22/02/07 B



1

Beam status
2021c

Final goal

Beame+e-e+e-Energy

4.0 GeV

7.0 GeV

4.0 GeV

7.0 GeV

Bunch charge
1st , 2nd [nC]

3.0 , 2.5

2.0 , -

4.0, 4.0

4.0, 4.0

Normalized
emmittance[mm-mrad]120, 5(Hor. , Ver. )50-20, 50-20(Hor. , Ver. )100, 15(Hor. , Ver. )40, 20(Hor. , Ver. )Energy spread

0.16 % ?

?

0.16 %

0.07 %

Simultaneous
top-upinjection

4+1 rings(LER, HER, DR, PF, PF-AR)

4+1 rings(LER, HER, DR, PF, PF-AR)

2

Electron beam charge 2021c

RF Gun generation

Linac end3

Positron beam charge 2021c
Electron

Gun generation
Primary electron at target

Positron after target
Linac end positron

Positron4Electron beam emittance 2021c
In upstream of Linac
10 to 20 mm-mrad

In BT line

Under 20 mm-mrad in goodcondition.

5

Positron beam emittance 2021c
Primary electron beam

In BT line
After dumping positron beamHor. 120 mm-mrad

Ver. 5 mm-mrad
6

FC modulator improvement• .?;5OFC:&8<>@ -2.6+'32+O.?:FC9 8<34$0?4(>P• 1*1O&9 87=)>DHAB&:
61434(2P• ..9DHAB&:;?8 9/@,#.14(2P• 9IMFGMD%8FCJCKLNE9!@"(O.9DHAB&97814(>P7FC head improvement (2020c)
  FC" 


FC#
Before Base 7

Base 8!yoke shape optimization!Insulator improvement

8Y. Enomoto 

#

 "!

 $

1
R1

1R1
66

D1
100kRps2

DC 20k AC 0 0Lsy
0.5u/21511

1.4u C1

Lline1
0.25u/2

0.2/2
Rline1121010nCline

4V1

Lline2
0.25u/20.2/2
Rline2

D1100k
9Rps2

L21u

80.1
Rfc

1111.4u C1

Lline10.25u/2

4V1

70.1
Rsy

DC 20k AC 0 0

Lsy
0.5u/25121010n
Cline

Lline2
0.25u/2

0.2/2
Rline2

9L21u

80.1
Rfc
720.1
Rsy

Lfc
1.1u

0.2/2
Rline1

Lfc
1.1u

R7133

FC_basic.CIR

18.00K
16.00K
14.00K

caused by parasitic
capacitance oftransmission cable12.00K
10.00K
8.00K
6.00K
4.00K

12.00K

15.00K

6.00K
4.00K
2.00K0.00K

0.00u- v(8) (V)

4.00u

8.00u

12.00u- 2.00K
16.00u 0.00u- v(8) (V)
15.00K

20.00u4.00u

8.00u

12.00u- 2.00K
16.00u 0.00u
20.00u4.00ui(Lfc) (A) i(L2) (A)

8.00u

12.00u12.00K

12.00K

10.00K

10.00K

8.00K

8.00K

6.00K

6.00K

4.00K

4.00K

2.00K

2.00K

0.00K

0.00K

- 2.00K

Reduce spike voltage

10.00K
8.00K

2.00K
0.00K
- 2.00K

FC_basic_wit hCR.CIR

20.00K

Spike voltage

14.00K

100n

SW120.00K
18.00K
16.00K

C43SW10.00ui(Lfc) (A) i(L2) (A)

4.00u

8.00u
T (Secs)

12.00uT (Secs)

9Set RC circuit to the FC modulator
RC circuit

10

FC# $&(!"$&(%'  2021cFC))
11

AJ0DKO@OE)<GO8(#$• AJ0DKO@OE);O6=>
%  ('-&('"$• .*0N815;O%)2?L4O
,$ Q• 2?L4O8=;O):O9*F8HMO;)HV8=;O&HV pulse shape!" Q• AJ0DKO@OE -3BMO7INC
0N>( $P2022)/+$-Q

12Energy jitter of AT line (Thermionic gun injector line) cussed beamloss at J-arc
R0_32 Charge

AT_J2 Energy

DC gunA sector

FCTargetC sector

RF gunRF gunR sector(J- arc)

B sector

DumpingRingLAS

1 sector

2 sector

3 sector

4 sector

5 sector131 "&0) *$+-0' 11#,!%(./*$+-0'  2#,!%(./ *$+-0' 214

Modulator feed pulse HV.

Flat pulse is necessary.
Vt

RF poewr-300 kV
5 usecNormalt usage
4 usec15

Modulator feed pulse HV.

Flat pulse is necessary.
Vt

RF poewr-300 kV
5 usec4 usecParallelconnectiont

At injector, gun wasconnected.
16

Sensitive to timing jitter

Modulator feed pulse HV.

Flat pulse is necessary.

Pulse shape was broken !!
Vt

Modulator pulse timing
jitter is 10 ns

RF poewr-300 kV
5 usec4 usecParallelconnectiont

At injector, gun wasconnected.
17HV'#*-&).+
0 !

2022/01/17 study

HV delay

Energy(AT_J2 Y)

HV delay
1 step = 8.8 ns

AT_22 Y/HV'#*-&).+$(,%."!018

Source of beam instability
:2(369* 10 nsec *%08'(+*9$
":/4+,-5)## !;•  A1_A&4%),78:-5) #" :.91 ;•10 nsec timing jitter

A1_A klystron pulse
Normal pulse
19

($+.'#*/,%)-&/#!"02022

*/,





#

 020

Conclusion 2021c• [b^1&/H F :B2F1&/O
;B4AB4L7cGc()FHG1&/H<MB4Ld• 01 /HG$O@=B4LGCc+-/O;B49TUXPbO!:B49d• 1 [b^J_bRbZ`b\bSaD6KG2Y
aV,*O#5MIE1&/HC8B4LDNMLd• Q]WUaTHO.>LD8J3L7c?MO
F">LFH%AB4E4GCc,*F :B O'AB49d21

Linac Upgrade 2022-2026• #'-&76 13,!
• # "
• PCB*5.5+
•e-%03(7• RF!
•! • $-2)47/






22

1st 2nd bunch
C. Mitsuda

23&-"Q
D12

IN+

D11

M0

M1

CHV

D4

M3

OUT+

OUT-J-arc/(+ ),.'.*  &-"Q&-"Q)!
%#$/

M2CHL
D2D3M424

! "' &$%$#'&$# &$(

25

PCB%PFNLXPXM
•0AJUHNQWX"SVN5?B40"PFN– 20APFNG2

••!PCB A
AB'600
PCBA+97E

.]

– -?/<>):8E•;FC?BKVYTA&?/• *5\47kV• 653\0.0155μF• ROLX,• 23\10kg#

• 1'15

Z$:[• 0/=E4B

• (B8I#• 1A(@DE26
Electron ECSHER277)"06/?
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28