the sample 6 .
- a light-emitting semiconductor material such as a metal halide perovskite which has a high light emission efficiency and emits photons 33 in a short time by reacting with the electrons 30, or YSO:Ce (Cerium- doped Yttrium Silicate) is used.
- the photon detection unit 32 detects photons 33 emitted from the light emitter 31 through the photon detection window 81 provided on the wall of the chamber, and outputs a signal indicating that the electrons 30 have been detected. output to As the photon detector 32, an avalanche photodiode, a photomultiplier tube, or the like capable of efficiently detecting a very small number of photons 33 is used.
- the photon detector 4 detects photons 40 emitted from the sample 6 when the electrons 30 pass through the sample 6 .
- the photon detector 4 has a time resolution capable of detecting photons 40 emitted from the sample 6 one by one.
- an avalanche photodiode or a photomultiplier tube capable of detecting each photon 40 is used, like the photon detector 32 of the electron detector 3.
- Photon detector 4 may comprise a plurality of avalanche photodiodes or photomultiplier tubes or the like.
- the photon detector 4 outputs a signal indicating that the photon 40 has been detected to the calculator 5 each time it detects each photon 40 emitted from the sample 6 .
- the photon detector 4 may be preceded by a bandpass filter or polarizer that passes only photons 40 in the desired wavelength band.
- the photon detector 4 can have a photon reflecting mirror 41 as shown in FIG. 1 in order to efficiently detect multiple photons 40 emitted from the sample 6 .
- the photon reflecting mirror 41 has, for example, a parabolic shape, and directs the photons 40 emitted in the direction opposite to the photon detector 4 among the photons 40 emitted from the sample 6 arranged at the focal position to the photon detector 4. reflect.
- Photon detector 4 may further comprise a photon converging lens 42 .
- the photon converging lens 42 spatially converges the photons 40 emitted from the sample 6 and guides them to the photon detector 4 .
- the photon detector 4 may also be used as the photon detection section 32 of the electron detector 3 .
- the photon detection window 81 and the photon detection window 82 of the chamber of the electron microscope main body 8 may be provided nearby or shared, and the light emitter 31 may be provided as a substrate on which the sample 6 is mounted.
- the photon detector 4 detects photons 40 emitted from the sample 6 and photons 33 emitted from the light emitter 31 and outputs detection signals to the calculator 5 .
- the photon detector 4 separates and detects the photons 40 emitted from the sample 6 and the photons 33 emitted from the light-emitting body 31.
- the photon detector 4 includes a filter for passing only one of the photons 40 and the photons 33 and the other. and a filter that only passes the In this case, the photon detector 4 includes a first detection section for detecting photons 40 emitted from the sample 6 and a second detection section for detecting photons 33 emitted from the light emitter 31. can have This simplifies the electron microscope 1 .
- the computing unit 5 has a processor, memory, communication I/F, etc. (not shown).
- a PC Personal Computer
- a processor is an example of a determination unit and an image generation unit, and has one or more arithmetic circuits and their peripheral circuits.
- the memory is an example of a storage unit, and includes semiconductor memory such as HDD (Hard Disk Drive), optical recording medium, RAM (Random Access Memory) and ROM (Read Only Memory), or a storage medium combining these.
- a communication I/F Interface connects the processor to the electron detector 3, the photon detector 4, and the scanning control unit 23 of the electron gun 2 by wire or wirelessly. , and the scanning control unit 23 of the electron gun 2 .
- the calculator 5 Based on the time at which the electron detector 3 detected the electron 30 and the time at which the photon detector 4 detected the photon 40, the calculator 5 detects the electron 30 from the sample for each detected photon 40. The time difference between the time of transmission through 6 and the time when photon 40 was emitted from sample 6 is calculated. Then, the computing unit 5 computes the electron-photon time correlation indicating the computed time difference distribution according to the procedure described below.
- FIG. 2A is a diagram schematically showing the electron-photon time correlation calculated by the electron microscope 1 of the first embodiment.
- FIG. 2A (a) shows an example of an electron detection signal received by the calculator 5 from the electron detector 3 via the communication I/F when the first electrons pass through the sample 6, and an example of the electron detection signal from the photon detector 4. 1 schematically illustrates an example of a photon detection signal received from a .
- (b) of FIG. 2A shows an example of an electron detection signal received by the calculator 5 from the electron detector 3 via the communication I/F when another second electron passes through the sample 6.
- FIG. The horizontal axes of (a) and (b) of FIG. 2A indicate time t, and each pulse signal indicates that one electron 30 or one photon 40 has been detected.
- the time interval from when the electron gun 2 irradiates the first electron until it irradiates the next second electron depends on the expected length of fluorescence lifetime of the sample 6 to be discriminated. adjusted in advance.
- the calculator 5 can digitally calculate the time difference ⁇ based on the time when the electron detector 3 detects the electrons 30 and the time when the photon detector 4 detects the photons 40. Arithmetic is also possible. In that case, the computing unit 5 uses, for example, an analog correlator with excellent time resolution such as a time-to-amplitude converter, and is triggered by the electron detector 3 detecting the electrons 30 , the time when the photon detector 4 detects the photon 40 is calculated as the time difference ⁇ .
- an analog correlator with excellent time resolution such as a time-to-amplitude converter
- a delay line may be inserted between the electron detector 3 and the calculator 5 or between the photon detector 4 and the calculator 5 to cancel out such a response time difference.
- the computing unit 5 calculates the distribution of the time difference ⁇ shown in (c) of FIG. Calculate the time correlation curve g.
- the horizontal axis of (c) of FIG. 2A indicates the time difference ⁇
- the vertical axis of (c) of FIG. 2A indicates the frequency at which the photons 40 are detected with the time difference ⁇ when the electrons 30 are detected.
- the fluorescence lifetime ⁇ 0 also includes environmental information such as the temperature of the sample 6, information such as the temperature of the environment of the sample 6 can be obtained based on the deviation from the value of the fluorescence lifetime ⁇ 0 at a known temperature that has been measured in advance. can also In addition, it is possible to calculate the luminescence transition probability from ⁇ , which is a parameter value that could not be measured with a fluorescence lifetime microscope that irradiates light. be. Characteristic values other than the fluorescence lifetimes ⁇ 0 and ⁇ may be used as the parameter values indicating the characteristics of the curve g.
- FIG. 2B is a diagram showing an example of electron-photon time correlation obtained by actual measurement using the electron microscope of the first embodiment.
- the electron-photon time correlation shown in FIG. 2B was measured using nanodiamond as the sample 6 and using YSO:Ce as the light emitter 31 that emits photons 33 by reacting with electrons 30 transmitted through the nanodiamond. This measurement was performed by irradiating the sample 6 with electrons 20 at a current value of about 2.5 pA at room temperature for about 1000 seconds until an electron-photon time correlation curve g of the required accuracy was obtained.
- the electron-photon time correlation curve g shown in FIG. 2B is different from the electron-photon time correlation curve g shown in FIG. 2A in that the curve g is measured even in the region where the time difference ⁇ is negative. This is because the time difference ⁇ on the horizontal axis of FIG. 2A uses the time when the electron 30 is detected as the reference time, whereas the time difference ⁇ on the horizontal axis of FIG. 2B uses the time when the photon 33 is detected as the reference time. is. Electrons 30 are detected indirectly via photons 33 as shown in FIG.
- FIG. The electron-photon time correlation measured using the electron microscope 1 is characterized in that asymmetrical data are obtained in the positive region and the negative region of the time difference ⁇ .
- the scanning control unit 23 of the electron gun 2 irradiates the sample 6 while scanning the electrons 20 spatially, so that the computing unit 5 calculates the image can be generated.
- the computing unit 5 transmits the coordinates of the position on the sample 6 irradiated with the electrons 20 by the electron gun 2 from the scanning control unit 23 via the communication I/F.
- the received positional coordinates are associated with the calculated electron-photon time correlation data and stored in the storage unit.
- the calculator 5 calculates the characteristic value of the electron-photon time correlation corresponding to the position coordinates on the sample 6 and generates an image of the measurement target range of the sample 6. can do.
- Information such as the defect structure of the sample 6 can be obtained from the image of the sample 6 thus obtained.
- the electron microscope 1 may determine the sample 6 by combining the photon-photon time correlation described below in addition to the electron-photon time correlation shown in FIG. 2A.
- FIG. 3 is a diagram schematically showing the photon-photon time correlation calculated by the electron microscope 1 of the first embodiment.
- FIGS. 3A and 3B schematically show examples of photon detection signals received by the calculator 5 from the photon detector 4 via the communication I/F.
- the horizontal axes of FIGS. 3A and 3B indicate time t, and each pulse signal indicates that one photon 40 has been detected.
- the photon-photon time correlation is measured using a photon detector 4 having detectors such as at least two avalanche photodiodes or photomultiplier tubes.
- the calculator 5 determines the number of photons emitted from the sample 6 due to the electrons 30 passing through the sample 6.
- a plurality of signals are received from the photon detector 4 indicating that a photon 40 has been detected.
- the computing unit 5 computes the photon-photon time correlation curve g (2) showing the distribution of the time difference ⁇ shown in FIG. 3(c).
- the horizontal axis of (c) of FIG. 3 indicates the time difference ⁇
- the vertical axis of (c) of FIG. 3 indicates the frequency of detection of another photon after the time difference ⁇ when one photon is detected at time t. is shown.
- the photon-photon time correlation curve g (2) is generally calculated by the second-order autocorrelation function shown in the following equation (3), where ⁇ > is the intensity I of the incident light for time t represents the average.
- the photon-photon time correlation calculated in this way is also peculiar to the material constituting the sample 6 and its structure.
- the sample 6 is a substance that simultaneously emits photons 40 when the electrons 30 pass through the sample 6, the photon-photon time correlation can be obtained even if the detection of the electrons 30 by the electron detector 3 is not used as a trigger.
- the position of the peak of the curve g (2) of is the position corresponding to the time for the electron 30 to pass through the sample 6 . Therefore, the calculator 5 can also calculate the fluorescence lifetime or the luminescence transition probability of the sample 6 from the electron-photon time correlation curve g (2) in the same manner as the electron-photon time correlation curve g.
- the discriminating section of the calculator 5 can discriminate the sample 6 with higher accuracy.
- the electron-photon correlation measuring device 7 which is a passive detection system, can also be provided as an attachment added to the existing electron microscope main body 8.
- the electron-photon correlation measurement device 7 includes an electron detector 3, a photon detector 4, and a calculator 5.
- the electron detector 3 and the photon detector 4 may be configured to be housed in a housing (not shown) and to be supplied with power from the outside through a power supply terminal provided in the housing.
- the housing is arranged so that the electron detector 3 can detect the electrons 30 transmitted through the sample 6 and the photon detector 4 can detect the photons 40 emitted from the sample 6 through the photon detection window 82.
- a jig or the like to the existing electron microscope body 8 .
- the photon detection section 32 of the electron detector 3 may also be used as the photon detector 4 .
- the photon detection window 81 and the photon detection window 82 of the chamber of the existing electron microscope main body 8 are provided close to each other or shared.
- the existing electron microscope main body 8 may be either a transmission electron microscope or a scanning electron microscope, and since a large-scale and expensive pulsed electron gun is not required, the electron-photon correlation measurement device 7 can be used in most general can be incorporated as an attachment into an existing electron microscope main body 8. Therefore, a fluorescence lifetime microscope with excellent spatial resolution can be realized simply and at low cost.
- FIG. 4 is a flow chart schematically showing the electron-photon correlation measurement method of the first embodiment.
- step S1 the electron gun 2 irradiates the sample 6 with electrons 20.
- step S2 the electron detector 3 detects the electrons 30 irradiated onto the sample 6.
- step S3 the photon detector 4 detects photons 40 emitted from the sample 6 when the sample 6 is irradiated with electrons 30.
- step S4 the computing unit 5 calculates an electron The time difference between the time when the sample 6 was irradiated with the photons 30 and the time when the photons 40 were emitted from the sample 6 is calculated.
- step S5 the computing unit 5 determines whether or not the predetermined number of photons 40 necessary for computing the electron-photon time correlation that satisfies the required accuracy has been detected. If the predetermined number of photons 40 are not detected (No in step S5), the calculator 5 repeats steps S1 to S5.
- step S6 the computing unit 5 computes an electron-photon time correlation indicating the distribution of time differences.
- FIG. 5 is a diagram schematically showing the configuration of an electron microscope 1b and an electron-photon correlation measuring device 7b of the second embodiment.
- the electron microscope 1 shown in FIG. 1 was a transmission electron microscope that detects electrons 30 transmitted through the sample 6 among the electrons 20 emitted from the electron gun 2.
- the electron microscope 1b shown in FIG. is a scanning electron microscope for detecting electrons 30 irradiated to a sample 6 and reflected by the sample 6 among electrons 20 irradiated from the electron gun 2 .
- the electron microscope 1b can also be realized by adding an electron-photon correlation measurement device 7b, which is a passive detection system, to an existing scanning electron microscope main body 8b having an electron gun 2 and a chamber. Differences from the electron microscope 1 shown in FIG. 1 will be described below.
- the electron microscope of the embodiment includes an electron gun that irradiates electrons onto a sample, an electron detector that detects the electrons irradiated onto the sample, and electrons emitted from the sample when the sample is irradiated. Based on the photon detector detecting the photon, the time at which the electron detector detected the electron, and the time at which the photon detector detected the photon, for each detected photon, the time at which the electron was irradiated to the sample and a computing unit that computes the time difference between the time when the photon was emitted from the sample and computes the electron-photon time correlation indicating the distribution of the time difference.
- This provides an electron-photon correlation measurement method with a high spatial resolution of less than 10 nm.
- This provides an electron microscope, an electron-photon correlation measurement device, and an electron-photon correlation measurement method with high spatial resolution.
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Abstract
Description
図1は、第1実施形態の電子顕微鏡1及び電子-光子相関測定装置7の構成を概略的に示した図である。電子顕微鏡1は、電子銃2、電子検出器3、光子検出器4、及び演算器5を備える。電子顕微鏡1は、電子銃2及びチャンバーを備える既存の電子顕微鏡本体8に、パッシブな検出系である電子-光子相関測定装置7を追加することによっても実現される。
1/d=k1(γ-γ’)2+k2(τ0-τ0’)2+1 (2)
図5は、第2実施形態の電子顕微鏡1b及び電子-光子相関測定装置7bの構成を概略的に示した図である。先の図1に示した電子顕微鏡1は、電子銃2から照射される電子20のうち、試料6を透過した電子30を検出する透過型電子顕微鏡であったが、図5に示す電子顕微鏡1bは、電子銃2から照射される電子20のうち、試料6に照射されて試料6により反射した電子30を検出する走査型電子顕微鏡である。電子顕微鏡1bは、電子銃2及びチャンバーを備える既存の走査型の電子顕微鏡本体8bに、パッシブな検出系である電子-光子相関測定装置7bを追加することによっても実現される。以下、図1に示した電子顕微鏡1と異なる点について説明する。
Claims (11)
- 試料に電子を照射する電子銃と、
前記試料に照射された前記電子を検出する電子検出器と、
前記電子が前記試料に照射されたときに前記試料から放出される光子を検出する光子検出器と、
前記電子検出器が前記電子を検出した時間と、前記光子検出器が前記光子を検出した時間とに基づいて、検出された前記光子ごとに、前記電子が前記試料に照射された時間と前記光子が前記試料から放出された時間との時間差を演算し、前記時間差の分布を示す電子-光子時間相関を演算する演算器と、
を備える、電子顕微鏡。 - 前記電子検出器は、前記試料を透過又は反射した前記電子を検出する、
請求項1に記載の電子顕微鏡。 - 前記演算器は、前記電子-光子時間相関に基づいて前記試料を判別する判別部を有する、
請求項1又は2に記載の電子顕微鏡。 - 前記判別部は、前記試料の蛍光寿命又は発光遷移確率を前記電子-光子時間相関から演算し、前記蛍光寿命又は前記発光遷移確率に基づいて前記試料を判別する、
請求項3に記載の電子顕微鏡。 - 前記判別部は、前記電子が検出されたときに前記時間差で前記光子が検出された頻度を示す曲線を前記電子-光子時間相関から演算し、前記曲線の原点におけるピーク値から前記試料の発光遷移確率を演算し、前記曲線において値が1/e倍に減少するまでに要する時間を、前記試料の蛍光寿命として演算する、
請求項4に記載の電子顕微鏡。 - 前記演算器は、一以上の既知の物質又は生体について予め測定された電子-光子時間相関の特徴を示すパラメータ値を記憶した記憶部を有し、
前記判別部は、演算された前記試料の前記電子-光子時間相関のパラメータ値と、既知の物質又は生体の電子-光子時間相関のパラメータ値との一致度を演算し、前記一致度が所定の閾値を超え、かつ最大となるパラメータ値を有する既知の物質又は生体を、前記試料の物質又は生体を示すものとして判別する、
請求項3から5のいずれか一項に記載の電子顕微鏡。 - 前記電子検出器は、
前記試料に照射された前記電子と反応して光子を放出する発光体と、
前記発光体から放出された光子を検出して前記演算器に検出信号を出力する光子検出部と、
を有する、請求項1から6のいずれか一項に記載の電子顕微鏡。 - 前記光子検出器は、前記電子検出器の前記光子検出部として兼用され、前記試料から放出される前記光子、及び前記発光体から放出される光子を検出して前記演算器に検出信号を出力する、
請求項7に記載の電子顕微鏡。 - 前記電子銃は、前記電子を空間的に走査しながら前記試料に照射し、
前記演算器は、前記電子-光子時間相関の空間的な変化に基づいて前記試料の像を生成する像生成部を有する、
請求項1から8のいずれか一項に記載の電子顕微鏡。 - 電子顕微鏡の電子銃から試料に照射された電子を検出する電子検出器と、
前記電子が前記試料に照射されたときに前記試料から放出される光子を検出する光子検出器と、
前記電子検出器が前記電子を検出した時間と、前記光子検出器が前記光子を検出した時間とに基づいて、検出された前記光子ごとに、前記電子が前記試料に照射された時間と前記光子が前記試料から放出された時間との時間差を演算し、前記時間差の分布を示す電子-光子時間相関を演算する演算器と、
を備える、電子-光子相関測定装置。 - 試料に電子を照射し、
前記試料に照射された前記電子を検出し、
前記電子が前記試料に照射されたときに前記試料から放出される光子を検出し、
前記電子を検出した時間と、前記光子を検出した時間とに基づいて、検出された前記光子ごとに、前記電子が前記試料に照射された時間と前記光子が前記試料から放出された時間との時間差を演算し、前記時間差の分布を示す電子-光子時間相関を演算する、
ことを含む、電子-光子相関測定方法。
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