Status of
Simultaneous Injection
from LINAC

2009/2/9 @KEKB Review
N. Iidafor LINAC Study groupMotivation
 Switching time for HER/LER injection was morethan 30sec.
 Faster switching are required to improve thecollision tuning with Crab cavities;
 Luminosity tuning at constant beam currents
 Operation at the shorter lifetimes
 Speed up of luminosity tunings (knob scanning) Prevention of current losses at the head of trains PF top-up operation will be started.

KEK Injector LINAC• Injector for 4-rings:• KEKB HER (8GeV e-/ 1-nC)• KEKB LER (3.5GeV e+/ 1-nC)• CIM(Continuous Injection Mode)• PF (2.5GeV e-/ 0.1-nC) Twice/ day• PF-AR (3GeV e-/ 0.1-nC) Twice/ day#3 Switchyard
e- Gun (A1 Gun; for KEKB and PF)
PF)

B
CPF

A
12e+ Target

e- Gun (CT Gun; for AR)

345
HER/LER/AR
HER/LER/AR

pulsed BendECSEnergy profiles and Charges
B

PF

A

RC

124

35HER/LER/AR
HER/LER/AR

Energy(GeV)

deceleratione-: 0.1nC

2.5 GeV → PF

1.78.0 GeV → HER

e-: 1.0nC

a c c e le r a ti

1.7

e-: 10nC
1.7

Ron

e+: 1nC
3.5 GeV → LER

end of LINAC

Hardware Progressin 2007~2008

Summer/2007
A pulse bend was installed at the branching point for PF beam.
 PF beam has been produced by A1-GUN.


Jun/2008


e- operation was done keeping the e+ target with a bypass holeinside the beam pipe.
• Before that, for life extension of bellows used for target insertion,
HER/LER injection cycle had been limited more than 5 min.

Oct/2008

10 pulse steerings were installed in LINAC.

Nov/2008
Event system was introduced for timing control.

“Simultaneous Injections”
PF/HER injection

1.

Achieved!

Fast switching beam injection■

Switching time ~ 2 sec.
Used in operation ( Oct./2007 ~ 10/Dec./2008 )-Pulse-to-pulse switching■

Conditional test injection was succeeded.

-HER/LER injection

2.

Fast alternating beam injection■-Switching time = 2 sec.
Used in operation (11 ~ 25/Dec./2008 )HER/LER Pulse-to-pulse switching injection

3.
Planned to be done in Apr./2009

PF/HER/LER Pulse-to-pulse switching injection

4.
Planned to be done in Oct./2009

1. PF/HER

1. PF/HER
Fast switching beam injection
 Compatible optics- DC Magnetic field(Quad, Steering):
Common parameter- Energy adjustment:
Change Sub-Booster Klystron phase quickly Orbit correction

1. PF/HER

PF/HER Compatible Optics(Y.Ohnishi)

Optics from C to 5 sector is designed by based on 2.5GeV beam(PF).
2.5 GeV PF
e+ Target hole

8.0 GeV HER
2008/06/09 20:39:21

Decelerating

Betatron phase advance
between 4 and 5 sector: 108 deg.

e+ Target hole

2008/06/09 23:07:31

AcceleratingBetatron phase advance
between 4 and 5 sector: 30‐50 deg.
8

(Y.Ohnishi)

1. PF/HER

Fudge factor measurements of Q-magnets
Single kicks by
SXC21/SYC21

Blue：Measurements
Green：Model calculations"x i = x(+)i # x(# )i

ΔPF BeamΔ"y i = y(+)i # y(# )i!

Responses by measurements are different
from model calculations.

9(Y.Ohnishi)

1. PF/HER

Q fudge factor
Definition of Q fudge factors:(j)~... :Differences of orbits
between measurement
and model kicked by
the j‐th steering magnet!

K PS,i = A f ,i " K model,iResponse matrix is
calculated with SAD(1)# x (1)& # R11(1)meas,1 " x model,1%( % (1)M%( % R21(2)% y (2)( % R11(2)meas,1 " y model,1%( % (2)M%( % R21(3)% x (3)(=% M
meas,1 " x model,1%( %M%( %(4 )
(4)
% y meas,1 " y model,1 ( %%( %M%
( %%( %M$' $R12(1) LO
R12(2)
OCorrection& factors of( K‐values((# )K1 &(%()K2(%((% )K 3 ((%()K4(%((%($ M '((('A"1f ,i = 1+

#K i
Ki

Solved with SVD!
10!

1. PF/HERPF Beam

(Y.Ohnishi)

AF‐1

Fudge factor

Field gradient

QD284

ΔB’ (T/m)

QD484

From AF and ΔB’ valuesof QD484, the magnet issuspected to havesomething wrong.

Miswiring on a power supply
of QD484 was discovered!
11(Y.Ohnishi)

1. PF/HER
PF BeamΔ

Single kicks by
SXC21/SYC21

Δ"x i = x(+)i # x(# )i"y i = y(+)i # y(# )iBlue：Measurements
Green：Model calculations

After•QD484 mis‐wiring
fixed•AF’s are innovated

ΔΔ!

Measurements arein good agreement withmodel calculations

12

PF BeamOptics measurementswith wire scanners

Design Optics
2008/06/09 20:39:21

After QD484 fixed and AF’s innovation

13

(Y.Ohnishi and K.Furukawa)

1. PF/HER

Orbit feedback
Accelerate

BPM
Steering
Bump Height
Feedback

Decelerate

The two orbit bumps
are closed at PF beam
but they generate orbit
distortion at HER

PFTargetbump

Accelerate

Pulse
BendAccelerate

HERECS

1,2 sector

3 sector

4,5 sector

(Y.Ohnishi)

1. PF/HERHER Orbit correction

PF Orbit

Before orbit correction

The difference of PF beam orbit
between before HER orbit correction
and after that.
2 bumps can be seen

Afterorbit
correction

Close up
The horizontal
positions canbe set to 0 mm
at the entranceof ECS

The orbits are
not affected at
the entrance ofpulsed bend.

1. PF/HER

Pulse-to-pulse Switching Event system PF/HER injection

Event system

K. Furukawa

Event system configuration

1nC)
Injection parts

1nC,

Event system

Event system
Fast switching of many device parameters
In 20ms / 50Hz

MRF Series 230 Event Generator / ReceiverVxWorks 5.5.1, MVME5500
Timing precision less than 10ps

◆Event Receivers
Phase switching of SHB and SB

Pulse magnet

Event system controls SHB and SB phases
instead of PLC.

ACC/STB switching of SB
GUN
GUN bias
High voltage
GUN delay

EVG & Timing

Pulse steering
Pulse bend
Pulse coil
Septum, kicker

Monitor

BPM
Wire scanner
RFInjection parts

Injection phase
Bucket selection

EVR & LLRF

Event system

K. Furukawa

Beam mode pattern generation
Manual pattern designer

A version for current operation

 10 different beam modes are defined (for LER, etc).
 Using a graphic interface, arbitrary pattern can be set.
 We can switch beam mode every 20ms pulse.
 Beam mode pattern specifies how to change beam

Beam mode patternmodes for 1 second.
 A new pattern is loaded at the end of the previouspattern.
 Otherwise, the pattern repeats forever.
 There are many pattern rules due to pulse device
features and limitations.

1. PF/HER

PF/HER Pulse-to-pulse switching
PF / 5Hz

HER / 12.5Hz• In 8/Dec/2008, we could injected beams to both of PF and HER with pulse-to-pulse.
• But the 25 Hz injection to PF mode, HER injection ratio was worse and the noise levelof Belle detector was also too bad.
• Now this problem is resolved.

2. HER/LER Switching Compatible optics
 Orbit correction

2. HER/LER

HER/LER Compatible optics
Setting of Quads
AB

High current
optics for LER

RC

Original
3-Ringcommonoptics

1 Target 2PF/HERcompatibleoptics

34

Positronoptics

Positron yield slightly decreases5

2. HER/LER

HER/LER Orbit correction
LINAC

BTLER
LER orbit correction
We corrected orbit so that
LER orbit becomes flat with
only DC steerings.

HER

Pulsesteerings

Target bump
For HER, electron beam
passes through the target
hole by making a bumpwith pulse steerings.
HER orbit correction
Pulse steerings cancorrect HER beam.

2. HER/LER

T.Kamitani, K.Yokoyama, M.Kikuchi, et.al.

10 pulse steerings are installed Bend Bending angle: 1mrad
 Gap: 35 mm
 Length: 150mm

 PS
 Max current:10A Pulse width: 19.5msec.
 Pulse shape: 1+cos(t) Ceramic chamber Mn-Mo coating2. HER/LER

HER/LER Fast Alternating Beam Injection





In 12/Nov/2008 HER/LER could be successfully switched in 2 sec.
The injection ratio is good as usual.
The beam current variations are one order decreased in both rings.
Quality of luminosity tuning is much improved.
Time for luminosity tuning cycle has speeded up.

1.7%

0.19%

2.5%

0.25%

HERLER

Plans for Pulse-to-pulse
Switching Injection
 2-rings(HER/LER)
 3-rings(PF/HER/LER)3. Pulse-to-pulse switching injectionplans for 2-rings

HER/LER pulse-to-pulse switching injection is the next
target by Apr/2009.


Pulse-to-pulse beams were successfully transported to bothends of BT lines.

Injection phase of KEKB
The switching time for an up-down module is 2 seconds/360
degrees, which is used for changing the injection phases ofHER and LER.
 This limits the HER/LER switching time now.
 We will replace the up-down module with two modules for HERand LER, which can be switched within 20ms.


Bucket selection of KEKBConnection from the event system to bucket selection system isunder development.

3. Pulse-to-pulse switching injectionplans for 2-rings (cont’d)Monitors
BPM’s in LINAC and BT are being prepared.
 Wire Scanner system is also under development.


Orbit feedback and Energy feedback system
 LINAC alignment at the downstream of the target.
4. Pulse-to-pulse switching injectionplans for 3-rings
 PF operation will be top-up mode from Oct./2009.

• We should realize the pulse-to-pulse injection for 3-rings,
PF/HER/LER.
 PF/HER/LER compatible optics• We tried to pass PF beam with the HER/LER compatible
optics, which worked well.
• Better optics will be designed, taking the energy profiles of 3modes into consideration.
• Response function for the new optics should be measured.
 Pulse steering• Kick angle will be adjusted for each mode.
• Additional pulse steerings are planning.

PF beam with the HER/LER
compatible optics
PF orbit (3-Ring compatible optics)

Now progressing

PF dedicated orbit• All phases of sub-boosterin 2 and 3 sectors are shiftedto “stand-by”.
• The orbit can be corrected
only with pulse steerings.
• The charge and orbits arecomparable to the PF
dedicated optics

Summary We achieved Fast Alternating Beam Injection toHER and LER, which improved the quality ofluminosity tunings.
 Pulse-to-pulse switching to HER and LER is
being prepared for the operation from Apr/2009.
 We aim at the pulse-to-pulse switching to PF,
HER and LER on Oct/2009.
 PF/HER compatible optics was reproduced in design

tool. The same method will be applied to the 3-ring
scheme.