Potential-compensated electrostatic shield and potential-detecting sensor

Abstract

A potential-compensating electrostatic shield that prevents the occurrence of abnormal electric fields within a housing is provided. [Solution] The potential-compensated electrostatic shield 1 comprises an outer housing 2 which is a conductor, an inner housing 3 which is a conductor arranged inside the outer housing 2 and electrically insulated from the outer housing, a detection unit 4 which detects the potential of the inner housing 3 or a physical quantity corresponding to said potential, and a variable voltage power supply 5 which applies a potential difference between the outer housing 2 and the inner housing 3, and the variable voltage power supply 5 controls the potential difference based on the potential detected by the detection unit 4 or the physical quantity corresponding to said potential.

Description

[Technical Field]

[0001] The present invention generally relates to an electrostatic shield and a potential detection sensor used to block the effects of electric fields, and more specifically to a potential-compensated electrostatic shield equipped with a potential compensation device and a potential detection sensor capable of detecting external potential, for use in, for example, spacecraft used in the harsh environment of outer space. [Background technology]

[0002] Nearly 70 years have passed since the history of spacecraft development around the world began with Sputnik 1 in 1957. Know-how on system and environmental testing conducted before launch must have been accumulated over this history.

[0003] Since the costs of developing and operating a spacecraft are enormous, ensuring reliability and increasing the success rate of the mission are of utmost importance. However, even in recent years, there have been numerous reports of malfunctions and breakdowns in the spacecraft. For example, both Hayabusa 1 and 2 experienced ion engine failures.

[0004] When NASA investigated cases of spacecraft malfunctions and anomalies that occurred between 1974 and 1994, they found that the most common malfunction was caused by plasma in space, accounting for 36% of the total. Plasma interfered with and degraded spacecraft equipment, causing logic inversions in digital circuits, memory bit defects, and performance degradation. The second most common cause was ion radiation, accounting for 33% of the total. Furthermore, transient malfunctions (single event upsets) accounted for over 42% of the malfunction modes. The number of malfunction cases investigated exceeded 100 [Non-Patent Document 1].

[0005] To solve the above-mentioned problems, spacecraft shielding technology has been developed with the main objective of avoiding cosmic radiation particles flying around in space ([Non-Patent Documents 2, 3, 4]).

[0006] In the space environment, cosmic radiation penetrates the shielding of a spacecraft, causing it to become charged and damaging electronic equipment. To avoid this problem, the main countermeasure is to place high-voltage electrodes on the hull of the spacecraft to repel electrically charged cosmic ray particles using Coulomb force.

[0007] Since malfunctions and breakdowns of spacecraft that occur in space are caused by the natural space environment, environmental tests conducted before launch are conducted to simulate the space environment. Despite these ongoing efforts, frequent breakdowns after the start of operations may be due to the environment assumed during testing being insufficient. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] [1] Sheldon D., Electronic Failures in Spacecraft Environments, IRPS2010, 759-762, 2010. [Non-patent document 2] [2] Tripathi R., Electrostatic space radiation shielding, Advances in Space Research, Volume 42, Issue 6, pp.1043-1049, 2008. [Non-patent document 3] [3] Metzger P., Asymmetric electrostatic radiation shielding for spacecraft, IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720), 2004. [Non-patent document 4] [4] Joshi R., Configuration studies for active electrostatic space radiation shielding, Acta Astronautica, Volume88, pp.138-145, 2013. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above-mentioned facts, and its object is to provide a potential-compensating electrostatic shield that prevents the generation of abnormal electric fields within a housing, and a potential detection sensor that can detect external potentials that may generate abnormal electric fields. [Means for solving the problem]

[0010] (One principle on which this invention is based) The inventors of the present invention discovered the existence of overlooked external disturbance effects during the development of the above shielding technology, and reported this in the following paper. According to this paper, the potential inside the shield affects the electron movement of electronic devices inside the shield, inducing an electric field, particularly during the electron acceleration process. This electric field may cause malfunction of the electronic devices. It is believed that conventional shielding technologies such as Faraday cages are ineffective against such disturbances. [paper] Sugiyama T., Generalization of the Lorentz Transformation of the Electromagnetic Four-potential and Concerns About Electrostatic Shielding, IJSCIA, Volume 5, Issue 6, pp.1153-1156, 2024 (https: / / doi.org / 10.51542 / ijscia.v5i6.16) The following describes aspects of the present invention for solving the above problems. The operation of electronic equipment on a spacecraft is guaranteed by tests conducted in an environment of earth's ground potential. The purpose of the present invention is to eliminate deviations from the earth's ground potential after launch and to avoid possible abnormalities, so the "potential" in the present invention is a potential with the earth's ground potential as the reference (0 volts). (potential compensation electrostatic shield) A potential-compensated electrostatic shield according to a first aspect of the present invention includes a conductive outer housing, a conductive inner housing that is disposed inside the outer housing and is electrically insulated from the outer housing, a detection unit that detects the potential of the inner housing or a physical quantity corresponding to the potential, and a variable voltage power supply that applies a potential difference between the outer housing and the inner housing, wherein the variable voltage power supply is configured to control the potential difference based on the potential detected by the detection unit or the physical quantity corresponding to the potential.

[0011] According to a first aspect of the present invention, when a potential-compensating electrostatic shield is placed under an external potential and the outer housing is charged for some reason, the outer housing has a potential that is the sum of the external potential and the potential increased by the charging, and the inner housing also has a potential corresponding to the potential of the outer housing. According to the first aspect, a detection unit detects the potential of the inner housing or a physical quantity corresponding to the potential, and a variable voltage power supply that applies a potential difference between the outer and inner housings controls the potential difference based on the potential detected by the detection unit or the physical quantity corresponding to the potential. For example, the variable voltage power supply controls the potential difference applied between the inner and outer housings so as to cancel out the potential detected by the detection unit or the potential calculated from the physical quantity corresponding to the potential detected by the detection unit. Preferably, the control of the potential difference by the variable voltage power supply is feedback control that sets the target potential to zero. Therefore, the potential-compensating electrostatic shield according to the first aspect of the present invention can maintain a constant potential of the inner housing, thereby suppressing the occurrence of abnormal electric fields that affect electronic devices and the like inside the inner housing.

[0012] A potential-compensating electrostatic shield according to a second aspect of the present invention comprises a conductive grounding body, a conductive housing arranged outside the grounding body and electrically insulated from the grounding body, a detection unit that detects the potential of the housing or a physical quantity corresponding to the potential, and a variable voltage power supply that applies a potential difference between the grounding body and the housing, wherein the variable voltage power supply is configured to control the potential difference based on the potential detected by the detection unit or the physical quantity corresponding to the potential.

[0013] According to a second aspect of the present invention, when a potential-compensated electrostatic shield is placed under an external potential and the grounded body becomes charged for some reason, the grounded body has a potential that is the sum of this external potential and the potential increased by the charging, and the housing also has a potential corresponding to the potential of the grounded body. According to the second aspect, a detection unit detects the potential of the housing or a physical quantity corresponding to the potential, and a variable voltage power supply that applies a potential difference between the grounded body and the housing controls the potential difference based on the potential detected by the detection unit or the physical quantity corresponding to the potential. For example, the variable voltage power supply controls the potential difference applied between the grounded body and the housing so as to cancel out the potential detected by the detection unit or the potential calculated from the physical quantity corresponding to the potential detected by the detection unit. Preferably, the control of the potential difference by the variable voltage power supply is a feedback control that sets a target potential to zero.

[0014] Therefore, the potential compensation electrostatic shield according to the second aspect of the present invention can keep the potential of the housing constant, thereby suppressing the occurrence of abnormal electric fields that affect electronic devices and the like inside the housing. (Detection unit of potential-compensated electrostatic shield) For example, the detection unit includes a mass spectrometer for detecting an apparent mass m' of a charged particle determined by a potential V, and the potential V is calculated based on the apparent mass m'.

[0015] In a preferred detection unit, the apparent mass m' detects the potential V observed in the S system (in the present invention, the potential compensation type electrostatic shield and the potential detection sensor) at a velocity of:

[0016]

number

[0017] When observed in the S' system (in the present invention, a charged particle moving within a potential-compensated electrostatic shield) moving in a 4-dimensional electromagnetic potential, the electric potential V is changed from the original mass m of the charged particle due to the electric field that appears due to the Lorentz transformation of the four-dimensional electromagnetic potential, and the electric potential V is calculated based on the difference between the mass m of the charged particle and the apparent mass m'. More specifically, when the charge of the charged particle is q, the speed of light is c, and the Lorentz factor at that speed is γ, the electric potential V can be expressed in SI units as follows:

[0018]

number

[0019] It is calculated as follows. For example, if the exterior of a spacecraft's hull becomes charged due to the influence of the ionosphere or solar plasma, an electric field will be generated in the electrons flowing through the electronic equipment inside the spacecraft due to the Lorentz transformation of the four-dimensional electromagnetic potential, which may affect the electrons inside the electronic equipment.

[0020] According to the above-mentioned detection unit, even if such an abnormal electric field occurs, the detection unit of the present invention accurately detects the electric potential inside the spacecraft, and the variable voltage power supply controls the electric potential difference between the housings so as to cancel out the electric potential, thereby preventing abnormal operation of electronic devices.

[0021] More preferably, the mass spectrometer includes a particle source that supplies the charged particles, a static magnetic field generator that applies a static magnetic field B to the charged particles, a high-frequency electromagnetic field generator that applies a high-frequency electromagnetic field to the charged particles that are circularly moving in a plane perpendicular to the static magnetic field B by the static magnetic field B, thereby causing cyclotron resonance, and a time waveform signal i of a current generated by the charged particles that caused the cyclotron resonance. d and a current acquisition unit that acquires the time waveform signal i(t). dThe cyclotron frequency ωc can be determined based on (t), and the apparent mass m' of the charged particle can be calculated from the cyclotron frequency ωc. This mass spectrometer, which utilizes cyclotron resonance, can detect the apparent mass of the charged particle very accurately, and therefore can also detect the external potential V very accurately. (potential detection sensor) According to a third aspect of the present invention, a potential detection sensor for detecting a potential V comprises a mass spectrometer for detecting an apparent mass m' of a charged particle determined by the potential V, and a potential calculation unit for calculating the potential V based on the apparent mass m'.

[0022] Preferably, the apparent mass m′ is such that the potential V observed in the S system (in the present invention, the potential detection sensor) is detected at a velocity of:

[0023]

number

[0024] When observed in the S' system (in the present invention, a charged particle (e.g., an electron) that is the detection target of the potential detection sensor) moving in the S' system, the mass m of the charged particle changes due to the electric field that appears due to the Lorentz transformation of the four-dimensional electromagnetic potential, and the potential calculation unit calculates the potential V based on the difference between the mass m of the charged particle and the apparent mass m'.

[0025] The potential calculation unit When the charge of the charged particle is q, the speed of light is c, and the Lorentz factor at the speed is γ, the potential V can be expressed in SI units as follows:

[0026]

number

[0027] It is characterized in that it is calculated by The preferred mass spectrometer includes a particle source that supplies the charged particles, a static magnetic field generator that applies a static magnetic field B to the charged particles, a high-frequency electromagnetic field generator that applies a high-frequency electromagnetic field to the charged particles that are circularly moving in a plane perpendicular to the static magnetic field B by the static magnetic field B, thereby causing cyclotron resonance, and a time waveform signal i of a current generated by the charged particles that caused the cyclotron resonance. d and a current acquisition unit that collects (t).

[0028] For example, the potential calculation unit may calculate the time waveform signal i of the current output from the current acquisition unit. d (t), and calculates the apparent mass m' of the charged particle from the cyclotron frequency ωc. More specifically, the potential calculation unit calculates the time waveform signal i of the current output from the current acquisition unit. d (t) is Fourier transformed to calculate a frequency spectrum I(ω), a frequency ωp that gives a peak value in the frequency spectrum I(ω) is detected, and the frequency ωp is used as the cyclotron frequency to calculate an apparent mass m' using the following equation:

[0029]

number

[0030] The potential V is calculated based on the difference between the mass m of the charged particle and the apparent mass m'. A potential detection sensor according to another embodiment is disposed in the S system to detect a potential V of the S system, The four-electromagnetic potential of the potential V is Speed ​​relative to S system:

[0031]

number

[0032] appears due to the Lorentz transformation of the S' system moving at electric fieldThe potential V is detected based on the motion of a charged particle in the S' system affected by the magnetic field. For example, the motion of the charged particle may be, but is not limited to, a radius of gyration that moves circularly in a static magnetic field.

[0033] Let the charge of the charged particle be q, the speed of light be c, and the Lorentz factor at that speed be γ. The aforementioned electric field teeth,

[0034]

number

[0035] The potential detection sensor according to the other embodiment can also be used as the detection unit of the potential compensation type electrostatic shield. [Effects of the Invention]

[0036] According to the present invention, the potential inside the enclosure to be shielded is detected by a potential detection sensor, and the potential difference generated by the power supply is controlled to apply a potential difference inside and outside the double enclosure or between the independent enclosure and the ground body, thereby making it possible to keep the potential inside the enclosure to be shielded constant. This measure prevents the generation of a potential different from that on Earth inside the enclosure, which means that unexpected induction can be prevented.

[0037] In any case, if the potential inside the spacecraft is made the same as the earth's ground potential by the potential compensation of the present invention, the electrons moving in the electronic equipment installed for the spacecraft's mission can perform as expected, just as when tested on the ground, regardless of the speed at which they move. In particular, the present invention can ensure the operation of equipment that handles significant acceleration of charged particles, such as ion engines and vacuum tubes. [Brief explanation of the drawings]

[0038] [Figure 1]FIG. 1 is a schematic diagram showing the configuration of a potential compensation electrostatic shield with a double-structure housing according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a potential compensation electrostatic shield in a stand-alone housing according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a block diagram of a variable voltage power supply provided in the potential compensation electrostatic shield according to the first and second embodiments of the present invention. [Figure 4] FIG. 4 is a schematic diagram of an example of a detection unit provided in the potential compensation electrostatic shield according to the first and second embodiments of the present invention. [Figure 5] FIG. 5 is a functional block diagram of a potential calculation circuit that calculates an external potential from a current signal output from the detection unit of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, potential compensation electrostatic shields according to first and second embodiments of the present invention will be described with reference to the drawings. <Potential Compensation Type Electrostatic Shield: First Embodiment> 1 shows a potential compensation electrostatic shield 1 according to a first embodiment of the present invention. As shown in the figure, the potential compensation electrostatic shield 1 comprises an outer casing 2 which is a conductor, an inner casing 3 which is a conductor arranged inside the outer casing 2 and electrically insulated from the outer casing 2, and a potential V safe or potential V safe and a variable voltage power supply 5 that applies a potential difference Vc between the outer housing 2 and the inner housing 3. That is, the potential compensation electrostatic shield 1 is configured as a housing with a double wall structure, and each housing has a shape surrounded by a conductive wall, for example, but is not limited to the shape example shown in the figure. The inner housing 3 has an internal space in which electronic devices can be placed. Note that the location where the variable voltage power supply 5 is placed is not limited to inside the inner housing 3.

[0040] The variable voltage power supply 5 detects the potential V safe or potential V safeThe potential difference Vc is controlled based on the physical quantity corresponding to the voltage Vc. Next, the operation of the potential compensation type electrostatic shield 1 will be described. The outer casing 2 is charged, and the potential component that increases due to the charging is compensated by V charge The potential outside the outer casing 2 is V ext When the potential V body teeth, V body =V ext +V charge (1-1) Note that the electric potential mentioned here does not refer to an absolute value. This is self-evident from knowledge of electromagnetism, and is a quantity that can be handled by determining a reference electric potential. Here, we will proceed with the explanation assuming that the Earth's surface electric potential is a reference value of 0 volts.

[0041] As described above, the variable voltage power supply 5 applies a potential difference Vc between the outer casing 2 and the inner casing 3, so that when the potential of the outer casing 2 is V body When this is the case, the potential V of the inner housing 3 safe is expressed as follows: V safe =V body +Vc (1-2) The variable voltage power supply 5 controls the potential V safe Vc is adjusted so that it is reduced to a threshold value or less that does not affect the electronic devices placed in the inner housing 3. safe Vc is adjusted so that Vc is substantially 0 (volts). In this case, Vc is expressed by the following equation: Vc=-V body (1-3) According to the potential compensation type electrostatic shield 1 according to the first embodiment of the present invention, a potential V ext If there is a V charge Even if the external casing 2 is charged with electricity, the potential V bodySince a potential difference Vc is applied between the outer housing 2 and the inner housing 3 so as to cancel out the above, it is possible to prevent breakdowns in electronic devices placed inside the inner housing 3 even in the above-mentioned case. Furthermore, even if the external potential changes, it is possible to keep the potential inside the housings approximately constant and prevent the occurrence of abnormal electric fields inside the housings.

[0042] The equations (1-1) and (1-2) are used to explain the distribution of potential, and V charge Ya, V ext may be agnostic to the operation of the control system. <Potential Compensation Type Electrostatic Shield: Second Embodiment> 2 shows a potential compensation electrostatic shield 1b according to a second embodiment of the present invention. As shown in the figure, the potential compensation electrostatic shield 1b comprises a grounding body 6 which is a conductor, a housing 7 which is a conductor arranged outside the grounding body 6 and electrically insulated from the grounding body 6, and a potential V safe or the potential V safe and a variable voltage power supply 5 that applies a potential difference Vc between a ground body 6 and a housing 7. Here, the same components as those in the first embodiment are given the same reference numerals. Note that the location of the variable voltage power supply 5 is not limited to inside the housing 7.

[0043] As described above, the potential compensation electrostatic shield 1b according to the second embodiment does not have a configuration in which the outer housing 2 covers the inner housing 3 as in the first embodiment, but has a grounding body 6 provided outside the housing 7 (corresponding to the inner housing 3 in the first embodiment).

[0044] The grounding body 6 may have a housing structure with an internal space like the outer housing 2 of the first embodiment, or any structure can be used as long as it is a conductor. The operation and effects of the potential compensation electrostatic shield 1b according to the second embodiment are similar to those of the potential compensation electrostatic shield 1 according to the second embodiment, and therefore detailed description thereof will be omitted. <An embodiment of a variable voltage power supply> Next, one embodiment (5a) of the variable voltage power supply 5 will be described with reference to Fig. 3. In Fig. 3, the same components as those in the first and second embodiments are given the same reference numerals, and detailed description thereof will be omitted.

[0045] As shown in FIG. 3, the variable voltage power supply 5a according to the embodiment converts the detection signal i output from the detection unit 4 into d a potential calculation circuit 10 that calculates the potential of the housings 3 and 7 from the potential V safe The power supply 10 includes a deviation calculation unit 11 that calculates a deviation e from a target potential 0, a PID calculator 12 that calculates a control amount based on PID (proportional-integral-derivative) control for the deviation e calculated by the deviation calculation unit 11, and an output voltage change circuit 13 that adjusts the voltage from a power supply 14 based on the control amount calculated by the PID calculator 12 and applies a control voltage Vc to the (internal) casings 3 and 7. The output voltage change circuit 13 can be configured to control the resistance of a variable resistor or a regulator that controls a transistor to output a desired voltage.

[0046] Control by the variable voltage power supply 5a quickly changes V as shown in the following equation. safe can be made substantially zero. V safe ~0 (1-4) That is, V charge Ya, V ext V safe Even if V changes, the feedback control by the detector 4 and the variable voltage power supply 5 is safe The deviation from the target value of 0 volts is automatically tracked and V safe is asymptotically approached to 0 volts.

[0047] The configuration of the variable voltage power supply of the present invention is not limited to the above embodiment, but can be modified arbitrarily and suitably. For example, feedback control other than PID control or feedforward control may be used. <One embodiment of the detection unit> The detection unit 4 can be configured as a potential detection sensor that directly detects the potential of the (internal) housings 3 and 7. In this case, the potential calculation circuit 10 shown in Fig. 3 does not necessarily have to be provided.

[0048] On the other hand, as published in the above-mentioned paper, the inventors of the present invention discovered that when a constant, position-independent background potential V observed in the S-system is observed in the S'-system, which is moving at a velocity ν relative to the S-system, a Lorentz transformation of the four-dimensional electromagnetic potential generates an electric field proportional to the background potential V and acceleration dv / dt. Therefore, it is understood that a charged particle is subjected to a force from the electric field caused by the background potential V, causing its apparent mass to change. By utilizing this fact, it is possible to calculate the background potential V from the measured apparent mass of a charged particle. As will be described in detail later, the desired potential V can be calculated in SI units using the following formula, where m is the mass of the charged particle, m' is the calculated apparent mass of the charged particle, c is the speed of light, q is the charge of the charged particle, and γ is the Lorentz factor.

[0049]

number

[0050] According to equation (1-5), the potential V can be measured by configuring the detection unit 4 as a sensor that measures the mass of the charged particle. The detection unit 4 shown in FIG. 3 is, for example, a mass spectrometer 4a. The mass spectrometer 4a is configured to observe the apparent mass m' of a charged particle having a known mass m generated from a particle source. Mass spectrometers 4a may be of various types, including quadrupole, double focusing, ion trap, and time-of-flight types, but the mass spectrometer of the present invention is not limited to these. (Omegatron mass spectrometer) One preferred embodiment of the mass spectrometer according to the present invention is an ion (electron) cyclotron resonance mass spectrometer, a so-called omegatron. A detector 4b configured as an omegatron will now be described with reference to FIG.

[0051] As shown in FIG. 4, detection unit 4b includes a particle source (not shown) that supplies charged particles into vacuum chamber 20, static magnetic field generator 21 that applies static magnetic field B in the z direction perpendicular to the xy plane (plane on the drawing), high-frequency electrodes 22, 22 that are arranged to apply a high-frequency electromagnetic field to the charged particles that are circularly moving in the xy plane by static magnetic field B, high-frequency oscillator 23 that applies a high-frequency AC voltage to high-frequency electrodes 22, 22 to generate the high-frequency electromagnetic field, current electrodes 25, 25 in which a current is generated due to the charged particles that are moving along trajectory 24 by causing cyclotron resonance due to the high-frequency electromagnetic field, and current electrodes 25, 25 that amplify the image current generated in current electrodes 25, 25 to generate a time waveform signal i of the image current. d and a current amplifier 26 that outputs a signal (t).

[0052] The operation of the detector 4b will now be described. A particle source supplies charged particles with charge q and mass m into vacuum chamber 20, and static magnetic field generator 21 applies a static magnetic field B (magnetic flux density B) in the z direction inside vacuum chamber 20. At this time, the Lorentz force generated by the static magnetic field B causes the charged particles to move circularly in the xy plane perpendicular to the z direction at a cyclotron (angular) frequency ωc expressed by the following equation:

[0053]

number

[0054] While the charged particles are in circular motion as described above, a high-frequency AC voltage is applied from the high-frequency oscillator 23 to the high-frequency electrodes 22, 22. This high-frequency AC voltage contains AC voltages of various frequencies over a certain range, including the cyclotron frequency ωc obtained by substituting the known mass of the charged particle into equation (1-6), so that the charged particles can induce cyclotron resonance even if their mass m changes to m' due to the potential V.

[0055] When a certain frequency of the high frequency electromagnetic field generated by the high frequency electrodes 22, 22 matches the frequency of the circular motion of a charged particle in the xy plane, cyclotron resonance occurs. The charged particle undergoing cyclotron resonance obtains kinetic energy from the high frequency electromagnetic field, and the radius of its rotational motion gradually increases as shown by trajectory 24. The charged particle moving along trajectory 24 approaches or hits current electrode 25, causing a current to flow between current electrodes 25, 25. The generated current is amplified by amplifier 26 to generate a time waveform signal i of the image current. d It is output as (t).

[0056] When electrons are used as the charged particles, the calculation is performed using q=e (electron charge) in equations (1-5) and (1-6). The charged particles in the vacuum chamber 20 are undergoing accelerated motion under the potential V as described above, and are therefore actually subjected to a force from the electric field expressed by equation (20) described below, as well as the Lorentz force from the static magnetic field B. Therefore, the charged particles are undergoing circular motion in a state where the resultant force of the Lorentz force and the force from the electric field of equation (20) is in balance with the centrifugal force. From this condition of balance, the radius of rotation r of the circular motion is given by

[0057]

number

[0058] Here, ν is the velocity of the charged particle, and the absolute value of the charge q of the charged particle is taken. Since the velocity ν of the charged particle can be considered to be sufficiently slow compared to the speed of light based on the dimensions of the omegatron actually used, the Lorentz factor γ in equation (1-7) is approximated to 1.

[0059] The rotational frequency f of a charged particle is ν=rω, ω=2πf, so from equation (1-7),

[0060]

number

[0061] get. If the potential V is 0V and the charged particle is an electron, the electron mass m = 9.109 × 10 -31 [kg], electron charge q = -1.602 × 10 -19 [C], and the speed of light c = 2.9978 × 10 8 Substituting [m / s] into equation (1-8), f=2.80×10 9 [Hz] get.

[0062] If the potential V is 100,000 V, then from equation (1-8) f=2.34×10 9 [Hz] get.

[0063] The above calculation results show that the rotational frequency f of electrons (cyclotron frequency) is affected by the potential V, with f decreasing when the potential V is positive and f increasing when the potential V is negative. This suggests that the omegatron can be used as a potential sensor.

[0064] Furthermore, it is suggested that the potential V can also be measured by detecting the radius of rotation of the charged particle from equation (1-7). <Potential calculation section> The potential calculation unit 10 shown in FIG. 3 calculates the time waveform signal i of the image current output from the detection unit 4b. d (t) to the potential V (= V safe The flow of the calculation process of the potential calculation unit 10 will be described with reference to FIG.

[0065] In the potential calculation unit 10, first, the calculation block 100 calculates the time waveform signal i d (t) is Fourier transformed to obtain the frequency spectrum I(ω), which is stored in memory 101. Next, in calculation block 102, a peak frequency ωp that gives a peak intensity is detected from the frequency spectrum I(ω). Since the detected peak frequency ωp is considered to be the cyclotron resonance frequency ωc (=ωp), calculation block 103 calculates the apparent mass m' of the charged particle according to the following equation, which is a modification of equation (1-6):

[0066]

number

[0067] The calculation block 104 calculates and outputs the potential V by substituting the apparent mass m' of the charged particle calculated by the formula (1-9) into the formula (1-5). Note that the formula (1-5) includes the Lorentz factor γ, but the velocity v of the charged particle relative to the potential compensation type electrostatic shields 1 and 1b is s When it can be considered that is sufficiently smaller than the speed of light, the calculation block 104 may calculate the formula (1-5) by approximating γ=1. s is accelerated to near the speed of light, the calculation block 104 calculates the velocity v s The Lorentz factor γ is calculated using <Basis of formula (1-5)> Equation (1-5) is based on the content published by the inventor of the present invention in the above paper, and is derived as follows.

[0068] The electromagnetic four-potential observed in the S system is

[0069]

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[0070] and the velocity for the S system is

[0071]

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[0072] The electromagnetic four-potential observed in the S' frame moving at

[0073]

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[0074] Let's say. The Lorentz transformation of the electromagnetic four-potential that has been used so far only refers to the case where the S' system moves linearly in the direction of each of the three axes, and the following transformation formula is known.

[0075] When the S' system is moving in the X-axis direction at a velocity ν, the Lorentz transformation of the electromagnetic four-potential is

[0076]

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[0077] When the S' system is moving in the Y-axis direction at a velocity ν, the Lorentz transformation of the electromagnetic four-potential is

[0078]

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[0079] When the S' system is moving in the Z-axis direction at a velocity ν, the Lorentz transformation of the electromagnetic four-potential is

[0080]

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[0081] In the above formula,

[0082]

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[0083] where ν is the velocity of motion of the S' system and c is the speed of light. Equation (1) can be written as follows for each component:

[0084]

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[0085] Similarly, the components of equations (2) and (3) can be written as follows:

[0086]

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[0087]

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[0088] When the direction of the velocity of motion of the S' frame is arbitrary, the electromagnetic four-potential observed from the S' frame can be obtained by integrating equations (6), (7), and (8) as follows:

[0089]

number

[0090] where:

[0091]

number

[0092]

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[0093] is the velocity vector

[0094]

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[0095] are parallel and perpendicular to the

[0096]

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[0097] Substituting equation (10) into equation (9), we obtain the following equation.

[0098]

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[0099] Equation (11) is an arbitrary velocity vector

[0100]

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[0101] Electromagnetic four-potential observed from the S' frame moving at

[0102]

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[0103]

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[0104] It is possible to calculate (Proof) The fact that equation (11) is reliable as a Lorentz transformation can be proved as follows.

[0105] If the four-electromagnetic potential is subject to the Lorentz transformation, the following relationship must hold:

[0106]

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[0107] By substituting equation (11) into equation (12), the right-hand side of equation (12) is obtained as follows:

[0108]

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[0109] In the process of this derivation, the following relationship was used:

[0110]

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[0111] As described above, it has been proven that equation (11) represents the Lorentz transformation of the electromagnetic four-potential. (Advantages of Equation (11)) The conventional equations (1), (2), and (3) are written under the assumption that they deal with linear motion along the coordinate axes, but are not appropriate for curvilinear motion. The advantage of equation (11) is that it can be applied even if the direction of the velocity vector is arbitrary, and it can be easily applied even when the direction of the velocity changes with time.

[0112]

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[0113] and therefore

[0114]

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[0115] Under this condition, equation (11) can be simplified as follows:

[0116]

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[0117] (Field of an accelerating system in a constant potential space) There exists a space in which the electromagnetic four-potential is given by the following equation:

[0118]

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[0119] Here, we assume that V is a constant value that does not depend on the position in space.

[0120]

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[0121] The electromagnetic four-potential that appears in the S' frame moving at is obtained by substituting equation (16) into equation (11).

[0122]

number

[0123] The electric field that appears in the S' system

[0124]

number

[0125] and magnetic field

[0126]

number

[0127] is expressed by the following equation:

[0128]

number

[0129] Substituting equation (17) into equations (18) and (19), the following equation is obtained:

[0130]

number

[0131] Equation (20) expresses that in a constant potential space, the acceleration system is determined by the background potential V and the acceleration

[0132]

number

[0133] This means that an electric field proportional to is generated. Also, as shown in equation (21), there is no magnetic field. If the electric field and magnetic field in the S-frame are Lorentz transformed into the electric field and magnetic field in the S'-frame without going through the electromagnetic four-potential, equation (20) cannot be obtained. The reason is that some information is lost when the electromagnetic four-potential is transformed into the electric field and magnetic field. The constant component contained in the electrostatic potential is lost through the operator grad. Also, the gradient component and constant vector component contained in the vector potential are lost through the operator rot. (Equation of motion for a charged particle moving through a space with constant potential) If there is a charged particle moving with the S' system and its charge is q, the force acting on the charged particle is

[0134]

number

[0135] is expressed as follows:

[0136]

number

[0137] where:

[0138]

number

[0139] is the electric field appearing in the S' system,

[0140]

number

[0141] teeth, electric field

[0142]

number

[0143] It is an external force acting on a charged particle due to factors other than the magnetic field. Substituting equation (20) into equation (22), we obtain the following equation:

[0144]

number

[0145] Here, the particle's equation of motion is given by the following equation:

[0146]

number

[0147] In the above equation, m is the mass of the particle. From equations (23) and (24), the following equation is obtained:

[0148]

number

[0149] On the right side of equation (25),

[0150]

number

[0151] Since is the dimension of mass, the particle is interpreted as having an apparent mass m' defined by

[0152]

number

[0153] By solving equation (26) for V, we can obtain equation (1-5). Equation (26) implies that the apparent mass of a charged particle varies with the background potential. This affects, for example, the cyclotron frequency. Therefore, as mentioned above, the apparent mass m' of a charged particle can be determined by measuring the cyclotron frequency.

[0154] In electronic devices that are highly sensitive to the movement of electrons, if care is not taken to control the electrical potential of the space in which the device is placed, the apparent mass of the electrons can change, causing malfunctions.

[0155] Even if the space probes pass sufficient system tests before launch, numerous unexpected malfunctions have been reported when they are actually deployed in space. The primary trigger for these malfunctions is thought to be electrical stimulation from the sun or the Earth's radiation belt.

[0156] While the reliability of spacecraft shielding technology is typically tested against the effects of ESD, EMI, and EMP, the above discussion suggests that the effects of external potentials should also be considered.

[0157] Even if the electric field inside the space inside the electrostatic shield of the probe is zero, external potentials penetrate the inside of the shield, so that even if the electronic device is placed inside the shield, the electrons in the circuit will be affected by the potential V according to equation (20).

[0158] Even if the electric potential within a space is constant, charged particles moving within the space can be affected by the electric potential. This prediction suggests that in an environment where high-voltage systems and electronic devices coexist, Faraday shields installed to protect electronic devices will not function effectively.

[0159] It is understood that the present invention can adequately protect electronic devices even in situations where the above-mentioned potentials exist. <Observed evidence showing that electric potential affects nearby current> Equation (20) shows that if the motion of a charged particle in the S' system is accelerating, the four-electromagnetic potential of the S' system changes over time, generating an electric field. Since the strength of the electric field shown in equation (20) is proportional to the electric potential V, the higher the electric potential V, the greater the effect of the generated electric field on the charged particle. I. Observed Facts The inventors of the present invention have observed the following (1) and (2) as examples of how a potential, particularly a high potential, affects nearby currents. (1) Telephone Test (1986) When an analog telephone receiver is taken off the hook and a timeout occurs, the phantom power supply and dial tone of the line are stopped, and the telephone goes into a high and dry (H&D) state. In this state, if the receiver is held to the ear, radio audio can sometimes be heard. When the radio in the room is turned on, it is discovered that the audio coming from the receiver is the same as that of an AM Tohoku Broadcasting program. It is assumed that the Tohoku Broadcasting transmitting station is nearby, and its radio waves are being induced onto the telephone line.

[0160] After phantom power was cut off, a high-voltage pulse was applied to the telephone line in the high-and-dry state once every 10 seconds to monitor whether the line was alive or dead. The radio broadcast could be heard from the receiver immediately after the alive-monitoring pulse was generated, and the volume then dropped suddenly, reaching almost zero one second later. Each time a high-voltage pulse was generated, the radio broadcast began to be heard from the receiver, and the volume gradually decreased.

[0161] The above observations indicate that the current signal induced in the telephone line is amplified or attenuated under high voltage. (2) Tesla coil experiment (1995) When the output of a high-frequency power supply was applied to a small Tesla coil wound with extremely fine wire (φ0.1 mm), a larger current flowed to the output side of the power supply than in the case of a short circuit. The inventors of this invention hypothesized that the Tesla coil resonated with the components inside the power supply (coil and capacitor), which would likely increase the output current, and measured the input power to the Tesla coil. However, the measured input power was actually reduced compared to the input power before the larger current was observed, demonstrating that this assumption was incorrect.

[0162] The above observations suggest that some kind of electromotive force that accelerates the current is generated under the high potential of the Tesla coil. Although the above is an embodiment of the present invention, the present invention is not limited to the above example and can be modified arbitrarily and suitably within the scope of the present invention. For example, in the mass spectrometer 4b shown in Fig. 4, the high-frequency AC voltage of the high-frequency oscillator 23 includes AC voltages of various frequencies over a certain range including the cyclotron frequency ωc obtained by substituting the known mass of the charged particle into equation (1-6), but it is also possible to continuously change the frequency of the AC voltage over the above certain range and detect the frequency that gives a peak value.

[0163] Furthermore, in the above embodiment, the apparent mass of the charged particle is detected to detect the potential V, but the present invention is not limited to the above example and includes other embodiments in which the potential V is detected by directly or indirectly detecting the electric field of equation (20). [Explanation of symbols]

[0164] 1. Potential-compensated electrostatic shield (first embodiment) 1b Potential-compensated electrostatic shield (second embodiment) 2 Outer casing 3. Inner housing 4. Detection unit 4a mass spectrometer 4b Omegatron-based mass spectrometer 5 Variable voltage power supply 6 Grounding body 7. Housing 10. Potential calculation circuit 11 Deviation calculation section 12 PID calculator 13 Output voltage change circuit 14 Power supply 20 Vacuum Chamber 21 Static magnetic field generator 22 High-frequency electrode 23 High frequency oscillator 24 orbit 25 Current electrode 26 Current Amplifier 100 Fourier Transform 101 Memory (Frequency Spectrum) 102 Peak Frequency Detection 103 Calculation of apparent mass 104 Calculation of background potential V

Claims

1. A potential-compensated electrostatic shield, an outer casing that is a conductor; an inner housing that is a conductor and is disposed inside the outer housing and is electrically insulated from the outer housing; a detection unit that detects a potential of the inner housing or a physical quantity corresponding to the potential; a variable voltage power supply that applies a potential difference between the outer casing and the inner casing; Equipped with The variable voltage power supply controls the potential difference so as to cancel out the potential detected by the detection unit or a potential calculated from a physical quantity corresponding to the potential.

2. A potential-compensated electrostatic shield, a grounding body that is a conductor; a housing that is a conductor disposed outside the grounding body and electrically insulated from the grounding body; a detection unit that detects a potential of the housing or a physical quantity corresponding to the potential; a variable voltage power supply that applies a potential difference between the ground body and the housing; Equipped with The variable voltage power supply controls the potential difference so as to cancel out the potential detected by the detection unit or a potential calculated from a physical quantity corresponding to the potential.

3. 3. The potential compensation electrostatic shield according to claim 1, wherein the control of the potential difference is a feedback control in which a target potential is set to zero.

4. the detection unit is disposed within the potential compensation electrostatic shield of the S system to detect the potential V of the S system, The four-dimensional electromagnetic potential of the potential V is Speed ​​for S system: [Equation 1] 3. The potential-compensated electrostatic shield according to claim 1, further comprising a mass spectrometer for detecting an apparent mass m′ of a charged particle in the S′ system affected by an electric field that appears as a result of Lorentz transformation into the S′ system moving in the S′ system, and the potential V is calculated based on the mass m of the charged particle and the apparent mass m′.

5. When the charge of the charged particle is q, the speed of light is c, and the Lorentz factor at the speed is γ, the potential V is expressed by the following formula in the SI unit system: [Equation 2] 5. The potential compensated electrostatic shield according to claim 4, wherein the potential compensated electrostatic shield is calculated by the following formula:

6. The mass spectrometer a particle source that supplies the charged particles; a static magnetic field generator for applying a static magnetic field B to the charged particles; a high frequency electromagnetic field generator that applies a high frequency electromagnetic field to charged particles that are circularly moving in a plane perpendicular to the static magnetic field B by the static magnetic field B, thereby causing cyclotron resonance; The time waveform signal i of the current generated by the charged particles that caused the cyclotron resonance ｄ a current acquisition unit that collects (t); 6. The potential compensated electrostatic shield of claim 5, comprising:

7. The current time waveform signal i ｄ 7. The potential compensated electrostatic shield according to claim 6, wherein a cyclotron frequency ωc is determined based on (t), and an apparent mass m' of the charged particle is calculated from the cyclotron frequency ωc.

8. The detection unit is disposed in the S system to detect a potential V of the S system, The four-dimensional electromagnetic potential of the potential V is Speed ​​for S system: [Equation 3] 3. The potential-compensated electrostatic shield according to claim 1, wherein the potential V is detected based on the motion of a charged particle in the S′ system affected by an electric field that appears due to a Lorentz transformation to the S′ system moving in the S′ system.

9. Let the charge of the charged particle be q, the speed of light be c, and the Lorentz factor at that speed be γ. The electric field is [Equation 4] 9. The potential compensated electrostatic shield according to claim 8, wherein:

10. An electric potential detection sensor, The potential detection sensor is disposed in the S system to detect the potential V of the S system, The four-dimensional electromagnetic potential of the potential V is Speed ​​for S system: [Equation 5] a mass spectrometer for detecting the apparent mass m' of the charged particle in the S' system affected by the electric field that appears as a result of the Lorentz transformation of the S' system moving in the a potential calculation unit that calculates the potential V based on the mass m and the apparent mass m' of the charged particle.

11. The potential calculation unit When the charge of the charged particle is q, the speed of light is c, and the Lorentz factor at the speed is γ, the potential V is expressed by the following formula in the SI unit system: [Equation 6] The potential detection sensor according to claim 10, wherein the potential is calculated by the following formula:

12. The mass spectrometer a particle source that supplies the charged particles; a static magnetic field generator for applying a static magnetic field B to the charged particles; a high frequency electromagnetic field generator that applies a high frequency electromagnetic field to charged particles that are circularly moving in a plane perpendicular to the static magnetic field B by the static magnetic field B, thereby causing cyclotron resonance; The time waveform signal i of the current generated by the charged particles that caused the cyclotron resonance ｄ a current acquisition unit that collects (t); 11. The potential sensing sensor of claim 10, comprising:

13. The potential calculation unit The time waveform signal i of the current output from the current acquisition unit ｄ 13. The electric potential detection sensor according to claim 12, wherein a cyclotron frequency ωc is determined based on (t), and an apparent mass m' of the charged particle is calculated from the cyclotron frequency ωc.

14. The potential calculation unit The time waveform signal i of the current output from the current acquisition unit ｄ (t) is Fourier transformed to calculate the frequency spectrum I(ω), Detecting a frequency ωp that gives a peak value in the frequency spectrum I(ω), The frequency ωp is set as the cyclotron frequency, and the apparent mass m' is calculated by the following equation: [Equation 7] 14. The electric potential detection sensor according to claim 13, wherein the electric potential V is calculated based on the difference between the mass m of the charged particle and the apparent mass m'.

15. An electric potential detection sensor, The potential detection sensor is disposed in the S system to detect the potential V of the S system, The four-dimensional electromagnetic potential of the potential V is Speed ​​for S system: [Equation 8] The potential detection sensor is configured to detect the potential V based on the movement of charged particles in the S' system affected by an electric field that appears as a result of the Lorentz transformation of the S' system moving in the S' system.

16. Let the charge of the charged particle be q, the speed of light be c, and the Lorentz factor at that speed be γ. The electric field is [Equation 9] 16. The electric potential detection sensor according to claim 15, wherein:

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