KAON09, 11 June, 2009

Introduction of the
J-PARC Accelerator Complex

Masashi Shirakata (Accelerator Laboratory, KEK)
J-PARC accelerator group

LinacRCS
Neutrino beams to SK

MLF

JFY 2006 / 2007
JFY 2008
JFY 2009

Hadron experimental hall

LINACFirst phase, but not installed yet.

Second phase

LINAC beam energy: 181 MeV at the present

Front-end part

DTL

Ion source, LEBT, RFQ,MEBT(2 choppers, 2 bunchers)

SDTL• Particle
H - (Negative hydrogen)• Energy
on day-one
181 MeVwith ACS
400 MeV• Peak current
at 181 MeV 30 mA
at 400 MeV 50 mA• Repetition25 Hz• Pulse width
0.5 msec

Ion : H- (Negative hydrogen)
Voltage among
electrodes
Ground| - 42 kV
Extraction| - 8 kV
PlasmaLaB6filament

Original slide from K. Hasegawa, ATAC2009

Original slide from K. Hasegawa, ATAC2009

Original slide from K. Hasegawa, ATAC2009

Ion source status in the last one year
Remarks(during beam commissioning)
24 hours continuous beam
operation has started fromRUN#15.

Filament
cutting off

Beam operation without ion source
operator has started from RUN#15(only in night time).
On 28th June, 2008 (duringRUN#17), filament had a trouble ofcutting off. The filament was usedin 9 commissioning runs (2030 h).

Operation history of ion source(May-2008 ~ Feb-2009)

The typical beam current is set to 5
mA for the MLF expreriments andMR commissioning.

Discharge problem in the RFQ• The first severe discharge problem in the RFQ
occured in September 2008.
• Before this problem, the availability of linac wasmore than 90 %.
• After the problem, we are suffering fromsporadic unscheduled shutdown due todischarge problem in RFQ.
• A run cycle scheduled in Oct. 2008 wascancelled for RFQ conditioning.
• The RFQ downtime (both scheduled andunscheduled) dominated the machine time inruns in Dec. 2008 and Jan. 2009.

Inside view of RFQ“RFQ backup group” has been organized, who
prepares the “backup RFQ” though it takes
about one year.

RFQ (Radio Frequency Quadrupole)uses electric quadrupole field forbeam focusing. Discharge may occur
at the surface with high voltage
potential.

Present Status of LINAC
General• The linac and RCS have been commissioned successfully.
• The stability of linac beam is sufficiently good for beam commissioning ofRCS, MLF, and MR. (except for the following problem...)• Availability and beam power is limited by mainly RFQ at the present.
• We decided to temporarily limit the beam power to 1.2 kW (corresponds
to 20 kW RCS beam) in order to ease the RFQ discharge problem.

For the high intensity• Ion source and RFQ must be upgraded for 1 MW beam power of RCS.
• The construction of 200 to 400MeV part (Annular Coupled Structure) of
the linac was funded through the supplementary budget of JFY2008.
• Design and construction of ACS is still going on.
• Installation of ACS modules is scheduled on January to March, 2011.

RCS (Rapid Cycling Synchrotron)
Neutron/Muon source and booster of the MR.
Two beam transport lines:
3NBT transport line to the MLF
3-50BT transport line to the MR

1st arc section

fromLinac

Beam injection section
Injection section

3NBT
Circumference 348 m
3-50BT
Repetition rate 25 Hz
Injection energy 181/400 MeV
MR
Extraction energy 3 GeV
Harmonic number 2to MLF

MLFto MRRCSring

RF section
Extraction section

Recent runs and operations(1) Run#16 (May 13~June 2, 2008)- Tuning and study for the transverse beam painting- Startup of the beam delivery to MLF and MR for their beam commissioning(5 mA peak/0.1 ms long/280 ns intermediate pulse width/1 bunch; 5 kW eq.)(2) Run#17 (June 12~30)- Tuning and study for the transverse and longitudinal beam painting- Beam delivery to MLF and MR (5 mA/0.1 ms/280 ns/1 bunch; 5 kW eq.)(3) Run#18 (September 11~29)- Tuning and study for the transverse and longitudinal beam painting- High-intensity demonstrations (10-15 mA/0.5 ms/560 ns/2 bunches; 200-300 kW eq.)
- High-power demonstration (15 mA/0.5 ms/420 ns/2 bunches/25 Hz; 225 kW)- Beam delivery to MLF (5 mA/0.1 ms/280 ns/1 bunch; 5 kW eq.)(4) Run#19 (November 3) Suspended due to RFQ trouble(5) Run#20 (December 2~26)- High-power demonstration (5 mA/0.5 ms/560 ns/2 bunches/25 Hz; 100 kW)- 25 Hz stable beam operation (Startup of user runs at MLF)
* MLF
5 mA/0.4-0.1 ms/280 ns/1 bunch/25 Hz; 20-5 kW* MR
5 mA/0.1 ms/140-280 ns/1 bunch/single shot or 0.16 Hz(6) Run#21 - #24 (January 13~June 1, 2009)- 25 Hz stable beam operation* MLF
5 mA/0.1 ms/560 ns/2 bunches/25 Hz; 20 kW* MR
5 mA/0.1 ms/140-280 ns/1 bunch/single shot or 0.16 Hz

Transverse painting
In order to reduce the space charge force, artificial
off-center injection scheme (painting) was tested withpaint-bump system for both horizontal and verticalplane.
Beam parameter
When the beam profile had a broad shape, space
5 mA peak, 0.5 ms long,charge force is eased. As a result, beam loss gets
560 ns intermediate-pulse width
smaller.
Mountain plot of the beam profile measured by IPM for the transverse painting injection

Longitudinal painting- Only Fundamental 0.35
0.30
0.250.20

Beam parameter
10 mA peak, 0.5 ms long,
560 ns intermediate-pulse width,
2 bunches* Vmax: 402 kV/turn (with 10 cavities)* Phase FB on

0.15
0.10
0.05
0.00
- 0.05- 0.10
600

700

800

900

1000

1100 1200 1300

1400 1500- 2nd harmonics: 80% 0.20
0.15
0.10
0.050.00

In the longitudinal painting, the RFfrequency and the phase of second
harmonic RF voltage are varied duringinjection.
Figure shows mountain plots and thebunching factors w/w.o longitudinalpainting.
Momentum offset: -0.2%
Phase sweep of 2nd harmonics:-80 to 0 degree- 0.05- 0.10
600

700

800

900

1000

1100 1200 1300

time [ns]1400 1500

200 kW output was achieved !

Original slide from M. Kinsho, ATAC2009

Original slide from M. Kinsho, ATAC2009

Original slide from M. Kinsho, ATAC2009

Present Status of RCS
The RCS have been commissioned successfully.
- The optics measurement and its correction were successfullyperformed.
- Transverse and longitudinal painting injections werewell-demonstrated.
- It was confirmed that the beam loss at the early stage ofacceleration was well-improved by the painting injection scheme
especially in the longitudinal plane for 200-300 kW-equivalentintensity beam.
- Consecutive 100 kW (for 1 hour to MLF) and 213 kW (for 70 s to3NBT dump) output operations at 25 Hz were well demonstrated.
- Stable beam operations for MLF (user run) and also MR
commissioning have been performed with 20 kW output beam
power since December 2008.
- For higher beam intensity, comissioning and study will continue...

MR (slow cycling Main Ring synchrotron)
Circumference
1567.5 m
Repetition rate
~ 0.3 Hz
Injection energy 3 GeV
Extraction energy 30 GeV
Superperiodicity 3
harmonic #9
No of bunches
8Transition
j 31.7
Typical tune
(22.4, 20.8)
Transverse emittanceAt injection~54 mm mrad
At extraction~10 mm mrad (30 GeV)
Three dispersion free straight sections of 116-m long:- Injection and collimator systems- Slow extraction SX)
to Hadron experimental Hall (Rare decay, hyper nucleus..)- Rf cavities and Fast extraction(FX) (beam is extracted inside/outside of the ring)outside: Beam abort line
inside: Neutrino beamline (intense beam is send to SK located 300 km west)

MR beam commissioning schedule
1st stage (May - June 2008)
Available beam dump: at the injection.
Beam transport in 3-50 BT, injection,
closed orbit, rf capture,extraction to beam dump at 3 GeV.
Installation of FX and SX components(July 2008-Nov. 2008)
FX septa (SM1,2, SM33), FX kickers,
SX devices,
neutrino beamline components,
tuning of main magnet power supplies.
Layout of beam dumps

2nd stage (Dec. 2008 - Feb. 2009)
Available beam dump: at the abort beamline and HD beamline.
Acceleration from 3 to 30 GeV,
extraction to abort line,
extraction to hadron beamline.
We‘ve just completed !!
3rd stage (April - June 2009)
Available beam dump: at the NU beamline.
Extraction to neutrino beamline.

3-50 Beam Transport Line

Pulsed bending magnet

LengthDipoleQuadrupole
Steering
Collimator
Monitor
BPM / MWPM
FCT / BLM

230 m
1 (pb), 3 (h), 2 (v)381412 units (120 - 54
14 / 5 (9)5 / 503NBT
3-50BT

BT collimators

Slope sectionmm mrad)

Magnet system
Main magnets
DipoleQuadrupole (11 families)
Sextupole (3 families)

96
216
72

Steering magnets
Hori. Steerings
Vert. Steerings
Abort Steering

92
93
1

Precise alignment of all the main
magnets was completed in 2007.
Hardware commissioning of the mainand steering magnet systems started
in December 2007 as scheduled.

Arc-C section

The total harmonics distortion (THD)
of AC voltage ~1% with a harmonic
filter of 6.5 Mvar unit when all thepower supplies operated in 30 GeV.

MA loaded rf cavity
The MA (magnetic alloy) cut core is adopted to the MR cavity.
At initial operation in the second stage of commissioning, required rf voltage is~ 160 kV for 30 GeV (Nominal voltage is 40 kV/cavity).
Long-term high power operation test of MA cores
All 90 cores (for 5 cavities) have been tested> 300 hrs with nominal rf gap voltage of 15 kVp
with 60% duty.
Serious core damages have not been observed.
For the first stage of beam commissioning, fourcavities have been installed.
Hardware commissioning started in March2007.
The fifth cavity will be installed in summer 2009.

Beam monitors
BPM
186
Abort/dump BPM
2+2
WCM (>100 MHz)
3
FCT (~ 20 MHz)
6DCCT(DC - 30 kHz)2
MWPM
1(inj.) + 1(SX) + 1(abort)
FWPM(H/V)
1/0
IPM(H/V)
1/1
Tune meter (H/V)
1/1
Quad. mode BPM
2
BPM (BT)FCT (BT)MWPM (BT)BLM(BT&MR)

BPM
MR beam

1456338

MWPM

Installation, cabling and calibration still continue.
BLM
WCM

BT beam

FCT
3-50 BT@just upstream of injection

Beam Commissioning

Linac/RCS beam for MR
commissioning

Linac: 5 mA, 100 µsec, chopped beamProcedure
RCS: without painting,
1st stage: Injection and 3 GeV DC~10 mm mrad
• 3-50BT orbit correction
one bunch operation (h=2)• Injection tuning
Itelate while necessary< 4e11 ppb (1 % intensity),• COD correction
single shot
• Closed orbit establishment• RF capture
Beam extraction to HD beamline• -function measurement Ring parameter • Establish optimum operating point• -function measurement measurement • Tune Survey• Tune measurement & survey• Physical aperture survey• Optimization of operating point• Dynamic aperture survey• RF parameter tuning• Beam extraction tuning• Chromaticity correction• HD beamline tuning

2nd stage: Acceleration• Acceleraion• Optimization process same as above• FX devices tuning• Confirmation of adiabatic damping• SX devices tuning• Spill control (Sep. 2009 ~)Beam extraction to NU beamline• Establish optimum operating point• Beam extraction tuning• NU beamline tuningOrbit correction in the 3-50BT
3NBT
MRRCS

3-50BT
Dedicated toMR injection
Orbit deviations
are suppressed
within 3 mm

Injection Tuning 1Injection beam envelope and layout of the components
Injection without bump orbit

Tunable knobs
Ring
Septum1, 2
kicker1, 2, 3
3-50BTzsh09, 10
zsv11, 12
Bump magnets are
installed to make a local
bump to secure thelarge physical aperture
for the circulating beam.
But we did not use thelocal bump in the 1ststage because of thesmall beam size.

Discrepancies from the design are small.

Injection Tuning 2
BPM: Turn-by-turn mode

BeforeInjection error was well suppressed.

After

COD Correction
BPM: COD mode

15 mm

In COD mode, BPM measures
the averaged position of thebeam.

Amplitude of orbit
distortions was suppressed!
9 mmOrbit analysis&Correction by steering
magnets

RF Capture
Mountain plot of longitudinal beamprofile measured by WCM

Matching between field of dipole
magnet and RF frequency
1000 turn mode:
Beam is extracted after 1000 turns
from the injection.

zoom up!

5 μsecfrf = 1.6715 MHz
Vrf = 160 kV
The frequency is well matched andno dipole oscillation is observed.

80 nsec

-function MeasurementThep/p dependence of the closed orbit is measured by changing RF frequency.

Time pattern of RF frequency change

Δff

x=x

p/p

RF shifts the beam momentum.
Beam orbit represents the -function.

100 msec
Injection 200 msec

Measured results agree well with design.

-function Measurement- We measured -function using the relation:k --->
Averagedat the position of each Q families- Measurement error :/ ~10 %.

Measured results agree with the designs within the measurement error.

Tune and Resonance• Particles in beam oscillates with a characteristic frequencies both in horizontal andvertical planes. These are called tune: x and y, respectively.
• When the error field existed, particles are affected periodically. When the particle
motion is synchronized to the affection, the amplitude of particle motion gets larger.
(This is called as the “resonance”)• Resonance conditions can be expressed in the tune diagram which is a 2D plot of xand y.
• Strength of resonances
Resonant condition:
m x+n y=k
x : horizontal tune,y : vertical tunem, n, k are integers.
( |m|+ |n| ): order of resonance; Low order resonances are strong and halmful.
• Expected resonances (example)x = 22(integral resonance: very strong)
2 x = 45
(half-integral resonance: very strong)x + y = 43(sum resonance: strong)x = 22.333(3 x = 67, third order resonance used in slow extraction)x + 2 y = 64

Tune Survey
Survival rate

2x = 45x = 22x+y=43

Fast extraction devices
Fast extraction system comprises 5 bipoler kicker magnets and 8 bipolar septum magnet
systems.

Fx septum magnets
FX kickers

Lumped constant kicker magnet
2.365mmagnet

magnetCoil supports with ceramics insulatorsVacuum chambers and ferrite cores of the traveling type kickers are used.
The maximum voltage between coil and ferrite cores is <1.5 kV/mm.

Fast extraction septum magnets
SMSM2

SM30

SM30

SM31

SM32

SM31, 32 on
a common support table

SM30-32 were Installed in the ring tunnel before the first MR beam.
SM33, SM1,2 were installed in summer of 2008.

SM33

SM33

Abort beam line
Abort beam is bent outward in the fast extraction section and transported
to 7.5 kW dump.
- Beamline length ~ 73 m- DC Q-doublet is installed at 10 m from the extraction point.

Quadrupole (recycled)
DC PS (recycled)

746 Beam duct

The abort beamline components was installed in summer of 2008.

Slow extraction system
Installed before the first MR beamResonant Sextupole (8)Manufactured in 2007,
installed in summer of 2008
Electro-static septum (2)Thin septum magnets:
1.5 mm (1), 3.5 mm (1), 7.5 mm (4)Resonant sextupoles

Strong field septum magnets (4)Shift bump magnet (4)Power supplies (recycled/manufactured)
Manufactured in 2007-2008,
to be installed in summer of 2009
Extraction Q’s for spill control

Vacuum vessel of ESS

Yoke and 30µm ribbon type septum of ESS
Details are given by M. Tomizawa

Slow Extraction procedure
SeptumESS

Hadronbunched beamTurn off the RFcoasting beam without RF
binding force (DC beam)
move tox = 22.333 and enhance the resonannce
Particle motion becomes unstable
due to the resonance.

expanding horizontallypeel off the spilled
particlesBeam peeling in Electro Static Septum
Observed beamby the luminescencescreen monitor
peeled byelectric field

Extracted
spill

Extractedspillbeam coreshadowof ribbons

104 kVribbons0.025 x 1 mm

Inside view of ESS

Observed Beam Spill
Beam spot can be observed in some luminescence screen
monitors in hadron beam line.

It was comfirmed that more than
90% beam was extracted.

Present status of MR
Installation of accelerator components is now in progress as schedule.
Off beam commissioning has started in December 2007.
Beam commissioning has started in May 2008.
1st stage (May - June 2008)
3 GeV DC opetration
2nd stage (Dec. 2007- Feb. 2008)
Acceleration to 30 GeV
Beam extraction to the abort dump and hadron beamline
3rd stage (April - June 2009)
Beam extraction to neutrino beamline

The first mission has been COMPLETED !!

Milestones
■■

■
■

■
■
■

■

■

■
■
■
■

Linac Beam Commissioning started in Nov, 2006.
The linac accelerated the beam to a design value, 181 MeV on 24th Jan,2007.
RCS Beam Commissioning started in Oct., 2007.
The RCS accelerated the beam to a design value, 3 GeV on 31st Oct,
2007.
Beam Commissioning of MR started in May, 2008.
Installation of FX and SX components were installed in summer, 2008.
Hadron and Neutrino beamline components were installed in summer,
2008.
MLF experiments started on 23rd Dec, 2008.
The MR accelerated the beam to a design value, 30 GeV on 23rd Dec,2009.
Extraction to hadron beamline on 27th Jan, 2009.
Secondary beam was comfirmed 11th Feb, 2009.
Extraction to neutrino beamline on 23rd April, 2009.
Neutrino beam was comfirmed 23rd April, 2009.

Present status of MLF
Since 30th May, 2008

Experiments
started.

Available beam lines:
BL01
BL03
BL04
BL08
BL10
BL14
BL16
BL19
BL20
D1

4D space access neutron spectrometer (4 SEASONS)IBARAKI Biological Crystal Diffractometer (iBIX)
Neutron-Nucleus Reaction Instrument (NNRI)
Super high resolution powder diffractometer (SuperHRPD)
NeutronBeam-line for Observation and Research Use (NOBORU)
Cold-neutron disk-chopper spectrometer (AMATERAS)
High-Performance Neutron Reflectometer with a Horizontal Sample Geometry(ARISA-II)
Engineering Diffractometer (TAKUMI)IBARAKI Materials Design Diffractometer (iMATERIA)
D1 instrument (Muon beam line)Observation of the neutrino beam production

Superconducting
bending magnets

Muon Monitor and its first muon signal.

Identification of kaons
Joint experimental team, E17 lead by Prof. R.
Hayano, University of Tokyo and E15, lead by
Dr. M. Iwasaki, Riken, has successfully
confirmed kaon generation in the secondary
beams at the K1.8BR.
(J-PARC News)

timeTOF spectrum

Please ask to the machine staff at J-PARC

Thank you for your attension !!