接地面上の円柱電荷による電位と電界の計算

(1)

ធ࿾㕙਄ߩ౞ᩇ㔚⩄ߦࠃࠆ㔚૏ߣ㔚⇇ߩ⸘▚

ᵻ ㊁ ๺ ବ

㧖,1

㧘↰ ᧛ ⵨ ਯ

㧖㧖,2

㧘᧻ ේ ⟤ ਯ

㧖㧖,3

㧔2006 ᐕ 6 ᦬ 30 ᣣฃઃ; 2006 ᐕ 11 ᦬ 13 ᣣฃℂ㧕

Field Distribution along the Center Axis of Space Charge Cylinder

Placed on a Grounded Plate

Kazutoshi ASANO

,*,1

Hiroyuki TAMURA

_**,2

and Yoshiyuki MATSUBARA

_**,3

(Received June 30, 2006; Accepted November 13, 2006)

Due to the big earthquake which occurred in September 2003 at Hokkaido, Japan, two oil tanks were burned and

completely destroyed. One of them is a crude oil tank and the other is a naphtha tank. According to the report of

the fire disaster investigation team, there is a possible cause of the ignition of oil with electrostatic discharge. From

the cracked pipe, crude oil was splashed upward and burned by forming a space charge cloud. The question arisen

was that the field strength due to such space charge could initiate the ignitable discharge. Since there is no suitable

model to calculate potential and electric field, a simple model with finite height of cylindrical charge and image charge

was made. Since our interest is concentrated on the potential and field at z axis, theoretical calculation is

straightforward. Theoretically derived result showed a very simple form of electric field at the ground plate, from

which the possibility of discharge could be estimated.

1. ߪߓ߼ߦ ᐕ ᦬ ᣣߦ⊒↢ߒߚචൎᴒ࿾㔡ߦࠃࠅർᶏ㆏⧴ዊ ’Ꮢߩ♖ᴤᚲߦ޽ࠆේᴤ࠲ࡦࠢߣ࠽ࡈࠨ࠲ࡦࠢ߇Ἳ਄ߒᄢ߈ ߥⵍኂࠍ߽ߚࠄߒߚ_{㧚␠ળ⊛ߦ㊀ᄢߥᓇ㗀ࠍ෸߷ߔἫἴߢ} ޽ߞߚߎߣ߆ࠄ㧘⁛┙ⴕ᡽ᴺੱᶖ㒐⎇ⓥᚲߦේ࿃ⓥ᣿ߩߚ߼ ߩኾ㐷ኅߦࠃࠆᆔຬળ߇⸳⟎ߐࠇࠆߎߣߣߥߞߚ㧚ߘߩ⺞ᩏ Ბ㓏ߢ㧘ේᴤ࠲ࡦࠢἫἴߦ㑐ߒߡ⠨߃ࠄࠇࠆ⌕Ἣේ࿃ߣߒߡ ޟේᴤߩ㈩▤⎕៊ㇱ߆ࠄߩྃ಴ߦࠃࠆᏪ㔚ޠ߇޽ߍࠄࠇ㧘ޟࡄ ࠗࡊߩ੉ⵚ㕙߆ࠄ਄ᣇ߳ྃ಴ߒߚᏪ㔚ේᴤߩᏪ㔚㔕ߦࠃࠆ㔚 ⇇߇᡼㔚⌕Ἣࠍᒁ߈⿠ߎߒ߁ࠆ߆ุ߆ޠߦߟ޿ߡ⸃ᨆߔࠆᔅ ⷐ߇޽ߞߚ㧚ᆔຬળߢߩ੐᡿ේ࿃ߩⓥ᣿ߦ޽ߚߞߡߪ㧘ࠟ࠙ ࠬߩቯℂࠍᔕ↪ߒ㧘৻᭽ߦᏪ㔚ߒߚ⃿ᒻߩ㔚⩄㔕߇ᒻᚑߔࠆ 㕒㔚႐ߦ㑐ߒߡ⸃ᨆ⊛ߦ⸘▚ߒߡ⚿⺰ࠍዉ޿ߚ_{㧚ធ࿾㕙߆} ࠄ㆙޿ਛⓨߦᶋ޿ߚ⃿⁁㔚⩄ߢࡕ࠺࡞ൻߔࠆߣ⸘▚♖ᐲ߇㜞 ߊߪߥ޿߇㧘৻ᣇߢ㧘Ყセ⊛ታ㓙ߩ㈩⟎ߦㄭ޿ᒻ⁁ߣ⠨߃ࠄ ࠇࠆ᦭㒢㐳౞ᩇ㔚⩄ߢࡕ࠺࡞ൻߔࠆߣ⸃ᨆ⸃߇㕖Ᏹߦා੺ߥ ߽ߩߣߥࠆ߆ࠄߢ޽ࠅ_{㧘ᤨ㑆⊛ߥ೙⚂ߩਛߢ⃻ታ⊛ߥㄭૃ} ࡕ࠺࡞ߣߒߡ⃿ᒻߩ㔚⩄㔕ࡕ࠺࡞ࠍណ↪ߒߚ㧚 ߘߩᓟ㧘⋥ᓘ ࠗࡦ࠴ߩ㊄ዻࡄࠗࡊߣᄢ࿾߇ធ࿾㕙ࠍᒻᚑ ߒߡ޿ࠆታ㓙ߩ⁁ᴫߦࠃࠅᒻ⁁߇ㄭ޿࿑㧝ߦ␜ߔࠃ߁ߥඨᓘ R 㧘㜞ߐ Z ߩ৻᭽ߥ㔚⩄ኒᐲǹߩ౞ᩇ⁁ⓨ㑆㔚⩄߇ធ࿾㕙਄ ߦ⟎߆ࠇߚ႐วߦᒻᚑߐࠇࠆ㕒㔚႐ߦߟ޿ߡ㧘⸃ᨆ⊛ߥ⸃߇ ࠠ࡯ࡢ࡯࠼㧦౞ᩇ㔚⩄㧘ⓨ㑆㔚⩄㧘࠲ࡦࠢἫἴ㧘㔚⇇㔚૏⸘ ▚㧘ᓇ௝㔚⩄ * ጊᒻᄢቇฬ⹷ᢎ᝼㧔300-0523 ⨙ၔ⋵ⒷᢝᏒᤨፒ 997-10㧕 997-10, Tokisaki, Inashiki-shi, Ibaraki 3000523, Japan

** ᶖ㒐ᐡᶖ㒐ᄢቇᩞᶖ㒐⎇ⓥ࠮ࡦ࠲࡯㧔182-8508 ᧲੩ㇺ⺞Ꮣ Ꮢᷓᄢኹ᧲↸4-35-3㧕

National Research Institute of Fire and Disaster Japan, 4-35-3, Jindaiji-higashimachi, Chofu, Tokyo 1828508, Japan

1_{asanokz2003@ybb.ne.jp} 2_{tamura@fri.go.jp} 3_{matsu@fri.go.jp}

࿑㧝 ធ࿾㕙਄ߩ౞ᩇ⁁ⓨ㑆㔚⩄

Fig.1 The space charge cylinder placed on a grounded plate.

㫑

㪩

㪱

㫑

㪩

㪱

5RCEG EJCTIG E[NKPFGT )TQWPFGF RNCVG +OCIG EJCTIG , 30, 6 (2006) 291 296 J. Inst. Electrostat. Jpn.

(2)

᳞߹ࠄߥ޿߆ߦߟ޿ߡᬌ⸛ߒߡߺߚߣߎࠈ㧘᡼㔚⊒↢ࠍ⹏ଔ ߔࠆ਄ߢ㊀ⷐߥਛᔃゲ਄ߩ㔚૏ߣ㔚⇇ᒝᐲߦߟ޿ߡߪᲧセ⊛ ◲නߥ⸃ߢ⴫ߖࠆߎߣ߇ಽ߆ߞߚ㧚 ৻᭽ߥ㔚⩄ኒᐲߩ౞ᩇ໧㗴ߪゲኻ⒓໧㗴ߣ⠨߃ࠆߎߣ߇಴ ᧪㧘࡝ࡦࠣ㔚⩄ߦࠃࠆ㔚⇇ߩ৻⥸⊛ߥ⸃ߪᬦ౞㑐ᢙߣߥࠆߎ ߣ߇⍮ࠄࠇߡ߅ࠅ㧕_{㧘◲නߥᑼߣߪߥࠄߥ޿߇㧘੹࿁ߩ໧㗴} ߪ৻⥸⊛ߥ㔚૏㧘㔚⇇ࠃࠅ߽ਛᔃゲ਄ߩ㔚૏ߣ㔚⇇ᒝᐲ߇㊀ ⷐߢ޽ࠆߎߣ߆ࠄ㧘ߘߩὐߦ⌕⋡ߒߡ⸃ࠍ⸃ᨆ⊛ߦ᳞߼ߚ߽ ߩߢ޽ࠆ㧚ߥ߅㧘ធ࿾㕙ࠍᒻᚑߔࠆߚ߼ߦᓇ௝㔚⩄߽⠨ᘦߒ ߡ⸘▚ࠍታᣉߒߡ޿ࠆ㧚 2. ⸘▚ߩᚻᴺ ၮᧄේℂߪᓸዊ㔚⩄ߦࠃߞߡ↢ߕࠆⓨ㑆ߩ㔚૏ࠍၮߦߒߡ 㔚⩄ో૕ߦᷰߞߡⓍಽߔࠆߛߌߢ޽ࠆ߇㧘㧟ᰴరⓍಽߥߩߢ ߘࠇ⒟◲නߢߪߥ޿㧚࿑㧞ߪᓸዊ㔚⩄ߣ᷹ⷰὐz ߣߩ㑐ଥࠍ ⴫ߒߡ޿ࠆ㧚౞╴ᐳᮡ♽ࠍ↪޿ࠆߩߢ⁛┙ᄌᢙߪr ,

\

, z ߢ ޽ࠆ㧚ߎߩr ߪ᳓ᐔᣇะߦߩߺᄌൻߔࠆ߽ߩߢ㧘⃿ᐳᮡߩ r ߣ ߪᗧ๧߇⇣ߥࠆ㧚౞╴ᐳᮡ♽ߢߪǹࠍ↪޿ࠆߎߣ߇ᄙ޿߇6) 㧘 ߎߎߢߪ㔚⩄ኒᐲߦǹࠍ↪޿ࠆߚ߼㧘޽߃ߡr ࠍ↪޿ࠆߎߣ ߦߒߚ㧚ߒ߆ߒ㧘࿑ߩr1ߣr2ߪ৻⥸⊛ߥᗧ๧ߦ↪޿ࠄࠇߡ ޿ߡ㧘㧟ᰴర⊛ߦᄌൻߔࠆ߽ߩߢ޽ࠆ㧚 ᷹ⷰὐࠍ৻⥸ᐳᮡr ,

\

, z ߢ⴫ߔߩߢ㧘࠰࡯ࠬߣߒߡߩᓸ ዊ㔚⩄ߩ૏⟎ߪrc , \c , zc ߣࡊ࡜ࠗࡓࠍઃߌߡ⴫ߔ㧚᷹ⷰὐ ߣ㔚⩄ߩ૏⟎ߣߩ㑐ଥߪᰴᑼߢ⴫ߐࠇࠆ㧚r1ߪᓸዊ㔚⩄ߣߩ 〒㔌㧘r2ߪᓇ௝㔚⩄ߣߩ〒㔌ߢ޽ࠆ㧚 (1) (2) ᷹ⷰὐz ὐߩ㔚૏ߪ㧘ᓸዊ㔚⩄㧔⌀㔚⩄㧕ߣߘߩᓇ௝㔚⩄߆ ࠄᰴᑼߩࠃ߁ߦ᳞߼ࠄࠇࠆ㧚ฝㄝ╙㧝㗄ߪ⌀㔚⩄ߩᓇ㗀ࠍ㧘 ฝㄝ╙㧞㗄ߪᓇ௝㔚⩄ߩᓇ㗀ࠍ⴫ߔ㧚 (3) ߎߎߢߪz ゲ਄ߩ㔚૏㧘㔚⇇ᒝᐲߩߺࠍ᳞߼ࠆߩߢ㧘ゲኻ⒓ ໧㗴ߣߥࠅⷺᐲߩᓇ㗀߇ήߊߥࠆ㧚ߘߎߢ

\

cߦߟ޿ߡ৻๟ ߦᷰߞߡⓍಽߔࠆߣ㧞Ǹߣߥࠆ㧚 (4) ᰴߦrc ߦߟ޿ߡⓍಽߔࠆߩߢ㧘㧔4㧕ᑼࠍᰴߩࠃ߁ߦᦠ߈឵߃ ߡ߅ߊ㧚 (5) ߹ߕpaߦߟ޿ߡⓍಽߔࠆ㧚 (6) ߎߩᑼࠍzc ߢߐࠄߦⓍಽߔࠆ㧚 (7) pbߪᰴߩࠃ߁ߦ᳞߹ࠆ㧚

³³³

2 0 1 0 4 ' ' ' ' 4 ' ' ' ' r dz dr d r r dz dr d r

SH

\

U

SH

\

U

I

³³

2 0 1 0 2 ' ' ' 2' ' ' r dz dr r r dz dr r

H

U

H

U

I

2 2 2

(

z

)'

r

'

r

2 2 1

(

z

)'

r

'

r

³

' 2 ' 2 ' )' ( ' ' ' 2 ' )' ( ' ' ' 2 0 0 2 2 0 2 2 0 dz p dz p r z z dr r dz r z z dr r dz b a

H

U

H

U

H

U

H

U

I

' )' ( ' )' ( ' )' ( ' ' 2 2 0 2 2 0 2 2 z z R z z r z z r z z dr r pa R R

³

㫏

㫑

㫐

㪩

㪱

1DUGTXKPI RQKPV

㫉㵭

㱄

㱄㵭

㵭

㫑㵭

㫉

_㪈

㫉

_㪉

㫑

㫏

㫑

㫐

㪩

㪱

1DUGTXKPI RQKPV

㫉㵭

㱄

㱄㵭

㵭

㫑㵭

㫉

_㪈

㫉

_㪉

㫑

࿑㧞 ᓸዊ㔚⩄ߣ᷹ⷰὐߩ㑐ଥ

Fig.2 Relative position between observing point and charge elements.

>

@

) ) ( ) ( ln ) ( ) ( ( 2 1 ' )' ( ' )' ( ' 2 2 2 2 2 2 2 2 2 0 0 2 2 0 2 2 Z z Z z z z R Z z Z z R z z R R Z z Z z R z z dz z z z d R z z dz z z R z z dz p Z Z Z a c c c

³

(3)

(8) ߎߩᑼߩⓍಽߪා੺ߥߩߢ㧘ੑߟߩ㗄ߦಽߌߡⓍಽߔࠆ㧚 (9) ╙㧞㗄ߩⓍಽߪz ߩ૏⟎ߦࠃߞߡᰴߩ㧟ᑼߦಽ߆ࠇࠆ㧚 (10) ⚿ዪpbࠍⓍಽߒߚ߽ߩߪᰴߩࠃ߁ߦߥࠆ㧚 (11) ో૕ߩ㔚૏ߪ㧔7㧕ᑼ߆ࠄ㧔11㧕ᑼࠍᒁߊߎߣߦࠃߞߡ᳞߹ࠆ ߇㧘㧔5㧕ᑼߩ㔚૏ࠍᰴߩࠃ߁ߦၮḰൻߒߡ߅ߊ㧚 (12) ੹߹ߢߩ⸘▚⚿ᨐࠍߔߴߡߎߩᑼߦઍ౉ߔࠆߣ㧘ၮḰൻߐࠇ ߚ㔚૏ߪᰴߩࠃ߁ߦ⴫ߐࠇࠆ㧚 (13) ߎߩᑼߪ߽߁ዋߒᢛℂߢ߈ࠆ߇㧘ᢛℂߒߡ߽ߘࠇ⒟ߩࡔ࡝࠶ ࠻߇ή޿ߩߢߎߩ߹߹૶↪ߔࠆ㧚 ᰴߦz ゲ਄ߩ㔚⇇ᒝᐲࠍ᳞߼ࠆ㧚㔚⇇ᒝᐲߪ㔚૏ࠍ z ߢ஍ ᓸಽࠍߒߚᓟ㧘ࡑࠗ࠽ࠬ╓ภࠍઃߌࠆ߇㧘ၮḰൻ㔚⇇ߪߣࠅ ޽߃ߕࡑࠗ࠽ࠬ╓ภࠍήⷞߔࠆ㧚 (14) ᦨ߽⥝๧ߩ޽ࠆㇱಽߪធ࿾㕙㧘ߔߥࠊߜz 㧩㧜ߢߩ㔚⇇ᒝ ᐲߢ޽ࠆ㧚 (15) ߎߩ᭽ߦធ࿾㕙ߢߩ㔚⇇ᒝᐲߪ㕖Ᏹߦ◲නߥᑼߣߥࠆ㧚 (16) d c R R b P P z z R z z r z z r z z dr r p

³

' )' ( ' )' ( ' )' ( ' ' 2 2 0 2 2 0 2 2 ) ) ( ln ) ( ) ( ( 2 1 ' )' ( ' 2 2 2 2 2 2 2 2 2 0 2 2 R Z z Z z R z z R R Z z Z z R z z dz R z z dz Pc Z

³

° ° ¿ °° ¾ ½ ° ° ¯ °° ®

³

z Z z Z z Z Z z Z z Z z Z z Z dz Pd 0 2 0 2 2 ' 2 2 2 2 ° ° ¿ °° ¾ ½ ° ° ¯ °° ®

³

z Z z Z z Z Z z Z z Z z Z z Z R Z z Z z R z z R R Z z Z z R z z dz pb 0 2 0 2 2 ) ) ( ln ) ( ) ( ( 2 1 ' 2 2 2 2 2 2 2 2 2 2 2 2 2

³

' ' 2 ' 0 _p _dz _p _dz b a

U

I

H

I

° ° ¿ °° ¾ ½ ° ° ¯ °° ® z Z z Z z Z Z z Z z Z z Z z Z R Z z Z z R z z R R Z z Z z 0 2 0 2 2 ) ) ( ln ) ( ) ( 2 2 2 2 2 2 2 2 2 2 2 ° ¿ ° ¾ ½ ° ¯ ° ® ¸ ¸ ¹ · ¨ ¨ © § w w w w z Z z Z Z z Z z Z R Z z R z R Z z R R Z z Z z R z z z Z z Z z R Z z Z z z z E 0 0 2 ) ( 1 2 ) ( 1 ) ( ) ( 2 ) ( ) ( ) ( ) ( 2 ' ' 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 0

I

U

H

I

) ( 2 2 2 2 2 2 2 ' 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 0 R Z R Z Z R Z R R R Z Z Z Z R Z R R R Z Z Z Z z _z ¸ ¸ ¹ · ¨ ¨ © § w w

I

)

(

)

(

2

2 '

2

2 2 0 2 2 0 0 0 0

R

Z

R

Z

R

Z

R

Z

z

E

z z

w

H

U

H

U

I

H

U

I

2 2 2 2 2 2 2 2 2 2 2 ( 2 1 ) ) ( ) ( ln ) ( ) ( ( 2 1 ' R z z Z z Z z z z R Z z Z z R z z R R Z z Z z R z z

I

293 (49)

(4)

- 4 - 3. ⚿ᨐߩᢙ୯⊛ᬌ⸛ ߎࠇࠄߩ⸃߇z ゲ਄ߢߤߩࠃ߁ߥᄌൻࠍ␜ߔ߆ߪ㧘ߎࠇࠄ ߩᑼߦታ㓙ߩᢙ୯ࠍ౉ࠇߡ⸘▚ߔࠆᔅⷐ߇޽ࠆ߇㧘߆ߥࠅᾘ 㔀ߥ⸘▚ߣߥࠆ㧚ᚻߞขࠅᣧ޿ᣇᴺߪMathematica ߩࠃ߁ߥ ⸘▚࠰ࡈ࠻ࠍ↪޿ࠆߎߣߢ޽ࠆ߇㧘޽߹ࠅ৻⥸⊛ߢߥ޿ߩߢ Excel ߦࠃࠆ⸃ᴺࠍ␜ߔ㧚Excel ߦࠃࠆታ㓙ߩ⸘▚ߩ߿ࠅᣇߦ ߟ޿ߡߪઃ㍳ߦ␜ߔ㧚 ᢙ୯⸘▚ࠍߔࠆߚ߼ߦߪ߽߁ዋߒၮḰൻߒߚᣇ߇߿ࠅ߿ߔ ޿㧚౞ᩇߩ㜞ߐZ ߢz ߣ R ࠍၮḰൻߔࠆ㧚 (17) (18) ߐࠄߦ㔚૏ࠍၮḰൻߒߚᑼࠍਅ⸥ߦ␜ߔ㧚 (19) ታ㓙ߩ㔚૏ߣၮḰൻ㔚૏ߩ㑆ߦߪᰴߩࠃ߁ߥ㑐ଥ߇޽ࠆ㧚 (20) ౞ᩇߩ㜞ߐߣඨᓘ߇╬ߒ޿႐ว㧘ߔߥࠊߜR~ 㧩㧝ߩᤨ㧘ၮ Ḱൻ㔚૏ߦߟ޿ߡ⸘▚ߒߚ߽ߩࠍ࿑㧟ߦ␜ߔ㧚࿑㧟ߪ㧔19㧕 ᑼࠍ⸘▚ߒߚ߽ߩߢz ゲ਄ߢߩ㔚૏ಽᏓࠍ⴫ߔ㧚 ᮮゲ߇ၮḰൻߐࠇߚz ᣇะߢ㧘❑ゲ߇ၮḰൻ㔚૏ߢ޽ࠆ㧚 ߎߩ࿑ߢಽ߆ࠆࠃ߁ߦᦨᄢ㔚૏ߪ౞ᩇౝߢ㧘ߘߩᦨᄢ㔚૏ߪ ౞ᩇߩ0.7 ૏ߩߣߎࠈߦ޽ࠆ㧚 ၮḰൻߐࠇߚ㔚⇇ᒝᐲߩᑼߪᰴߩࠃ߁ߦᢛℂߐࠇࠆ㧚 (21) ߎߩၮḰൻ㔚⇇ߣታ㓙ߩ㔚⇇ߣߪᰴߩࠃ߁ߥ㑐ଥ߇޽ࠆ㧚 (22) ࿑㧠ߪ㧔21㧕ᑼࠍ߽ߣߦ⸘▚ߒߚ߽ߩߢz ゲ਄ߩ㔚⇇ᒝᐲಽ 2 2 2 2 2 2 2 2 2

~

)

1 ~

(

)

1 ~

(

~

2 ~

~

)

1 ~

(

)

1 ~

(

~

)

1 ~

(

)

1 ~

(

2

1 '

~

R

z

R

z

R

z

Z

I

H

U

I

~

2

₀ 2

Z

° ¿ ° ¾ ½ ° ¯ ° ® ¸ ¸ ¹ · ¨ ¨ © § w w z z z z R z R z R z R R z z R z z z z z R z z z Z Z E E ~ 0 1 0 ~ 1 1 ~ 2 1 ~ 1 ~ ) 1 ~ ( 1 ~ ~ 2 ~ ) 1 ~ ( 1 ~ ~ ) 1 ~ ( ) 1 ~ ( ~ ~ ~ 2 ~ ) 1 ~ ( ) 1 ~ ( ~ ) 1 ~ ( ) 1 ~ ( ~ 2 ' ~ 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 0 I U H

E

Z

z

Z

z

E

~

2 ~

~

2

2 ~

~

0 0 2 0 2

H

U

I

H

U

H

I

U

I

w

°

¿

°°

¾

½

°

¯

°°

®

d

z

R

z

R

z

R

z

R

z

R

~

0 ~

2

1

0 ~

1

2

1 ~

~

1 ~

~

2

1 )

~

)

1 ~

(

1 ~

~

ln

~

)

1 ~

(

1 ~

~

ln

~

2 2 2 2 2 2 2 2 2 2 2

㪄㪇㪅㪌

㪄㪇㪅㪋

㪄㪇㪅㪊

㪄㪇㪅㪉

㪄㪇㪅㪈

㪇

㪇㪅㪈

㪇㪅㪉

㪇㪅㪊

㪇㪅㪋

㪇㪅㪌

㪄㪊

㪄㪉

㪄㪈

㪇

㪈

㪉

㪊

࿑㧟㨆ゲ਄ߩၮḰൻ㔚૏ಽᏓߩᒻ⁁

Fig.3 Profile of the normalized potential distribution on Z-axis. 0QTOCNK\GF RQVGPVKCN 0QTOCNK\GF JGKIJV ࿑㧠㨆ゲ਄ߩၮḰൻ㔚⇇ᒝᐲಽᏓ

Fig.4 Distribution of the normalized electric field strength on Z-axis.

㪄㪇㪅㪌

㪄㪇㪅㪉㪌

㪇

㪇㪅㪉㪌

㪇㪅㪌

㪇㪅㪎㪌

㪈

㪈㪅㪉㪌

㪄㪊

㪄㪉

㪄㪈

㪇

㪈

㪉

㪊

0QTOCNK\GF JGKIJV 0QTOCNK\GFHKGNF UVTGPIVJ Z z z / ~ Z R R~ / z~ z~ I~ E~

(5)

- 5 - Ꮣࠍ⴫ߔ㧚ᮮゲߪၮḰൻߐࠇߚz ߩ୯ߢ㧘❑ゲ߇ၮḰൻ㔚⇇ ᒝᐲࠍ⴫ߒߡ޿ࠆ㧚೨ㅀߒߚࠃ߁ߦᦨ㜞㔚૏ߩὐ㧘ߔߥࠊߜ 㔚⇇ᒝᐲ㧜ߩὐߪ౞ᩇߩ㜞ߐߩ⚂0.7 ߩ૏⟎ߦ޽ࠆ㧚 4. ታ㓙ߩ໧㗴߳ߩㆡ↪଀ ੉ⵚࡄࠗࡊ߆ࠄ਄ᣇ߳ྃ಴ߒߚේᴤᓸ☸ሶ߇Ꮺ㔚㔕ࠍ૞ࠆ ႐วߦߟ޿ߡߩࡕ࠺࡞ൻ߇ߎߩ⸘▚ߩ⋡⊛ߩ৻ߟߢ޽ߞߚߩ ߢ㧘ታ㓙ߩᢙ୯ࠍ౉ࠇߡ࿾ᐔ㕙ߢߩ㔚⇇ᒝᐲࠍផቯߔࠆ㧚 ႎ๔ᦠߩ౮⌀ߦࠃࠆߣࡄࠗࡊ߆ࠄߩἫἻߩ⋥ᓘߪ 14㨪 15㨙㧘㜞ߐߪ 40㨪50㨙ߢ޽ࠆ㧚৻ᔕඨᓘ㧣㨙㧘㜞ߐ 45㨙ߣߔ ࠆ㧚㔚⩄ኒᐲߦߟ޿ߡߪ࠺࡯࠲߇ή޿ߩߢ㧘ផቯ୯ߣߒߡ⺞ ᩏᆔຬળႎ๔ᦠߩᢙሼ10-8_C/m3_{ࠍ↪޿ࠆ㧚}_{ߎࠇࠄߩ୯ࠍ} 㧔16㧕ᑼߦઍ౉ߔࠆ㧚㧱㧩10-8_C/m3_{(45+7-45.5) / (8.8510}-12₎ 㧩0.73104_V/m ߎߩ㔚⩄ኒᐲߢ⷗ࠆ㒢ࠅߪ㧘㔚⩄㔕ߩᒻ⁁ࠍࠃࠅ⃻ታߦㄭ ߠߌߚࡕ࠺࡞ߦࠃࠆ㕒㔚႐⸘▚ߦࠃߞߡ߽㧘᡼㔚ߦࠃࠆ⌕Ἣ ߩน⢻ᕈߪ⪺ߒߊૐ޿ߣ⸒߃ߘ߁ߢ޽ࠆ㧚ߥ߅㧘੹࿁ߩࡕ࠺ ࡞ൻߢߪࡄࠗࡊߩᦛ₸ࠍ߹ߞߚߊήⷞߒߡ޿ࠆ߇㧘ᦛ₸ࠍ߽ ߞߚធ࿾㕙ߢߪ߽߁ዋߒ᭽ሶ߇⇣ߥࠆߣᕁࠊࠇ㧘ߐࠄߦ⎇ⓥ ߩ૛࿾߇޽ࠆ㧚 ෳ⠨ᢥ₂ 1) චൎᴒ࿾㔡⸥㍳✬㓸ᆔຬળ✬㧦ޟᐔᚑ 15 ᐕ㧔2003 ᐕ㧕ච ൎᴒ࿾㔡⸥㍳ޠᶖ㒐⎇ⓥᚲ㧔2004.9㧕 2) ⮮↰ᐢ৻㧦㔚⏛᳇ቇࡁ࡯࠻㧘p44㧘ࠦࡠ࠽␠(1971) 3) ᵻ㊁๺ବ㧦㕒㔚᳇ቇળ⹹ 11, 1 (1987) 47-53 4) ᵻ㊁๺ବ㧦㕒㔚᳇ቇળ⹹ 11, 2 (1987) 126-133 5) 㕒㔚᳇ቇળ✬㧦㕒㔚᳇ࡂࡦ࠼ࡉ࠶ࠢ㧘p.1002㧘ࠝ࡯ࡓ␠ (1998)

6) M. Zahn: “Electromagnetic field theory”, Chap. 1, R.E.Kri eger Pub., Malabar, Florida, USA (1987)

ઃ㍳ ࠛࠢ࠮࡞ߦࠃࠆ⸘▚ߩ߿ࠅᣇ 㔚૏⸘▚߽㧘㔚⇇ᒝᐲ⸘▚߽ߤߜࠄ߽ห᭽ߦ಴᧪ࠆ߇㧘ߎ ߎߢߪ㔚⇇ᒝᐲ⸘▚ࠍ଀ߣߒߡ⸘▚ߩ߿ࠅᣇࠍ␜ߔ㧚࿑5 ߪ ߘߩ⸘▚ࠍⴕߞߚ⴫ߩ৻ㇱߢ޽ࠆ㧚㧔21㧕ᑼߩฦ㗄ࠍߘࠇߙࠇ ߩ೉ߦ޿ࠇ㧘z~ ࠍᄌൻߐߖߡߘࠇߙࠇߩ೉ࠍ⸘▚ߔࠆ㧚 z~ ߪ ⸘▚ߒߚ޿▸࿐ߦᄌൻߐߖࠆᔅⷐ߇޽ࠆߎߣߣ㧘ࠣ࡜ࡈൻߒ ߚߣ߈ߦߤߩ⒟ᐲߩ♖ᐲ߇ᔅⷐ߆ߢᄌൻߩഀว߇㆑ߞߡߊࠆ㧚 ߎߎߢߪz~ ࠍ-3߆ࠄ+3߹ߢᄌൻߐߖ㧘ో૕ࠍ60ಽഀߦߒߚ㧚 ߔߥࠊߜ0.1 ߕߟߩᄌൻߢ޽ࠆ㧚ߎߩ z~ ߪ㧰೉ߦ౉ߞߡ޿ ࠆ߇㧯೉ߩᢙሼࠍరߦߒߡ⸘▚ߒߚ߽ߩߢ޽ࠆ㧚⋧ኻඨᓘߪ 㧮೉ߩ㧞ߦ౉ߞߡ޿ࠆ㧚㪚㪛㪜㪝㪞㪟㪠㪡㪢㪣㪤㪥㪦㪧㪨㪩㪇㪄㪊㪐㪈㪍㪋㪋㪅㪈㪉㪊㪈㪇㪍㪊㪅㪈㪍㪉㪉㪎㪏㪉㪅㪉㪊㪍㪇㪍㪏㪊㪅㪏㪏㪇㪌㪎㪋㪊㪌㪅㪍㪐㪉㪈㪈㪅㪎㪏㪏㪐㪄㪇㪅㪇㪌㪎㪊㪄㪈㪄㪇㪅㪇㪊㪋㪍㪉㪈㪄㪉㪅㪐㪏㪅㪋㪈㪈㪌㪅㪉㪈㪊㪅㪍㪈㪋㪅㪇㪉㪍㪈㪍㪋㪊㪅㪇㪍㪎㪌㪎㪉㪉㪅㪈㪋㪎㪇㪐㪈㪊㪅㪎㪎㪎㪎㪏㪐㪊㪅㪐㪉㪅㪐㪌㪅㪋㪏㪊㪉㪈㪅㪍㪏㪈㪊㪄㪇㪅㪇㪍㪉㪈㪄㪈㪄㪇㪅㪇㪊㪏㪈㪈㪉㪄㪉㪅㪏㪎㪅㪏㪋㪈㪋㪅㪋㪋㪊㪅㪉㪋㪊㪅㪐㪉㪐㪊㪎㪎㪉㪅㪐㪎㪊㪉㪈㪋㪉㪅㪇㪌㪐㪈㪉㪍㪊㪅㪍㪎㪋㪏㪏㪊㪊㪅㪏㪉㪅㪏㪌㪅㪉㪎㪊㪏㪈㪅㪌㪎㪊㪌㪄㪇㪅㪇㪍㪎㪌㪄㪈㪄㪇㪅㪇㪋㪉㪇㪏㪊㪄㪉㪅㪎㪎㪅㪉㪐㪈㪊㪅㪍㪐㪉㪅㪏㪐㪊㪅㪏㪊㪉㪎㪌㪋㪉㪅㪏㪎㪐㪉㪊㪍㪈㪅㪐㪎㪉㪊㪇㪏㪊㪅㪌㪎㪈㪏㪋㪌㪊㪅㪎㪉㪅㪎㪌㪅㪇㪍㪊㪏㪈㪅㪋㪍㪌㪊㪄㪇㪅㪇㪎㪊㪊㪄㪈㪄㪇㪅㪇㪋㪍㪌㪐㪋㪄㪉㪅㪍㪍㪅㪎㪍㪈㪉㪅㪐㪍㪉㪅㪌㪍㪊㪅㪎㪊㪍㪊㪇㪏㪉㪅㪎㪏㪌㪍㪎㪏㪈㪅㪏㪏㪍㪎㪐㪍㪊㪅㪋㪍㪏㪍㪍㪋㪊㪅㪍㪉㪅㪍㪋㪅㪏㪌㪊㪋㪈㪅㪊㪌㪍㪏㪄㪇㪅㪇㪎㪐㪎㪄㪈㪄㪇㪅㪇㪌㪈㪎㪌㪌㪄㪉㪅㪌㪍㪅㪉㪌㪈㪉㪅㪉㪌㪉㪅㪉㪌㪊㪅㪍㪋㪇㪇㪌㪌㪉㪅㪍㪐㪉㪌㪏㪉㪈㪅㪏㪇㪉㪎㪎㪍㪊㪅㪊㪍㪌㪊㪊㪋㪊㪅㪌㪉㪅㪌㪋㪅㪍㪋㪉㪋㪈㪅㪉㪋㪏㪈㪄㪇㪅㪇㪏㪍㪍㪄㪈㪄㪇㪅㪇㪌㪎㪍㪎㪍㪄㪉㪅㪋㪌㪅㪎㪍㪈㪈㪅㪌㪍㪈㪅㪐㪍㪊㪅㪌㪋㪋㪇㪇㪐㪉㪅㪍㪈㪅㪎㪉㪇㪋㪍㪌㪊㪅㪉㪍㪈㪏㪋㪊㪊㪅㪋㪉㪅㪋㪋㪅㪋㪊㪇㪏㪈㪅㪈㪊㪐㪉㪄㪇㪅㪇㪐㪋㪉㪄㪈㪄㪇㪅㪇㪍㪋㪋㪎㪎㪄㪉㪅㪊㪌㪅㪉㪐㪈㪇㪅㪏㪐㪈㪅㪍㪐㪊㪅㪋㪋㪏㪈㪏㪏㪉㪅㪌㪇㪎㪐㪏㪎㪈㪅㪍㪋㪇㪈㪉㪉㪊㪅㪈㪌㪏㪈㪏㪈㪊㪅㪊㪉㪅㪊㪋㪅㪉㪈㪏㪌㪈㪅㪇㪊㪇㪋㪄㪇㪅㪈㪇㪉㪊㪄㪈㪄㪇㪅㪇㪎㪉㪊㪋㪏㪄㪉㪅㪉㪋㪅㪏㪋㪈㪇㪅㪉㪋㪈㪅㪋㪋㪊㪅㪊㪌㪉㪍㪈㪈㪉㪅㪋㪈㪍㪍㪇㪐㪈㪅㪌㪍㪉㪇㪌㪊㪅㪇㪌㪋㪊㪊㪍㪊㪅㪉㪉㪅㪉㪋㪅㪇㪇㪌㪍㪇㪅㪐㪉㪈㪐㪄㪇㪅㪈㪈㪇㪐㪄㪈㪄㪇㪅㪇㪏㪈㪋㪋㪐㪄㪉㪅㪈㪋㪅㪋㪈㪐㪅㪍㪈㪈㪅㪉㪈㪊㪅㪉㪌㪎㪉㪐㪐㪉㪅㪊㪉㪌㪐㪋㪈㪈㪅㪋㪏㪍㪍㪇㪎㪉㪅㪐㪌㪇㪉㪐㪎㪊㪅㪈㪉㪅㪈㪊㪅㪎㪐㪉㪇㪅㪏㪈㪊㪐㪄㪇㪅㪈㪈㪐㪏㪄㪈㪄㪇㪅㪇㪐㪉㪇㪊㪈㪇㪄㪉㪋㪐㪈㪊㪅㪈㪍㪉㪉㪎㪏㪉㪅㪉㪊㪍㪇㪍㪏㪈㪅㪋㪈㪋㪉㪈㪋㪉㪅㪏㪋㪍㪇㪌㪊㪉㪊㪅㪌㪎㪎㪎㪇㪅㪎㪇㪎㪈㪄㪇㪅㪈㪉㪏㪐㪄㪈㪄㪇㪅㪈㪇㪋㪊㪍㪈㪈㪄㪈㪅㪐㪊㪅㪍㪈㪏㪅㪋㪈㪇㪅㪏㪈㪊㪅㪇㪍㪎㪌㪎㪉㪉㪅㪈㪋㪎㪇㪐㪈㪈㪅㪊㪋㪌㪊㪍㪉㪉㪅㪎㪋㪈㪌㪏㪉㪉㪅㪐㪈㪅㪐㪊㪅㪊㪍㪉㪎㪇㪅㪍㪇㪉㪈㪄㪇㪅㪈㪊㪎㪏㪄㪈㪄㪇㪅㪈㪈㪏㪎㪌㪈㪉㪄㪈㪅㪏㪊㪅㪉㪋㪎㪅㪏㪋㪇㪅㪍㪋㪉㪅㪐㪎㪊㪉㪈㪋㪉㪅㪇㪌㪐㪈㪉㪍㪈㪅㪉㪏㪇㪍㪉㪌㪉㪅㪍㪊㪍㪏㪎㪎㪉㪅㪏㪈㪅㪏㪊㪅㪈㪋㪎㪇㪅㪋㪐㪐㪏㪄㪇㪅㪈㪋㪌㪐㪄㪈㪄㪇㪅㪈㪊㪌㪌㪐㪈㪊㪄㪈㪅㪎㪉㪅㪏㪐㪎㪅㪉㪐㪇㪅㪋㪐㪉㪅㪏㪎㪐㪉㪊㪍㪈㪅㪐㪎㪉㪊㪇㪏㪈㪅㪉㪉㪇㪍㪌㪍㪉㪅㪌㪊㪈㪐㪉㪉㪉㪅㪎㪈㪅㪎㪉㪅㪐㪊㪇㪍㪇㪅㪋㪇㪈㪋㪄㪇㪅㪈㪌㪉㪌㪄㪈㪄㪇㪅㪈㪌㪌㪉㪎㪈㪋㪄㪈㪅㪍㪉㪅㪌㪍㪍㪅㪎㪍㪇㪅㪊㪍㪉㪅㪎㪏㪌㪍㪎㪏㪈㪅㪏㪏㪍㪎㪐㪍㪈㪅㪈㪍㪍㪈㪐㪉㪅㪋㪉㪍㪍㪐㪐㪉㪅㪍㪈㪅㪍㪉㪅㪎㪈㪊㪍㪇㪅㪊㪇㪏㪎㪄㪇㪅㪈㪌㪍㪌㪄㪈㪄㪇㪅㪈㪎㪏㪉㪏㪈㪌㪄㪈㪅㪌㪉㪅㪉㪌㪍㪅㪉㪌㪇㪅㪉㪌㪉㪅㪍㪐㪉㪌㪏㪉㪈㪅㪏㪇㪉㪎㪎㪍㪈㪅㪈㪈㪏㪇㪊㪋㪉㪅㪊㪉㪈㪈㪐㪉㪉㪅㪌㪈㪅㪌㪉㪅㪋㪐㪍㪉㪇㪅㪉㪉㪊㪍㪄㪇㪅㪈㪌㪍㪋㪄㪈㪄㪇㪅㪉㪇㪌㪇㪎㪈㪍㪄㪈㪅㪋㪈㪅㪐㪍㪌㪅㪎㪍㪇㪅㪈㪍㪉㪅㪍㪈㪅㪎㪉㪇㪋㪍㪌㪈㪅㪇㪎㪎㪇㪊㪊㪉㪅㪉㪈㪌㪊㪏㪌㪉㪅㪋㪈㪅㪋㪉㪅㪉㪎㪏㪌㪇㪅㪈㪋㪏㪍㪄㪇㪅㪈㪌㪇㪍㪄㪈㪄㪇㪅㪉㪊㪍㪈㪈㪎㪄㪈㪅㪊㪈㪅㪍㪐㪌㪅㪉㪐㪇㪅㪇㪐㪉㪅㪌㪇㪎㪐㪏㪎㪈㪅㪍㪋㪇㪈㪉㪉㪈㪅㪇㪋㪋㪇㪊㪈㪉㪅㪈㪇㪐㪉㪍㪈㪉㪅㪊㪈㪅㪊㪉㪅㪇㪍㪇㪏㪇㪅㪇㪏㪍㪉㪄㪇㪅㪈㪊㪎㪈㪄㪈㪄㪇㪅㪉㪎㪈㪎㪎㪈㪏㪄㪈㪅㪉㪈㪅㪋㪋㪋㪅㪏㪋㪇㪅㪇㪋㪉㪅㪋㪈㪍㪍㪇㪐㪈㪅㪌㪍㪉㪇㪌㪈㪅㪇㪈㪐㪏㪇㪋㪉㪅㪇㪇㪉㪏㪇㪍㪉㪅㪉㪈㪅㪉㪈㪅㪏㪋㪊㪎㪇㪅㪇㪊㪐㪉㪄㪇㪅㪈㪈㪋㪄㪈㪄㪇㪅㪊㪈㪉㪊㪈㪈㪐㪄㪈㪅㪈㪈㪅㪉㪈㪋㪅㪋㪈㪇㪅㪇㪈㪉㪅㪊㪉㪌㪐㪋㪈㪈㪅㪋㪏㪍㪍㪇㪎㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪏㪐㪍㪇㪇㪎㪉㪅㪈㪈㪅㪈㪈㪅㪍㪉㪎㪐㪇㪅㪇㪈㪄㪇㪅㪇㪎㪐㪍㪄㪈㪄㪇㪅㪊㪌㪎㪎㪈㪉㪇㪄㪈㪈㪋㪇㪉㪅㪉㪊㪍㪇㪍㪏㪈㪅㪋㪈㪋㪉㪈㪋㪈㪈㪅㪎㪏㪏㪏㪌㪋㪉㪈㪈㪅㪋㪈㪋㪉㪇㪄㪇㪅㪇㪊㪊㪄㪈㪄㪇㪅㪋㪇㪎㪍㪋㪉㪈㪄㪇㪅㪐㪇㪅㪏㪈㪊㪅㪍㪈㪇㪅㪇㪈㪉㪅㪈㪋㪎㪇㪐㪈㪈㪅㪊㪋㪌㪊㪍㪉㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪍㪏㪈㪊㪋㪌㪈㪅㪐㪇㪅㪐㪈㪅㪉㪇㪋㪈㪇㪅㪇㪈㪇㪅㪇㪉㪌㪏㪄㪇㪅㪏㪄㪇㪅㪉㪍㪈㪊㪌㪉㪉㪄㪇㪅㪏㪇㪅㪍㪋㪊㪅㪉㪋㪇㪅㪇㪋㪉㪅㪇㪌㪐㪈㪉㪍㪈㪅㪉㪏㪇㪍㪉㪌㪈㪅㪇㪈㪐㪏㪇㪋㪈㪅㪌㪎㪊㪋㪏㪊㪈㪅㪏㪇㪅㪏㪇㪅㪐㪐㪐㪌㪇㪅㪇㪊㪐㪉㪇㪅㪇㪐㪌㪌㪈㪄㪇㪅㪍㪄㪇㪅㪈㪈㪎㪍㪏㪉㪊㪄㪇㪅㪎㪇㪅㪋㪐㪉㪅㪏㪐㪇㪅㪇㪐㪈㪅㪐㪎㪉㪊㪇㪏㪈㪅㪉㪉㪇㪍㪌㪍㪈㪅㪇㪋㪋㪇㪊㪈㪈㪅㪋㪍㪌㪉㪏㪏㪈㪅㪎㪇㪅㪎㪇㪅㪏㪇㪉㪏㪇㪅㪇㪏㪍㪉㪇㪅㪈㪎㪊㪍㪉㪄㪇㪅㪋㪇㪅㪇㪉㪋㪐㪎㪉㪉㪋㪄㪇㪅㪍㪇㪅㪊㪍㪉㪅㪌㪍㪇㪅㪈㪍㪈㪅㪏㪏㪍㪎㪐㪍㪈㪅㪈㪍㪍㪈㪐㪈㪅㪇㪎㪎㪇㪊㪊㪈㪅㪊㪌㪍㪎㪐㪎㪈㪅㪍㪇㪅㪍㪇㪅㪍㪈㪎㪋㪇㪅㪈㪋㪏㪍㪇㪅㪉㪌㪍㪌㪈㪄㪇㪅㪉㪇㪅㪈㪍㪏㪌㪌㪉㪉㪌㪄㪇㪅㪌㪇㪅㪉㪌㪉㪅㪉㪌㪇㪅㪉㪌㪈㪅㪏㪇㪉㪎㪎㪍㪈㪅㪈㪈㪏㪇㪊㪋㪈㪅㪈㪈㪏㪇㪊㪋㪈㪅㪉㪋㪏㪇㪎㪌㪈㪅㪌㪇㪅㪌㪇㪅㪋㪋㪎㪉㪇㪅㪉㪉㪊㪍㪇㪅㪊㪊㪐㪎㪊㪇㪇㪅㪊㪈㪌㪉㪌㪏㪉㪍㪄㪇㪅㪋㪇㪅㪈㪍㪈㪅㪐㪍㪇㪅㪊㪍㪈㪅㪎㪉㪇㪋㪍㪌㪈㪅㪇㪎㪎㪇㪊㪊㪈㪅㪈㪍㪍㪈㪐㪈㪅㪈㪊㪐㪉㪉㪎㪈㪅㪋㪇㪅㪋㪇㪅㪉㪐㪎㪈㪇㪅㪊㪇㪏㪎㪇㪅㪋㪈㪏㪉㪉㪇㪅㪉㪇㪅㪋㪍㪎㪋㪈㪉㪎㪄㪇㪅㪊㪇㪅㪇㪐㪈㪅㪍㪐㪇㪅㪋㪐㪈㪅㪍㪋㪇㪈㪉㪉㪈㪅㪇㪋㪋㪇㪊㪈㪈㪅㪉㪉㪇㪍㪌㪍㪈㪅㪇㪊㪇㪋㪈㪈㪈㪅㪊㪇㪅㪊㪇㪅㪈㪎㪉㪋㪇㪅㪋㪇㪈㪋㪇㪅㪋㪏㪍㪎㪈㪇㪅㪋㪇㪅㪍㪉㪎㪉㪏㪋㪉㪏㪄㪇㪅㪉㪇㪅㪇㪋㪈㪅㪋㪋㪇㪅㪍㪋㪈㪅㪌㪍㪉㪇㪌㪈㪅㪇㪈㪐㪏㪇㪋㪈㪅㪉㪏㪇㪍㪉㪌㪇㪅㪐㪉㪈㪏㪍㪍㪈㪅㪉㪇㪅㪉㪇㪅㪇㪎㪏㪋㪇㪅㪋㪐㪐㪏㪇㪅㪌㪋㪇㪈㪈㪇㪅㪍㪇㪅㪎㪐㪍㪐㪊㪊㪉㪐㪄㪇㪅㪈㪇㪅㪇㪈㪈㪅㪉㪈㪇㪅㪏㪈㪈㪅㪋㪏㪍㪍㪇㪎㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪊㪋㪌㪊㪍㪉㪇㪅㪏㪈㪊㪐㪊㪋㪈㪅㪈㪇㪅㪈㪇㪅㪇㪈㪐㪐㪇㪅㪍㪇㪉㪈㪇㪅㪌㪎㪋㪈㪈㪇㪅㪏㪇㪅㪐㪎㪏㪇㪇㪍㪊㪇㪇㪇㪈㪈㪈㪅㪋㪈㪋㪉㪈㪋㪈㪈㪅㪋㪈㪋㪉㪈㪋㪇㪅㪎㪇㪎㪈㪇㪎㪈㪇㪇㪇㪅㪎㪇㪎㪈㪇㪅㪌㪏㪌㪎㪐㪈㪈㪅㪈㪎㪈㪌㪎㪊 ࿑㧡㔚⇇ᒝᐲߩ⸘▚⚿ᨐߩ଀

Fig.5 An example of the calculation of electric field strength.

295 (51) - 5 - Ꮣࠍ⴫ߔ㧚ᮮゲߪၮḰൻߐࠇߚ_{z ߩ୯ߢ㧘❑ゲ߇ၮḰൻ㔚⇇} ᒝᐲࠍ⴫ߒߡ޿ࠆ㧚೨ㅀߒߚࠃ߁ߦᦨ㜞㔚૏ߩὐ㧘ߔߥࠊߜ 㔚⇇ᒝᐲ㧜ߩὐߪ౞ᩇߩ㜞ߐߩ⚂_{0.7 ߩ૏⟎ߦ޽ࠆ㧚} 4. ታ㓙ߩ໧㗴߳ߩㆡ↪଀ ੉ⵚࡄࠗࡊ߆ࠄ਄ᣇ߳ྃ಴ߒߚේᴤᓸ☸ሶ߇Ꮺ㔚㔕ࠍ૞ࠆ ႐วߦߟ޿ߡߩࡕ࠺࡞ൻ߇ߎߩ⸘▚ߩ⋡⊛ߩ৻ߟߢ޽ߞߚߩ ߢ㧘ታ㓙ߩᢙ୯ࠍ౉ࠇߡ࿾ᐔ㕙ߢߩ㔚⇇ᒝᐲࠍផቯߔࠆ㧚 ႎ๔ᦠߩ౮⌀ߦࠃࠆߣࡄࠗࡊ߆ࠄߩἫἻߩ⋥ᓘߪ_14㨪 15㨙㧘㜞ߐߪ 40㨪50㨙ߢ޽ࠆ㧚৻ᔕඨᓘ㧣㨙㧘㜞ߐ 45㨙ߣߔ ࠆ㧚㔚⩄ኒᐲߦߟ޿ߡߪ࠺࡯࠲߇ή޿ߩߢ㧘ផቯ୯ߣߒߡ⺞ ᩏᆔຬળႎ๔ᦠߩᢙሼ₁₀-8_C/m3ࠍ↪޿ࠆ㧚ߎࠇࠄߩ୯ࠍ 㧔_{16㧕ᑼߦઍ౉ߔࠆ㧚} 㧱㧩₁₀-8_C/m3_{(45+7-45.5) / (8.8510}-12₎ 㧩_0.73104_V/m ߎߩ㔚⩄ኒᐲߢ⷗ࠆ㒢ࠅߪ㧘㔚⩄㔕ߩᒻ⁁ࠍࠃࠅ⃻ታߦㄭ ߠߌߚࡕ࠺࡞ߦࠃࠆ㕒㔚႐⸘▚ߦࠃߞߡ߽㧘᡼㔚ߦࠃࠆ⌕Ἣ ߩน⢻ᕈߪ⪺ߒߊૐ޿ߣ⸒߃ߘ߁ߢ޽ࠆ㧚ߥ߅㧘੹࿁ߩࡕ࠺ ࡞ൻߢߪࡄࠗࡊߩᦛ₸ࠍ߹ߞߚߊήⷞߒߡ޿ࠆ߇㧘ᦛ₸ࠍ߽ ߞߚធ࿾㕙ߢߪ߽߁ዋߒ᭽ሶ߇⇣ߥࠆߣᕁࠊࠇ㧘ߐࠄߦ⎇ⓥ ߩ૛࿾߇޽ࠆ㧚 ෳ⠨ᢥ₂ 1) චൎᴒ࿾㔡⸥㍳✬㓸ᆔຬળ✬㧦ޟᐔᚑ 15 ᐕ㧔2003 ᐕ㧕ච ൎᴒ࿾㔡⸥㍳ޠᶖ㒐⎇ⓥᚲ㧔_2004.9㧕 2) ⮮↰ᐢ৻㧦㔚⏛᳇ቇࡁ࡯࠻㧘p44㧘ࠦࡠ࠽␠(1971) 3) ᵻ㊁๺ବ㧦㕒㔚᳇ቇળ⹹ 11, 1 (1987) 47-53 4) ᵻ㊁๺ବ㧦㕒㔚᳇ቇળ⹹ 11, 2 (1987) 126-133 5) 㕒㔚᳇ቇળ✬㧦㕒㔚᳇ࡂࡦ࠼ࡉ࠶ࠢ㧘p.1002㧘ࠝ࡯ࡓ␠ (1998)

6) M. Zahn: “Electromagnetic field theory”, Chap. 1, R.E.Kri eger Pub., Malabar, Florida, USA (1987)

ઃ㍳ ࠛࠢ࠮࡞ߦࠃࠆ⸘▚ߩ߿ࠅᣇ 㔚૏⸘▚߽㧘㔚⇇ᒝᐲ⸘▚߽ߤߜࠄ߽ห᭽ߦ಴᧪ࠆ߇㧘ߎ ߎߢߪ㔚⇇ᒝᐲ⸘▚ࠍ଀ߣߒߡ⸘▚ߩ߿ࠅᣇࠍ␜ߔ㧚࿑_{5 ߪ} ߘߩ⸘▚ࠍⴕߞߚ⴫ߩ৻ㇱߢ޽ࠆ㧚㧔_{21㧕ᑼߩฦ㗄ࠍߘࠇߙࠇ} ߩ೉ߦ޿ࠇ㧘_{z ࠍᄌൻߐߖߡߘࠇߙࠇߩ೉ࠍ⸘▚ߔࠆ㧚 z ߪ} ⸘▚ߒߚ޿▸࿐ߦᄌൻߐߖࠆᔅⷐ߇޽ࠆߎߣߣ㧘ࠣ࡜ࡈൻߒ ߚߣ߈ߦߤߩ⒟ᐲߩ♖ᐲ߇ᔅⷐ߆ߢᄌൻߩഀว߇㆑ߞߡߊࠆ㧚 ߎߎߢߪ_{z ࠍ-3߆ࠄ+3߹ߢᄌൻߐߖ㧘ో૕ࠍ60ಽഀߦߒߚ㧚} ߔߥࠊߜ_{0.1 ߕߟߩᄌൻߢ޽ࠆ㧚ߎߩ z ߪ㧰೉ߦ౉ߞߡ޿} ࠆ߇㧯೉ߩᢙሼࠍరߦߒߡ⸘▚ߒߚ߽ߩߢ޽ࠆ㧚⋧ኻඨᓘߪ 㧮೉ߩ㧞ߦ౉ߞߡ޿ࠆ㧚㪚㪛㪜㪝㪞㪟㪠㪡㪢㪣㪤㪥㪦㪧㪨㪩㪇㪄㪊㪐㪈㪍㪋㪋㪅㪈㪉㪊㪈㪇㪍㪊㪅㪈㪍㪉㪉㪎㪏㪉㪅㪉㪊㪍㪇㪍㪏㪊㪅㪏㪏㪇㪌㪎㪋㪊㪌㪅㪍㪐㪉㪈㪈㪅㪎㪏㪏㪐㪄㪇㪅㪇㪌㪎㪊㪄㪈㪄㪇㪅㪇㪊㪋㪍㪉㪈㪄㪉㪅㪐㪏㪅㪋㪈㪈㪌㪅㪉㪈㪊㪅㪍㪈㪋㪅㪇㪉㪍㪈㪍㪋㪊㪅㪇㪍㪎㪌㪎㪉㪉㪅㪈㪋㪎㪇㪐㪈㪊㪅㪎㪎㪎㪎㪏㪐㪊㪅㪐㪉㪅㪐㪌㪅㪋㪏㪊㪉㪈㪅㪍㪏㪈㪊㪄㪇㪅㪇㪍㪉㪈㪄㪈㪄㪇㪅㪇㪊㪏㪈㪈㪉㪄㪉㪅㪏㪎㪅㪏㪋㪈㪋㪅㪋㪋㪊㪅㪉㪋㪊㪅㪐㪉㪐㪊㪎㪎㪉㪅㪐㪎㪊㪉㪈㪋㪉㪅㪇㪌㪐㪈㪉㪍㪊㪅㪍㪎㪋㪏㪏㪊㪊㪅㪏㪉㪅㪏㪌㪅㪉㪎㪊㪏㪈㪅㪌㪎㪊㪌㪄㪇㪅㪇㪍㪎㪌㪄㪈㪄㪇㪅㪇㪋㪉㪇㪏㪊㪄㪉㪅㪎㪎㪅㪉㪐㪈㪊㪅㪍㪐㪉㪅㪏㪐㪊㪅㪏㪊㪉㪎㪌㪋㪉㪅㪏㪎㪐㪉㪊㪍㪈㪅㪐㪎㪉㪊㪇㪏㪊㪅㪌㪎㪈㪏㪋㪌㪊㪅㪎㪉㪅㪎㪌㪅㪇㪍㪊㪏㪈㪅㪋㪍㪌㪊㪄㪇㪅㪇㪎㪊㪊㪄㪈㪄㪇㪅㪇㪋㪍㪌㪐㪋㪄㪉㪅㪍㪍㪅㪎㪍㪈㪉㪅㪐㪍㪉㪅㪌㪍㪊㪅㪎㪊㪍㪊㪇㪏㪉㪅㪎㪏㪌㪍㪎㪏㪈㪅㪏㪏㪍㪎㪐㪍㪊㪅㪋㪍㪏㪍㪍㪋㪊㪅㪍㪉㪅㪍㪋㪅㪏㪌㪊㪋㪈㪅㪊㪌㪍㪏㪄㪇㪅㪇㪎㪐㪎㪄㪈㪄㪇㪅㪇㪌㪈㪎㪌㪌㪄㪉㪅㪌㪍㪅㪉㪌㪈㪉㪅㪉㪌㪉㪅㪉㪌㪊㪅㪍㪋㪇㪇㪌㪌㪉㪅㪍㪐㪉㪌㪏㪉㪈㪅㪏㪇㪉㪎㪎㪍㪊㪅㪊㪍㪌㪊㪊㪋㪊㪅㪌㪉㪅㪌㪋㪅㪍㪋㪉㪋㪈㪅㪉㪋㪏㪈㪄㪇㪅㪇㪏㪍㪍㪄㪈㪄㪇㪅㪇㪌㪎㪍㪎㪍㪄㪉㪅㪋㪌㪅㪎㪍㪈㪈㪅㪌㪍㪈㪅㪐㪍㪊㪅㪌㪋㪋㪇㪇㪐㪉㪅㪍㪈㪅㪎㪉㪇㪋㪍㪌㪊㪅㪉㪍㪈㪏㪋㪊㪊㪅㪋㪉㪅㪋㪋㪅㪋㪊㪇㪏㪈㪅㪈㪊㪐㪉㪄㪇㪅㪇㪐㪋㪉㪄㪈㪄㪇㪅㪇㪍㪋㪋㪎㪎㪄㪉㪅㪊㪌㪅㪉㪐㪈㪇㪅㪏㪐㪈㪅㪍㪐㪊㪅㪋㪋㪏㪈㪏㪏㪉㪅㪌㪇㪎㪐㪏㪎㪈㪅㪍㪋㪇㪈㪉㪉㪊㪅㪈㪌㪏㪈㪏㪈㪊㪅㪊㪉㪅㪊㪋㪅㪉㪈㪏㪌㪈㪅㪇㪊㪇㪋㪄㪇㪅㪈㪇㪉㪊㪄㪈㪄㪇㪅㪇㪎㪉㪊㪋㪏㪄㪉㪅㪉㪋㪅㪏㪋㪈㪇㪅㪉㪋㪈㪅㪋㪋㪊㪅㪊㪌㪉㪍㪈㪈㪉㪅㪋㪈㪍㪍㪇㪐㪈㪅㪌㪍㪉㪇㪌㪊㪅㪇㪌㪋㪊㪊㪍㪊㪅㪉㪉㪅㪉㪋㪅㪇㪇㪌㪍㪇㪅㪐㪉㪈㪐㪄㪇㪅㪈㪈㪇㪐㪄㪈㪄㪇㪅㪇㪏㪈㪋㪋㪐㪄㪉㪅㪈㪋㪅㪋㪈㪐㪅㪍㪈㪈㪅㪉㪈㪊㪅㪉㪌㪎㪉㪐㪐㪉㪅㪊㪉㪌㪐㪋㪈㪈㪅㪋㪏㪍㪍㪇㪎㪉㪅㪐㪌㪇㪉㪐㪎㪊㪅㪈㪉㪅㪈㪊㪅㪎㪐㪉㪇㪅㪏㪈㪊㪐㪄㪇㪅㪈㪈㪐㪏㪄㪈㪄㪇㪅㪇㪐㪉㪇㪊㪈㪇㪄㪉㪋㪐㪈㪊㪅㪈㪍㪉㪉㪎㪏㪉㪅㪉㪊㪍㪇㪍㪏㪈㪅㪋㪈㪋㪉㪈㪋㪉㪅㪏㪋㪍㪇㪌㪊㪉㪊㪅㪌㪎㪎㪎㪇㪅㪎㪇㪎㪈㪄㪇㪅㪈㪉㪏㪐㪄㪈㪄㪇㪅㪈㪇㪋㪊㪍㪈㪈㪄㪈㪅㪐㪊㪅㪍㪈㪏㪅㪋㪈㪇㪅㪏㪈㪊㪅㪇㪍㪎㪌㪎㪉㪉㪅㪈㪋㪎㪇㪐㪈㪈㪅㪊㪋㪌㪊㪍㪉㪉㪅㪎㪋㪈㪌㪏㪉㪉㪅㪐㪈㪅㪐㪊㪅㪊㪍㪉㪎㪇㪅㪍㪇㪉㪈㪄㪇㪅㪈㪊㪎㪏㪄㪈㪄㪇㪅㪈㪈㪏㪎㪌㪈㪉㪄㪈㪅㪏㪊㪅㪉㪋㪎㪅㪏㪋㪇㪅㪍㪋㪉㪅㪐㪎㪊㪉㪈㪋㪉㪅㪇㪌㪐㪈㪉㪍㪈㪅㪉㪏㪇㪍㪉㪌㪉㪅㪍㪊㪍㪏㪎㪎㪉㪅㪏㪈㪅㪏㪊㪅㪈㪋㪎㪇㪅㪋㪐㪐㪏㪄㪇㪅㪈㪋㪌㪐㪄㪈㪄㪇㪅㪈㪊㪌㪌㪐㪈㪊㪄㪈㪅㪎㪉㪅㪏㪐㪎㪅㪉㪐㪇㪅㪋㪐㪉㪅㪏㪎㪐㪉㪊㪍㪈㪅㪐㪎㪉㪊㪇㪏㪈㪅㪉㪉㪇㪍㪌㪍㪉㪅㪌㪊㪈㪐㪉㪉㪉㪅㪎㪈㪅㪎㪉㪅㪐㪊㪇㪍㪇㪅㪋㪇㪈㪋㪄㪇㪅㪈㪌㪉㪌㪄㪈㪄㪇㪅㪈㪌㪌㪉㪎㪈㪋㪄㪈㪅㪍㪉㪅㪌㪍㪍㪅㪎㪍㪇㪅㪊㪍㪉㪅㪎㪏㪌㪍㪎㪏㪈㪅㪏㪏㪍㪎㪐㪍㪈㪅㪈㪍㪍㪈㪐㪉㪅㪋㪉㪍㪍㪐㪐㪉㪅㪍㪈㪅㪍㪉㪅㪎㪈㪊㪍㪇㪅㪊㪇㪏㪎㪄㪇㪅㪈㪌㪍㪌㪄㪈㪄㪇㪅㪈㪎㪏㪉㪏㪈㪌㪄㪈㪅㪌㪉㪅㪉㪌㪍㪅㪉㪌㪇㪅㪉㪌㪉㪅㪍㪐㪉㪌㪏㪉㪈㪅㪏㪇㪉㪎㪎㪍㪈㪅㪈㪈㪏㪇㪊㪋㪉㪅㪊㪉㪈㪈㪐㪉㪉㪅㪌㪈㪅㪌㪉㪅㪋㪐㪍㪉㪇㪅㪉㪉㪊㪍㪄㪇㪅㪈㪌㪍㪋㪄㪈㪄㪇㪅㪉㪇㪌㪇㪎㪈㪍㪄㪈㪅㪋㪈㪅㪐㪍㪌㪅㪎㪍㪇㪅㪈㪍㪉㪅㪍㪈㪅㪎㪉㪇㪋㪍㪌㪈㪅㪇㪎㪎㪇㪊㪊㪉㪅㪉㪈㪌㪊㪏㪌㪉㪅㪋㪈㪅㪋㪉㪅㪉㪎㪏㪌㪇㪅㪈㪋㪏㪍㪄㪇㪅㪈㪌㪇㪍㪄㪈㪄㪇㪅㪉㪊㪍㪈㪈㪎㪄㪈㪅㪊㪈㪅㪍㪐㪌㪅㪉㪐㪇㪅㪇㪐㪉㪅㪌㪇㪎㪐㪏㪎㪈㪅㪍㪋㪇㪈㪉㪉㪈㪅㪇㪋㪋㪇㪊㪈㪉㪅㪈㪇㪐㪉㪍㪈㪉㪅㪊㪈㪅㪊㪉㪅㪇㪍㪇㪏㪇㪅㪇㪏㪍㪉㪄㪇㪅㪈㪊㪎㪈㪄㪈㪄㪇㪅㪉㪎㪈㪎㪎㪈㪏㪄㪈㪅㪉㪈㪅㪋㪋㪋㪅㪏㪋㪇㪅㪇㪋㪉㪅㪋㪈㪍㪍㪇㪐㪈㪅㪌㪍㪉㪇㪌㪈㪅㪇㪈㪐㪏㪇㪋㪉㪅㪇㪇㪉㪏㪇㪍㪉㪅㪉㪈㪅㪉㪈㪅㪏㪋㪊㪎㪇㪅㪇㪊㪐㪉㪄㪇㪅㪈㪈㪋㪄㪈㪄㪇㪅㪊㪈㪉㪊㪈㪈㪐㪄㪈㪅㪈㪈㪅㪉㪈㪋㪅㪋㪈㪇㪅㪇㪈㪉㪅㪊㪉㪌㪐㪋㪈㪈㪅㪋㪏㪍㪍㪇㪎㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪏㪐㪍㪇㪇㪎㪉㪅㪈㪈㪅㪈㪈㪅㪍㪉㪎㪐㪇㪅㪇㪈㪄㪇㪅㪇㪎㪐㪍㪄㪈㪄㪇㪅㪊㪌㪎㪎㪈㪉㪇㪄㪈㪈㪋㪇㪉㪅㪉㪊㪍㪇㪍㪏㪈㪅㪋㪈㪋㪉㪈㪋㪈㪈㪅㪎㪏㪏㪏㪌㪋㪉㪈㪈㪅㪋㪈㪋㪉㪇㪄㪇㪅㪇㪊㪊㪄㪈㪄㪇㪅㪋㪇㪎㪍㪋㪉㪈㪄㪇㪅㪐㪇㪅㪏㪈㪊㪅㪍㪈㪇㪅㪇㪈㪉㪅㪈㪋㪎㪇㪐㪈㪈㪅㪊㪋㪌㪊㪍㪉㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪍㪏㪈㪊㪋㪌㪈㪅㪐㪇㪅㪐㪈㪅㪉㪇㪋㪈㪇㪅㪇㪈㪇㪅㪇㪉㪌㪏㪄㪇㪅㪏㪄㪇㪅㪉㪍㪈㪊㪌㪉㪉㪄㪇㪅㪏㪇㪅㪍㪋㪊㪅㪉㪋㪇㪅㪇㪋㪉㪅㪇㪌㪐㪈㪉㪍㪈㪅㪉㪏㪇㪍㪉㪌㪈㪅㪇㪈㪐㪏㪇㪋㪈㪅㪌㪎㪊㪋㪏㪊㪈㪅㪏㪇㪅㪏㪇㪅㪐㪐㪐㪌㪇㪅㪇㪊㪐㪉㪇㪅㪇㪐㪌㪌㪈㪄㪇㪅㪍㪄㪇㪅㪈㪈㪎㪍㪏㪉㪊㪄㪇㪅㪎㪇㪅㪋㪐㪉㪅㪏㪐㪇㪅㪇㪐㪈㪅㪐㪎㪉㪊㪇㪏㪈㪅㪉㪉㪇㪍㪌㪍㪈㪅㪇㪋㪋㪇㪊㪈㪈㪅㪋㪍㪌㪉㪏㪏㪈㪅㪎㪇㪅㪎㪇㪅㪏㪇㪉㪏㪇㪅㪇㪏㪍㪉㪇㪅㪈㪎㪊㪍㪉㪄㪇㪅㪋㪇㪅㪇㪉㪋㪐㪎㪉㪉㪋㪄㪇㪅㪍㪇㪅㪊㪍㪉㪅㪌㪍㪇㪅㪈㪍㪈㪅㪏㪏㪍㪎㪐㪍㪈㪅㪈㪍㪍㪈㪐㪈㪅㪇㪎㪎㪇㪊㪊㪈㪅㪊㪌㪍㪎㪐㪎㪈㪅㪍㪇㪅㪍㪇㪅㪍㪈㪎㪋㪇㪅㪈㪋㪏㪍㪇㪅㪉㪌㪍㪌㪈㪄㪇㪅㪉㪇㪅㪈㪍㪏㪌㪌㪉㪉㪌㪄㪇㪅㪌㪇㪅㪉㪌㪉㪅㪉㪌㪇㪅㪉㪌㪈㪅㪏㪇㪉㪎㪎㪍㪈㪅㪈㪈㪏㪇㪊㪋㪈㪅㪈㪈㪏㪇㪊㪋㪈㪅㪉㪋㪏㪇㪎㪌㪈㪅㪌㪇㪅㪌㪇㪅㪋㪋㪎㪉㪇㪅㪉㪉㪊㪍㪇㪅㪊㪊㪐㪎㪊㪇㪇㪅㪊㪈㪌㪉㪌㪏㪉㪍㪄㪇㪅㪋㪇㪅㪈㪍㪈㪅㪐㪍㪇㪅㪊㪍㪈㪅㪎㪉㪇㪋㪍㪌㪈㪅㪇㪎㪎㪇㪊㪊㪈㪅㪈㪍㪍㪈㪐㪈㪅㪈㪊㪐㪉㪉㪎㪈㪅㪋㪇㪅㪋㪇㪅㪉㪐㪎㪈㪇㪅㪊㪇㪏㪎㪇㪅㪋㪈㪏㪉㪉㪇㪅㪉㪇㪅㪋㪍㪎㪋㪈㪉㪎㪄㪇㪅㪊㪇㪅㪇㪐㪈㪅㪍㪐㪇㪅㪋㪐㪈㪅㪍㪋㪇㪈㪉㪉㪈㪅㪇㪋㪋㪇㪊㪈㪈㪅㪉㪉㪇㪍㪌㪍㪈㪅㪇㪊㪇㪋㪈㪈㪈㪅㪊㪇㪅㪊㪇㪅㪈㪎㪉㪋㪇㪅㪋㪇㪈㪋㪇㪅㪋㪏㪍㪎㪈㪇㪅㪋㪇㪅㪍㪉㪎㪉㪏㪋㪉㪏㪄㪇㪅㪉㪇㪅㪇㪋㪈㪅㪋㪋㪇㪅㪍㪋㪈㪅㪌㪍㪉㪇㪌㪈㪅㪇㪈㪐㪏㪇㪋㪈㪅㪉㪏㪇㪍㪉㪌㪇㪅㪐㪉㪈㪏㪍㪍㪈㪅㪉㪇㪅㪉㪇㪅㪇㪎㪏㪋㪇㪅㪋㪐㪐㪏㪇㪅㪌㪋㪇㪈㪈㪇㪅㪍㪇㪅㪎㪐㪍㪐㪊㪊㪉㪐㪄㪇㪅㪈㪇㪅㪇㪈㪈㪅㪉㪈㪇㪅㪏㪈㪈㪅㪋㪏㪍㪍㪇㪎㪈㪅㪇㪇㪋㪐㪏㪏㪈㪅㪊㪋㪌㪊㪍㪉㪇㪅㪏㪈㪊㪐㪊㪋㪈㪅㪈㪇㪅㪈㪇㪅㪇㪈㪐㪐㪇㪅㪍㪇㪉㪈㪇㪅㪌㪎㪋㪈㪈㪇㪅㪏㪇㪅㪐㪎㪏㪇㪇㪍㪊㪇㪇㪇㪈㪈㪈㪅㪋㪈㪋㪉㪈㪋㪈㪈㪅㪋㪈㪋㪉㪈㪋㪇㪅㪎㪇㪎㪈㪇㪎㪈㪇㪇㪇㪅㪎㪇㪎㪈㪇㪅㪌㪏㪌㪎㪐㪈㪈㪅㪈㪎㪈㪌㪎㪊 ࿑㧡㔚⇇ᒝᐲߩ⸘▚⚿ᨐߩ଀

(6)

ធ࿾㕙਄ߩ౞ᩇ㔚⩄ߦࠃࠆ㔚૏ߣ㔚⇇ߩ⸘▚㧔ᵻ㊁๺ବࠄ㧕 - 6 - ߤߩ೉ߦߤߩ㗄߇౉ߞߡ޿ࠆ߆ࠍએਅߦ೉⸥ߒߡ߅ߊ㧚 ᦨ ᓟߩ㧾೉߇⚿ᨐߩ୯ߢ޽ࠆ㧚 D ೉㧦C ೉ࠍၮߦߒߡz~ ࠍ⸘▚ߔࠆ㧚 E ೉㧦z~2 F ೉㧦

₍

~

_z

₁

₎

2 G ೉㧦

₍

~

_z

₁

₎

2 H ೉㧦 I ೉㧦 J ೉㧦 K ೉㧦 L ೉㧦 M ೉㧦

~z

2 N ೉㧦 O ೉㧦 P ೉㧦 Q ೉㧦 R ೉㧦ฦ㗄ߩ๺(= -K ೉+L ೉-M ೉+N ೉-O ೉+P ೉+Q ೉) 㧘 හߜ⋧ኻ⊛㔚⇇ᒝᐲE~ߢ޽ࠆ㧚 ࿑㧠ߪR ೉ߩ୯ࠍၮߦឬ޿ߡ޿ࠆ㧚 2 2

~

)

1 ~

(

z

R

2 2

~

_z

_R

2 2

~

)

1 ~

(

z

R

2 2 2

~

)

1 ~

(

)

1 ~

(

R

z

2 2

)

1 ~

(

)

1 ~

(

z

2 2 2

~

2 R

z

2 2 2

~

)

1 ~

(

)

1 ~

(

R

z

¸

¹

· ¨

¨

©

§

2 2 2 2 2 2 2

~

)

1 ~

(

1 ~

~

2 ~

)

1 ~

(

1 ~

R

z

R

z

R

z

R

°

¿

°

¾

½

°

¯

°

®

z

~

0

1

0 ~

1

1 ~

2

1 ~

1

接地面上の円柱電荷による電位と電界の計算

ធ࿾㕙਄ߩ౞ᩇ㔚⩄ߦࠃࠆ㔚૏ߣ㔚⇇ߩ⸘▚

ᵻ ㊁ ๺ ବ

㧘↰ ᧛ ⵨ ਯ

㧘᧻ ේ ⟤ ਯ

Field Distribution along the Center Axis of Space Charge Cylinder

Placed on a Grounded Plate

Kazutoshi ASANO

Hiroyuki TAMURA

and Yoshiyuki MATSUBARA

Due to the big earthquake which occurred in September 2003 at Hokkaido, Japan, two oil tanks were burned and

completely destroyed. One of them is a crude oil tank and the other is a naphtha tank. According to the report of

the fire disaster investigation team, there is a possible cause of the ignition of oil with electrostatic discharge. From

the cracked pipe, crude oil was splashed upward and burned by forming a space charge cloud. The question arisen

was that the field strength due to such space charge could initiate the ignitable discharge. Since there is no suitable

model to calculate potential and electric field, a simple model with finite height of cylindrical charge and image charge

was made. Since our interest is concentrated on the potential and field at z axis, theoretical calculation is

straightforward. Theoretically derived result showed a very simple form of electric field at the ground plate, from

which the possibility of discharge could be estimated.

㫑

㪩

㪱

㫑

㪩

㪱

\

\

\

³³³

³³³

SH

\

U

SH

\

U

I

³³

³³

H

U

H

U

I

(

z

z

)'

r

'

r





(

z

z

)'

r

'

r





³

³

³

³

³

³

H

U

H

U

H

U

H

U

I

³

㫏

㫑

_㪈

_㪉

_㪈

_㪉