JPH0652997A - High-efficiency oxygen ion neutralizer and oxygen-atomic resistance evaluation system using high-efficiency oxygen ion neutralizer - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to select the oxygen gas that maximizes the neutralization efficiency to enable the best ground simulation and to enable efficient deterioration acceleration experiments. [Structure] The gas flowing from the orifice of the differential exhaust chamber to the deterioration reaction chamber is minimized, and the vacuum exhaust passage has a double structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground simulation device for simulating a surface deterioration phenomenon of a space material due to oxygen atoms in a low earth orbit on the ground, and a high efficiency used for a deterioration acceleration test device for the space material. The present invention relates to an oxygen ion neutralizer and an oxygen atom resistance evaluation apparatus using the high efficiency oxygen ion neutralizer.

[0002]

2. Description of the Related Art Since a successful flight in a low earth orbit (altitude of about 100 to 1,000 km) by a space shuttle, development of low earth orbit spacecraft (spacecraft) including a space station has been actively conducted. Became. However, J Spacecraft and Rockets Volume 23 (J.S.
placecraft and Rockets, Vo
l. 23 (1986)), p. As shown in 505-511, the main component of the atmosphere in low earth orbit is oxygen atom, and when a spacecraft flies in this, the oxygen atom has energy: 5 eV, flux: 10 ¹³ -10 ¹⁵ / cm ²
・ Since the collision occurs in sec, the surface of the part of the spacecraft that is exposed to the atmosphere (space material) is significantly deteriorated. Therefore, for example, “Twenty Third Aero Simite Paper (23rd Aero.Sci.M
eet, Paper) ”No. 85-0415 (19
As can be seen in the results of the flight experiment on the deterioration of the surface material of the spacecraft due to the oxygen atoms shown in 84), the carbon fiber-based material such as CFRP used as the space material has the surface deterioration such as the film thickness reduction. Occurs, and it is difficult to use it as a structural material for long-term use (several months to several decades or more) of spacecraft currently under development or planned to be developed in the future.

Therefore, in order to investigate the mechanism of material deterioration due to atomic oxygen and to establish a preventive measure against it, a neutral oxygen atomic beam is applied to a space material by a ground simulation experiment equipment in a space environment, and its influence is affected. It is important to quantitatively evaluate. So far, for example, Gary Woolen's Jolender Materials Degradation in Low Earth Orbit (The Minerals, Metals and Materials Society, 1
990) (Gary W. Sjolander, Mat.
initials Degradation in Low
Earth Orbit (The Minerals,
metals & Materials Society,
1990), 175-188. As shown in,
A ground simulation experiment device has been developed which irradiates a space oxygen material in a vacuum container with a neutral oxygen atom beam generated by an oxygen atom beam generator.

FIG. 6 is a schematic structural diagram of an oxygen atom beam generator exemplified as a conventional ground simulation device. In the figure, 1 is an ion source for generating oxygen ions (O ') by performing arc discharge with respect to oxygen gas, 3 is an accelerating electrode for accelerating the oxygen ions (O') to the order of keV, and 4 is an accelerating electrode. A mass separation magnet 5 for selecting only oxygen ions (O ′) incident from the accelerating electrode 3, a deceleration electrode of a decelerator for decelerating the irradiation speed of the oxygen ions (O ′) onto a sample to a predetermined speed (5 eV), Reference numeral 6 denotes an oxygen ion neutralizer (hereinafter, simply referred to as neutralization) that neutralizes the oxygen ion (O ') beam incident from the deceleration electrode 5 by charge exchange with oxygen gas to generate a neutral oxygen atom beam. 7) is a deflection electrode, and these constitute the main part of the oxygen atom beam generator.

FIG. 7 is a schematic sectional view showing the structure of the neutralizer used in the ground simulator of FIG. In the figure, 60 is a neutralization chamber of the neutralizer 6, 61 is an inlet-side orifice for injecting the oxygen ion (O ′) beam 8 into the neutralization chamber 60, and 62 is from the neutralization chamber 60. It is an exit side orifice for emitting the neutral oxygen atom beam 9, and the entrance side orifice 61 and the exit side orifice 62 are provided in the beam path of the neutralization chamber 60. Reference numeral 63 is a gas introduction pipe for introducing and filling oxygen gas into the neutralization chamber 60, and the gas introduction pipe 63 is equipped with a gas flow controller (not shown). Reference numeral 64 denotes an exhaust pipe for exhausting reaction product ions and unreacted oxygen gas from the neutralization chamber 60, and the exhaust pipe 64 is connected to a vacuum exhaust device (not shown).

Next, the operation will be described. First, in the ion source 1, oxygen discharge (O ′) is generated by performing arc discharge with respect to oxygen gas. This oxygen ion (O ′) is accelerated to the order of keV by the next acceleration electrode 3, and then only the oxygen ion (O ′) is selected by the mass separation magnet 4. Next, the deceleration electrode 5
The oxygen ion (O ′) beam 8 is decelerated to the speed (5 eV) at which the sample is irradiated, and the oxygen ion (O ′) beam 8 enters the neutralizer 6. In the neutralizer 6, the incident oxygen ions are neutralized to generate neutral oxygen atoms. Then, the neutral oxygen atom beam emitted from the neutralizer 6 is finally removed from charged oxygen ions (O ′) at the deflection electrode 7, and the neutral oxygen atom beam consisting of only oxygen atoms. 9 is generated.

In the process of generating the neutral oxygen atom beam 9 as described above, in the neutralizer 6, as shown in FIG. 7, the oxygen ions (O ') incident from the inlet side orifice 61 into the neutralization chamber 60 are introduced. ) Is neutralized by charge exchange with the oxygen gas filled in the neutralization chamber 60, whereby the neutral oxygen atom beam 9 is generated. The neutral oxygen atom beam 9 is emitted from the outlet side orifice 62, and the reaction product ions and unreacted oxygen gas are exhausted from the exhaust pipe 64. In this case, if the oxygen ion (O ′) beam 8 is stably generated, the amount of oxygen gas introduced into the neutralization chamber 60 is adjusted by the gas flow rate controller, and the neutralization chamber 60 is supplied with the oxygen gas. By keeping the oxygen gas pressure constant, the neutral oxygen atom beam 9 is stably generated.

Here, the flux of the oxygen atom beam generated by the neutralizer 6 is neutralized when the flux of the oxygen ion (O ') beam 8 entering the neutralization chamber 60 is constant. It rises by increasing the oxygen gas pressure in the chamber 60, takes a peak value, and then decreases.
Therefore, the flux of the oxygen atom beam can also be changed by changing the oxygen gas pressure according to the conditions of the ground simulation experiment.

When the energy of the oxygen ion (O ') beam generated by such a ground simulation apparatus was measured with an energy analyzer, the peak energy was 4.5 eV and the full width at half maximum was 1.5 eV. The oxygen ion (O ') beam flux is 5 * 10 ¹⁴ /
It was cm ² sec, and it was found that the low earth orbit environment was well reproduced for the ion beam. That is, in the above-mentioned ground simulation apparatus, once the oxygen ions (O ′) are accelerated to a high speed by the acceleration electrode 3 and then decelerated to 5 eV by the deceleration electrode 5, the spread of the ion beam due to the space charge effect is reduced. Is obtained, and there is an advantage that a highly reliable method can be used as a method for mass selection. Therefore, according to the above ground simulation apparatus, the surface deterioration phenomenon of the space material due to oxygen atoms can be simulated on the ground.

[0010]

Since the conventional oxygen ion neutralizer and ground simulation device using the oxygen ion neutralizer are configured as described above, the ground simulation device is In order to reproduce the atmospheric pressure in the low earth orbit, the pressure in the degradation reaction chamber must be kept below 10 ^-5 Torr, while in the neutralizer, the oxygen that collides with the spacecraft surface in the low earth orbit. Atomic flux: 10 ¹³ to 10 ¹⁵ /
In order to reproduce cm ² · sec, the oxygen gas pressure in the neutralization chamber 60 is changed to the pressure (about 10 ⁻⁶ Torr) in the deterioration reaction chamber.
The neutralization efficiency should be much higher than that (about 10 ^-2 Torr). However, in the above-described conventional neutralizer 6, when the oxygen gas pressure in the neutralization chamber 60 is increased, the reaction products ions and oxygen gas in the neutralization chamber 60 will cause the inlet 61 and the outlet side orifice 61, In addition to increasing the pressure in the deterioration reaction chamber and flowing out from 62, the reaction product ions may go around the sample and cause some reaction with the sample. There is a problem that the surface analysis of the sample is greatly affected. Further, when the neutralizer 6 is installed in the vacuum container, the vacuum container must be provided with two holes for passing the gas introduction pipe 63 and the exhaust pipe 64 of the neutralizer 6, respectively. Must therefore be
There is also a problem that the vacuum container has a high probability of vacuum leakage due to the gap between the holes.

Further, in the above-mentioned conventional ground simulator, the amount of neutral oxygen atoms generated in the neutralizer 6 is stable, and the space material (sample) is actually irradiated. Accurate understanding of the amount of oxygen atoms is important for quantitative evaluation of material deterioration, and is essential for conducting accelerated experiments. However, since a complicated reaction of atoms and molecules occurs in the neutralization chamber 60 of the neutralizer 6, the amount of neutral oxygen atoms generated in the neutralizer 6 is theoretically calculated from the reaction cross section. There is a limit to the accuracy and it is very difficult to obtain. Therefore, the amount of neutral oxygen atom and its stability can only be measured by some method,
Since the above-mentioned conventional ground simulation device does not have means for that, for example, it is difficult to quantitatively evaluate deterioration such as investigating the relationship between the dose of the oxygen atom beam on the sample and the mass decrease due to deterioration. There was a problem that the acceleration experiment lacked reliability.

Further, in the above ground simulation experiment device, in order to efficiently convert the oxygen ion (O ′) beam 8 into the neutral oxygen atom beam 9, the neutralization efficiency of the neutralizer 6 is maximized. There is a need. However, as described above, the neutralizer 6
Since it is difficult to theoretically determine the amount of neutral oxygen atoms generated in, the optimum condition should be determined by some method, but in the case of the above ground simulation experiment device, the density of generated neutral oxygen atoms is measured. Since there is no means, there is a problem that it is not possible to investigate the conditions that maximize the neutralization efficiency.

The invention of claim 1 has been made in order to solve the above-mentioned problems, and it is possible to minimize the amount of reaction product ions and oxygen gas flowing out to the outside. , Even if the oxygen gas pressure in the neutralization chamber is increased to enhance the neutralization efficiency, the pressure in the deterioration reaction chamber can be maintained at the same level as in the low earth orbit environment, and The purpose is to obtain a high-efficiency oxygen ion neutralizer that enables the best ground simulation experiment by selecting oxygen gas that maximizes the neutralization efficiency without the reaction product ions reacting with the sample. .

According to the second aspect of the present invention, a high-concentration production of a beam consisting of only neutral oxygen atoms is possible, and the absolute density of the oxygen atoms can be measured in-situ. It is possible to accurately grasp the irradiation conditions of the oxygen atom, to quantitatively evaluate the relationship between the irradiation amount of oxygen atoms and deterioration of space materials, and to improve the reliability even in accelerated experiments. The purpose is to get.

According to the third aspect of the invention, the relationship between the irradiation angle of the oxygen atom beam to the sample and the material deterioration can be investigated.
It is an object of the present invention to obtain an oxygen atom resistance evaluation device that can accurately simulate the difference in deterioration of space materials depending on the part of the spacecraft surface.

According to the invention of claim 4, the continuous deterioration acceleration test of a plurality of samples is performed without releasing the vacuum suction force of the deterioration reaction chamber and regenerating the vacuum suction force every time the sample is exchanged. An object is to obtain an oxygen atom resistance evaluation device that can be used.

It is an object of the invention of claim 5 to obtain an oxygen atom resistance evaluation apparatus capable of analyzing the generated gas before and after irradiating a sample with oxygen atoms to obtain information on a material deterioration mechanism.

[0018]

A high-efficiency oxygen ion neutralizer according to the present invention comprises a gas inflow controller for introducing oxygen gas into the neutralization chamber and controlling the oxygen gas introduction amount. Surrounding the gas introduction pipe and the neutralization chamber,
Further, a differential exhaust chamber having an inlet-side orifice and an outlet-side orifice which are respectively opposed to the inlet-side orifice and the outlet-side orifice of the neutralization chamber, and the differential exhaust chamber is used as a vacuum exhaust device. A vacuum exhaust pipe that is connected to the gas inlet pipe and forms a vacuum exhaust passage between the gas inlet pipe and the gas inlet pipe. The conductance of the inlet side and outlet side orifices of the neutralization chamber is C ₂ ,
C ₃ , C ₁ and C ₄ for the conductance of the inlet side and outlet side orifices of the differential exhaust chamber, S ₁ for the effective exhaust speed of the vacuum exhaust device of the differential exhaust chamber system, and vacuum exhaust of the vacuum container system Assuming that the effective pumping speed of the device is S ₂ , (C ₁ + C ₄ ) * (C ₂ + C ₃ ) / (S ₁ * S ₂ ) <1
It is designed to satisfy 0 ^-2 .

An oxygen atom resistance evaluation apparatus according to a second aspect of the present invention is an oxygen atom beam generator configured by arranging an ion source, an acceleration means, a deceleration means, and an oxygen ion neutralizer in this order. And a sample holder installed on the beam line connected to this oxygen atom beam generator, and a vacuum degradation reaction chamber with at least two windows, and laser-induced measurement of the density of atomic oxygen irradiated to the sample. And a fluorescence measurement device, the deterioration reaction chamber is connected to a vacuum exhaust device, the laser-induced fluorescence measurement device, through the window of the deterioration reaction chamber, laser to the oxygen atom beam generated by the oxygen atom beam generator It is arranged so that light is irradiated and the intersection of this laser beam and the oxygen atom beam becomes the observation volume for fluorescence detection.

In the oxygen atom resistance evaluation apparatus according to the third aspect of the present invention, the sample holder in the deterioration reaction chamber is rotatably supported.

In the oxygen atom resistance evaluation apparatus according to the invention of claim 4, the sample holder is detachably supported in the deterioration reaction chamber, and the deterioration reaction chamber is provided with a vacuum sample preparation in which a plurality of samples are provided. A chamber is connected via a vacuum valve, the sample holder is movable between the deterioration reaction chamber and the sample preparation chamber by a manipulator, and the sample holder in the deterioration reaction chamber is provided in the sample preparation chamber. And can be exchanged sequentially.

In the oxygen atom resistance evaluation apparatus according to the fifth aspect of the present invention, the deterioration reaction chamber is equipped with a quadrupole mass spectrometer using the gas released from the sample as the sample gas.

[0023]

In the high-efficiency oxygen ion neutralizer according to the first aspect of the invention, the neutralization chamber is filled with oxygen gas from the gas introduction pipe, and the oxygen ions (O ') are passed through the inlet and outlet orifices. Then, the oxygen ion (O ′) beam that has entered the neutralization chamber from the inlet-side orifice is neutralized by charge exchange with oxygen gas in the neutralization chamber, thereby neutralizing neutral oxygen atoms. A beam is generated and the neutral oxygen atom beam is emitted from the exit orifice. In this case, reaction product ions and unreacted oxygen gas flow out from at least two orifices of the neutralization chamber,
It is exhausted from the vacuum exhaust pipe of the differential exhaust chamber. In addition, the oxygen atom beam can be stably generated because it can be kept constant by the gas flow rate controller in the neutralization chamber. Here, the conductances of the inlet side and the outlet side orifices of the neutralization chamber are C ₂ and C ₃ , and the conductances of the inlet side and the outlet side orifice of the differential exhaust chamber are C ₂ .
₁ and C ₄ , the effective pumping speed of the vacuum pumping device of the differential pumping chamber system is S ₁ , and the effective pumping speed of the vacuum pumping device of the vacuum container system is S ₂ , (C ₁ + C ₄ ) * (C ₂ + C ₃ ) / (S ₁ * S ₂ ) <1
By satisfying 0 ^-2 , the gas flowing from the orifice of the differential exhaust chamber to the deterioration reaction chamber is minimized. Therefore, even if the oxygen gas pressure in the neutralization chamber is increased to increase the neutralization efficiency to about 10 ^-2 Torr, the pressure in the deterioration reaction chamber is maintained at 10 ^-5 Torr or less. Therefore, even if the oxygen gas pressure in the neutralization chamber is increased to increase the neutralization efficiency, the pressure in the deterioration reaction chamber is maintained at the same level as in the low earth orbit environment, and
Reaction product ions in the neutralization chamber do not react with the sample. Further, since the vacuum exhaust path is formed by the double structure of the gas introduction pipe and the vacuum exhaust pipe, the gas introduction / exhaust section becomes compact, and when the neutralization chamber is installed in the vacuum container, This vacuum container has the advantage that it is only necessary to provide one common hole for inserting the gas introduction pipe and the vacuum exhaust pipe.

In the oxygen atom resistance evaluation apparatus according to the second aspect of the present invention, in the oxygen atom beam generator, the oxygen ions ionized by the ion source are accelerated to the sample irradiation speed by the acceleration means, and then the mass separation means is used. Only the oxygen ions are selected, and the selected oxygen ions are decelerated by the deceleration means to the speed at which the sample is desired to be irradiated. After that, a substantially uniform particle energy is obtained by the charge exchange by the oxygen ion neutralizer according to claim 1. A neutral oxygen atom beam is generated. The neutralization method by such charge exchange has higher efficiency than, for example, recombination with electrons. Further, an extraction electrode can be used as the accelerating means, and the energy of the oxygen atom beam becomes equal to the voltage of the extraction electrode, so that it can be easily controlled by changing the voltage of the extraction electrode. Further, in the laser-induced fluorescence measuring device, for example, a laser for laser-induced fluorescence is used.
A 26 nm laser beam is generated to irradiate the oxygen atom beam. The laser light of 226 nm excites only neutral oxygen atoms, and the excited oxygen atoms emit fluorescence of 844 nm. This fluorescence is detected by the laser-induced fluorescence measuring device, and the absolute density of oxygen atoms is obtained by constituting the fluorescence intensity. Therefore, the laser-induced fluorescence measuring device can accurately measure the oxygen atom density on the spot. The neutralization efficiency of oxygen ions in the neutralizer depends on the introduction amount of oxygen gas when the exhaust volume of the vacuum exhaust device is constant, but the introduction amount of oxygen gas that maximizes the neutralization efficiency. Is the laser-induced fluorescence measuring device,
It can be clarified by examining the relationship between the amount of introduced oxygen gas and the density of neutral oxygen atoms. Also, the flux of the oxygen ion beam changes depending on the oxygen ion generation conditions in the ion source. Therefore, the laser-induced fluorescence measuring device enables quantitative evaluation of deterioration by a deterioration simulation experiment while controlling the flux, and reliability is improved even in an acceleration experiment.

In the oxygen atom resistance evaluation apparatus according to the third aspect of the present invention, by rotating the sample holder, it becomes possible to clarify the relationship between the irradiation angle of the oxygen atom beam to the sample and the deterioration. , It is possible to accurately investigate the difference in material deterioration depending on the part of the spacecraft surface.

The oxygen atom resistance evaluation apparatus according to the invention of claim 4 is provided with a sample preparation chamber, and a plurality of samples are provided in advance in the sample preparation chamber, so that the vacuum of the deterioration reaction chamber is changed every time the sample is replaced. After releasing the suction force, the trouble of generating the vacuum suction force again can be saved, and continuous deterioration acceleration experiments of a plurality of samples can be performed.

In the oxygen atom resistance evaluation apparatus according to the fifth aspect of the present invention, the quadrupole mass spectrometer can analyze the generated gas before and after irradiating the sample with oxygen atoms. Get information about.

[0028]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional configuration diagram of a high-efficiency oxygen ion neutralizer according to Embodiment 1 corresponding to claim 1 of the present invention, and the same or corresponding parts to those in FIG. Is omitted. In the figure, reference numeral 65 denotes a differential exhaust chamber that surrounds the outside of the neutralizer 6, and a vacuum exhaust pipe 64 that is connected to the differential exhaust chamber 65 and surrounds the gas introduction pipe 63 of the neutralizer 6.
The vacuum exhaust pipe 64 forms a vacuum exhaust passage 64a with the gas introduction pipe 63. Therefore, the vacuum exhaust passage 64a has a double pipe structure including the gas introduction pipe 63 and the vacuum exhaust pipe 64. 66 is an inlet-side orifice that is provided on one side of the differential exhaust chamber 65 and faces the inlet-side orifice 61 of the neutralizer 6,
Reference numeral 7 is an outlet side orifice provided on the other side of the differential exhaust chamber 65 and facing the outlet side orifice 62 of the neutralizer 6, and these orifices 61, 62, 66, 67 are provided.
Are arranged on the same straight line as the beam path.

The neutralizer 6 thus constructed is installed near the entrance of the oxygen ion (O ') beam in the deterioration reaction chamber of the oxygen atom resistance evaluation apparatus. The gas introduction pipe 63 of the neutralizer 6 has a gas flow controller (not shown) as in the conventional case.

Then, the neutralizer 6 and the differential exhaust chamber 65
The diameter of each of the orifices 61, 62, 66, 67 of 4 mm,
Conductance C ₁ = C ₂ = C ₃ = C ₄ = 1.51 / s
A turbo molecular pump (effective pumping speed of 150 l / s) is used as a vacuum pumping device of the differential pumping chamber 65, and a climb pump (effective pumping speed of 700 l / s) is used as a vacuum pumping device of the deterioration reaction chamber. Here, the condition (C ₁ + C ₄ ) * (C ₂ + C ₃ ) / (S ₁ * S ₂ ) = for reducing the amount of gas flowing out from the orifice
8.6 * 10 ^-5 <10 ^-2 is satisfied.

Next, the operation will be described. Neutralization of the oxygen ion (O ′) beam 8 by the neutralizer 6 having the above-described structure is performed as follows. First, the oxygen atom resistance evaluation apparatus is brought into a state capable of generating an oxygen ion (O ′) beam.
In this state, the vacuum exhaust device connected to the differential exhaust chamber 65 is operated, and the neutralizer 6 is passed through the gas introduction pipe 63.
Oxygen gas is introduced into the inside. At this time, the gas introduction pipe 63
By adjusting the gas flow rate controller provided in, the pressure in the neutralizer 6 is adjusted to about 5 * 10 ^-2 Torr. The oxygen gas in the neutralizer 6 is the orifice 6 of the neutralizer 6.
1, 62, but most of them are discharged from the differential exhaust chamber 65 by the differential exhaust mechanism through the vacuum exhaust passage 64a.

In this state, when the oxygen ion (O ′) beam 8 enters the neutralizer 6 from the inlet side orifice 61, neutral oxygen atoms are generated by charge exchange with oxygen gas, and the neutral oxygen atoms are generated. The oxygen atom beam 9 causes the exit side orifices 62 and 67 of the neutralizer 6 and the differential exhaust chamber 65 to be transmitted.
Is emitted from. In this case, a part of the outflow gas from the neutralizer 6 flows out of the neutralizer 6 through the orifice without being operated and exhausted, but the conductance of the orifice and the effective exhaust speed of the vacuum exhaust device are In this case, the pressure in the deterioration reaction chamber is approximately 4.3 * 10 ⁻⁶ Torr, which is maintained at a value similar to the low earth orbit environment. Therefore, the neutralizer 6
Even if the oxygen gas pressure is increased to increase the neutralization efficiency, the pressure in the deterioration reaction chamber is maintained at the same level as in the low earth orbit environment, and
Reaction product ions in the neutralizer 6 do not react with the sample.

Example 2. FIG. 2 is a schematic sectional configuration diagram of an oxygen atom resistance evaluation apparatus according to an embodiment corresponding to the invention of claim 2. In the figure, 11 is a low energy oxygen atom beam generator (oxygen atom beam generator). This low energy oxygen atom beam generator 11 includes an ion source 1 for ionizing oxygen gas and oxygen from the ion source 1. An extraction electrode (accelerating means) 2 for accelerating the ion irradiation speed of the sample, an acceleration electrode (accelerating means) 3 for further accelerating the oxygen ions, and a mass separation magnet (mass separation means) 4 for selecting only the oxygen ions. The deceleration electrode (deceleration means) 5 for decelerating the sample to be irradiated with the selected oxygen ions and the neutralizer 6 described in Embodiment 1 are arranged in this order. In the mass separation magnet 4, the path of the oxygen ion (O ′) beam 8 is 90
It can be bent.

Reference numeral 12 is a deterioration reaction chamber, and the deterioration reaction chamber 12 and the low energy oxygen atom beam generator 11
Are connected to a vacuum exhaust device (not shown) and are evacuated. Therefore, the deterioration reaction chamber 12 is kept at a low pressure and is brought close to the space environment.

Reference numeral 13 is a laser-induced fluorescence measuring device, 14 is a laser-induced fluorescence laser which is one component of the laser-induced fluorescence measuring device 13, and 15 is another component of the laser-induced fluorescence measuring device 13. It is a fluorescence detection device for laser-induced fluorescence. Here, the laser 14 for laser-induced fluorescence is installed at a position where the laser beam 16 can be applied to the oxygen atom beam through the window of the deterioration reaction chamber 12. Further, the fluorescence detection device 15 for laser-induced fluorescence is installed in a direction perpendicular to the laser light 16 and detects the fluorescence 17 emitted from the intersection of the laser light 16 and the oxygen atom beam through the window of the deterioration reaction chamber 12. It is like this.

Next, the operation will be described. In the oxygen atom resistance evaluation apparatus configured as described above, the low energy oxygen atom beam is generated as follows. First,
In the ion source 1, after oxygen gas is ionized (O ′) by arc discharge with a tungsten filament, the extraction electrode 2 accelerates to a speed (V) at which the sample is irradiated with oxygen ions (O ′), and the acceleration electrode 3 generates oxygen. The ions (O ′) are further accelerated (25 keV), and only the oxygen ions (O ′) are selected by the mass separation magnet 4. Next, the deceleration electrode 5 decelerates to a speed (V) at which oxygen ions (O ′) are irradiated to the sample, and the neutralizer 6 exchanges oxygen gas with the neutral gas 6 to generate a neutral oxygen atom beam 9.

As a result, the neutral oxygen atom beam 9 having a substantially uniform particle energy is generated. Since the energy of the oxygen atom beam is equal to the voltage of the extraction electrode 2, by changing the voltage of the extraction electrode 2, 10 eV
It can be controlled in the range of up to 5 keV.

Low energy oxygen atom beam generator 11
Neutral oxygen atom beam 9 generated by
The sample 18 in 2 is irradiated. In the laser-induced fluorescence measuring device 13, the laser for fluorescence-induced fluorescence 14 is used for 226
A laser beam 16 of nm is generated and irradiated to the neutral oxygen atom beam 9. The laser light 16 of 226 nm excites only neutral oxygen atoms. The excited oxygen atom emits a fluorescence 17 of 844 nm. This fluorescence 17 is detected by the fluorescence detection device 15 for laser-induced fluorescence, and the absolute density of oxygen atoms is obtained by calibrating the fluorescence intensity. Therefore, the laser-induced fluorescence measuring device 13 can accurately measure the oxygen atom density on the spot.

The flux can be controlled by changing the oxygen ion (O ') generation conditions in the ion source 1. Therefore, by attaching the laser-induced fluorescence measuring device 13, it becomes possible to quantitatively evaluate the deterioration by the deterioration simulation experiment while controlling the flux, and also to improve the reliability in the acceleration experiment.

Example 3. FIG. 3 is a sectional configuration diagram of a sample holder mounting portion according to an embodiment corresponding to claim 3, in which 19 is a sample holder to which a sample 18 is attached, and S is a rotatably supporting sample holder 19. This is a vertical axis. In this embodiment, not only is the sample 18 fixed to the sample holder 19 but also the sample holder 19 has a rotatable support structure so that the neutral oxygen atomic beam 9 can be supported on the sample 18. The relationship between irradiation angle and deterioration can be investigated.

Example 4. FIG. 4 is a sectional view of a deterioration reaction chamber according to an embodiment corresponding to claim 4. In the figure, 20
Is a support tool for supporting the sample holder 19 provided in the deterioration reaction chamber 12, and this support tool 20 is rotatable about a vertical axis. Reference numeral 21 is a sample preparation chamber having a vacuum container structure connected to the deterioration reaction chamber 12, 22 is a vacuum valve for opening and closing a connecting portion between the sample preparation chamber 21 and the deterioration reaction chamber 12, 23 is a manipulator, and this manipulator 23 Is for moving the sample holder 19 between the support 20 and the sample preparation chamber 21 in the deterioration reaction chamber 12. Reference numeral 25 is a sample table arranged in the sample preparation chamber 21, 26 is a plurality of receiving tools integrally arranged on the sample table 25, and the sample holder 19 can be attached to and detached from each of these receiving tools 26. It can be installed. Reference numeral 26a is a hook-shaped engaging slit provided in the receiving tool 26, such as an L-shape, and P is provided in an outer peripheral wall portion of the sample holder 19 for engaging with the engaging slit 26a in a detachable manner. It is an engagement pin.
In the fourth embodiment, the manipulator 23 is used to support the support 20 in the deterioration reaction chamber 12 and the sample preparation chamber 21.
The sample holder 19 can be moved to and from the sample table 25 inside. In this case, the support tool 20 in the deterioration reaction chamber 12 is rotated so that the sample holder 19 supported by the support tool 20 faces the sample preparation chamber 21 side. As described above, the sample preparation chamber 21 is provided, and the plurality of samples 18 are provided in advance in the sample preparation chamber 21, and the manipulator 23 can move the sample 18 between the sample preparation chamber 21 and the support tool 20 in the deterioration reaction chamber 12. , Every time the sample is replaced,
After releasing the vacuum suction force of the deterioration reaction chamber 12, the labor of regenerating the vacuum suction force can be saved, and continuous deterioration acceleration experiments can be performed using the plurality of samples 18. If a vacuum exhaust device is also attached to the sample preparation chamber 21, the sample in the sample preparation chamber 21 can be exchanged while the inside of the deterioration reaction chamber 12 remains vacuum.

Example 5. FIG. 5 is a schematic sectional view of a deterioration reaction chamber according to an embodiment corresponding to claim 5, and in the drawing, 24 is a quadrupole mass spectrometer provided in the deterioration reaction chamber 12. The mass spectrometer 24 uses the gas released from the sample 18 in the deterioration reaction chamber 12 as a sample gas and analyzes the generated gas before and after irradiating the sample 18 with oxygen atoms to obtain information on the material deterioration mechanism. Can be obtained.

[0043]

As described above, according to the first aspect of the present invention, since the neutralization chamber is surrounded by the differential exhaust chamber, reaction product ions and oxygen gas are generated from the neutralization chamber. Oxygen atomic flux to which the spacecraft is exposed in low earth orbit can be minimized, resulting in:
It is possible to generate an oxygen atom beam having a flux of about 10 ¹³ to 10 ¹⁵ pieces / cm ² sec. Therefore, it is possible to increase the oxygen gas pressure in the neutralization chamber to increase the neutralization efficiency. However, it is possible to obtain the effect that the pressure in the deterioration reaction chamber is maintained at the same level as in the low earth orbit environment and that the reaction product ions in the neutralization chamber do not react with the sample. Further, since the vacuum exhaust path is formed by the double structure of the gas introduction pipe and the vacuum exhaust pipe, the gas introduction / exhaust section becomes compact, and when the neutralization chamber is installed in the vacuum container, This vacuum container has the advantage that it is only necessary to provide one common hole for inserting the gas introduction pipe and the vacuum exhaust pipe.

According to the second aspect of the present invention, the oxygen ions ionized by the ion source are accelerated to the sample irradiation speed by the accelerating means, and then only the oxygen ions are selected by the mass separation means. The deceleration means decelerates to a speed at which the sample is desired to be irradiated, and thereafter, by the charge exchange by the oxygen ion neutralizer according to claim 1, a neutral oxygen atom beam having substantially uniform particle energy is generated.
For example, there is an effect that efficiency is higher than that of recombination with electrons. Moreover, since an extraction electrode can be used as the acceleration means and the energy of the oxygen atom beam becomes equal to the voltage of the extraction electrode, it is possible to easily control by changing the voltage of the extraction electrode. is there. Further, in the laser-induced fluorescence measuring device, for example, a laser for laser-induced fluorescence is used.
A 6 nm laser beam is generated and irradiated with the oxygen atom beam. The laser light of 226 nm excites only neutral oxygen atoms, and the excited oxygen atoms emit fluorescence of 844 nm.
This fluorescence is detected by the laser-induced fluorescence measuring device, and the absolute density of oxygen atoms is obtained by constituting the fluorescence intensity. Therefore, there is an effect that the oxygen atom density can be accurately measured on the spot by the laser-induced fluorescence measuring device. The neutralization efficiency of oxygen ions in the neutralizer depends on the introduction amount of oxygen gas when the exhaust volume of the vacuum exhaust device is constant, but the introduction amount of oxygen gas that maximizes the neutralization efficiency. Can be clarified by investigating the relationship between the introduction amount of oxygen gas and the density of neutral oxygen atoms by the laser-induced fluorescence measuring device. Also, the flux of the oxygen ion beam changes depending on the oxygen ion generation conditions in the ion source. Therefore, the laser-induced fluorescence measuring device enables quantitative evaluation of deterioration by a deterioration simulation experiment while controlling the flux, and has an effect of improving reliability even in an acceleration experiment.

According to the third aspect of the present invention, since the sample holder is configured to be rotatable, the relationship between the irradiation angle of the oxygen atom beam on the sample and the deterioration can be clarified. Therefore, there is an effect that it is possible to accurately examine the difference in material deterioration depending on the part of the spacecraft surface.

According to the fourth aspect of the present invention, the sample preparation chamber is provided, and a plurality of samples are provided in advance in the sample preparation chamber, so that the vacuum suction force of the deterioration reaction chamber is released each time the sample is replaced. After that, there is an effect that the trouble of generating a vacuum suction force again can be saved, and continuous deterioration acceleration experiments of a plurality of samples can be performed.

According to the fifth aspect of the present invention, the quadrupole mass spectrometer can analyze the generated gas before and after irradiating the sample with oxygen atoms, thereby obtaining information on the material deterioration mechanism. There is an effect.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional configuration diagram showing a high-efficiency oxygen ion neutralizer according to Embodiment 1 corresponding to claim 1 of the present invention.

FIG. 2 is a schematic cross-sectional configuration diagram of an oxygen atom resistance evaluation apparatus according to an embodiment corresponding to the invention of claim 2.

FIG. 3 is a cross-sectional configuration diagram of a sample holder mounting portion according to an embodiment corresponding to claim 3;

FIG. 4 (a) is a sectional view of a deterioration reaction chamber according to an embodiment corresponding to claim 4; FIG. 4B is a side view for explaining a related configuration between the sample table and the sample in FIG. 4A.

FIG. 5 is a schematic sectional view of a deterioration reaction chamber according to an embodiment corresponding to claim 5;

FIG. 6 is a schematic structural diagram of an oxygen atom beam generator exemplified as a conventional ground simulation device.

7 is a schematic cross-sectional configuration diagram of a neutralizer used in the ground simulation experiment device of FIG.

[Explanation of symbols]

 1 ion source 2 extraction electrode (accelerating means) 3 acceleration electrode (accelerating means) 4 mass separation means 5 deceleration means 6 neutralizer 8 oxygen ion (O ') beam 9 neutral oxygen atom beam 10 oxygen ion (O') 11 Oxygen Atom Beam Generator 12 Degradation Reaction Chamber 13 Laser Induced Fluorescence Measuring Device 16 Laser Light 17 Fluorescence 18 Sample 19 Sample Holder 20 Support 21 Sample Preparation Room 23 Manipulator 24 Quadrupole Mass Spectrometer 60 Neutralization Chamber 61 Inlet Side orifice 62 outlet side orifice 63 gas introduction pipe 64 vacuum exhaust pipe 64a vacuum exhaust path 65 differential exhaust chamber 66 inlet side orifice 67 outlet side orifice

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01J 49/42 4230-5E

Claims (5)

[Claims] 1. An oxygen ion neutralization device, which is installed in a vacuum container equipped with a vacuum exhaust device, neutralizes an oxygen ion (O ′) beam by charge exchange with oxygen gas, and produces a neutral oxygen atom beam. In the reactor, a neutralization chamber having an inlet side orifice and an outlet side orifice of the oxygen ion (O ′) beam on the same straight line, and introducing oxygen gas into the neutralization chamber and controlling the oxygen gas introduction amount A gas inlet pipe having a gas inflow controller for enclosing the neutralization chamber,
Further, a differential exhaust chamber having an inlet-side orifice and an outlet-side orifice which are respectively opposed to the inlet-side orifice and the outlet-side orifice of the neutralization chamber, and the differential exhaust chamber is used as a vacuum exhaust device. A vacuum exhaust pipe that is connected to the gas inlet pipe and forms a vacuum exhaust passage between the gas inlet pipe and the gas inlet pipe. The conductance of the inlet side and outlet side orifices of the neutralization chamber is C ₂ ,
C ₃ , C ₁ and C ₄ for the conductance of the inlet side and outlet side orifices of the differential exhaust chamber, S ₁ for the effective exhaust speed of the vacuum exhaust device of the differential exhaust chamber system, and vacuum exhaust of the vacuum container system Assuming that the effective pumping speed of the device is S ₂ , (C ₁ + C ₄ ) * (C ₂ + C ₃ ) / (S ₁ * S ₂ ) <1
A highly efficient oxygen ion neutralizer characterized by satisfying 0 ^-2 . 2. An ion source for ionizing oxygen gas, an accelerating means for accelerating oxygen ions from this ion source to a sample irradiation speed, a mass separation means for selecting only oxygen ions, and irradiating the selected oxygen ions on a sample. Deceleration means for decelerating to a desired speed, the oxygen ion beam that has passed through this deceleration means and is neutralized by charge exchange with oxygen gas,
An oxygen atom beam generator configured by arranging oxygen ion neutralizers that generate a neutral oxygen atom beam with almost uniform particle energy in this order, and connected to the oxygen atom beam generator. A sample holder is installed on the beam line, and a vacuum deterioration reaction chamber having at least two windows and a laser-induced fluorescence measuring device for measuring the density of atomic oxygen with which the sample is irradiated are provided. The laser-induced fluorescence measurement apparatus is connected to a vacuum exhaust apparatus, and the oxygen atom beam generated by the oxygen atom beam generator is irradiated with laser light through the window of the deterioration reaction chamber. Oxygen atomic resistance evaluation using a high-efficiency oxygen ion neutralizer characterized in that the intersection with the beam is arranged so as to be the observation volume for fluorescence detection. Apparatus. 3. The oxygen atom resistance evaluation apparatus according to claim 2, wherein the sample holder in the deterioration reaction chamber is rotatably supported. 4. The sample holder is detachably supported in the deterioration reaction chamber, and the deterioration reaction chamber is connected to a vacuum sample preparation chamber equipped with a plurality of samples via a vacuum valve, and the sample holder is attached to the deterioration reaction chamber. The manipulator for moving between the deterioration reaction chamber and the sample preparation chamber is provided, and the sample holder in the deterioration reaction chamber can be sequentially replaced with the sample holder provided in the sample preparation chamber. Alternatively, the oxygen atom resistance evaluation apparatus according to item 3. 5. The quadrupole mass spectrometer using a gas released from a sample as a sample gas, is provided in the deterioration reaction chamber, and the quadrupole mass spectrometer according to claim 2, wherein Oxygen resistance tester.