T2K presents first CP violation search result (Aug. 8, 2016)

Beam Operation at the Materials and Life Science Experimental Facility (MLF), J-PARC (Aug. 1, 2016)

Operation schedule for the second half of FY 2016 (June 22, 2016)

First look at antineutrino appearance from T2K (Jul. 24, 2015)

Operation schedule for the second half of FY 2014 (Sep. 24, 2014)

Discovery of a New Crystal Structure Family of Oxide-Ion Conductors NdBaInO₄ (May. 16, 2014)

Operation schedule for the second half of FY 2014 (Apr. 1, 2014)

The web site of ″The 2^nd International Symposium on Science at J-PARC″ opens. (Mar. 14, 2014)

Restarted the user operation at MLF of J-PARC (Feb. 21, 2014)

Operation schedule for the second half of FY 2013 (Feb. 17, 2014)

The cause of the malfunction of the EQ magnets for the slow extraction system of the 50-GeV synchrotron in J-PARC (Nov. 27, 2013)

Submission of the 3^rd statutory report on the radioactive material leak at the HD facility of J-PARC to the Nuclear Regulation Authority (Aug. 12, 2013)

About the maintenance of server (Aug. 12, 2013)

Minutes (Summary) and appendixes of the 2^st External Expert Panel Meeting to Review the Radioactive Material Leak Accident at the Hadron Experimental Facility of the J-PARC (Aug. 7, 2013)

Message from Director of J-PARC Center (July 26, 2013)

the 1st J-PARC Colloquium - November 20 - (Oct. 24, 2012)

Operation schedule for the first half of FY 2013 (October 23, 2012)

Operation schedule for the second half of FY 2012 (Sep. 3, 2012)

The open house of J-PARC on July 29 2012 (July 11, 2012)

The Announcement of the Next Director of J-PARC Center (June. 19, 2012)

Operation schedule for the second half of FY 2012 (May 16, 2012)

Notice of operations in J-PARC (Update:3) (Apr. 6, 2012)

Notice of operations in J-PARC (Update:2) (Mar. 30, 2012)

Notice of operations in J-PARC (Update) (Mar. 29, 2012)

Notice of operations in J-PARC (Mar. 23, 2012)

Annual Report 2010 Isssued (Feb. 23, 2012)

We have redesigned J-PARC website (Dec. 19, 2011)

About the restoration of East Japan Great Earthquake (J-PARC)(Dec. 9, 2011)

Confirmation of neutral kaons in the KL beam line at Hadron Hall, J-PARC(Dec. 7,2009)
TOKAI-MURA, IBARAKI - The collaboration of Experiment E14, led by Professor Taku Yamanaka of Osaka University and abbreviated as KOTO, has successfully confirmed neutral kaons in the KL beam line at the Hadron Hall of J-PARC.

Birth of Pulsed Neutrons in J-PARC (J-PARC Newsletter Special Issue(Birth of neutrons)-2008/5/30-)
On May 30th, 2008. At 14:25, a shot of 3GeV protons from RCS (3 GeV synchrotron) was injected to the mercury target at MLF. http://j-parc.jp/MatLife/1stBeam/PromptReport.JPG . 
-->more

MR: Successful injection of 3GeV proton beam, RF captured and extraction
At 22:27 of May 22nd 2008, the 3 GeV proton beams from the RCS (3GeV proton synchrotron) were successfully injected into the Main Ring (50GeV proton synchrotron). The beam was captured by RF and extracted to the beam dump after 1000 turns. The day after, the beam storage time was extended up to 1 second. It is the major milestone for the J-PARC. The next step is to accelerate beams to 30GeV (Phase I) and to extract beams to the experimental holes, which will start in the end of this year. (by nh 2008.5.27)

Successful in accelerating a proton beam to the design energy of 3 GeV in the RCS at J-PARC(October 31, 2007)

Protons are successfully accelerated at the J-PARC Linac(PressRelease 2007/01/31)

J-PARC Project Newsletter (2007/1/24)
The J-PARC linac accelerated the H-minus beam up to the energy of 181 MeV

J-PARC Linac Accelerated Its First Beam(PressRelease 2006/11/22)
■ KEK: http://www.kek.jp/intra-e/press/2006/J-PARCLinac.html
■ JAEA: http://www.jaea.go.jp/english/news/p061127/index.shtml

J-PARC Started Magnets Installation to 50GeV Synchrotron (Photo Nov. 15, 2005) (KEK NEWS TOPICS)

The proton accelerator facility under construction was opened to the press. Photo -Jan. 26, 2005-

The negative hydrogen ion beam has been accelerated up to 19.7MeV at Drift-Tube Linac.

• JAERI News Release
• KEK Press Release( In Japanese)
  

The J-PARC T2K Neutrino Experiment was featured in CERN COURIER. (Jul 8, 2008)
Construction is well under way in Japan on the new facility to send neutrinos from J-PARC to the Super-Kamiokande detector nearly 300 km away. --> more
<CERN Courier, July /August 2008, Volume 48 Issue 6>

J-PARC accelerates protons to 3GeV (Nov 20, 2007)
On 31 October a team at the Japan Proton Accelerator Research Complex (J-PARC) accelerated a proton beam to the design energy of 3 GeV in the new Rapid-Cycling Synchrotron (RCS). ...
<CERN Courier, December 2007, Volume 47 Issue 10>

J-PARC linac accelerates hydrogen ions up to 181 MeV design value
(CERN COURIER-VOLUME 47 | NUMBER 2- /News)
The J-PARC team celebrate their success at reaching the 181 MeV Phase I design energy.

BEAM OPERATION RESUMPTION AFTER SUMMER SHUTDOWN. ---more
(J-PARC Project Newsletter No.72, Jan. 18, 2019)

STABLE OPERATION AND 1 MW DEMONSTRATION OF THE ACCELERATORS.---more
(J-PARC Project Newsletter No.71, Sep. 5, 2018)

OPERATION STATUS OF THE ACCELERATORS. ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING.---more
(J-PARC Project Newsletter No.70, May 17, 2018)

STABLE OPERATION OF THE ACCELERATORS FROM OCTOBER TO DECEMBER.---more
(J-PARC Project Newsletter No.69, Jan. 2018)

MAINTENANCE AND IMPROVEMENT WORK DURING SUMMER SHUTDOWN. ---more
(J-PARC Project Newsletter No.68, Dec. 1, 2017)

OPERATION STATUS OF THE ACCELERATORS. ---more
(J-PARC Project Newsletter No.67, Aug 24, 2017)

OPERATION STATUS OF THE ACCELERATORS. ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING.---more
(J-PARC Project Newsletter No.66, May 22, 2017)

OPERATIONAL STATUS OF THE ACCELERATORS. ---more
(J-PARC Project Newsletter No.65, Jan. 2017)

J-PARC IS BACK ONLINE AFTER THE SUMMER/AUTUMN SHUTDOWN. ---more
(J-PARC Project Newsletter No.64, Nov. 15, 2016)

OPERATION STATUS OF THE ACCELERATORS: FOUGHT WITH FAILURES.---more
(J-PARC Project Newsletter No.63, Aug 19, 2016)

ACCELERATOR STUDY FOR HIGHER USER OPERATION PARAMETERS AND BEAM DELIVERY TO USERS. ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING.---more
(J-PARC Project Newsletter No.62, May 9, 2016)

J-PARC AIMS FOR HIGHER STABILITY AND EFFICIENCY FOR MORE SCIENCE.---more
(J-PARC Project Newsletter No.61, Jan. 2016)

MAINTENANCE AND IMPROVEMENT WORK DURING SUMMER SHUTDOWN.---more
(J-PARC Project Newsletter No.60, Oct. 29, 2015)

STEADY PERFORMANCE IMPROVEMENT AND BEAM DELIVERY OF ACCELERATORS.---more
(J-PARC Project Newsletter No.59, July 30, 2015)

HADRON EXPERIMENTAL FACILITY RESTARTED THE USER OPERATION. ---more
(J-PARC Project Newsletter special issue, May 21, 2015)

ACCELERATION OF A PROTON BEAM PULSE EQUIVALENT TO 1-MW WAS SUCCESSFULLY DEMONSTRATED.---more
(J-PARC Project Newsletter No.58, Apr. 2015)

1-MW EQUIVALENT BEAM WAS DEMONSTRATED SUCCESSFULLY IN ACCELERATION AND EXTRACTION.---more
(J-PARC Project Newsletter No.57, Feb. 12, 2015)

FRONT END SYSTEM OF THE LINAC HAS BEEN REPLACED.---more
(J-PARC Project Newsletter No.56, Oct. 24, 2014)

USER RUNS AT THE NEUTRINO EXPERIMENTAL FACILITY WERE RESTARTED ON MAY 26 FOLLOWING THE COMPLETION OF THE STRICT INSPECTION TO ENSURE THE SAFETY.---more
(J-PARC Project Newsletter No.55, July 30, 2014)

THE DESIGNED 400 MEV BEAM WAS ACHIEVED IN THE LINAC ON JANUARY 17, 2014.---more
(J-PARC Project Newsletter No.54, April 2014)

LINAC STARTED BEAM COMMISSIONING WITH NEWLY INSTALLED ANNULAR-RING COUPLED STRUCTURE (ACS) SYSTEMS.---more
(J-PARC Project Newsletter No.53, Jan. 31, 2014)

NEW RESULTS FROM T2K CONCLUSIVELY SHOW MUON NEUTRINOS TRANSFORM TO ELECTRON NEUTRINOS---more
(J-PARC Project Newsletter Special Issue, July 2013)

STATUS OF THE ACCELERATOR FACILITIES. / ACCELERATOR TECHNICAL ADVISORY COMMITTEE (A-TAC) MEETING.---more
(J-PARC Project Newsletter No.52, Apr. 26, 2013)

BEAM OPERATION RESUMPTION AFTER THE SUMMER SHUTDOWN.---more
(J-PARC Project Newsletter No.51, Jan. 30, 2013)

MAINTENANCE AND UPGRADE WORK DURING SUMMER SHUTDOWN. ---more
(J-PARC Project Newsletter No.50, Oct. 30, 2012)

STATUS OF ACCELERATOR FACILITIES：STABLE BEAM OPERATION TO USERS.---more
(J-PARC Project Newsletter No.49 July 31, 2012)

STATUS OF THE ACCELERATOR FACILITIES: USER SERVICE WAS STARTED ---more
(J-PARC Project Newsletter No.48, Apr. 23, 2012)

MAGNIFICENT RECOVERY FROM THE EARTHQUAKE ---more
(J-PARC Project Newsletter No.47, Jan. 26, 2012)

RECOVERY STATUS OF THE ACCELERATOR FROM THE EARTHQUAKE DISASTER ---more
(J-PARC Project Newsletter No.46, Oct. 21, 2011)

RECOVERY STATUS OF THE ACCELERATOR FROM THE EARTHQUAKE DISASTER ---more
(J-PARC Project Newsletter No.45, Jul. 25, 2011)

STATUS OF ACCELERATOR FACILITIES ---more
(J-PARC Project Newsletter Special Issue, May 27, 2011)

145 KW BEAM FOR THE NEUTRINO USER RUN ---more
(J-PARC Project Newsletter No.44, Apr. 26, 2011)

THE SCHEDULED MAINTENANCE AND IMPROVEMENTS WERE SUCCESSFULLY FINISHED---more
(J-PARC Project Newsletter No.43, Jan. 25, 2011)

THE SCHEDULED MAINTENANCE AND IMPROVEMENTS WERE SUCCESSFULLY FINISHED.---more
(J-PARC Project Newsletter No.42, Oct. 26, 2010)

AVAILABILITY EXCEEDS 92 % IN 120 KW OPERATION FOR THE COMMON USE OF MLF (MATERIAL AND LIFE SCIENCE FACILITY).---more
(J-PARC Project Newsletter No.40, June.8, 2010)

THE FIRST T2K NEUTRINO EVENT OBSERVED AT SUPER-KAMIOKANDE ---more
(J-PARC Project Newsletter -Special Issue-, Mar. 5, 2010)

SUCCESS IN 300 kW TEST OPERATION OF RCS (3-GeV Rapid Cycling Synchrotron) ---more
(J-PARC Project Newsletter No.39, Mar. 1, 2010)

Beam commisioning restarted with steady improvement of RFQ (Radio-Frequency Quadrupole) LINAC---more
(J-PARC Project Newsletter No.38, Nov. 13, 2009)

Success of Extraction to Neutrino Target from MR---more
(J-PARC Project Newsletter No.37, July 23, 2009)

Extraction of 30 GeV proton beam to hadron beam dump---more
(J-PARC Project Newsletter No.36, May 7, 2009)

Success of 30GeV acceleration and extraction in MR ---more
(J-PARC Project Newsletter No.35, Feb. 4, 2009)

EXCITING NEWS FROM THE 3 GEV ACCELERATOR April15, 2008
J-PARC Project Newsletter #32(April15, 2008) [Overview] by Shoji NAGAMIYA

At the end of October we had a successful acceleration in the
3 GeV ring. Four months later, at the end of February of 2008, the beam power per pulse reached 5 kW/pulse. Since the 3 GeV ring will operate at 25 Hz (25 pulses per second), this power/pulse is equivalent to 130 kW per second if 25 pulses were accelerated.
Since the neutron target is not yet ready to accept the primary proton beam, the accelerator crew decided to deliver 50 kW beams to a beam dump for about four minutes before the accelerator operation was terminated for the March shutdown for machine inspection. We had not expected to reach such a high power level within the first four-month period after the injection and extraction were achieved at 3 GeV. It is, therefore, exciting news for us.
Note that the goal at 3 GeV is 600 kW by using the present Linac energy and 1 MW by boosting the Linac energy to 400 MeV.

J-PARC Project Newsletter #32 April 15, 2008
ONE SHOT OF 1.07E13 PROTONS WAS EXTRACTED FROM THE RCS AT 3 GeV, WITH A MODEST BEAM LOSS, CORRESPONDING TO THE BEAM POWER OF 130 kW, IF OPERATED AT DESIGNED REPETITION RATE OF 25 Hz.

J-PARC Project Newsletter #31 Feb., 2008
RADIATION SAFETY INSPECTION FOR THE RCS WAS CLEARED, BEING READY FOR THE NEXT STEP TO INJECT THE TEST BEAM TO BOTH THE NEUTRON PRODUCTION TARGET IN THE MLF AND MR

J-PARC Special News and J-PARC Newsletter No.30 dispatch, Nov. 1, 2007
The accelerator group succeeded in accelerating the beams from the Linac to the design beam energy of 3 GeV via the Rapid-Cycling Synchrotron Special news from J-PARC project on 2007.10.31.

J-PARC Project Newsletter #30 Oct. 30, 2007
THE RCS STARTED THE BEAM COMMISSIONING AS SCHEDULED
INTERLOCK SYSTEMS ARE READY FOR THE BEAM COMMISSIONING OF THE RCS

J-PARC newsletter #29 July 23, 2007
THE BEAM COMMISSIONING OF THE RCS IS COMING SOON.
THE LINAC IS READY TO INJECT, WHILE THE RCS IS TRYING TO SOLVE THE ELECTROMAGNETIC COMPATIBILITY ISSUE WITH ALL THE ACTIVE ELEMENTS.
J-PARC newsletter #28 May 28, 2007
THE LINAC ACCELERATED THE NEGATIVE HYDROGEN BEAM TO THE DESIGN ENERGY OF 181 MEV THREE MONTHS BEFORE SCHEDULED.
J-PARC Newsletter No.27 dispatch (Feb 8, 2007)
THE LINAC BEAM COMMISSIONING STARTED AS SCHEDULED,ACCELERATING THE BEAMS UP TO 50 MEV BY THE END OF 2006.
J-PARC newsletter #26 Oct. 19, 2006
THE RADIATION SAFETY AUTHORITY ISSUED THE PERMISSION FOR THE J-PARC CENTER TO START THE BEAM COMMISSIONING.THE RCS RF SYSTEM WAS SUCCESSFULLY POWER-TESTED FOR 1,000 HOURS.
J-PARC newsletter #25 31 July, 2006
THE J-PARC RING RF TEAM IS BREAKING THROUGH MANY TECHNOLOGICAL DIFFICULTIES
J-PARC newsletter #24 17 May 2006
THE RING RF TEAM IS FOCUSING ON FINDING THE METHOD OF CUTTING THE MAGNETIC ALLOY CORES, WHICH CAN STAND THE LONG-TERM HIGH POWER LOADING.
J-PARC Newsletter #23 Feb. 1, 2006
THE INSTALLATION OF THE ACCELERATOR COMPONENTS IS IN PROGRESS FOR ALL THREE ACCELERATORS, WHILE SOME R&D IS STILL NECESSARY FOR SOME COMPONENTS INSTALLATION OF CONTROL SYSTEMS FOR LINAC IS IN PROGRESS.
J-PARC Newsletter #22 Oct 28, 2005
THE CERAMICS VACUUM CHAMBERS FOR THE BENDING MAGNETS OF THE 1-MW RAPID-CYCLING SYNCHROTRON ARE NOW UNDER MASS PRODUCTION
J-PARC Newsletter #21 Aug., 2005 THE RFQ LINAC AND DTL WERE TRANSPORTED FROM KEK TSUKUBA SITE TO JAERI TOKAI SITE.
J-PARC Newsletter #20 May, 2005
REPORTS FROM ALL THE FRONTLINES OF THE ACCELERATOR CONSTRUCTION BATTLEFIELD
J-PARC Newsletter #19 Feb, 2005

▼March, 2007
RCS: Major components of the RCS have been installed. The left photo is acceleration cavities and the right is the switching yard from the RCS to the MLF (Materials and Life Science Facility) and the MR.
MR: The injection/extraction system has been tested. They could be highly radio activated and their maintenance is very important. The left shows that the septum magnet, which is the heaviest among the injection system, is set on the linear guide. It allows disconnecting the septum magnet out of the beam line smoothly and safely even with small gap, after semi-remote flange (right photo) separates the connected vacuum chambers.
▼February, 2007
Linac: Early morning of January 24th , 2007, the beam energy of the J-PARC linac reached 180MeV, which is the important milestone of the project. The bellow plot shows comparison between the design value at each beam monitor location (horizontal axis) and the measured energy by TOF (Time-Of-Flight) method (red circle).
RCS: Both quadrupole magnets and its power supplies were tested and the system has been operated with full current under standard pattern of 3.64 seconds period. The bellow shows the MR quadrupole testing area.
▼January, 2007
Both quadrupole magnets and its power supplies were tested and the system has been operated with full current under standard pattern of 3.64 seconds period. The bellow shows the MR quadrupole testing area.
▼December, 2006
A proton beam test has begun on Nov. 20th and the acceleration was confirmed on 21st.. The beam is transported to the RFQ downstream. The machine is operated with 5mA or 30mA beam current, 50usec width and 5Hz repetition.
The magnet power supplies for the 7-familiy quadrupole and bending magnets have been tested in the RCS.
View of power supply test in the magnet power supply room
Installed RCS magnets in the machine tunnel.
▼November, 2006
Klystron test and microwave aging had been continued at the Linac successively. Beam commissioning has begun on November 20th and the first proton beam was accelerated up to 3MeV at RFQ.
The foil exchanger and the shift-bump magnet for the RCS beam injection system have been preparing. The exchange mechanism for the charge-exchange foil The shift-bump magnets for the RCS injection
Installation works of the collimator at the RCS-MR transport line
Installation works of the collimator

KEK NEWS TOPICS
50GeV Magnet Installation Begins (Photo Oct. 27, 2005)

▼October, 2006
A radiation area of the Linac has been set on October 11. After high power test, the linac beam comissioning would be started one by one. A0BT (from SDTL to the arc section) View of the klystron gallery
The installation of the bending, quadrupole and sextupole magnets for the RCS almost finished. Now ceramics ducts for the quadrupoles has been set. The beam collimators, vacuum chambers, the kicker magnet, diagnostic instruments and ring RF would be installed until next February.The beam collimator The kicker magnet tank
In two arc section of the MR and at the 3-50BT line, most of the bending and quadrupole magnets are installed. layout
▼September, 2006
The installation of the ceramics ducts for the RCS bending magnets (BM) proceeds. The 22 ducsts out of 24 have been completed.
The 36 RCS quadrupole magnets out of 60 are carried into the machine tunnel.
▼August, 2006
The collimator system at the 3-50BT line has been installed

The final construction area of the MR machine tunnel is close to completion
▼June, 2006
Vacuum ducts between the bending or quadrupole magnets have been installed and connected to the neighbors.
Installation works of the vacuum instruments.
Magnet alignment works are also proceeding.
▼20051201
Seventeen bending magnets (photo), two quadrupole magnets and some steering magnets for MR (50GeV synchrotron) are transported to their installed position.(right)
▼20051006
View from downtream into the DTL-1 inside. Drift tube (center), stem (supporting the drift tube from the top) and post-coupler (side bar) are seen with three consecutive section.(right)
A titanium vacuum chamber is being installed at L3BT (Linac-RCS Beam Transport) line. Upper yoke of the bending magnet is removed and the magnet alignment is confirmed during the installation procedure.(right)
▼ 20050922
On September 21th, an air-pallet (special cart) has been installed, which transports a bending magnet inside the MR tunnel. This is the first instruments delivery into the MR tunnel.
▼ 20050908
<Magnet and power supplies for MR have been delivered and kept at storage area.
▼20050825
The first ceramic duct has been completed with welding a titanium flange.
▼20050811
The RFQ linac cavity was installed by July 25.(right)

The Linac Krystron gallary (August)

The first ceramic duct for RCS was succeed of electroforming.
20050707
The RFQ linac cavity was transported from KEK on July 6.

The DTLtanks was transported from KEK on June 27.
▼20050526
The Linac Krystron gallery (May)