JPH01225098A - Discharge lamp lighting system, magnetic field generating source layout and discharge lamp device - Google Patents

Abstract

PURPOSE:To reduce the diffusion loss or plasma in a discharge lamp, suppress the rise of the lamp voltage within a small range, and prevent the quenching of the discharge lamp by arranging a magnetic field generating source and the discharge lamp of a discharge lamp device so that the direction of the magnetic field and the lamp axis are made parallel with each other. CONSTITUTION:The discharge lamp 4a of a discharge lamp device and a magnetic field generating source 1 are arranged respectively so that the lamp axis and the direction of the magnetic field are made parallel. The magnetic field is applied to the discharge lamp in parallel with the lamp axis, the component in the tube radial direction of the electric field generating the EXB drift in the plasma in the discharge lamp is made smaller than the component in the lamp axial direction. The diffusion loss of the plasma in the discharge lamp is thereby reduced, the rise of the lamp voltage is suppressed within a small range, the quenching of the discharge lamp being lighted is prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to the field of magnetic field generated by a magnetic field generation source such as a nuclear magnetic resonance diagnostic apparatus.
The present invention relates to a discharge lamp device and a method for arranging a magnetic field source when the discharge lamp device is installed in a strong magnetic field, a discharge lamp illumination system with an improved discharge lamp, a method for arranging a magnetic field source, and a discharge lamp device.

(Prior art) It has long been known that a magnetic field affects discharge plasma. For example, in a fluorescent lamp, when a magnetic field is applied to the end of the tube where a pair of electrodes are each sealed, the lamp lights up. It is known to prevent time flickering and to improve the luminous efficiency of a fluorescent lamp by applying a magnetic field to almost the entire fluorescent lamp.

However, these systems mainly take advantage of the positive effects that magnetic fields have on fluorescent lamps, and the negative effects that magnetic fields have on fluorescent lamps have not been sufficiently examined in the past, and countermeasures have also been insufficient. Met.

However, in recent years (nuclear magnetic resonance diagnostic equipment) has become popular, for example, 5000 to 200 Q
There is a magnetic field source C' that generates a high magnetic field of causs, and due to its structure, it leaks a magnetic field into the crowd, and there are multiple fluorescent lamps installed on the ceiling of the room where the nuclear magnetic resonance diagnostic equipment is installed. For example, a magnetic field of several Gaussian magnitude may be generated around the earth.
The magnetic field is extremely high compared to the s-culm degree.

Due to this high magnetic field, the starting performance of fluorescent lamp equipment deteriorates, resulting in problems such as taking a long time to turn on or causing stagnation. '! In the past, this issue has not been sufficiently investigated, and almost no countermeasures have been taken.

(Problem to be solved by the invention) The above-mentioned conventional fluorescent lamp device This results in problems such as poor starting performance, a long time required for lighting, and problems such as Yl etc. turning off.

Therefore, the present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a discharge lamp lighting system that can improve the starting performance of discharge lamps installed in a magnetic field and prevent them from extinguishing. 3. [Structure of the invention] (Means for solving the problem) The present inventor has conducted research on discharge lamp devices such as fluorescent lamps. 7 years in a row
As a result, we have determined that magnetic fields have an adverse effect on discharge lamp devices such as fluorescent lamps, and have investigated the cause and mechanism thereof, and have completed the present invention.

In other words, the inventor's knowledge is that when a magnetic field is applied to a discharge lamp such as a fluorescent lamp in a direction perpendicular to the lamp axis (A), the lamp voltage of the discharge lamp fluctuates by one degree for the following reason.

In general, when an electric field E and a magnetic field B are applied to a plasma containing electrons such as J shown in Fig. 5, the plasma will have EX
It is known that when the force B acts, electrons and ions both move in a direction perpendicular to the electric field E and the magnetic field B, resulting in the occurrence of ``xB drift 1''.

And the inventor is S1? We thought that when a magnetic field is applied to a discharge lamp such as a light lamp, this EXB drift 1- occurs within the discharge lamp and improves the lamp voltage.

That is, in a fluorescent lamp device, discharge plasma is generated within the fluorescent lamp due to discharge between a pair of electrodes when the lamp is lit.
When electric WE is applied along the lamp axis direction, the magnetic field B
is applied in the direction perpendicular to the lamp axis direction of the fluorescent lamp 1, that is, in the tube diameter direction.

For this reason, the diffusion loss of ions and electrons that diffuse into the tube wall of the fluorescent lamp 1 increases and disappears. To achieve this, it is necessary to reduce the lamp voltage (potential gradient), avoid increasing the energy input to the plasma, and increase electron starvation.When the lamp voltage cannot be increased due to power supply voltage constraints, etc., the lighting may not turn on. It is thought that it can be used.

On the other hand, when a magnetic field B is applied to the fluorescent lamp 1 parallel to the lamp axis, the plasma inside the fluorescent lamp 1 undergoes an FXB drift due to the radial component of the electric field E; Since the component in the radial direction is sufficiently smaller than the component in the tube axis direction, the diffusion loss of plasma within the fluorescent lamp 1 is reduced, and the increase in lamp voltage is suppressed to a small extent. For example, when the potential gradient in the lamp axis direction is 1.0 V/c+, the potential gradient in the tube radial direction is 0.2 V/cm. .

In this way, when the magnetic field B is applied to the fluorescent lamp 1 in parallel and perpendicular to the lamp axis, the strength of the magnetic field B that deteriorates the startability of the fluorescent lamp 1 is shown in FIG. In addition, in the table, F
L is a straight tube fluorescent lamp, SS is a tube diameter of 28 m, 20 J: and /10 are W numbers, and -. When a magnetic field B is applied to the end of the tube, as shown in Fig. 7, the plasma density of the negative glow is approximately one order of magnitude higher than that of the positive column.For example, the plasma density of the negative glow is 1012
/c/I, while the plasma density of the positive column is 1
111 pieces/cnl), therefore, the amount of loss of the fissure due to the E-B drift 1 which falls on the front width portion of the fluorescent lamp 1 increases.

Roughly speaking, as shown in Figure 7, the potential gradient of the cathode fall section is larger than that of the positive column (for example, the cathode fall voltage is 11
('', the potential gradient is 1000■/c#I~10000
V/cm, whereas the solar column? U position inclination is 1
．． OV/cm. ), the lamp voltage v, - increases.

Therefore, the first invention is to arrange an electric lamp of a discharge lamp device installed in the magnetic field of a magnetic field generation source so that its lamp axis is parallel to the direction of the magnetic field of the magnetic field generation source. It is characterized by

Further, the second invention is characterized in that the magnetic field generation source is arranged so that the direction of the magnetic field is substantially parallel to the lamp axis of the discharge lamp of the discharge lamp device installed in the magnetic field.

Furthermore, the third invention is characterized in that the outer periphery of the discharge lamp from the pair of electrodes and each negative electrode to each Faraday 13 is coated with a magnetic shielding material.

(Operation) In the first and second inventions, the discharge lamp and the magnetic field generation source of the discharge lamp device are both parallel to each other, and the lamp axis of the discharge lamp is parallel to the direction of the magnetic field of the magnetic field generation source. Each is placed.

Therefore, the magnetic field is 715! EXB is added to the discharge lamp parallel to the lamp axis, and EXB is added to the plasma inside the discharge lamp.
Since the component in the tube diameter direction of the electric field that causes drift is smaller than the component in the lamp axis direction, the number of diffused species of plasma within the discharge lamp is reduced, and the increase in lamp voltage is suppressed to a small extent. As a result, the discharge lamp that is being lit is also prevented from going out.

In addition, in the third invention, a pair of electrodes of a discharge lamp with a high plasma density and a large potential gradient and the outer periphery from each negative glow to each Faraday dark area are magnetically shielded by a magnetic shielding material, so a fluorescent lamp At the end of the tube
It is possible to almost eliminate the influence of the magnetic field, and it is possible to prevent the lamp voltage from decreasing and turning off the discharge lamp.

Therefore, according to the first, second, and third inventions, it is possible to prevent the lamp voltage of the discharge lamp from extinguishing at one end.

(Example) Each example of the first to third inventions will be described below based on FIGS. 1 to 4.

FIG. 1 is a front view of an embodiment of both the first and second inventions, and in the figure, a nuclear magnetic resonance diagnostic apparatus 1 as a magnetic field generation source is installed and fixed on the floor 2 of a desired room, A plurality of fluorescent lamp devices 4, which are discharge lamp devices, are fixed to the ceiling 3 of the 8IS shop.

The nuclear magnetic resonance diagnostic apparatus 1 incorporates, for example, a Helmholtz coil, etc., and when operated with a human body 6 accommodated in the human body storage section 5, the Helmholtz coil or the like generates a
000 to 20,000 Gauss (7) Generates a high magnetic field, and since this Helmholtz coil is an open system, the magnetic field B shown by the dashed line leaks outside the device as shown in Figure 1 J3 and Figure 2, and the ceiling 3 A magnetic field of several hundred Gauss is generated around the plurality of fluorescent lamp devices 4.

- On the other hand, each fluorescent lamp device 4 includes, for example, two fluorescent lamps 4a.
A pair of left and right tube ends are detachably supported by each fluorescent lamp fixture 4b, and the fluorescent lamps 4a, 4a are turned on and off by a lighting circuit (not shown) of the fluorescent lamp fixture 4b.

Each fluorescent lamp 4a has a fluorescent film coated on the inner peripheral surface of an elongated circular glass bulb over almost its entire length, and is sealed inside the bulb by a pair of electrodes sealed at the left and right ends of the tube, respectively. It is designed to be lit by discharging in an atmosphere of mercury and rare gas, and when it is lit, a positive column of discharge plasma is generated between the pair of electrodes and the fluorescent film is excited. It is designed to emit light.

As shown in FIGS. 1 and 2, each fluorescent lamp device 4 has its respective fluorescent lamp 4a arranged so that the lamp axis is parallel to the direction of the magnetic field B. As shown in FIGS.

Therefore, the magnetic field B is applied to each fluorescent lamp 4 of each fluorescent lamp device 4.
a, parallel to the lamp axis, and a component of an electric field (not shown) in the tube diameter direction is applied to the discharge plasma of the fluorescent lamp/la while it is lit, thereby avoiding the generation of EXB drift.

The tube radial direction component of the electric field is a component in which the electric field acts in the tube radial direction of the fluorescent lamp 4E-1, and is larger than the tube axial direction component of the electric field that acts in the tube axis direction (lamp axis direction) of the fluorescent lamp 4a. Because it is small, EXB drift 1 in fluorescent lamp/Ia
is also small, reducing the number of diffused species in the discharge plasma.

For this reason, an increase in the lamp voltage of the fluorescent lamp 4a is suppressed to a small extent. Therefore, it is possible to prevent the lamp voltage of the fluorescent lamp 4a while it is being lit from rising too high to cause the fluorescent lamp 4a to go out.

Figure 4 shows the relationship between the lamp voltage V of each fluorescent lamp 4a, such as magnetic JJj B, and the magnetic field B applied to the fluorescent lamp 4a parallel to its lamp axis, as shown by the characteristic line ■ in the figure. When applied, the magnetic field B
This shows that the increase in the lamp voltage V1- is suppressed to a small extent compared to the case where the lamp '1111+ is applied in the vertical direction.

FIG. 3 shows an embodiment in which the third invention is applied to a fluorescent lamp 11, and the fluorescent lamp 11 of this embodiment is the same as that of the first and second inventions shown in FIGS. The structure is almost the same as that of the fluorescent lamp/Ia of the embodiment, but the difference is that the outer periphery of the left and right tube ends that stop the left and right pair of electrodes 12a and 12b, respectively, is made of iron or permalloy. A pair of left and right magnetic shields such as vJ13a, 13
B and J: are respectively covered points.

That is, the magnetic shields U13a, 13b are formed, for example, in a double cylindrical shape, and are fitted and fixed to the outer periphery of the pair of left and right tube ends of the fluorescent lamp 11, and each negative 1- generated around the pair of electrodes 12a, 12b. From the glows 14a, 14b, these glows 148. The outer periphery up to each Faraday dark area 16a, 16b generated between 11b and the positive column 15 is coated.

Therefore, in this embodiment, the outer periphery of the pair of left and right extreme parts where the pair of electrode parts 12a, 12b of the fluorescent lamp 11 are arranged is covered from each negative glow 14a, 14b to each Faraday dark part 16a, 16b. Therefore, the electrode part 12a,
12t) The magnetic field B applied to the magnetic shielding material 13a,
13b, it is almost shielded.

For this reason, when a magnetic field B is applied to the fluorescent lamp 11,
Regardless of whether the direction of the magnetic field B is parallel or perpendicular to the lamp axis, the lamp voltage V of the fluorescent lamp 11 is determined by the characteristic line
or ■V, the magnetic field B changes as shown in the fluorescent lamp 4a.
, the characteristic line when applied parallel to the lamp axis■
It is possible to suppress the increase in the lamp voltage V to a smaller amount than the lamp voltage V shown by ]-. In addition, in Figure 3, the middle mark ゛
No. 17 is a fluorescent film.

Furthermore, from each end of the fluorescent lamp 11, each Faraday dark area 16 is
The length from a to 16b is, for example, 50 to 60 am 11
Furthermore, since the areas from each end of the fluorescent lamp 17 to the Faraday dark areas 16a and 16b have lower luminous efficiency than the positive column area, the magnetic shielding materials 13a and 13
Even if it is coated with b, it is difficult to significantly reduce the light emission of the fluorescent lamp 11. Note that the magnetic shielding material 13a',
13b is inside the glass bulb of the fluorescent lamp 11. The outer circumference of the pair of electrodes 12a and 12b is a Faraday dark area 16a,
Therefore, according to the present embodiment, the increase in the lamp voltage V of the fluorescent lamp 11 can be changed to the first and second portions shown in FIGS. 1 and 2.
The increase in the lamp voltage V1 of the fluorescent lamp 4a according to the embodiment of the present invention can be suppressed to a much smaller extent than the increase in voltage V1, and the startability of the fluorescent lamp 11 can be improved, and the lamp voltage V1 can be stabilized. Therefore, it is possible to prevent the fluorescent lamp 11 from going out while it is being lit.

Although the fluorescent lamps 4a and 11 have been described as discharge lamp devices in each of the embodiments of the first to third inventions, the first to third inventions of the present invention are not limited to these, and can be applied to discharge lamp devices in general. It can be applied to

〔Effect of the invention〕

In the above-described first and second inventions, the magnetic field generation source and the discharge lamp of the discharge lamp device are arranged so that the direction of the magnetic field and the lamp axis are parallel to each other, so that the discharge lamp It is possible to improve the startability of the discharge lamp by reducing the diffusion loss of the plasma inside the discharge lamp and by suppressing the rise in lamp voltage to a small extent.

Further, since the increase in lamp voltage can be suppressed to a small extent, the lamp voltage can be stabilized, and it is possible to prevent the discharge lamp from going out during lighting.

Further, in the third aspect of the invention, the outer periphery of the pair of electrode parts of the discharge lamp of the discharge lamp device is coated with a magnetic shield up to the Faraday dark area, so that the magnetic field applied to these pairs of electrode parts can be shielded.

Therefore, the increase in lamp voltage of the discharge lamp due to the magnetic field can be suppressed to a much smaller extent, so that the startability of the discharge lamp can be improved. In addition, since the -IX field of the lamp voltage of the discharge lamp can be suppressed to a smaller extent and stabilized, it is possible to prevent the discharge lamp from going out during lighting.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the discharge lamp illumination system and the method of arranging the magnetic field generation source according to the first and second inventions of the present invention, partially in longitudinal section - a first view, and FIG. The right side view and FIG. 3 are longitudinal sectional views of essential parts of the discharge lamp device according to the third invention of the present invention, and FIG. 4 shows the changes in lamp market pressure with respect to the magnetic field of each embodiment of the first to third inventions. The graphs shown respectively, Fig. 5 is a schematic diagram explaining ExB drift 1-, and Fig. 6 is a schematic diagram explaining ExB drift 1-.
FIG. 7 is a schematic diagram showing the diffusion loss due to the EXB drift of ions, and FIG. 7 is a graph showing the plasma density and potential distribution of a fluorescent lamp. 1...Nuclear magnetic resonance diagnostic device (magnetic field generation source), 4...
Fluorescent lamp device, 48.11...Fluorescent lamp, 12a. 12b... Electrode, 13a, 13b... Magnetic shield shrine, 14a, 14b... Negative glow, 15... Positive column, 16a, 16b... Faraday dark area. Applicant's agent Hisashi Hatano 〉 〉 Figure 6

Claims (1)

[Claims] 1. A discharge lamp of a discharge lamp device installed in the magnetic field of a magnetic field generation source is arranged so that its lamp axis is substantially parallel to the direction of the magnetic field of the magnetic field generation source. Features a fluorescent lighting system. 2. A method for arranging a magnetic field source, which comprises arranging the magnetic field source so that the direction of the magnetic field is approximately parallel to the lamp axis of a discharge lamp of a discharge lamp device installed in the magnetic field. 3. A discharge lamp device characterized in that the pair of electrodes of the discharge lamp and the outer periphery from each negative glow to each Faraday dark area are covered with a magnetic shielding material.