JP3167444B2 - Highly Efficient Oxygen Ion Neutralizer and Oxygen Atomic Resistance Evaluation System Using Highly Efficient Oxygen Ion Neutralizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Since the successful flight of the Space Shuttle in low earth orbit (altitude of about 100 to 1,000 km), the development of low earth orbit spacecraft (space vehicles) including the Space Station has been actively carried out. Became. However, J Spacecraft and Rockets 23 (JS
pacecraft and Rockets, Vo
l. 23 (1986)), p. As shown in 505-511, the main component of the atmosphere in low earth orbit is oxygen atoms, and when a spacecraft flies through them, the oxygen atoms become energy: 5 eV and flux: 10 ¹³ to 10 ¹⁵ / cm ²
・ Because of the collision in sec, the surface of the part of the spacecraft that is exposed to the atmosphere (space material) is significantly deteriorated. For this reason, for example, “Twenty Third Aero Cymeet Paper (23rd Aero. Sci. M.)
eet, Paper) "No. 85-0415 (19
As shown in the results of a flight experiment on the deterioration of spacecraft surface material due to oxygen atoms shown in 84), carbon fiber-based materials such as CFRP used as space materials have surface deterioration such as reduced film thickness. It is difficult to use it as a structural material for spacecraft for long-term use (several months to several decades or more), including a space base currently under development or to be developed in the future.

[0003] Therefore, it explores the material degradation mechanisms by atomic oxygen, in order to establish the degradation prevention measures, the ground simulation device space environment, irradiating the oxygen atom beam of neutral space for material that It is important to evaluate the impact quantitatively. So far, for example, Gary W. Sjolender Materials Degradation in Low Earth Orbit (The Minerals, Metals and Materials Society, 1
990) (Gary W. Sjolander, Mat.
erials Degradation in Low
Earth Orbit (The Minerals,
metals & Materials Society,
1990) , p. 1 75-188. A simulated ground-based apparatus for irradiating a neutral oxygen atom beam generated by an oxygen atom beam generator to a space material in a vacuum vessel as shown in (1) has been developed.

FIG. 6 is a schematic structural view of an oxygen atom beam generator exemplified as a conventional ground simulation test apparatus. In the figure, reference numeral 1 denotes an arc discharge with respect to oxygen gas, and oxygen ions ( O ⁺ ), And 3 is the oxygen ion ( O ⁺ ) To the order of keV, and 4 is an oxygen ion ( O ⁺ ) Is selected, and 5 is the oxygen ion ( O ⁺ ) Is reduced to a predetermined speed (5 eV), and a deceleration electrode 6 of a speed reducer is provided with oxygen ions ( O ⁺ ) An oxygen ion neutralizer (hereinafter simply referred to as a neutralizer), which neutralizes the beam by charge exchange with oxygen gas to generate a neutral oxygen atom beam, 7 is a deflection electrode, and The main part of the oxygen atom beam generator is constituted.

FIG. 7 is a schematic sectional view of a neutralizer used in the ground simulation test apparatus shown in FIG. In the figure, reference numeral 60 denotes a neutralization chamber of the neutralizer 6 and 61 denotes oxygen ions ( O ⁺ A) an inlet orifice for receiving the beam 8; 62 an outlet orifice for emitting the neutral oxygen atom beam 9 from the neutralization chamber 60; and the inlet orifice 61 and the outlet orifice 62 for the neutralization. It is provided in the beam path of the chamber 60. Reference numeral 63 denotes a gas introduction pipe for introducing and filling oxygen gas into the neutralization chamber 60. The gas introduction pipe 63 has 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. 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, arc discharge is performed on oxygen gas, so that oxygen ions ( O ⁺ ) Is generated. This oxygen ion ( O ⁺ ) Is accelerated to the order of keV by the next accelerating electrode 3 and then oxygen ions ( O ⁺ ) Is sorted out. Next, the deceleration electrode 5
Oxygen ions ( O ⁺ ) Decelerates the beam 8 to the speed <br/> degree of irradiating a sample (5 eV), the oxygen ions (O ⁺ 3.) Beam 8 is incident on neutralizer 6. The neutralizer 6 neutralizes incident oxygen ions to generate neutral oxygen atoms. Finally, the neutral oxygen atom beam emitted from the neutralizer 6 is converted into oxygen ions ( O ⁺ ) Is removed, and a neutral oxygen atom beam 9 consisting of only oxygen atoms is generated.

In the process of generating the neutral oxygen atom beam 9, as shown in FIG. 7, in the neutralizer 6, oxygen ions ( O ⁺⁾ entering the neutralization chamber 60 from the inlet orifice 61. ) Is neutralized by charge exchange with the oxygen gas filling the neutralization chamber 60, thereby generating a neutral oxygen atom beam 9. The neutral oxygen atom beam 9 is emitted from the outlet side orifice 62, and reaction product ions and unreacted oxygen gas are exhausted from the exhaust pipe 64. In this case, the oxygen ions ( O ⁺ If the beam 8 is generated stably, the amount of oxygen gas introduced into the neutralization chamber 60 is adjusted by a gas flow controller, and the oxygen gas pressure in the neutralization chamber 60 is kept constant. Thus, the neutral oxygen atom beam 9 is stably generated.

[0008] Here, the flux of the oxygen atom beam generated by the neutralizer 6 is based on oxygen ions ( O ⁺ 3.) When the flux of the beam 8 is constant, it rises by increasing the oxygen gas pressure in the neutralization chamber 60, and after having a certain peak value, it decreases on the contrary.
Therefore, by changing the oxygen gas pressure in accordance with the conditions of the ground simulation experiment, the flux of the oxygen atom beam can also be changed.

[0009] The oxygen ions ( O ⁺ ) When the energy of the beam was measured with an energy analyzer, the peak energy was 4.5 eV and the full width at half maximum was 1.5 eV. In addition, oxygen ions ( O ⁺ ) Beam flux is 5 * 10 ¹⁴ /
cm ² sec, indicating that the low earth orbit environment was well reproduced with respect to the ion beam. That is, in the ground simulation apparatus, oxygen ions ( O ⁺ ) Is accelerated to a high speed once by the acceleration electrode 3 and then decelerated to 5 eV by the deceleration electrode 5. This has the effect of reducing the spread of the ion beam due to the space charge effect. There is the advantage that a high method can be used. Therefore, according to the ground simulation test apparatus, it is possible to simulate the surface deterioration phenomenon of the space material due to oxygen atoms on the ground.

[0010]

Since the conventional oxygen ion neutralizer and the above-mentioned ground simulation apparatus using the oxygen ion neutralizer are configured as described above, in this ground simulation apparatus, In order to reproduce the atmospheric pressure in low earth orbit, the pressure in the degraded reaction chamber must be kept at 10 ^-5 Torr or less, while the neutralizer uses oxygen that strikes the spacecraft surface in low earth orbit. Atomic flux: 10 ¹³ -10 ¹⁵ /
In order to reproduce cm ² · sec, the oxygen gas pressure in the neutralization chamber 60 is reduced to the pressure in the degradation reaction chamber (about 10 ⁻⁶ Torr).
The neutralization efficiency must be much higher (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 product ions and oxygen gas in the neutralization chamber 60 are supplied with the orifices 61, 62, not only raises the pressure in the degradation reaction chamber, but also causes the possibility that reaction product ions may flow around the sample and cause some reaction with the sample, thereby lowering the accuracy of the simulation test. There is a problem in that the surface analysis of the sample is greatly adversely affected. When the neutralizer 6 is installed in a vacuum vessel, the vacuum vessel must be provided with two holes through which the gas introduction pipe 63 and the exhaust pipe 64 of the neutralizer 6 pass. Must therefore,
There is also a problem that the probability of vacuum leakage occurring in the vacuum container is increased due to the gap formed by the holes.

Further, in the above-mentioned conventional ground simulation test apparatus, 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 degradation, and is also essential for acceleration 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 and the like. It is very difficult to determine the accuracy of the data because of the limited accuracy. For this reason, the amount of neutral oxygen and its stability must be measured by some method,
Since the above-mentioned conventional ground simulation apparatus has no means for that, it is difficult to quantitatively evaluate the deterioration, for example, by examining the relationship between the irradiation amount of the oxygen atom beam to the sample and the mass loss due to the deterioration, There was a problem that the reliability of the acceleration experiment was lacking.

Further, in the above ground simulation test apparatus, oxygen ions ( O ⁺ In order to convert the beam 8 to the neutral oxygen atom beam 9, it is necessary to maximize the neutralization efficiency in the neutralizer 6. However, as described above, the neutralizer 6
Since it is difficult to theoretically determine the amount of neutral oxygen atoms generated in the above, there is no other way but to determine the optimal conditions by measuring by some method, but in the case of the above ground simulation experiment device, measure the density of the generated neutral oxygen atoms Since there is no means, there is a problem that the condition for maximizing the neutralization efficiency cannot be checked.

The first aspect of the present invention has been made to solve the above-mentioned problems, and has a structure capable of minimizing the amount of reaction product ions and oxygen gas flowing out. Even if the neutralization efficiency is increased by increasing the oxygen gas pressure in the neutralization chamber, the pressure in the degradation reaction chamber can be maintained at the same level as in a low earth orbit environment, and The objective is to obtain a high-efficiency oxygen ion neutralizer that enables the best ground simulation by selecting oxygen gas that maximizes the neutralization efficiency without reaction product ions reacting with the sample. .

According to a second aspect of the present invention, a high-concentration beam having only neutral oxygen atoms can be generated, and the absolute density of the oxygen atoms can be measured in situ. Oxygen resistance test equipment that can accurately grasp the irradiation conditions of oxygen, quantitatively evaluate the relationship between the irradiation amount of oxygen atoms and the deterioration of space materials, and improve the reliability even in acceleration experiments. The purpose is to gain.

According to the third aspect of the present invention, it is possible to examine the relationship between the irradiation angle of the oxygen atom beam on the sample and the material deterioration,
It is an object of the present invention to obtain an oxygen-resistant atomic resistance evaluation apparatus capable of accurately simulating a difference in deterioration of a space material depending on a portion of a spacecraft surface.

The invention according to claim 4 is a method for continuously accelerating the deterioration of a plurality of samples without releasing the vacuum suction force in the deterioration reaction chamber and releasing the vacuum suction force again each time the sample is exchanged. It is an object of the present invention to obtain an oxygen-resistant atomic resistance evaluation device that can be used.

A fifth object of the present invention is to provide an oxygen atom resistance evaluation apparatus capable of analyzing a generated gas before and after irradiating a sample with oxygen atoms and obtaining information on a material deterioration mechanism.

[0018]

According to a first aspect of the present invention, there is provided a high-efficiency oxygen ion neutralizer comprising a gas inflow controller for introducing oxygen gas into a neutralization chamber and controlling the amount of oxygen gas introduced. Having a gas introduction pipe, and surrounding the neutralization chamber,
A differential exhaust chamber having an inlet orifice and an outlet orifice facing the inlet orifice and the outlet orifice of the neutralization chamber, respectively, on the same straight line; And a vacuum exhaust pipe surrounding the gas introduction pipe and forming a vacuum exhaust path with the gas introduction pipe, and the conductance of the orifices on the inlet side and the outlet side of the neutralization chamber is set to C. ₂ ,
C ₃ , the conductances of the inlet and outlet orifices of the differential pumping chamber are C ₁ and C ₄ , the effective pumping speed of the vacuum pumping system of the differential pumping chamber system is S ₁ , and the vacuum pumping of the vacuum vessel system When the effective pumping speed of the system and _{S 2, (C 1 + C} 4) * (C 2 + C 3) / (S 1 * S 2) <1
0 ^-2 is satisfied.

According to a second aspect of the present invention, there is provided an oxygen resistance atom evaluating apparatus, comprising: an ion source, an accelerating means, and a decelerating means .
Each oxygen ion neutralizer, and an oxygen atom beam generator configured by arranging in this order, the sample holder is installed is connected to the oxygen atom beam generator on the beam line, at least two windows A vacuum degradation reaction chamber having a laser-induced fluorescence measurement device for measuring the density of atomic oxygen applied to the sample, wherein the degradation reaction chamber is connected to a vacuum exhaust device, and the laser-induced fluorescence measurement device is The laser beam is applied to the oxygen atom beam generated by the oxygen atom beam generator through the window of the deterioration reaction chamber, and the intersection of the laser beam and the oxygen atom beam becomes an observation volume for fluorescence detection. It is arranged as follows.

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

According to a fourth aspect of the present invention, in the oxygen resistance evaluation apparatus, the sample holder is removably supported in the degradation reaction chamber, and the degradation reaction chamber is provided with a vacuum sample preparation in which a plurality of samples are provided. Chambers are connected via a vacuum valve, the sample holder is movable by a manipulator between the degradation reaction chamber and the sample preparation chamber, and a sample holder in the degradation reaction chamber is provided in the sample preparation chamber. And can be exchanged sequentially.

The resistance to oxygen atom evaluation apparatus according to the invention of claim 5, the degradation reaction chamber is the Ketamo with equipped with a quadrupole mass spectrometer to a gas sample gas released from the sample.

[0023]

The high-efficiency oxygen ion neutralizer according to the first aspect of the present invention fills a neutralization chamber with oxygen gas from a gas introduction pipe and fills the neutralization chamber with oxygen ions ( O ⁺ ), Oxygen ions ( O ⁺⁾ incident from the inlet orifice into the neutralization chamber. 2.) The beam is neutralized by charge exchange with oxygen gas in the neutralization chamber, thereby generating a neutral oxygen atom beam, which is emitted from the exit orifice. In this case, reaction product ions and unreacted oxygen gas flow out of at least two orifices of the neutralization chamber,
Air 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 controller in the neutralization chamber. Here, the conductance of the inlet and outlet orifices of the neutralization chamber is C ₂ , C ₃ , and the conductance of the inlet and outlet orifices of the differential exhaust chamber is C ₂ .
₁ , C ₄ , assuming that the effective pumping speed of the vacuum pumping system in the differential pumping chamber system is S ₁ and the effective pumping speed of the vacuum pumping device in the vacuum vessel system is S ₂ , (C ₁ + C ₄ ) * (C _{2 + C 3) / (S} 1 * S 2) <1
By satisfying 0 ^-2 , gas flowing out of the orifice of the differential exhaust chamber into the degradation 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 degradation reaction chamber is maintained at 10 ⁻⁵ Torr or less. Therefore, even if the neutralization efficiency is increased by increasing the oxygen gas pressure in the neutralization chamber, the pressure in the degradation reaction chamber is maintained at the same level as in the low earth orbit environment, and
The reaction product ions in the neutralization chamber do not react with the sample. In addition, 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 installing the neutralization chamber in the vacuum vessel, This vacuum vessel has an advantage that only one common hole is required 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 a speed higher than the sample irradiation speed by the acceleration means. Only the oxygen ions are selected by the mass separation means, and the selected oxygen ions are decelerated to the speed at which the sample is to be irradiated by the deceleration means. A neutral oxygen atom beam with particle energy is generated. Such a neutralization method by 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. Therefore, the energy can be easily controlled by changing the voltage of the extraction electrode. Further, in a laser-induced fluorescence measuring apparatus, a laser beam of 226 nm is generated by, for example, a laser for laser-induced fluorescence and is irradiated with an oxygen atom beam. The 226 nm laser beam excites only neutral oxygen atoms, and the excited oxygen atoms
emits nm fluorescence. This fluorescence is detected by the laser-induced fluorescence measurement device, and the absolute density of oxygen atoms is determined by constructing the fluorescence intensity. Therefore, the oxygen atom density can be accurately measured on the spot by the laser-induced fluorescence measurement apparatus. The neutralization efficiency of oxygen ions in the neutralizer depends on the amount of oxygen gas introduced when the displacement of the evacuation device is constant, but the amount of oxygen gas introduced to maximize the neutralization efficiency Can be clarified by examining the relationship between the introduced amount of oxygen gas and the density of neutral oxygen atoms using the laser-induced fluorescence measurement device. Further, the flux of the oxygen ion beam changes depending on the oxygen ion generation conditions in the ion source. Therefore, the laser-induced fluorescence measurement device enables a quantitative evaluation of deterioration by a deterioration simulation experiment while controlling the flux, thereby improving reliability even in an acceleration experiment.

In the oxygen atom resistance evaluation apparatus according to the third aspect of the present invention, the rotation of the sample holder makes it possible to clarify the relationship between the irradiation angle of the oxygen atom beam on the sample and the deterioration. In addition, it is possible to accurately examine a difference in material deterioration depending on a portion of a spacecraft surface.

According to the fourth aspect of the present invention, the oxygen resistance evaluation apparatus includes a sample preparation chamber, and a plurality of samples are provided in advance in the sample preparation chamber. After releasing the suction force, the trouble of generating the vacuum suction force again can be omitted, and a continuous accelerated degradation test 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 gas produced before and after the sample is irradiated with oxygen atoms can be analyzed by a quadrupole mass spectrometer. The information about is obtained.

[0028]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a high-efficiency oxygen ion neutralizer according to a first embodiment of the present invention, in which the same or corresponding parts as those in FIG. Is omitted. In the drawing, reference numeral 65 denotes a differential exhaust chamber surrounding the outside of the neutralizer 6, and a vacuum exhaust pipe 64 connected to the differential exhaust chamber 65 and surrounding the gas introduction pipe 63 of the neutralizer 6 is integrally formed. Yes to us is, the vacuum exhaust pipe 64 is the gas inlet pipe 63
And a vacuum evacuation path 64a is formed between them. Therefore, the evacuation path 64a is provided between the gas introduction pipe 63 and the evacuation pipe 6.
4 and a double tube structure. An inlet orifice 66 is provided on one side of the differential exhaust chamber 65 and faces the inlet orifice 61 of the neutralizer 6, and 67 is provided on the other side of the differential exhaust chamber 65 and An outlet orifice facing the outlet orifice 62 of the oxidizer 6, and the orifices 61, 62, 66, and 67 are arranged in the same straight line as a beam path.

The neutralizer 6 configured as described above is provided with an acid-resistant
Oxygen ions (O
⁺ ) Installed near the beam entrance. In addition, the neutralization
The gas inlet pipe 63 of the heater 6 is connected to the gas flow controller as in the prior art.
A roller (not shown).

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

Next, the operation will be described. Oxygen ions ( O ⁺ ) Neutralization of the beam 8 is performed as follows. First, an oxygen resistance ( O ⁺ ) Make beam generation possible.
In this state, the evacuation device connected to the differential evacuation chamber 65 is operated, and the neutralizer 6 is connected via the gas introduction pipe 63.
Oxygen gas is introduced inside. At this time, the gas introduction pipe 63
The pressure inside the neutralizer 6 is adjusted to about 5 * 10 ^-2 Torr by adjusting the gas flow controller provided in the apparatus. The oxygen gas in the neutralizer 6 is supplied to the orifice 6 of the neutralizer 6.
Most of the gas flows out from the differential pumping chamber 65 by the differential pumping mechanism through the vacuum pumping path 64a.

In this state, oxygen ions ( O ⁺ When the 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 atom beam 9 is generated by the neutralizer 6 and Exit side orifices 62, 67 of the differential exhaust chamber 65
Is emitted from. In this case, a part of effluent gas from the neutralizer 6 flows out to the neutralizer 6 outside through the orifice without being differential exhaust, the effective pumping speed of the conductance and the evacuation device of the orifice In this case, the pressure in the degradation reaction chamber is approximately 4.3 * 10 ^-6 Torr, which is maintained at a value similar to that in 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 degradation reaction chamber is maintained at the same level as that in the low earth orbit environment, and
The reaction product ions in the neutralizer 6 do not react with the sample.

Embodiment 2 FIG. FIG. 2 is a schematic cross-sectional configuration diagram of an oxygen resistance evaluation apparatus according to an embodiment corresponding to the second aspect of the present invention. In the figure, reference numeral 11 denotes a low-energy oxygen atom beam generator (oxygen atom beam generator). The 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 (acceleration means) 2 for accelerating ions to a sample irradiation speed , an acceleration electrode (acceleration means) 3 for further accelerating the oxygen ions, and a mass separation magnet (mass separation means) 4 for selecting only the oxygen ions. A deceleration electrode (deceleration means) 5 for decelerating the selected oxygen ions to the speed at which the sample is to be irradiated;
And the neutralizer 6 described in (1) is arranged in this order. In the mass separation magnet 4, oxygen ions ( O ⁺ ) The path of the beam 8 is designed to be bent 90 °.

Numeral 12 denotes a degradation reaction chamber. The degradation reaction chamber 12 and the low energy oxygen atom beam generator 11
Are connected to a vacuum exhaust device (not shown) and are evacuated. For this reason, the degradation reaction chamber 12 is kept at a low pressure and is brought close to the space environment.

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

Next, the operation will be described. As above
In the configured oxygen resistance atomic resistance evaluation device, low energy
-An oxygen atom beam is generated as follows. First,
Arc by tungsten filament in ion source 1
Discharges oxygen gas into ions (O ⁺ ) And then withdraw
Electrode 2 is an oxygen ion (O ⁺ ) To irradiate the sampleEvery time
Accelerates, and oxygen ions (O ⁺ Further acceleration
(25 keV) and oxygen ions
(O ⁺ ). Next, the deceleration electrode 5 is
on(O ⁺ ) To irradiate the sampleDegreeSlow down at the next
Exchange with oxygen gas in the oxidizer 6
A program 9 is generated.

As a result, a neutral oxygen atom beam 9 having 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
The neutral oxygen atom beam 9 generated by the
The sample 18 in 2 is irradiated. In the laser-induced fluorescence measuring device 13, 226
A laser beam 16 of nm is generated and irradiated to the neutral oxygen atom beam 9. The 226 nm laser light 16 excites only neutral oxygen atoms. The excited oxygen atoms emit fluorescence 17 at 844 nm. The fluorescence 17 is detected by the fluorescence detector 15 for laser-induced fluorescence, and the absolute density of oxygen atoms is obtained by calibrating the fluorescence intensity. Therefore, the laser-induced fluorescence measurement device 13 can accurately measure the oxygen atom density on the spot.

The flux is oxygen ions ( O ⁺ ) It can be controlled by changing the generation conditions. Therefore, by attaching the laser-induced fluorescence measurement device 13, it is possible to quantitatively evaluate the deterioration by the simulation of deterioration while controlling the flux, and to improve the reliability even in the acceleration experiment.

Embodiment 3 FIG. FIG. 3 is a cross-sectional view of a sample holder mounting portion according to the third embodiment. In FIG.
Is a vertical axis which rotatably supports the sample holder 19. In this embodiment, not only the sample holder 19 is mounted on the sample holder 19, but also the sample holder 19 is rotated. With a possible support configuration, the sample 18 of the neutral oxygen atom beam 9 can be used.
It is possible to examine the relationship between the irradiation angle and the deterioration.

Embodiment 4 FIG. FIG. 4 is a sectional view of a deterioration reaction chamber according to an embodiment of the present invention. In the figure, reference numeral 20 denotes a support provided in the degradation reaction chamber 12 for supporting the sample holder 19, and the support 20 is rotatable about a vertical axis. Reference numeral 21 denotes a sample preparation chamber configured as a vacuum vessel connected to the deterioration reaction chamber 12, and 22 denotes a vacuum valve for opening and closing a connection between the sample preparation chamber 21 and the deterioration reaction chamber 12.
Reference numeral 3 denotes a manipulator.
Is for moving the sample holder 19 between the support 20 in the degradation reaction chamber 12 and the sample preparation chamber 21. Reference numeral 25 denotes a sample table arranged in the sample preparation chamber 21, and reference numeral 26 denotes a plurality of receiving tools arranged integrally with the sample table 25. The sample holder 19 is detachably attached to each of these receiving tools 26. It can be attached.
Reference numeral 26a denotes a hook-like engaging slit provided on the receiving device 26, such as an L-shaped slit, and P denotes an outer peripheral wall of the sample holder 19 for engaging with the engaging slit 26a in a detachable manner. It is an engagement pin. In this embodiment 4,
The sample holder 19 can be moved between the support 20 in the degradation reaction chamber 12 and the sample table 25 in the sample preparation chamber 21 by the manipulator 23. In this case, the support 20 in the deterioration reaction chamber 12 is rotated so that the sample holder 19 supported by the support 20 faces the sample preparation chamber 21 side. As described above, the sample preparation chamber 21 is provided, and a plurality of samples 18 are provided in the sample preparation chamber 21 in advance, and can be moved between the support 20 in the degradation reaction chamber 12 by the manipulator 23. Each time a sample is exchanged, the trouble of releasing the vacuum suction force of the deterioration reaction chamber 12 and then regenerating the vacuum suction force can be omitted, and a continuous deterioration acceleration experiment can be performed using the plurality of samples 18. It is. If a vacuum evacuation device is also installed in the sample preparation chamber 21, the sample in the sample preparation chamber 21 can be exchanged while keeping the inside of the degradation reaction chamber 12 vacuum.

Embodiment 5 FIG. FIG. 5 is a schematic sectional view of a deterioration reaction chamber according to an embodiment of the present invention.
The quadrupole mass spectrometer 24 is equipped with the sample 1 in the degradation reaction chamber 12.
8 is used as a sample gas, and the sample 1
By analyzing the product gas before and after irradiating 8 with oxygen atoms, 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 generated ions and oxygen gas can be discharged from the neutralization chamber. The amount of outflow can be minimized, resulting in the oxygen atom flux to which the spacecraft is exposed in low earth orbit:
An oxygen atom beam having a flux of about 10 ¹³ to 10 ¹⁵ / cm ² sec can be generated. Therefore, the oxygen gas pressure in the neutralization chamber is increased to increase the neutralization efficiency. However, the effect is obtained that the pressure in the degradation reaction chamber is maintained at the same level as that in the low earth orbit environment, and that the reaction product ions in the neutralization chamber do not react with the sample. In addition, 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 installing the neutralization chamber in the vacuum vessel, This vacuum vessel has an advantage that only one common hole is required 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 by the acceleration means to a speed higher than the irradiation speed of the sample, and then only the oxygen ions are selected by the mass separation means and selected. The reduced oxygen ions are decelerated to the speed at which the sample is to be irradiated by the deceleration means, and thereafter, the charge is exchanged by the oxygen ion neutralizer according to claim 1, whereby
Since a neutral oxygen atom beam having substantially uniform particle energy is generated, there is an effect that efficiency is increased as compared with, for example, recombination with electrons. Further, 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. Therefore, the effect that the voltage can be easily controlled by changing the voltage of the extraction electrode can be obtained. is there. Further, in a laser-induced fluorescence measuring apparatus, a laser beam of 226 nm is generated by, for example, a laser for laser-induced fluorescence and is irradiated with an oxygen atom beam. The 226 nm laser beam excites only neutral oxygen atoms, and the excited oxygen atoms emit 844 nm fluorescence. This fluorescence is detected by the laser-induced fluorescence measurement device, and the absolute density of oxygen atoms is obtained by calibrating the fluorescence intensity. Therefore, the laser-induced fluorescence measuring device has an effect that the oxygen atom density can be accurately measured on the spot. The neutralization efficiency of oxygen ions in the neutralizer depends on the amount of oxygen gas introduced when the displacement of the evacuation device is constant, but the amount of oxygen gas introduced to maximize the neutralization efficiency Can be clarified by examining the relationship between the introduced amount of oxygen gas and the density of neutral oxygen atoms using the laser-induced fluorescence measurement device. Further, the flux of the oxygen ion beam changes depending on the oxygen ion generation conditions in the ion source. Therefore, the laser-induced fluorescence measurement apparatus enables quantitative evaluation of deterioration by a simulation simulation of deterioration while controlling the flux, and has an effect of improving reliability even in an acceleration experiment.

According to the third aspect of the invention, since the sample holder has a rotatable support structure, it is possible to clarify the relationship between the irradiation angle of the oxygen atom beam on the sample and the deterioration. In addition, there is an effect that a difference in material deterioration depending on a portion of the spacecraft surface can be accurately examined.

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

According to the fifth aspect of the present invention, the generated gas before and after irradiating the sample with oxygen atoms can be analyzed by the quadrupole mass spectrometer, whereby information on the material deterioration mechanism can be obtained. This has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a high-efficiency oxygen ion neutralizer according to a first embodiment of the present invention.

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

FIG. 3 is a sectional configuration view 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 of the present invention. FIG. 4B is a side view for explaining a related configuration between the sample stage 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 test apparatus.

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

[Explanation of symbols]

Reference Signs List 1 ion source 2 extraction electrode (acceleration means) 3 acceleration electrode (acceleration 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 Deterioration reaction chamber 13 Laser-induced fluorescence measurement 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 room 61 Inlet orifice 62 Outlet orifice 63 Gas introduction pipe 64 Vacuum exhaust pipe 64a Vacuum exhaust path 65 Differential exhaust chamber 66 Inlet orifice 67 Outlet orifice

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01J49 / 42 H01J49 / 42 (56) References JP-A-62-229100 (JP, A) JP-A-2-44633 (JP) JP-A-2-90580 (JP, A) JP-A-5-190295 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05H 3/02 B64G 7/00 G01N 17/00 G21K 5/02 C01B 13/02 H01J 49/42

Claims (5)

(57) [Claims] An oxygen ion ( O ⁺ ) is provided in a vacuum vessel equipped with a vacuum exhaust device. ) Beam neutralized by charge exchange with oxygen gas, in an oxygen ion neutralizer to produce neutral oxygen atom beam, the oxygen ion (O ⁺ A) a neutralization chamber having a beam inlet orifice and an outlet orifice on the same straight line, and a gas inlet having a gas inflow controller for introducing oxygen gas into the neutralization chamber and controlling the oxygen gas introduction amount. Surrounding the tube and the neutralization chamber,
A differential exhaust chamber having an inlet orifice and an outlet orifice facing the inlet orifice and the outlet orifice of the neutralization chamber, respectively, on the same straight line; And a vacuum exhaust pipe surrounding the gas introduction pipe and forming a vacuum exhaust path with the gas introduction pipe, and the conductance of the orifices on the inlet side and the outlet side of the neutralization chamber is set to C. ₂ ,
C ₃ , the conductances of the inlet and outlet orifices of the differential pumping chamber are C ₁ and C ₄ , the effective pumping speed of the vacuum pumping system of the differential pumping chamber system is S ₁ , and the vacuum pumping of the vacuum vessel system When the effective pumping speed of the system and _{S 2, (C 1 + C} 4) * (C 2 + C 3) / (S 1 * S 2) <1
0 efficient oxygen ion neutralizer characterized by satisfying ^-2. 2. An ion source for ionizing oxygen gas, an acceleration unit for accelerating oxygen ions from the ion source to a speed higher than a sample irradiation speed, a mass separation unit for selecting only oxygen ions, and the selected oxygen ions Deceleration means that decelerates the sample to the speed at which it is desired to irradiate the sample.The oxygen ion beam that has passed through this deceleration means is neutralized by charge exchange with oxygen gas to produce a neutral oxygen atom beam with nearly uniform particle energy. each of claim 1 oxygen ion neutralizer according you, and this was placed in the order oxygen atom beam generator configured to, the sample holder to the oxygen atom beam generator is connected to the beamline A vacuum-induced degradation reaction chamber having at least two windows, and a laser-induced fluorescence measurement device for measuring the density of atomic oxygen applied to the sample. The degradation reaction chamber is connected to a vacuum exhaust device, and the laser-induced fluorescence measurement device irradiates a laser beam to the oxygen atom beam generated by the oxygen atom beam generator through a window of the degradation reaction chamber. An oxygen atom resistance evaluation apparatus using a highly efficient oxygen ion neutralizer, wherein an intersection of light and the oxygen atom beam is arranged so as to be an observation volume for fluorescence detection. 3. The oxygen-resistant atomic 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 degradation reaction chamber. The degradation reaction chamber is connected to a vacuum sample preparation chamber provided with a plurality of samples via a vacuum valve, and the sample holder is connected to the sample holder. 3. The apparatus according to claim 2, further comprising a manipulator that moves between the degradation reaction chamber and the sample preparation chamber, wherein a sample holder in the degradation reaction chamber is sequentially replaceable with a sample holder provided in the sample preparation chamber. Or the oxygen resistance atomicity evaluation apparatus according to 3. 5. The degradation reaction chamber according to claim 2, further comprising a quadrupole mass spectrometer using a gas released from the sample as a sample gas. Oxygen resistance evaluation equipment.