JP3803908B2 - Luminescence detection camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light emission detection camera that measures a change in temporal brightness of light changing at a high speed.
[0002]
[Prior art]
FIG. 15 is a configuration diagram showing a configuration of a conventional streak camera, and FIG. 16 is an explanatory diagram showing an imaging position on the MCP when signals are incident on the conventional streak camera with a time lag. 17 is an explanatory diagram showing an imaging position on the MCP when a signal is incident on a conventional streak camera with a time and a position shifted.
Conventionally, a streak camera, which is a light emission detection camera, has a streak tube 1, a photocathode 2, an acceleration electrode 3, a focusing electrode 4, a deflection electrode 5, and a microchannel plate 6 (hereinafter referred to as MCP 6) as shown in FIG. 15. And a fiber 8 provided with a phosphor (phosphor surface) 7 and a voltage control circuit 9 for controlling the voltage applied to the deflection electrode 5 so that electrons can fly inside the streak tube 1. It is in a vacuum state.
[0003]
An optical signal incident from the front portion of the streak tube 1 made of glass or the like is converted into electrons by the photocathode 2, accelerated by the acceleration electrode 3, focused by the focusing electrode 4, and deflected by the deflection electrode 5. After deflecting the electrons with the MCP 6 and multiplying the electrons with the MCP 6, the electrons enter the phosphor 7, return the electrons to light, and output the light from the rear surface portion of the streak tube 1 through the fiber 8 to the outside as Reading is performed by a CCD detector outside the streak tube 1, and data processing is performed as necessary.
[0004]
When the signals 1 and 2 are incident on the center of the photocathode 2 with a time lag, when passing through the accelerating electrode 3 and the focusing electrode 4 and coming to the deflection electrode 5, as shown in FIG. A voltage corresponding to the shift of the incident time is applied, and the signal 1 image and the signal 2 image on the MCP 6 are formed at different positions as shown in FIG. The image and the image of signal 2 are electron multiplied and sent to the phosphor 7, which again converts the electrons into light.
[0005]
As shown in FIG. 17A, when three signals 1, 2, and 3 are incident on the photocathode 2 at different positions, they pass through the acceleration electrode 3 and the focusing electrode 4 and are deflected. When coming to the electrode 5, as shown in FIG. 17 (b), a voltage corresponding to the shift in the incident time is applied, and the signal 1 image, the signal 2 image and the signal 3 image on the MCP 6 are shown in FIG. 17 (c). The MCP 6 multiplies the image of the signal 1, the image of the signal 2 and the image of the signal 3 and sends them to the phosphor 7. The phosphor 7 converts the electrons into light again. Convert.
[0006]
In FIG. 16B and FIG. 17C, the vertical shift of the image on the MCP 6 indicates a shift in the signal incident time, and the horizontal shift indicates a shift in the incident position of the signal. Are output with their positions shifted vertically and horizontally according to the shift in the incident time of the signal and the shift in the incident position.
[0007]
In order to detect one photoelectron photoelectrically converted by the photocathode 2, the MCP 6 applies a gain of about 10,000 times to perform electron multiplication, and the phosphor 7 can be detected with an amount of light that can be sufficiently detected outside the streak tube 1. The light is emitted.
[0008]
FIG. 18 is an explanatory diagram for explaining the operation of a conventional framing camera.
A framing camera which is a light emission detection camera is a kind of streak camera, and has the same structure as the streak camera. The function as a framing camera is to take an image by time-resolving and keeping the voltage of the deflection electrode 5 at the same voltage for a certain time, and the certain time is one frame. As shown in FIG. 18, a constant voltage is deflected step by step, and each frame is photographed. The skipped voltage becomes a shift in the position of each frame, and is read as a time shift in output.
[0009]
Signals 1, 2, and 3 that are incident on the photocathode 2 with a time lag are deflected, enter the respective frames, and are read out as outputs. The signal 2 and the signal 3 are captured in the frame 3 in a time-resolved manner.
[0010]
[Problems to be solved by the invention]
However, in the prior art, when measuring the electrons photoelectrically converted by the photocathode 2, electron multiplication in the MCP 6 is required, so that the resolution is lost and the phosphor 7 converts the electrons into light. Furthermore, there was a problem that the resolution was lost.
[0011]
Furthermore, in the prior art, when measuring the electrons photoelectrically converted by the photocathode 2, it is necessary to separate the noise by increasing the amount of light per signal by multiplying the electrons by the MCP 6 and increasing the gain. Therefore, there is a problem that the signal output gradation width becomes small, and since reading can only be performed with a fixed gain in one reading, the phenomenon to be measured is a bright place, If the signal intensity ratio in the dark place is large and the dark place is adjusted to the bright place, the bright place cannot be measured if it is set to the dark place, and if the change in the signal intensity is large, the signal is read according to the bright place and then to the dark place. There is a problem that a plurality of operations such as reading together are required.
[0012]
Furthermore, in the prior art, since measurement cannot be performed without photoelectric conversion by the photocathode 2, incident light alignment cannot be performed unless signals are actually captured, and signals cannot be detected during measurement. In this case, since it is not possible to confirm that a signal is being output, there is a problem that it is difficult to adjust the streak operation time.
[0013]
Furthermore, in the prior art, since there is only one type of photocathode 2, there is a problem that a plurality of streak tubes 1 must be used properly when measurement is to be performed using different types of photocathodes.
[0014]
Furthermore, in the prior art, the streak tube 1 is made of a sealed glass tube, and damaged parts such as the photocathode 2, MCP6, and phosphor 7 are damaged by the excessive incident light. In this case, replacement is not possible, and parts cannot be replaced. For example, when the type of the photocathode 2 is to be changed, a plurality of streak tubes 1 must be used properly.
[0015]
The present invention has been made in view of such problems, and its object is to require electron multiplication and electron to light conversion when measuring electrons photoelectrically converted by a photocathode. In addition, the present invention is to provide a light emission detection camera capable of reducing loss of resolution.
[0016]
Further, an object of the present invention is that when measuring electrons photoelectrically converted by the photocathode, it is possible to increase the signal output gradation width, and measure by changing the gain by one reading, The present invention is to provide a light emission detection camera that can be measured by a single operation even when a change in signal intensity is large.
[0017]
Furthermore, an object of the present invention is to provide an easy-to-use luminescence detection camera that can easily align incident light and can easily adjust the streak operation time. There is in point to do.
[0018]
A further object of the present invention is to provide a light emission detection camera capable of performing measurement using different types of photocathode with one streak tube.
[0019]
A further object of the present invention is to provide a luminescence detection camera that can replace the internal components of the streak tube and can improve maintainability and expandability of functions.
[0020]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is that light is converted into electrons by a photocathode, the converted electrons are caused to fly in a streak tube, and a temporal change in brightness of light is based on the emitted electrons. A light emission detection camera for measuring, wherein the electron from the photocathode is incident and incident energy detection means disposed in the streak tube for generating a charge according to the incident energy of the incident electron, and the incident Cooling means for cooling the energy detection means; The gain control means for controlling the gain when reading the electric charge from the incident energy detection means is provided, and the gain is changed and measured by one reading. It exists in the light emission detection camera characterized by this.
The gist of the invention of claim 2 is as follows: A light emission detection camera for converting light into electrons by a photocathode, causing the converted electrons to fly in a streak tube, and measuring a change in temporal brightness of light based on the emitted electrons, Incident energy detection means arranged in the streak tube that receives the electrons from the photocathode and generates charges according to the incident energy of the incident electrons, and cooling means for cooling the incident energy detection means. In addition, the photocathode comprises a first photocathode and a second photocathode of different types, a slit that changes a width through which light passes, and an image that changes an imaging position of light on the photocathode. A light emission detection camera, wherein a light imaging position on the photocathode is selected by a lens Exist.
The gist of the invention of claim 3 is as follows: A light emission detection camera for converting light into electrons by a photocathode, causing the converted electrons to fly in a streak tube, and measuring a change in temporal brightness of light based on the emitted electrons, Incident energy detection means arranged in the streak tube that receives the electrons from the photocathode and generates charges according to the incident energy of the incident electrons, and cooling means for cooling the incident energy detection means. And the streak tube has a plurality of members connected by an interface of a type that can be vacuum sealed. Exist.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
(First embodiment)
FIG. 1 is a configuration diagram showing the configuration of the first embodiment of the light emission detection camera according to the present invention, and FIG. 2 is a configuration diagram showing the configuration of the incident energy detection unit shown in FIG. These are block diagrams which show the structure of the rear surface part of the streak tube shown in FIG.
[0023]
The present embodiment includes a streak tube 1, a photocathode 2, an acceleration electrode 3, a focusing electrode 4, a deflection electrode 5, a voltage control circuit 9 for controlling a voltage applied to the deflection electrode 5, and incident energy detection. Unit 10, cooling unit 11 that cools incident energy detection unit 10, signal readout control circuit 12 that performs readout control of signals from incident energy detection unit 10, and vacuum pump 13 that sucks air inside streak tube 1 And a vacuum gauge 14 for measuring the vacuum state inside the streak tube 1, and the light emission phenomenon is detected by making a vacuum state so that electrons can fly inside the streak tube 1.
[0024]
The incident energy detection unit 10 is a semiconductor chip that converts incident electrons into an electrical signal. Specifically, a CCD (Charge Coupled Device), a PDA (Photo Diode Array), or the like is used, and the interior of the streak tube 1 is used. Is arranged.
[0025]
An example in which a full frame transfer type CCD is used as the incident energy detection unit 10 is shown in FIG. The incident energy detection unit 10 includes an image area 15, a read register 16, an output amplifier 17, and a gain switching control circuit 18. Further, the gain of the output amplifier 17 can be made variable, and the gain can be changed by the gain switching control circuit 18 according to the number of electrons.
[0026]
The CCD can sufficiently detect one electron as long as it is accelerated at about 10 KV, and a device having a small element size can be used, and a resolution of 10 μm or less can be achieved.
[0027]
The cooling unit 11 is a cooling mechanism for cooling the incident energy detection unit 10. As shown in FIG. 3A, the cooling unit 11 composed of a Peltier element or the like is arranged inside the streak tube 1 and directly The case where it cools, and the case where the cooling part 11 comprised by the liquid nitrogen dewar etc. is arrange | positioned outside the streak pipe | tube 1 as shown in FIG.3 (b), and it cools indirectly via a heat conductor (metal). Conceivable.
[0028]
When the cooling unit 11 is disposed inside the streak tube 1, the incident energy detection unit 10 can be directly cooled, so that the cooling efficiency is high, and the rear surface portion of the streak tube 1 is configured with a member having high thermal conductivity. In addition, the cooling efficiency is further increased by using it as a heat radiating part that releases heat generated from the cooling part 11.
[0029]
Normally, CCD has noise that is more than thermal noise called dark current at normal temperature, but by cooling the CCD itself, the dark current is reduced to less than the reading noise level and the signal reading performance is brought to the limit. be able to.
[0030]
The cooling of the CCD is determined by the relationship between the noise and the signal ratio. If sufficient performance is obtained, sufficient performance may be ensured without cooling. For example, when electrons are incident at an acceleration of 10 KV, about 1,500 electrons are generated inside the CCD chip. However, in order to obtain 1,500 electrons due to readout noise or dark current, it may take as long as 10 seconds. In such a case, if the exposure time is 1 second, cooling is not necessary.
[0031]
Next, the operation of the first embodiment will be described in detail with reference to FIG.
FIG. 4 is an explanatory diagram for explaining a gain switching operation by the gain switching control circuit shown in FIG.
[0032]
An optical signal incident from the front portion of the streak tube 1 made of glass or the like is converted into electrons on the photocathode 2, and the converted electrons are accelerated by the acceleration electrode 3 and focused by the focusing electrode 4. After being deflected by the deflection electrode 5, it is incident on the incident energy detection unit 10.
[0033]
When electrons are incident on the incident energy detection unit 10, that is, the image area 15, one or a plurality of electrons corresponding to the incident energy of the electrons are generated at the position where the electrons are incident on the image area 15, and the generated electrons are When reading out charges from the incident energy detection unit 10 accumulated as charges, the charges in the image area 15 are shifted to the read register 16 (charge transfer 1), and the charges in the read register 16 are read in order ( Charge transfer 2). Note that the read register 16 has a larger capacity than the other parts, can read a plurality of elements together (hereinafter referred to as binning), and can output many electrons without overflowing.
[0034]
A CCD is used as the incident energy detection unit 10 to change the signal output gradation width by changing the binning or gain on the CCD chip. Hereinafter, based on the case where the number of electrons that can be read from one element in the image area 15 is 150,000 and one element in the read register 16 can accumulate the number of electrons up to 900,000, which is six times the image area 15. The operation of changing the signal output gradation width will be described.
[0035]
In the case of the full frame transfer type CCD shown in FIG. 2, since 150,000 electrons inside the device can be read out at 65,535 to 1, a charge addition process called binning is performed and 6 devices are read out collectively. In this case, 900,000 electrons are read out at 65,535 to 1, and a signal strength that is six times stronger can be measured.
[0036]
Therefore, when the amount of change in signal intensity can be predicted in advance, by setting to read out 900,000 electrons as 65,535-to-1 for a strong signal and 150,000 electrons as 65,535-to-1 for a dark place, It becomes possible to read out a signal whose signal output gradation width of one measurement is 393, 210 to 1.
[0037]
Specifically, when measuring the phenomenon that the brightness, that is, the signal intensity changes according to the elapsed time as shown in FIG. 4, the gain switching control circuit 18 causes the amplifier on the CCD to be used in a bright place where the signal intensity is strong. Reading with a low gain and reading with a high gain in a dark place where the signal intensity is weak makes it possible to read a signal with a signal output gradation width of 393, 210 to 1 for one measurement.
[0038]
In addition, by using a CCD as the incident energy detection unit 10, accumulation measurement of the detected signal is performed. That is, the signal in the image area 15 is stored by converting the optical signal into an electric signal until it is transferred to the read register 16. Since the CCD stores a signal inside and reads it later, the signal amount is increased by integrating the signals without multiplication.
[0039]
As described above, according to the first embodiment, when the electrons photoelectrically converted by the photocathode 2 are measured, the electrons photoelectrically converted by the photocathode 2 are directly measured by the incident energy detection unit 10. This eliminates the need for electron multiplication and electron-to-light conversion, thereby reducing the resolution loss.
[0040]
Further, according to the first embodiment, when measuring electrons photoelectrically converted by the photocathode 2, the electrons photoelectrically converted by the photocathode 2 are directly measured by the incident energy detection unit 10, so that the signal output gradation The width can be increased, and even when integration processing is performed to improve the signal / noise ratio, integration can be performed in a situation where the signal output gradation width can be secured, so that electron multiplication and conversion from electron to light are possible. However, it is possible to perform measurement even if the signal has an intensity that causes saturation.
[0041]
Further, according to the first embodiment, the signal output gradation width of the electronic image is changed by the gain change and binning by the gain switching control circuit 18, and the gain is increased in a dark place and the gain is lowered in a bright place. As a result, even when the change in the signal intensity is large, the measurement can be performed with a single operation.
[0042]
(Second Embodiment)
FIG. 5 is a block diagram showing the configuration of the second embodiment of the light emission detection camera according to the present invention, and FIG. 6 shows the image of the light transmitted through the photocathode shown in FIG. FIG. 7 is an explanatory diagram illustrating a method for adjusting the streak operation time in the second embodiment of the light emission detection camera according to the present invention.
[0043]
In the second embodiment, the photocathode 2 is thinned to provide a light transmission function for transmitting light, and an imaging lens 22 for imaging the light transmitted through the photocathode 2 on the incident energy detection unit 10 is provided as a streak tube. 1 is different from the first embodiment in that it is provided inside 1 and monitors the incident state of light. The imaging lens 22 is attached in a different shape so that electrodes and the like arranged inside the streak tube 1 do not interfere with each other.
[0044]
When signals 1, 2 and 3 as shown in FIG. 6 (a) are incident on the photocathode 2 from the front surface portion of the streak tube 1, the incident energy detection unit 10 is shown in FIG. 6 (b). As described above, image formation by electrons (signal 1 image, signal 2 image and signal 3 image) and light image formation (signal 1 image image, signal 2 image image and signal 3 image image) are performed. can get. Moreover, since it is necessary to separate and detect the time-resolved image (image formation by electrons) imaged on the surface of the incident energy detection unit 10 and the photocathode image (image formation by light), the incident energy detection unit On the surface 10, a glass mask 23 or the like that does not transmit electrons but transmits light is disposed.
[0045]
When using a luminescence detection camera as a streak camera, it is used to see the phenomenon of nanoseconds from pico, and is not often used for slow phenomena of microseconds or more, but by using photocathode images (image formation by light) Measure slow phenomena over microseconds.
[0046]
That is, when the full-frame transfer type CCD shown in FIG. 2 is used as the incident energy detection unit 10, the charge operation speed on the image area 15 is on the order of microseconds. Can do.
[0047]
Further, the control of the deflection electrode 5 by the voltage control circuit 9 and the readout timing control from the incident energy detection unit 10 by the signal readout control circuit 12 are independently controlled, and the photocathode image (image formation by light) is simultaneously performed with the streak operation. Monitor and obtain reference information at the same time, such as being able to monitor the time zone where you want to see the phenomenon. The streak operation for applying the deflection voltage of the deflection electrode 5 requires time adjustment and the signal cannot be detected if there is a deviation. Therefore, from the beginning to the end of the phenomenon by the photocathode image (image formation by light). Monitor the time and adjust the time for the streak operation while confirming that the signal is output.
[0048]
For example, when measuring the phenomenon as shown in the graph of FIG. 7, when the streak operation time adjustment is set to streak capture 1, a time-resolved image (image formation by electrons) can be detected. When the streak operation time adjustment is set to streak capture 2, a time-resolved image (image formation by electrons) cannot be detected. The deflection time (streak operation time) of the deflection electrode 5 is about nanoseconds.
[0049]
If the time-resolved image (image formation by electrons) cannot be detected in the streak operation, the detection of only the time-resolved image (image formation by electrons) does not output the signal itself, or the streak operation timing is shifted. I don't know if this is the case, but the fact that the signal is being output by monitoring the phenomenon from the beginning to the end of the phenomenon (image capture time width in Fig. 7) in milliseconds by the photocathode image (image formation by light). Check and adjust the streak operation time within the image capture time range.
[0050]
As described above, according to the second embodiment, the streak tube 1 can be used even when measuring invisible light such as X-rays by monitoring the photocathode image (image formation by light). It is easy to align the incident light incident from the front part of the slab, and furthermore, it is possible to adjust the streak operation time while confirming that a signal is being output. There is an effect that the work is easy to perform.
[0051]
Furthermore, according to the second embodiment, by simultaneously detecting a time-resolved image (image formation by electrons) and a photocathode image (image formation by light), different measurements of the same phenomenon can be performed simultaneously. There is an effect that it becomes possible to perform.
[0052]
(Third embodiment)
FIG. 8 is a block diagram showing the configuration of the photocathode of the third embodiment of the luminescence detection camera according to the present invention, and FIG. 9 shows the streak of the third embodiment of the luminescence detection camera according to the present invention. It is a block diagram which shows the relationship between the slit arrange | positioned in the tube front surface, and an imaging lens.
[0053]
In the third embodiment, the photocathode 2 includes a first photocathode 201 and a second photocathode 202 as shown in FIG. 8A, and a streak tube as shown in FIG. 9A. 1 is incident by a slit 30 that is arranged in front of the front surface portion 1 and adjusts the signal amount by changing only the width of incident light passing therethrough and an imaging lens 31 that changes the imaging position of the incident light on the photoelectric surface 2. The imaging position of the light on the photocathode 2 is variable.
[0054]
8B and 8C, the slit 30 is moved up and down as shown in FIG. 9B, or the imaging lens 31 is moved up and down as shown in FIG. 9C. As described above, the signal incident from the slit 30 is selectively imaged on either the first photocathode 201 or the second photocathode 202.
[0055]
Further, when a portion that transmits light is provided below the photocathode 2 and adjustment is performed using the transmission of the portion, the two blades of the slit 30 disposed in front of the front portion of the streak tube 1 are two. If it is configured to move independently, the ratio of the area of the photocathode 2 and the area of the transmissive portion can be changed, so that both signals can be successfully captured by adjusting the ratio of the quantity of light of both.
[0056]
As described above, according to the third embodiment, by moving the slit 30 or the imaging lens 31 without changing the setting of the optical system for signal measurement, the first photocathode 201 and the second photocathode 201 are moved. The photocathode 202 of the first photocathode 201 and the second photocathode 202 can be switched and used. When using photocathodes with different signal wavelength ranges for the first photocathode 201 and the second photocathode 202, one streak tube 1 is used. Thus, measurement can be performed using different types of photocathodes, and the workability is improved.
[0057]
(Fourth embodiment)
FIG. 10 is a block diagram showing the configuration of the fourth embodiment of the light emission detection camera according to the present invention.
[0058]
In the fourth embodiment, as shown in FIG. 10, the streak tube 1 includes a main body 101 in which the acceleration electrode 3, the focusing electrode 4 and the deflection electrode 5 are disposed, and the first in which the photocathode 2 is disposed. The exchange unit 102 and the second exchange unit 103 in which the incident energy detection unit 10 is arranged can be vacuum-sealed between the main body 101, the first exchange unit 102, and the second exchange unit 103. It is configured to be connected by an ICF flange 21 which is a type interface. The main body 101 is provided with a vacuum valve port 25 for drawing a vacuum inside the streak tube 1.
[0059]
If the first replacement unit 102 or the second replacement unit 103 is replaced, a large amount of gas adheres to the inside of the streak tube 1 during the replacement operation. Therefore, after the replacement operation, the vacuum valve port 25 has a certain degree of vacuum. The vacuum is closed by the vacuum valve port 25 and is controlled to a required degree of vacuum by the vacuum pump 13 provided in the main body 101. Since the gas is generated very slowly from the components inside the streak tube 1, the vacuum pump 13 controls the adsorption of the generated gas and the necessary degree of vacuum while measuring the vacuum with the vacuum gauge 14. To do.
[0060]
As described above, according to the fourth embodiment, the streak tube 1 is constituted by the main body 101, the first replacement part 102, and the second replacement part 103, and each is connected by the ICF flange 21. Since the inside can be evacuated, the components inside the streak tube 1 can be exchanged, and there is an effect that the maintainability and the expandability of functions can be improved.
[0061]
(Fifth embodiment)
FIG. 11 is a configuration diagram showing a configuration of the protective electrode used in the fifth embodiment of the light emission detection camera according to the present invention, and FIG. 12 is a configuration diagram showing an arrangement example of the protective electrode shown in FIG. FIG. 13 is a block diagram showing a configuration in which a flange surface supporting the CCD is used instead of the protective electrode shown in FIG.
[0062]
In the fifth embodiment, the protective electrode 40 shown in FIG. 11 is arranged in front of the incident energy detection unit 10 as shown in FIG. 12, and the portion other than the detection surface (image area 15) of the incident energy detection unit 10 is arranged. Is invisible from the incident direction of electrons. The protective electrode 40 is provided with an opening 41, and the size of the opening 41 and the protective electrode so that electrons passing through the opening 41 are incident only on the detection surface of the incident energy detection unit 10. The arrangement position of 40 is adjusted.
[0063]
As shown in FIG. 12, the protective electrode 40 and the incident energy detection unit 10 are connected to a constant potential point, and the potential between the protective electrode 40 and the incident energy detection unit 10 is adjusted by the potential adjustment resistor 42. As a result, the potential of the protective electrode 40 can be adjusted to a voltage with less disturbance on the potential surface when viewed from the acceleration electrode 3, and the positional deviation when electrons are incident can be reduced. In some cases, the potential adjusting resistor 42 may be 0 ohms. Further, the position of the protective electrode 40 does not have to be immediately in front of the incident energy detection unit 10, and may be disposed between the incident energy detection unit 10 and the deflection electrode 5.
[0064]
When a CCD is used as the incident energy detection unit 10 and the CCD mount is made of a material that is less affected by metal or charging, it is not necessary to provide the protective electrode 40. However, as shown in FIG. The flange surface supporting the CCD is connected to a constant potential point and the flange surface supporting the CCD is connected to the constant potential point. Is adjusted by the potential adjusting resistor 42, the discharge process of electrons incident on the flange surface and the adjustment process of the potential surface can be performed.
[0065]
As described above, according to the fifth embodiment, by providing the protective electrode 40, electrons passing through the deflection electrode 5 hit the ceramic part of the incident energy detection unit 10 (CCD) and are charged. Since it is possible to prevent charging by hitting the ceramic of the cooling unit 11 (Peltier element), it is possible to prevent erroneous operation due to charging, and by adjusting the potential of the protective electrode 40, performance resulting from disturbance of the potential surface There exists an effect that a fall can be prevented.
[0066]
(Sixth embodiment)
FIG. 14 is a configuration diagram showing the arrangement positions of the phosphors used in the sixth embodiment of the light emission detection camera according to the present invention.
[0067]
In the sixth embodiment, a phosphor 50 is provided between the deflection electrode 5 and the incident energy detection unit 10 so that electrons flying by the phosphor 50 are converted into light and incident on the incident energy detection unit 10. It is configured. Instead of the phosphor 50, an electron photon conversion material such as a scintillator may be used.
[0068]
Even if the phosphor 50 is applied directly on the incident energy detection unit 10 as shown in FIG. 14A, an indirect material such as a fiber plate 51 is put on the fiber plate 51 as shown in FIG. It may be applied to. Further, the phosphor 50 may be provided with a function of a protective electrode.
[0069]
When the phosphor 50 is applied directly on the incident energy detection unit 10, electrons are converted into light inside the phosphor 50, and only the incident part emits light. Therefore, by reducing the thickness of the phosphor 50, the resolution is reduced to a great extent. Without being lost, it is possible to prevent electrons from directly entering the incident energy detection unit 10.
[0070]
Alternatively, the phosphor 50 may be applied on the fiber reducer 52 as shown in FIG. 14C so that the output image of the large phosphor 50 is reduced by the fiber reducer 52 and transferred. The fiber reducer 52 is composed of bundles of optical fibers, and the diameter of one side of each fiber is smaller than that of the other side, and the overall image is reduced by this ratio.
[0071]
As described above, according to the sixth embodiment, by using the phosphor 50, it is possible to prevent damage to the incident energy detection unit 10 and extend the life of the incident energy detection unit 10. The effect that it can improve property is produced.
[0072]
Furthermore, according to the sixth embodiment, since the electronic image formed on the phosphor 50 is reduced and transferred by the fiber reducer 52, the size of the captured electronic image is limited to the size of the incident energy detection unit 10. There is an effect that a large area can be taken in by the small incident energy detection unit 10.
[0073]
Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention. In each figure, the same numerals are given to the same component.
[0074]
【The invention's effect】
In the light emission detection camera of the present invention, when measuring the electrons photoelectrically converted by the photocathode, the electrons photoelectrically converted by the photocathode are directly measured by the incident energy detection unit. There is an effect that loss of resolution can be reduced without requiring conversion.
[0075]
Furthermore, when measuring the electrons photoelectrically converted by the photocathode, the light emission detection camera of the present invention directly measures the electrons photoelectrically converted by the photocathode by the incident energy detector, so that the signal output gradation width is increased. In addition, even when integration processing is performed to improve the signal / noise ratio, it is possible to perform integration in a situation where the signal output gradation width can be secured, so measurement that requires electron multiplication and conversion from electron to light is required. Then, even if it is the intensity | strength which a signal saturates, there exists an effect that it can measure.
[0076]
Furthermore, the light emission detection camera of the present invention changes the signal output gradation width of the electronic image by changing the gain and binning by the gain switching control circuit, and increases the gain in a dark place and lowers the gain in a bright place. Thus, even when the change in the signal intensity is large, an effect is obtained that the measurement can be performed by one operation.
[0077]
Furthermore, the light emission detection camera of the present invention is incident from the front portion of the streak tube even when measuring invisible light such as X-rays by monitoring the photocathode image (image formation by light). The incident light can be easily aligned, and the streak operation time can be adjusted while confirming that a signal is being output. This makes it easy to adjust the streak operation time. Play.
[0078]
Furthermore, the luminescence detection camera of the present invention simultaneously performs different measurements of the same phenomenon by simultaneously detecting a time-resolved image (image formation by electrons) and a photocathode image (image formation by light). There is an effect that becomes possible.
[0079]
Furthermore, the light emission detection camera of the present invention can be used by switching the first photocathode and the second photocathode by moving the slit or the imaging lens without changing the setting of the optical system for signal measurement. Therefore, when using a photocathode with different signal wavelength ranges for the first photocathode and the second photocathode, measurement is performed using different types of photocathodes with one streak tube. This is advantageous in that workability is improved.
[0080]
Furthermore, in the light emission detection camera of the present invention, since the streak tube is constituted by the main body, the first replacement part and the second replacement part, and the inside can be evacuated after being connected by the ICF flange, The internal parts can be exchanged, and there is an effect that the maintainability and the expandability of functions can be improved.
[0081]
Furthermore, in the light emission detection camera of the present invention, by providing a protective electrode, electrons passing through the deflecting electrode hit the ceramic part of the incident energy detection part (CCD) and are charged or hit the ceramic of the cooling part (Peltier element). Since charging can be prevented, erroneous operation due to charging can be prevented, and by adjusting the potential of the protective electrode, it is possible to prevent performance deterioration caused by disturbance of the potential surface. .
[0082]
Furthermore, the use of the phosphor in the luminescence detection camera of the present invention prevents damage to the incident energy detection unit, extends the life of the incident energy detection unit, and improves the system reliability. Play.
[0083]
Furthermore, since the light emission detection camera of the present invention transfers the electronic image formed on the phosphor after being reduced by the fiber reducer, the size of the captured electronic image is not limited by the size of the incident energy detector, and the There is an effect that the acquisition is possible with a small incident energy detector.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a light emission detection camera according to the present invention.
FIG. 2 is a configuration diagram illustrating a configuration of an incident energy detection unit illustrated in FIG. 1;
3 is a configuration diagram showing a configuration of a rear surface portion of the streak tube shown in FIG. 1. FIG.
4 is an explanatory diagram for explaining a gain switching operation by the gain switching control circuit shown in FIG. 2;
FIG. 5 is a configuration diagram showing a configuration of a second embodiment of a light emission detection camera according to the present invention;
6 is an explanatory diagram showing a state of image formation on an incident energy detection unit of light transmitted through the photocathode shown in FIG. 5;
FIG. 7 is an explanatory diagram for explaining a method for adjusting the streak operation time in the second embodiment of the light emission detection camera according to the present invention;
FIG. 8 is a configuration diagram showing a configuration of a photocathode of a third embodiment of the light emission detection camera according to the present invention.
FIG. 9 is a configuration diagram showing a relationship between a slit arranged on the front surface of a streak tube and an imaging lens in a third embodiment of the light emission detection camera according to the present invention.
FIG. 10 is a configuration diagram showing a configuration of a fourth embodiment of a light emission detection camera according to the present invention.
FIG. 11 is a configuration diagram showing a configuration of a protective electrode used in a fifth embodiment of the light emission detection camera according to the present invention;
12 is a configuration diagram showing an example of arrangement of the protective electrodes shown in FIG.
13 is a configuration diagram showing a configuration in which a flange surface supporting a CCD is used instead of the protective electrode shown in FIG.
FIG. 14 is a configuration diagram showing the arrangement positions of phosphors used in a sixth embodiment of the light emission detection camera according to the present invention.
FIG. 15 is a configuration diagram showing a configuration of a conventional streak camera.
FIG. 16 is an explanatory diagram showing an imaging position on the MCP when signals are incident on a conventional streak camera with a time lag.
FIG. 17 is an explanatory diagram showing an image formation position on the MCP when a signal is incident on a conventional streak camera with a time and position shifted.
FIG. 18 is an explanatory diagram for explaining the operation of a conventional framing camera.
[Explanation of symbols]
1 Streak tube
2 Photocathode
3 Accelerating electrode
4 Focusing electrode
5 Deflection electrodes
6 Microchannel plate (MCP)
7 Phosphor (phosphor screen)
8 Fiber
9 Voltage control circuit
10 Incident energy detector
11 Cooling unit
12 Signal readout control circuit
13 Vacuum pump
14 Vacuum gauge
15 Image area
16 Read register
17 Output amplifier
18 Gain switching control circuit
21 ICF flange
22 Imaging lens
23 Glass mask
25 Vacuum valve port
30 slits
31 Imaging lens
40 Protective electrode
41 opening
42 Resistance adjustment resistor
50 Phosphor
51 Fiber plate
52 Fiber Reducer
101 body
102 1st exchange part
103 2nd exchange part
201 First photocathode
202 second photocathode

Claims (3)

A light emission detection camera that converts light into electrons by a photocathode, causes the converted electrons to fly in a streak tube, and measures a change in temporal brightness of light based on the electrons that have been caused to fly,
Incident energy detection means disposed in the streak tube that receives the electrons from the photocathode and generates a charge corresponding to the incident energy of the incident electrons.
Cooling means for cooling the incident energy detection means ;
Comprising the gain control means for controlling the gain when reading the charge from the incident energy detection means;
A light emission detection camera characterized in that a gain is changed by one reading and measurement is performed . A light emission detection camera that converts light into electrons by a photocathode, causes the converted electrons to fly in a streak tube, and measures a temporal change in light brightness based on the electrons that have been caused to fly,
  Incident energy detection means disposed in the streak tube that receives the electrons from the photocathode and generates charges according to the incident energy of the incident electrons;
  Cooling means for cooling the incident energy detection means,
  The photocathode comprises a first photocathode and a second photocathode of different types,
  A slit that changes the width that light passes through;
  An emission detection camera, wherein an imaging position of light on the photocathode is selected by an imaging lens that changes an imaging position of light on the photocathode. A light emission detection camera that converts light into electrons by a photocathode, causes the converted electrons to fly in a streak tube, and measures a temporal change in light brightness based on the electrons that have been caused to fly,
  Incident energy detection means disposed in the streak tube that receives the electrons from the photocathode and generates charges according to the incident energy of the incident electrons;
  Cooling means for cooling the incident energy detection means,
  The streak tube has a plurality of members connected by an interface of a type that can be vacuum-sealed.

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