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RFTV`w(ʃ)

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RFTV`w(1)+ƒ*RFTV`w(2)&Ǵ5é

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$&)=ƌ(IJ*ġÄǥ+

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½ę+SuperKEKBÏɏõAʼnĕ

$ =*%ÏɏǞƣ+ɑǹƠʀCWʁɔɂ):

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Ļ×%+SuperKEKBÏɏõ)=RFT

V`w*¼¥Dž(ªAdz—ėƵAȚ&

( Ȯȁ%8Ex„UƬ:) &ņ

Ï$SuperKEKB*Ǡ ‡ų)Ǡ Ÿ

ĭɔAƽȗŧ*Ǟƣ*£NJA'*:) ş*Adz—=¼¥Dž(ȰŨƟ& * +>4%4<OHO`LVb%+ȡ>;>

$ ( &ņ*%¦*ÝȀ)(>,ĭ %

=

RF )ɧ=ũƹ9ŦǘŶ+ɵĩ)Ċ=

*%ũŒ%+Ǘ*ũǡAŶ*)ÝȀ) ɕÜ*OHO`LVbA)ijƾ=&) Ǘ8%=ŷÆ+Ůżȫ*`LVb )Ñ;>=&ɵĩ)Ċ &ņƶ)1994 Ĭ2004Ĭ*OHO+KEKB`„u%<

`LVb)+ȩDz%Ÿƾ(ȠȭĊ=*%

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2. ǎ!$&­È(&

2.1. :©@>=Ȣȋ

2.1.1. ǭĐ*Hf~M„ƒɏƒɔÔɠ

SuperKEKB+ɳЃɬɳĐÏɏõ%<

*Hf~M„+ɳĐ7 GeVɬɳĐ3.5 GeV %

=*:(ɿHf~M„Ïɏõ%+ɳĐ +23¸ɏ)Éɗ$ =%

𝛽𝛽 =𝑣𝑣 𝑐𝑐

𝛾𝛾 = 1

'1 − 𝛽𝛽⁾

(2-1)

Aĕǿ=𝑣𝑣+ǭĐ*ɏ𝑐𝑐+¸ɏ𝛾𝛾+€„

‚_÷Đ%=ǭĐ*Hf~M„ 𝐸𝐸 +

𝐸𝐸 = 𝑚𝑚_,𝑐𝑐⁾

'1 − 𝛽𝛽⁾= 𝑚𝑚,𝛾𝛾𝑐𝑐⁾ (2-2)

%ȑ>=𝑚𝑚_,+ɴƕȺɠ%=4ɔÔɠ 𝑝𝑝+

𝑝𝑝 = 𝑚𝑚_,𝑣𝑣

'1 − 𝛽𝛽⁾ = 𝑚𝑚_,𝛽𝛽𝑐𝑐

'1 − 𝛽𝛽⁾= 𝑚𝑚,𝛽𝛽𝛾𝛾𝑐𝑐 (2-3)

%<Hf~M„&ɔÔɠ*ɧ®+

𝑝𝑝 = 𝐸𝐸 𝑐𝑐⁾𝑣𝑣 𝐸𝐸⁾− 𝑝𝑝⁾𝑐𝑐⁾ = 𝑚𝑚_,⁾𝑐𝑐^.

(2-4)

&(=

2.1.2. ɳǒƠ*îƠŧ&Ơɢ

îƠŧʆ𝑓𝑓Ơɢʆ𝜆𝜆ȟîƠŧʆ𝜔𝜔&$œ

ˆ*ɧ®)=

𝑓𝑓 =𝑐𝑐

𝜆𝜆 𝜔𝜔 = 2𝜋𝜋𝑓𝑓 (2-5)

2.1.3. öɂîƠŧ (revolution frequency) öɂîƠŧ+l„wʃǙɦ)}‚OAöɂ

=öŧ%=Ȥç&$𝑓𝑓₄₅₆:©@>=

𝑓𝑓₄₅₆ = 𝑣𝑣/𝐶𝐶 (2-6)

𝐶𝐶 +}‚O*îɢ%=4öɂîƠŧ*Ɍ ŧʇ…î)ńș(ųɦArevolution time&ð/

SuperKEKB %+îɢǰ3 kmǭĐ*ɏİ+

23¸ɏ%=*%

𝑓𝑓₄₅₆≈ 100 kHz

%<revolution time ≈ 10 µsec%=

2.1.4. RFîƠŧ

ɿîƠÏɏǞƣ)ŕ¹=ɿîƠɳǒƠ*î Ơŧ%<𝑓𝑓4<&ȑ&Ċ 4ȟîƠ

ŧ 𝜔𝜔_4< = 2𝜋𝜋𝑓𝑓_4< ©@>=&8Ċ Ċ*Ă

é Ǟ ƣ * » Ś î Ơ ŧ & … ȅ $ = SuperKEKB*Ăé

𝑓𝑓4< ≈ 508.9 MHz

%=*RFîƠŧ&öɂîƠŧ*ɧ®+

𝑓𝑓4< = ℎ𝑓𝑓456 (2-7)

%ȑ>ℎ+harmonic number&ð,>ń ŨŧAá=SuperKEKB%+ƖǑ(³+5120

%=>+ǭĐ}‚OA…î=ɦ*ɿ îƠɳĂ*ŚÔöŧ%<Ļɉ=ēĕ£NJ*

ŧʀRF bucketŧ&8ð/ʁ%=

Fig. 1)}‚O*ƎIJùAǔǭĐ+ăʀi

‚]ʁ)(!$ $ÏɏǞƣ%*£NJ*ɳĂ)

=&ēĕ)}‚OAîö=ÏɏǞƣ) 𝑓𝑓_4<

%ɳĂÒȼ>$ =&=i‚]1"

&=&ÏɏǞƣAɎɕ=ɯ)+ĩ)ēĕ

£NJ)=:([Ev‚O%(>,(;(

"4<𝑓𝑓_4< 𝑓𝑓₄₅₆ *Ũŧ²ʀ%+ ℎ ʁ

%(>,£NJ>$4&)(=4

*1"*i‚]…î$¿.Ǟƣ)ÉǍ

=4%*ɦ)8Ǟƣ½)+ ℎöēĕ£NJ*[

Ev‚Oƀ=*%*öŧÅʀ"4<ℎ±ʁ*

i‚]A}‚O)¹>=&%=

Fig. 1 }‚O‡*i‚]&ÏɏǞƣ

2.1.5. l„wɳƤ

l„wɳƤ 𝐼𝐼_C +DZɳȊ 𝑒𝑒 &}‚OAîö

=ºǭĐŧ 𝑁𝑁 ;

𝐼𝐼_C = 𝑓𝑓₄₅₆𝑒𝑒𝑁𝑁 (2-8)

%ȑ=i‚]ŧ 𝑁𝑁_C &1"*i‚])ì4

>=ɳȊɠ 𝑞𝑞 ;

𝐼𝐼_C= 𝑓𝑓₄₅₆𝑞𝑞𝑁𝑁_C (2-9)

&=ŬėƾDž%=

SuperKEKB*ɬɳĐ}‚O*ȥȣl„wɳƤ

+3.6 Aȥȣi‚]ŧ+2500%=*%1i

‚]<*ɳȊɠ+14 nCi‚]<*ɬ ɳĐŧ+9×10¹⁰±& &)(=

2.2. £NJēĕŇ*ÛƼ

ŷ8ɟș(ÛƼ*…"%=£NJēĕŇ*Û Ƽ)" $ǬØ)ȡ>$ȩ ȭŰ+[1-4]

('Ċŧ*OHO`LVb9–ö*OHO*Žż B):=l„w\Edv^NV*āǓAÝ Ʋ$ %+%=īű (ȭŰA

ɿîƠÏɏǞƣ*ɳû 𝑉𝑉 +m„Nɳû 𝑉𝑉H

&=&

𝑉𝑉 = 𝑉𝑉Hcos(𝜔𝜔4<𝑡𝑡) (2-10)

&ȑ>=ɳĐ}‚O%+ɳЅî%č!

ŤğŢčHf~M„ 𝑈𝑈_, AȕĄ=*Ïɏ Ǟƣ*˜’%=*7Fig. 2*:) ǭĐ+ 𝑈𝑈_, &ɡ<éHf~M„Aľ=ńș

<ǭĐ+IJ(2-11)%ĕǿ>=£NJ ±𝜙𝜙_R%Ǟ ƣAɎɕ(>,(;(

𝑈𝑈_, = 𝑒𝑒𝑉𝑉_,= 𝑒𝑒𝑉𝑉_Hcos(±𝜙𝜙_R) (2-11) * : ( Ƽ ʼn Dž ( ǭ Đ A ê Ź ǭ Đ ʀsynchronous particleʁ&ð/ėɯ)+

i‚])+ǭĐ*ɒȎŬë)Į<=*%

êŹǭĐ:<·)ÉǍ<ɓ><

=ǭĐ=>;8ēĕ)îö(>

,(;( >;*ǭĐ*Ś=ȇ )" $Ȁ

=%IJ(2-11)Œ*£NJ ±𝜙𝜙_R %=

& ) ơ Lj = ē ĕ ) Ï ɏ % = ê Ź £ NJ ʀsynchronous phaseʁ+ +𝜙𝜙R −𝜙𝜙R*' ; …"%=' ;Aá=*AȀ$5=

Fig. 2 Ǟƣɳû&êŹ£NJ 𝜙𝜙_R

Fig. 3(a)(b)+ǞƣAɎ=i‚]&Ǟƣɳû 𝑉𝑉 Aǔ$ =*ù%+ƏɃ+ųɦAŊï

=*%i‚]+B´A·ɼ&$ǞƣAɎɕ

=êŹ£NJ ±𝜙𝜙_R *[Ev‚O%Ǟƣ)ÉǍ

*êŹǭĐS&=êi‚]*Œ*A, B )8ǭĐ =&="4<B) =ǭĐ+

S:<8·)A) =ǭĐ+S:<8ɓ>$Ǟ ƣ)ÉǍ=ÉǍųɦǃ(=*%ĵƱŋ

=ǞƣɳûS&+ǃ(=

Fig. 3(a)*ĂéA) =ɓƀǭĐ+ǭ

ĐS:<8ɿ ǞƣɳûAŋ=*%:<ċ(

Hf~M„Aâá=–SuperKEKBÏɏõ Aʼnĕ$ =*%ǭĐ*ɏİ+23¸ɏ%

<Ļɉ=momentum compaction factor+Ɏ ĩ+Ɩ*³)(!$ ="4<Hf~M„

ċ(!$8ǭĐ*ɏİ+Ĉ@;ĉ´*Ɂ ɖAɎ=ʇɁɖɢɢ(=ʇ…î=ųɦ ɢ(<Ǟƣ)ŏ!$=*S:<8'B'B ɓ>$44B) =ůƀǭĐ+¤

ǞƣɳûAŋ=*%âá=Hf~M„

Ģ½´*ɁɖAɎ<…î=ųɦǐ(

<'B'Bůŏ!$$4"4<A, B >8ēĕ)îö=&%(

…ŬFig. 3(b)*ĂéA) =ɓ>ǭĐ+

ǭĐS:<Ģ Hf~M„Aâá=ǭĐ*

Hf~M„Ģ(<Ɂɖ½´AɎ=ʇɁ ɖɢǐ(=7…î=ųɦǐ(=

*7…î$ŏ!$ǭĐ+ǭĐS)ɇ

#9$S)Ɋ "ǭĐ*Hf~M„

+S:<Ģ 7;)ůÉǍ=:) (<i‚]*ËŬʀB*Ŭʁ)ë=&

âá>=Hf~M„ċ(!$ 9

$S&êHf~M„&(=ʇ…î=ųɦ+ê )(=i‚]ËŬ) $S:<ůÉ Ǎ$ =*%ċ(Hf~M„Aâá<S :<8ĉ´*ɁɖAɎ<…î=ųɦ+ɢ(

=ʇS)ɇ#9$S&êų)ŏ!$=

Hf~M„ċ 7;)ɓ>$ÉǍ=

:)(<i‚]*ĻŬ)냃ƒAǼ<

Ɉ8îö$ ==i‚]*Œ*ǭĐ

*£ǽA!&Ȟě&=&}‚OA¦î

=ɦ)i‚]*Œ%ËĻ)ĸŀ:) Ț=*ĸŀɔÔ+"4<+£NJ*ŚÔ%

<…ĕ*îŹ%ēĕ)Ǽ<Ɉêƌ)S&*H f~M„Ĩ8Ɩȶ)ŚÔ(;ēĕ)Ǽ<Ɉ

"4<ǭĐ*ɏİ23¸ɏ%>, +𝜙𝜙_R ēĕ)Ïɏ%=êŹ£NJ%=

…ŬɏİĢHf~M„):<ɏİ ĈÕ=Ăé+−𝜙𝜙_R êŹ£NJ)(=

*:)êŹǭĐ*îɅ*ǭĐ+£NJ&H f~M„ŚÔ(;ēĕ)îö=>

£NJēĕŇ*ÛƼ%=

Fig. 4)‡ɉ*ȭŰAêŹǭĐʀ£NJ 𝜙𝜙_RH f~M„ 𝐸𝐸,ʁ;ɓ>ǭĐʀ£NJ 𝜙𝜙Hf~M Fig. 3 Ǟƣɳû&îöi‚]êŹ£NJ ±𝜙𝜙R

) =ǭĐS&i‚]*ĻŬA9ËŬB)

=ǭĐ&+ŋ=ɳûǃ(=

Fig. 4 ǭĐ*êŹǭĐ)ĝ=£NJĨ&Hf

~M„*>*ɧ®

„+êŹǭĐ&ê𝐸𝐸_,&ĕʁ*êŹǭĐ&*£

NJĨ&Hf~M„Ĩ*ɧ®%ȑŷÆ+ù*(1) ) =Fig. 3(b)%ǭĐA) =*&êſž

%=ļ)êŹǭĐ)ɇ#£NJĨ((

=&Hf~M„Ĩŷċ)(<(2)Hf~M„Ĩ ((=&£NJĨŷċ)(=(3)& ¼é )£NJŚÔ&Hf~M„ŚÔAǼ<Ɉ$ =

*:Å=*ǭĐ*ŚÔAT‚N€b€

‚ŚÔ&ð/

2.3. Transition EnergyʀɚǚHf~M„ʁ ËǪ*ȭŰAŧIJ%ȑ$5=

%îöųɦAT^ɏİ 𝑣𝑣}‚O*îɢAC^&

=&

𝑇𝑇 =𝐶𝐶

𝑣𝑣 (2-12)

%=*%

𝛥𝛥𝑇𝑇 𝑇𝑇 =

∆𝐶𝐶 𝐶𝐶 −

𝛥𝛥𝑣𝑣

𝑣𝑣 (2-13)

ľ;>=%momentum compaction factor 𝛼𝛼*ĕǿ;

∆𝐶𝐶 𝐶𝐶 = 𝛼𝛼

𝛥𝛥𝑝𝑝

𝑝𝑝 (2-14)

%=SuperKEKB%+Ɏĩ 0 < 𝛼𝛼 < 1 &ȥĕ

>$ =4

∆𝑣𝑣 𝑣𝑣 =

1 𝛾𝛾⁾

∆𝑝𝑝

𝑝𝑝 (2-15)

%=*%IJ(2-13)+ 𝛥𝛥𝑇𝑇

𝑇𝑇 = Y𝛼𝛼 − 1 𝛾𝛾⁾Z𝛥𝛥𝑝𝑝

𝑝𝑝 (2-16)

&(=%

𝜂𝜂 = Y𝛼𝛼 − 1

𝛾𝛾⁾Z (2-17)

&$𝜂𝜂A slippage factor &ð/ 𝜂𝜂 > 0 &

𝜂𝜂 < 0 *ąǁ*Hf~M„A transition energy

&ð.

𝛾𝛾_]= 1

√𝛼𝛼 (2-18)

%ȑǭĐ*Hf~M„* 𝛾𝛾] :<8ċ Ăé"4< 𝜂𝜂 > 0 *ųɔÔɠċ(=

2'îöųɦɢ(=SuperKEKB*:) ǭĐ*ɏİ23¸ɏ*Ăé𝛾𝛾 ≫ 1%=*%

IJ(2-16)+ 𝛥𝛥𝑇𝑇

𝑇𝑇 ≈ 𝛼𝛼 𝛥𝛥𝑝𝑝

𝑝𝑝 (2-19)

%=*ų*ēĕ£NJ+Fig. 2* +𝜙𝜙 ´&

&)(=

…ŬǭĐ*Hf~M„ 𝛾𝛾] :<8Ģ Ă

é+ 𝜂𝜂 < 0 &(=*%ɔÔɠċ 2'îö

ųɦǐ(=ēĕ£NJ+ Fig. 2 * −𝜙𝜙 ´%

=

2.4. T‚N€b€‚îƠŧ

T‚N€b€‚îƠŧ*IJAġÄ$

êŹ£NJ 𝜙𝜙_R ;ųɦ 𝜏𝜏 ɓ>$ =ǭĐʀ£

NJ 𝜙𝜙 = 𝜔𝜔_4<𝜏𝜏 + 𝜙𝜙_Rʁ)" $Ȁ=*ǭĐ*

1îö<*Hf~M„*>+

𝛥𝛥𝐸𝐸 = 𝑒𝑒𝑉𝑉Hcos(𝜔𝜔4<𝜏𝜏 + 𝜙𝜙R) − 𝑈𝑈, (2-20)

%=êŹǭĐ*Hf~M„ 𝐸𝐸, &=&ɓ

>ǭĐ*Hf~M„*> 𝛿𝛿 + 𝛿𝛿 =𝐸𝐸 − 𝐸𝐸,

𝐸𝐸_, (2-21)

:<

𝛿𝛿 =𝛥𝛥𝛥𝛥 𝛥𝛥_,

= 1

𝛥𝛥_,b𝑒𝑒𝑉𝑉_Hcos(𝜔𝜔_4<𝜏𝜏 + 𝜙𝜙_R) − 𝑈𝑈_,c

(2-22)

% = ê Ź ǭ Đ * î ö ų ɦ + Ë ) ɉ 1 revolution time (𝑇𝑇_,)%<Ø£ųɦ<*H f~M„*>+

∆𝛿𝛿 𝑇𝑇_, = 1

𝑇𝑇_,𝛥𝛥_,b𝑒𝑒𝑉𝑉Hcos(𝜔𝜔4<𝜏𝜏 + 𝜙𝜙R) − 𝑈𝑈,c (2-23)

&Ŷ=%𝑇𝑇_, +Hf~M„*ŚÔîŹ ʀ"4<T‚N€b€‚ŚÔ*îŹʁ:<8ÖÅ

)Ģ &ĕ=&

∆𝛿𝛿 𝑇𝑇_, =𝑑𝑑𝛿𝛿

𝑑𝑑𝑑𝑑 (2-24)

&ɇ¢%=

SuperKEKB%+ɳĐ+23¸ɏ%=*%

ɔÔɠ&Hf~M„*ɧ®+

𝑝𝑝 =𝛥𝛥

𝑐𝑐 (2-25)

&$: ; 𝛥𝛥𝑝𝑝

𝑝𝑝 =

∆𝛥𝛥

𝛥𝛥 (2-26)

&(<IJ(2-19):<

𝛥𝛥𝑇𝑇

𝑇𝑇_, = 𝛼𝛼𝛥𝛥𝑝𝑝 𝑝𝑝 = 𝛼𝛼

𝛥𝛥𝛥𝛥

𝛥𝛥 = 𝛼𝛼𝛿𝛿 (2-27)

%=𝛥𝛥𝑇𝑇 +îö<*ųɦɓ>(*%𝑇𝑇,% Ì=&Ø£ųɦ<*ųɦɓ>)(<

𝛥𝛥𝑇𝑇 𝑇𝑇_, =𝑑𝑑𝜏𝜏

𝑑𝑑𝑑𝑑 = 𝛼𝛼 𝛥𝛥𝛥𝛥

𝛥𝛥 (2-28)

&Ŷ=IJ(2-23)IJ(2-28);

𝑑𝑑⁾𝜏𝜏 𝑑𝑑𝑑𝑑⁾= 𝛼𝛼

𝑇𝑇,𝛥𝛥,b𝑒𝑒𝑉𝑉_Hcos(𝜔𝜔_4<𝜏𝜏 + 𝜙𝜙_R) − 𝑈𝑈_,c (2-29)

&(=ųɦɓ> 𝜏𝜏 +Ģ𝜔𝜔4<𝜏𝜏 ŁĢ%

=&>,

𝑑𝑑⁾𝜏𝜏

𝑑𝑑𝑑𝑑⁾ = − 𝛼𝛼

𝑇𝑇_,𝛥𝛥_,𝑒𝑒𝑉𝑉_H𝜔𝜔_4<𝜏𝜏 sin 𝜙𝜙_R (2-30)

&Ŷ=:ǎ;>$ =:)

𝑑𝑑⁾𝜏𝜏

𝑑𝑑𝑑𝑑⁾= −𝜔𝜔⁾𝜏𝜏 (2-31)

%=*%;T‚N€b€‚ŚÔ*ȟî Ơŧ 𝜔𝜔R +

𝜔𝜔_R= g 𝛼𝛼

𝑇𝑇_,𝛥𝛥_,𝑒𝑒𝑉𝑉_H𝜔𝜔_4<sin 𝜙𝜙_R (2-32)

%=𝜔𝜔_R ;

𝜔𝜔R= 2𝜋𝜋𝑓𝑓R = 2𝜋𝜋𝑓𝑓456𝜈𝜈R (2-33)

&(<T‚N€b€‚îƠŧ 𝑓𝑓_RT‚N€b€

‚]z„‚ 𝜈𝜈R ľ;>=SuperKEKB*ɳĐ }‚O%*³+2019ĬŲ*ɔɂėǻ%7 GeV, 𝑉𝑉_H = 14.2 MV&=&

𝑓𝑓₄₅₆ ≈ 100 kHz 𝑓𝑓_R≈ 2.7 kHz

𝜈𝜈_R≈ 0.027

%=T‚N€b€‚]z„‚+…î*ɦ)

¦öT‚N€b€‚ŚÔ=Aǔ$ ="

4<SuperKEKB}‚O*Ăéi‚]*Œ*

ǭĐ*£NJƒHf~M„*ŚÔ+}‚Oǰ37î

%1ö%=

%+ǭĐ*Hf~M„Ţč+ĕŧ𝑈𝑈_,&

ėɯ)+ǭĐ*Hf~M„)¬đ=4 ŚÔċ Ăé)" $8%+ȡ>(

>8[1-4]ǥ) B&ȭŰ>$ =

*%ÝƲ$2

3. SuperKEKB*RFTV`w

*ǡ%+SuperKEKB Ïɏõ)= RF

TV`w*¼¥ªAdz—=

SuperKEKB * RF T V` w + āż Dž ) KEKB*TV`wA¿Èƾ;(=ċɳƤl

„w)ĝŅ=7*ĆĴAȎ!Fig. 5 ) KEKB&SuperKEKB*j|x„[Aǔ[5,6]

SuperKEKB* RF*(ȯɽ+(1) ɳƤǰ 2²(2) ĩ ġǞƣ*l„wȶȊǰ3²(3) ċɳƤʂǐ i‚]ɢ):<ɿȰƠ(HOM)j

„Ćċ& &%=KEKB*RFTV

`w)ɧ$+ɕÜ*OHOXvd„%8ȗŧ

*Ȳǿ[4,7-11]Ȏ(@>$ =ȩDzAĒ.

Ŭ+- ;AÝƲ$

3.1. RFTV`w*ɞǽ&ƋŎ

Fig. 6)ƻü*SuperKEKB}‚Oº¥*RF TV`w*ɞǽAǔb‚f~*3ǧŐ*ljǺ ɜA>>2ÅÌȣ6ǧŐ*RFXNT{

‚<4ǧŐ)ĩ ġǞƣʀARESʁ2ǧŐ )Ƚ ġǞƣʀSCCʁɞǽ>$ =Fig. 7 )ƊșAǔ:)RF TV`w+¤ɳÍ RF (Low Level RF, LLRF) ÊĿǯN|EVb€

‚&*ɳƭġƠǩ9S„Lz„[„ċɳ Íßğj„Aíà=FI„[„€„c9Á Ú T V ` w ( ' * ċ ɳ Í ʀHigh Power RF, HPRFʁǯ$ÏɏǞƣ;Ŏ<Ǡ!$ = LLRF ÊĿǯ:. HPRFǯ+è RF XNT{

‚*ý‡ɜıĤ)ɞǽ>$ =

N|EVb€‚AŒŃ)c|Eo>=Ǟƣ Aì7$šɮ= RF ȥµǾAO~„pÕ$

Fig. 5 KEKB&SuperKEKB*RF)ɧɑ=j|x„[

Fig. 6 SuperKEKB}‚O*RFTV`wɞǽ ʀ2019Ĭƻüʁ6ǧŐ*RFXNT{‚*4ǧ Ő)ARES2ǧŐ)SCCȥǽ>$ = HER (electron) : SCC 8æ+ ARES 8æ, LER (positron) : ARES 22æ

RFV`„T{‚&ðB% =1"*RFV`„

T{‚)+1 æ*N|EVb€‚&ʃIJ*

LLRF Aì5c|Eo>=Ǟƣ+SCC %

>,1æARES%>,1æ4+2æ*Ăé

=Fig. 6 )ǔ:)ƻü+ɳĐ}‚O

ʀHigh Energy Ring, HERʁ)14IJɬɳĐ}‚

OʀLow Energy Ring, LERʁ)16IJéȣ30 IJ* RF V`„T{‚=Ǟƣ+HER ) ARES 8æ&SCC 8æLER)ARES 22æȥ ǽ>$ =

Fig. 7 SuperKEKB*RFTV`wƊș

Fig. 8+ý‡ɜ*N|EVb€‚;b‚f

~½*Ǟƣ4%ġƠǩ%Şǹ>$ =ƌĐA ǔ$ =ARES *16 æ+N|EVb€‚1 æ%2æ*ǞƣʀFig. 8(a)1:2ʁARES*14æ

&SCC+N|EVb€‚1æ%1æ*ǞƣʀFig.

8(b)1:1ʁ)ɿîƠċɳÍA«Ƿ$ =Ġƀ Dž)+ċɳƤl„w)ĝŅ=71:1 * ARES*æŧAĆ9ȣǀ%=

3.2. €„r~RF (LLRF) ÊĿ

RF *ÊĿǯ+¤ j„* RF AŒ&

; … Ȉ ) Low Level RF & ð , > = SuperKEKB*LLRF+ý‡ɜ*èıĤ½ÊĿ Ę)ȥǽ>$ =[7](LjDž+(1) Ǟƣ) ŕ¹=RFɳÍ*ŚĪ£NJAÊĿ$Ǟƣɳ ûA…ĕ)¯"(2) ]z„d„AÊĿ$Ǟƣ

*»ŚîƠŧAāƮ°çʀ𝑓𝑓_4<ʁʀ= +ŊùDž

) 𝑓𝑓_4< ;; 𝑓𝑓_,ʁ&êŹ=&%

=šɮ$ƌ(ǃĩ(°çAƉǎ$E‚[

„€^NADŽƽRF ɳÍ«ǷAƕ7<l

„wACs„b<=

Fig. 9)LLRF*o€^NùAǔRF*n D„ci^NÊĿ*ȩDz)ɧ$+[8]AÝƲ

$2 Ǟƣ)ȥǽ>m^NC^pt„b

;*RF°çAƉǎr~ʀǞƣɳû)NJ ĵʁƉÄ:.£NJƉÄȥĕ³&ƚɄ$

Ǟƣ)¹Í=RFɳÍ*r~:.£NJAn D„ci^NÊĿ$ =l„wɳƤĈÕ

=&Ǟƣ½)Òȼ>=l„wȶȊɳûĈÕ Ǟƣɳûƒ£NJ8ĈÕ=%m^NC

^p°çAɳû&£NJ*ȥĕ³Aĩ)ƚɄǞ ƣɳûƒ£NJ…ĕ)¯>=:)ÊĿ=

Fig. 8 ý‡ɜ*N|EVb€‚;ýˆb‚

f~½*Ǟƣ4%*ġƠǩŞǹ*ƎIJù(a) N|EVb€‚1æʆARES 2æ(b) N|E Vb€‚1æʆARES 1æ

4Ǟƣ*»ŚîƠŧ+ƪİĈÕ9Ƚ ġǞ ƣ%+q}FwûÍ('):=ĈĶį*ŚÔ(

'%8ĈÕ=…Ŭ¹Í=RFɳÍ*îƠ ŧ+úĕ>$ =*%Ǟƣ*îƠŧ]z„d

„AȰŨĩ)êŹ=ńș=]z„

d„*ƐƋ+Ǟƣ):!$ɘARES*Ăé +V[o]z„d„*Ǟƣ½0*ǟÄɠA ĈÕ$îƠŧAȰŨ=…ŬȽ ġǞƣ

%+Ǟƣº¥*ɢAĈÕ$îƠŧAȰŨ

=ËÄ*Ǟƣm^NC^pt„b;*°ç

&Ǟƣ¹ÍɳÍ*ye[„°ç*£NJAƉăƚ Ʉ$nD„ci^NÊĿ$ =ėɯ) LLRF%ÊĿ=*+è]z„d„AÔ¨=

V`^m‚Oy„[„0*j~VɳÍ9mHZ CN]zH„[0ÙÏɳû%=

SuperKEKB * LLRF TV`w*ÀnjA Fig.

10)ǔ(a)+Ľƀ©ƾ>$Cd€OÊ ĿyUz„~AǴ5é@TV`w(b)+

SuperKEKBƾ)ɥDŽaU[~ÊĿTV`w

% = aU[ ~TV `w+ µTCA ț Ɔ*

EPICS-IOC Ǵ5Ɇ5ÿ FPGA s„cAāLJ&

TV`w%<ƻüARES*9V`„T{

‚ʀ1:1ʁ)ġ¹aU[~TV`w%+Ï ɏɳǁ*ŚĪƒ£NJ*ēĕŇ&$0.02%

0.02°(r.m.s)*nD„ci^NÊĿēĕŇʀÊĿǮ İʁAėƻ[12-14]aU[~LLRFÊĿ)ɧ

Fig. 9 LLRFÊĿǯ*o€^N\ECO|w

Fig. 10 LLRFÊĿ|^N

(a) Ľƀ*Cd€OTV`w(b) ūțġ¹aU[~ÊĿTV`w

$+SuperKEKB%+( [15,16])ȩ Ƞȭ>$ =4ėɯ*RFÊĿ*āżÛ Ƽ)" $+RFTV`w2%ȩDz)Ƞȭ>

$ =*%`LVbAÝƲ$

SuperKEKB * LLRF )+Ǟƣ*njǞdžȜ9 Q„bi~oÊĿǥ8ì4>=Ǟƣ+njǞň Õ*ķɷAċâ=ʀŤɳǞƣŇȃ*ÐÕ ('ʁ*%ĩ)džȜ=ńș=4Ǟ ƣ9hEj„Ɛõ*ÁÚƜ9ƪİèǜƐõ*

V`„[Vǥ8džȜǃĩ*ɯ)+RFAOFF l„wACs„b4Ăé):!$+Q

„bi~oAɤ7=('E‚[„€^N):=

Ɛõ*¯ȴ8LLRFŖ!$ = 3.2.1. ċɳÍ*ƫĕ

SuperKEKB%+ŧ100 kW;ŷċ1 MW* ċɳÍAÊĿ=ńș=LLRF %+ŧ mW*j„Œ( %ċɳÍƫĕ

%+…ɜAá<Ä& ħČ=

&,Ǟƣm^NC^p°ç+Ǟƣ)á

<š;>C‚`dǥ):<Ǟƣ½)Òȼ

>ɿîƠɳǒĂ*…ɜAá<Ä8*%

=Fig. 9Œ*KLYÄÍǞƣßğ('+

ġƠǩ½A ɋ>=j„*ye[AŊï

$ =>;+ŬëŇǶéõʀFig. 11Ŭ Ƕʁ):!$ċɳÍ*…ɜAá<Ä$ =ġ Ơǩ½+ɒȎƠ&ßğƠ*‹Ŭđü$ =

*ŬǶ):<…Ŭë*5Aá<Ä&

%=ėɯ*ċɳÍ&ŬǶ= +m^NC^

pt„b%á<ÄɳÍ*ƚƺ+ǶéİʀK^

p}‚O𝐶𝐶ʁ&:,>$ =>;Ƕéİ+

;7ƫĕ$SuperKEKB%+ġ Ơǩ+ŷċ1 MW*ċɳÍ ɋ>=LLRF

%Œ=*+10 mWœˆ*r~%=*%

ŷċ%8ƇɇƩȒ=ńș=%Ƕ

éİ −50~ − 60 dB *ġƠǩŬëŇǶéõ©

ƾ>$ =

%dB &+ɳÍ*ƚAĝŧ%ȑ8*

%=&, Fig. 11 %ɳÍ 𝑃𝑃, & 𝑃𝑃m *ƚ ƺʀǶéİ𝐶𝐶ʁ+

𝐶𝐶[dB] = 10 × log_m,𝑃𝑃m

𝑃𝑃_, (3-1)

% ȑ > ª , 𝑃𝑃m⁄ = 1 100𝑃𝑃, ⁄ ( ; ,𝐶𝐶 =

−20 dB &(<10 dB 1Ƈ)NJĵ=>

+¦Ƈ8J„\„*ɘɳÍAŒ&)&$

8­È%=ġƠǩ*ŬǶ*Ƕéİ −60 dB

& &+6Ƈ*ƩȒƺ%ɳÍAá<Ä=

Ƕéõ& Ŋï%="4<Fig. 11%+

𝑃𝑃, = 1 MW → 𝑃𝑃m= 1 W & &%=

;)*ġƠǩŬǶ*=ĂŐ;LLRF*

=ÊĿĘ4%+êɃP„o~% ɋC^`f

„[ʀƩȒõʁǥ):<−20 dB 2'ƩȒ b„[~% −80 dB ǛİƩȒ$ LLRF TV

`w%á<Œ=r~)$ =

%8…"dBm & Ø£8ȝ:

>+1 mW = 0 dBm &ĕǿɳÍ*Ø£%

=[mW];[dBm]0*Ĉš+

[dBm] = 10 × log_m,𝑃𝑃 [mW] (3-2)

%=ɳÍØ£dBm&ɳÍƚdBA©!$ġ Ơǩ;LLRF4%* ɋAȑ$5=ġƠǩ

½ *   ɋ j  „ 𝑃𝑃tu= 1 MW Ŭ Ƕ Ƕ é İ ʆ

−60 dBP„o~€Vʆ−5 dBC^`f„[ʆ

−15 dB&=&LLRF %âá!j„

𝑃𝑃_vvwx +

Fig. 11 ġƠǩ*ŬëŇǶéõ

𝑃𝑃_tu = 10 × log_m,10^y= 90 dBm 𝑃𝑃_vvwx = 90 dBm − 60 − 5 − 15

= 10 dBm = 10 mW

(3-3)

&ijǨ%Ȁ=&%=ĆĪõ*Ć Īƺ8dB %ȑ>=*%ȾǨ>,:

4ȣǨ>,@=ɳÍƚ2²ʀ=

+×Åʁ(; +3 dB (−3 dB) & *8ȝ

$&­È% =IJ(3-3)*ª%+;)

−3 dB * C ^ ` f „ [ A ¹ > > , 𝑃𝑃vvwx = 5 𝑚𝑚𝑚𝑚 &(<LLRF%Œ ű r~)(=

ŬëŇǶéõ+ɒȎƠ&ßğƠAÅɱ$&

<Ä=*ƶł%+=Ĕº)Åɱ=*

+ɲ Fig. 11* 𝑃𝑃₎ %ǔ:)ɌŬë*

j„*…ɜ8á<Ä>$4*ɌŬë

*Ƕéİʀ𝑃𝑃, )ĝ= 𝑃𝑃) *ƚʁACEY„T {‚ 𝐼𝐼𝑃𝑃_m )ĝ= 𝑃𝑃₎ *ƚAŬëŇ 𝐷𝐷&ð/

𝐼𝐼[dB] = 10 × log_m,𝑃𝑃)

𝑃𝑃_, 𝐷𝐷[dB] = 10 × log_m,𝑃𝑃₎

𝑃𝑃_m 𝐷𝐷 = 𝐼𝐼 − 𝐶𝐶

(3-4)

%=ġƠǩŬǶ*ŬëŇ+Ɏĩ −20~ − 30 dB %<"4< 1%Ǜİ+ɌŬë*°ç ƨ=4ŬǶ*Ƕéİ*ƅƖ+ɲċ ɳÍƫĕ)+ ±5%Ǜİ*ȬĨì4>=&Ȁ

;>=

*ɸ%+ŬǶ('*ƩȒƺ+−20 dB ('

&ȶ%ĆĪƺ+Ɩ%ȑŮĩDž)+ǣ çANjǂ$Ø) 20 dB *ŬǶ&20 dB * C‚p('&ð/&Ċ ɧ®ȁ&ŸȨ

=&)+șơŊ%=

3.3. hEj„RF (HPRF)

hEj„RF*ƐõAFig. 12)ǔLLRF

;+ŧ mW Ǜİ%ÄÍ> RF ɳÍ+C‚

p%ŧ W )ĆĪ>N|EVb€‚)¹Í

>=SuperKEKB*N|EVb€‚ʀFig. 12(a), Fig. 13ʁ+ĆĪƺ50dBʀ5Ƈʁ*QE‚Aŗ

ŷċ1 MW*ċɳÍRFAÄÍ%=ċ(H f~M„AŒ7Ɛõ*¯ȴ&NjHf~M„

*7)ĈšÓƺ*ŷəÕńɺ%<ńș) Ņ$ÔDž)Cg„cɳûAÊĿ=&):

<RN[„€VAŷəÕÓƺÕAù!$

=N|EVb€‚+2æ%1IJ*ɳƭ (Fig.

12(b)) ):<ÊĿ>$ $KY„cƾɿûɳ ƭCg„cƾɳƭk„[„ɳƭàžRE~

ɳƭN€„i„öɀǥ%ƋŎ>$ =[17- 19]N|EVb€‚;ÄÍ>ċɳÍ RF +ġƠǩAɎ!$ýˆ*Ǟƣ)ġ>=>

AǠ¥öɀ&ð/ (Fig. 12(c))ɍŒ)+S„L z„[„ś¹>$ $Ǟƣ0ɋ=j„

&Ǟƣ;*ßğj„AÅßğj„N

|EVb€‚)ŏ;( :) 1MW FI„[

„€„c%Ƴ&$íà=41:2 %Ǟƣ )Şǹ>$ =Ăé+Magic Tee (MT, Fig.

12(d)) &ð,>=Power Divider%ÅĦ$2æ

*Ǟƣ4% ɋ=*Ăé1MW FI„[

„€„c+MT*Ǥ4t„b)ȥǽ>ßğj

„Aíà=ġƠǩýˆ)¹=ljË)+ġ ƠǩÿǚNJõ (Fig.12 (d)) <RF*£NJA ċ4)ȰŨ=&%=ġƠǩ*ǵɀɢ +Ǟƣ&)ǃ(=7‘7*ǚNJõ%Ǟƣ ɦ*£NJĨAȥȣ³)ɇ#$2 æǞƣ

;MT)ŏ!$=ßğj„+” Ɍ£

NJ)(!$ >,º$Ǥ4t„b)éŎ>$Ä Í>=8êNJ%=&‡Ƥ*S„Lz

„[9N|EVb€‚´)ŏ!$4"4

<ʄǞƣ*ġƠǩɢ+ĸŀ%Ɍ£NJ)(=:

)ƴɖ% 90 İ£NJ>=:)*ǚNJõ

%ȥĕ=ńș=ġƠǩ*èŐ)+RFƫ ĕƾ*ŬëŇǶéõȥǽ>$<>>

LLRF)$ye[„ÊĿ)©ƾ$ =

Fig. 12 hEj„RFǯ*Ɛõ(a) 1MW N|EVb€‚(b) N|EVb€‚ɿûɳƭTV`

w(c) Ǡ¥öɀǯʀġƠǩS„Lz„[„1MW FI„[„€„c™ʁ(d) Magic Tee (e) ġƠǩǚNJõ

3.4. ĩ   ġ Ǟ ƣ ʀ Accelerator Resonantly- coupled with Energy Storage, ARESʁ SuperKEKB*ARES +KEKB Ïɏõ*ċ ɳƤl„wʀȥȣ%+2.6 A @LERʁ)ĝŅ=

7 ) Ƹ Ȅ ) ɥ DŽ > SuperKEKB %+

upgradeAŭ$¿Èƾ$ =Ǟƣȥȣ('

*ȩDz+[7,9,20-22]AȚ$ Fig. 14 )Ïɏõb‚f~½*ARESFig. 15) ARES

*ƎIJùAǔ8!&8ƶłDž(*+3 æ*

ǞƣAɑǶƋɐ)(!$ =&%=Ï ɏǞƣ&Hf~M„ȷȍǞƣ*ɦ*ǶéǞ ƣA—$Ƕé$ =ȷȍǞƣÏɏǞƣ*

9 ²*Hf~M„AȌ=&%l„wȶȊA 1/10)Ț=ÓƂ=>):<ċɳƤl

„w):<Ǟƣ* detune ɠċ(=&Ƕé i‚]‰ēĕŇÒȼ>=ʀȩDz+RFTV`

w29[11]ʁdetuneɠAŔÊ=&%

=ċɳƤl„w):!$Òȼ>=ɿȰƠɳÍ (HOM)+ÏɏǞƣ)á<š;>őīǏĶÿ HOM ġƠǩ:.ÏɏǞƣ*‡ƒˆƤ)+Ư

šl„wjEp)ȥǽ>SiCȖɳƠíà¥

%á<ɫ&%=SuperKEKB0*(

upgrade+ċɳƤl„w)ĝŅ=7:<

ɳƤ*ċ LER)HER;ǞƣAǚȥ 4N|EVb€‚&1:1ƋŎ*ǞƣAĆ9

"¹ÍǶéõ*Ƕéİ 𝛽𝛽 A3;5)ĆĴ 𝛽𝛽 +l„w( &)Ǟƣ½%Ʀȹ>

=j„&¹ÍǶéõ;Ä$Ȏj„*ƚ

%ĕǿ>l„wȌǝų)ßğj„AĢ ʀ%>, 0ʁ)=7)Ɏĩ 𝛽𝛽 > 1 )$

𝛽𝛽 = 5& *+ǞƣƦȹj„)ĝ$

l„wȶȊ4²*&)ßğj„0)(=

ȥĕ%=ȩ+RFTV`w2%Ƞȭ

Fig. 13 N|EVb€‚*Ƌɐ

Fig. 14 SuperKEKBb‚f~½*ARESǞƣ

Fig. 15 ARESǞƣ

$ =*%ÝƲ$2 *Ƕéİ 𝛽𝛽 *Ć Ĵ):<:<ċ(l„wȶȊAȶŖ=&

%=SuperKEKB*ARESǞƣ*ɔɂj|

x„[ʀȥȣ³ʁATable 1)ǔ Table 1: ARESɔɂj|x„[

Parameters SuperKEKB

(design) Number of ARES cavities HER: 8, LER: 22 Beam power [kW/cavity] 600 RF voltage [MV/cavity] 0.5

3.5. Ƚ ġǞƣʀSuperconducting Cavity, SCC) SuperKEKB*SCC+KEKBÏɏõƾ)ɥ DŽ>ɿȰƠƩȒÿȽ ġǞƣA¿Èƾ$

=Ǟƣȥȣ*ȩDz+[23-25]AÝƲ$

Fig. 16)b‚f~½*SCC:.Fig.

17)SCC*ĉȞ&ŪɶùAǔeJoȖØX

~Ƚ ġǞƣ*ĉ´)Ƨ¥q}Fwƍ*ĉ´

)ŪƳnjǞƍ*ʅɟƋɐ)(!$<*ɜÅ AN|EJyUz„~&ð/4SuperKEKB

* SCC %+N|EJyUz„~*‡ƒˆƤ*

ĘƪɜÅ)Ļɉ*ɿȰƠʀHOMʁíà¥9njǞŝ ƛǯƒnjǞȣAá<šl„wjEpAŞǹ

*‹Ǣ)Q„bi~oAȥĉɜ*l„

wjEp;ƸǠ%=Ƌɐ&Ƚ ġǞƣ +½ȑɶ*Ɲ>)ɵĩ)ťŋ%=*Ƌɐ ):<ĉɜ;*ƝƃA%=ɨ % = 4­Ė‡*Q„bi~o4%A SCC yUz

„~('&ð/&=

Ǟƣ*‡ƒˆƤ*l„wjEpAċãĹ)=

&%l„w):!$Òȼ>HOMj„

AǞƣ*ĉ)á<Ä9l„wjEp)

¾Ǧÿ*nG|EbȖHOMíà¥Aá<š$

HOM j„Aíà%=¹Íj„+êɃÿ

*¹ÍKp|;Ǟƣ½)«Ƿ$ = KEKB;SuperKEKB0*upgrade%+

SCC)ɧ=ɔɂſž+2&B'¯đ>=

7ċ(Ĉŵ+( …Ŭ%ċɳƤÕ)¡

HOM j„Ćċ=7Q„bi~o*ĉ

´)SiCȖ*HOMíà¥AɊÏċɳƤɔ ɂ)µ$ =HOM +ǞƣAɎɕ=l„

w):!$Òȼ>=ɿ îƠŧŎÅ*j„

%=i‚]ɢǐ(=2'l„wɳƤ Þ.i‚]ɳƤċ(=2'ċ(j„

)(=SuperKEKB*SCC%+KEKB*3~4

²)ĆÏ=&‘ƫ[26]$ =

4SCC +KEKB ų›;10Ĭœ‡*l

„wɔɂ)©ƾ$ =7ǞƣŇȃʀQ0³9

Fig. 16 SuperKEKBb‚f~½*SCC

Fig. 17 SCCĉȞ&Ūɶù

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