=== Injector Upgrade ===for Fast Beam-Mode Switch
M. Satoh (Linac Control G.)
for the Injector Upgrade (IUC) WG members

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee, Mar. 19-21, 2007

KEK Injector Linac:• J-like shaped Linac (600-m-long )• Injector for 4-rings:• PF (2.5-GeV e-/ 0.1-nC) Once/ day• PF-AR (3-GeV e-/ 0.1-nC) Twice/ day• KEKB HER (8-GeV e-/ 1-nC) CIM• KEKB LER (3.5-GeV e+/ 1-nC) CIM
e- Gun (A1 Gun; for KEKB)

PF#3 Switchyarde- Gun (CT Gun; for PF/ PF-AR）
KEKB/ AR

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Beam Operation Statistics of Linac
Continuous Injection Mode (CIM)
since 2004

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

KEKB Injection (CIM)• Frequent Switch of Linac Beam-Mode:

KEKB e+Current

10 s
e+ injection
30 s

Beam-Mode Switch (e- <=> e+): 30 s
KEKB eCurrent

M. SATOH/ KEK Linac Control

e-injection
30 s

10 min.

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Beam-Mode Switch =Change magnetic field Change timing
 Insert/ Remove e+ target (e-/ e+) Klystron mode (Acceleration/ Standby mode) Klystron (Sub-Booster Klystron) phase Etc.
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Consumed Time for Parameter Switch
109Timing parameter

8Time [s]76Magnet parameter

5

Pulsed coile+ taeget
insert/ remove

BPM-DAQ

4e+ => ee- => e+32Item
M. SATOH/ KEK Linac Controltgtintmloadtmloa
dx61loadfpon

tdloa
dtgtouttgtout2

gdls etguloadnims
s6aphagldphls bscinit
shdif
f
speak
spmo
d0
synckbtda gl
d1bun0chbeamof
bs58onbt2kb
e
bta gl
d
btfkb
e
btlan
schon
chopen
ecsm
ax
fpdiv
5
fptele1

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Why need to Upgrade Injector Linac? =• PF ring needs Top-up Injection under KEKB CIM.
• PF-AR ring needs CIM for Machine Study.
• Fast Beam-Mode Switch scheme is strongly
required. (Simultaneous Injection)
Beam-Mode Switch

KEKB e- KEKB e+ KEKB e- KEKB e+ PF e- PF-AR e-PF e-KEKB e+20-ms (50-Hz) RF pulse cycle

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Injector Upgrade Plan =• Phase I, II, III• Phase-I (completed): Construction of New PF-BT line (bypassECS)• Save time for switching beam mode between KEKB and PF
5 min. 30 s => 2 min. 30 s(KEKB mode => PF mode => PF injection => KEKB mode)=== Multi-Energy Linac Scheme ===• Phase-II: Fast Beam-Mode Switch (KEKB e-, PF)• Phase-III: Fast Beam-Mode Switch (KEKB e-/ e+, PF)• (?): Fast Beam-Mode Switch (KEKB e-/ e+, PF. PF-AR)
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Phase-I [Completed, Summer 2005]
ECS is always ON. (KEKB e-/ e+ and PF modes)
 It shorten time for beam mode change. (KEKBÙPF)PF (2.5-GeV e-)
PF modeECS ON

New PF-BT
Old PF-BT

DC Bend (BM_58)

Beam dump#3 SwitchyardECS

PresentPF-BT

Past PF-BTM. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Injector Upgrade Plan =• Phase I, II, III• Phase-I (completed): Construction of New PF-BT line (bypassECS)• Save time for switching beam mode between KEKB and PF
5 min. 30 s => 2 min. 30 s
(KEKB mode => PF mode => PF injection => KEKB mode)=== Multi-Energy Linac Scheme ===• Phase-II: Fast Beam-Mode Switch (KEKB e-, PF)• Phase-III: Fast Beam-Mode Switch (KEKB e-/ e+, PF)• (?) : Fast Beam-Mode Switch (KEKB e-/ e+, PF, PF-AR)
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Fast Beam Mode Switch =•Fast change of the magnetic field is difficult by using current system.

= Multi-Energy Linac Scheme =•Magnetic Field：•Common Parameter (Quadrupole and Steering magnets)• Energy Adjustment：•Change Sub-Booster Klystron Phase quickly.
（Low-Level RF Phase）

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Phase-II

Phase-II= Fast Beam-Mode Switch (PF and KEKB e-) =Multi-Energy Linac Scheme PF injection will be performed by A1-Gun.
 DC bend (BM_58) will be replaced by pulsed bend.
e- Gun (A1 Gun; for KEKB and PF)

PF#3 Switchyard

e- Gun (CT Gun; for PF-AR）
KEKB/ ARDC Bend

M. SATOH/ KEK Linac Control

ECS

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Pulsed Bend and Power Supply (Summer 2007) =•PS

•Bend
•Bending Angle： 7-deg. (3-GeV)•Max. Current:•Max. Field：1.2217-T•32-kA (12.5-Hz),•Gap： 157 x 30 mm•27-kA (25-Hz)•Ceramic chamber•Ti coating (1-µm)

M. SATOH/ KEK Linac Control•Pulse Width: 200-us•Stability: < 0.1%

Twelfth KEKB Accelerator Review Committee,
M. Tawada, T. Mimashi, M. Kikuchi, Mar.
et al.19-21, 2007

Phase-II•= Multi-Energy Linac Study =“2.5-GeV” ・“8-GeV” e- beam: accelerated by common magnet parameter

2.5-GeV e- optics (for PF)

8-GeV e- optics (for KEKB e-)

Y. Ohnishi, M. Kikuchi, N. Iida, et al.

Deceleration phase・γεx = 2.5x10-4 m, γεy = 4x10-5 m= PF / KEKB e- Injection Rate =•PF: 1.5 mA/s (25 Hz)•KEKB e- : 4 mA/s (1-bunch/ 50 Hz)•Noiselevel for Belle detector: No problem

PF Injection Study using Multi-Energy Linac Scheme
2.0

Injection Rate [mA/s]・γεx = 3.6x10-4 m, γεy = 6x10-5 m

1.5

1.0

0.5

0.0

14:30

M. SATOH/ KEK Linac Control

14:35

14:40

14:45

Twelfth KEKB Accelerator
Time [hh:ss] Review Committee,
Mar. 19-21, 2007

Phase-III= Fast Beam-Mode Switch (PF, KEKB e-/ e+) =For fast switch (e-/ e+ mode) :• e+ target with a hole.
• Fast control of e- beam orbit
by pulsed steering magnet.

primary e- for e+e- beam (e- mode)
Hole for e- bypass

Crystal tungsten target:φ5 mmview from upstream

4.5 mmHole: φ3 mm
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Passage rate of e- (target hole): 95%
 2nd bunch: Not Easy

w/o e+ target(normal operation)
X [mm]
Y [mm]
I [nC]

e+ target
w/ e+ target
X [mm]
Y [mm]
I [nC]

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,T. Kamitani,Ohnishi, et al.
Mar. 19-21,Y.
2007

BPM-DAQ System Upgrade:

BPM-DAQ System should be upgraded to measure
beam position up to 50-Hz.
Old System:
 5-GSa/s, 8-bit, 1-GHz Analogue BW
 GPIB control
 DAQ performance: 1-Hz
BPM DAQ system
New System:(VME + Oscilloscope with GPIB) 10-GSa/s, 8-bit, 1-GHz Analogue BW
 100-Mbps/ GbE Network
 DAQ performance: Enough for 50-Hz

Thirteen systems have been installed.
 Remaining old systems (8) will be replacedin this summer.
New system(Fast Win. Based-Oscilloscope)
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

= Repetitive DAQ Performance =(Fast Digital Oscilloscope)350

ch1ch2ch3ch4

DAQ Speed [Hz]300
250200150100500050 100 150 200 250 300 350 400 450 500
Data length [k-points]

M. SATOH/ KEK Linac Control

M. Satoh,
T.Suwada,
et al.
Twelfth KEKBAccelerator
Review Committee,
Mar. 19-21, 2007

Result of 3-BPM Measurement
KEKB e- mode
(1-nC)

Resolution [mm]0.20.18

KEKB e+ mode(e- 7-nC)

0.160.140.12
0.1
0.08
0.06
0.04
0.02
0Old System

New System

Old System

New System

M. Satoh, T.Suwada, et al.

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

New Timing System (under test):
Timing system should
control the complicatedoperation mode.
(after Phase-II/ III) Event generator (EG) andReceiver (ER) based on
VME-64x is under test.
A. Kazakov, K. Furukawa, et al.

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

Scenario for PF-AR Injection:
PF-AR Top-up (6.5-GeV) needs large budget.
Current PF-AR BT: 3.1-GeV max.
 Some part of BT is common between PF-AR and KEKB e-.


One solution: Use KEKB e+ (3.5-GeV) beam for PFAR injection. It also needs large budget.
Need to replace some PS of bend (@AR-BT).
 Need to replace Septum and Kicker PS
 Need pulsed bend and PS
 Cost estimation and design work will be done soon.
M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,Mar. 19-21, 2007

=== Schedule ===FY2005
SummerBeam
operationHardware2006Summer2007Mar.

2007
SummerPhase-I

New PF-BT
construction

New BPMDAQ

Software

M. SATOH/ KEK Linac Control

BPM
Softwarefor newDAQ2008
SummerPhase-IITEST

PF Top-Up foruser
experiment

Phase-III
TEST(Phase-II/III)New BPMDAQ
Pulsed BendTEST

INSTALL

Pulsed Steering
TEST (e+target bump)

INSTALL

Pulsed sterrgin
TEST (5Sector)

INSTALL

New Timing
System TESTINSTALL

200X ?

Software for
New Timing
SystemTESTOperation
SoftwareUpgradeTEST

Simultanious
injection 4-rings

AR-BT Upgrade?

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007

=== Summary ===KEKB injector linac upgrade project has started in
the summer 2005 toward Fast Beam-Mode Switch.
(KEKB e-/ e+, PF e-, PF-AR e-).

Phase-I completed (New PF-BT line):

It can shorten time for beam mode switch (KEKBÙPF)Phase-II, III
Use “Multi-Energy Linac scheme”:
 Use common magnetic field and fast change of rf phase.
 Machine study result shows feasibility.
 Machine study is going on.
 Need to upgrade the operation software.


After complete upgrade, the linac beam operation will
become more effective.

M. SATOH/ KEK Linac Control

Twelfth KEKB Accelerator Review Committee,
Mar. 19-21, 2007