[Neutron] J-PARC Newsletter No. 72

shibata.kaoru shibata.kaoru at jaea.go.jp
Tue Jan 22 03:54:15 CET 2019


=====================================================================
     J-PARC Project Newsletter
                                                     No.72, October 2018
Japan Proton Accelerator Research Complex under operation jointly by 
the High Energy Accelerator Research Organization (KEK) and the Japan 
Atomic Energy Agency (JAEA) 
http://j-parc.jp/index-e.html

=====================================================================

HEADLINES AND CONTENTS

1. [Overview]

 POWER TO THE USERS, PRESENT AND FUTURE.

2. [Accelerator Division]

BEAM OPERATION RESUMPTION AFTER SUMMER SHUTDOWN.
  
3. [Particle and Nuclear Physics Division]

 UPGRADES OF HADRON EXPERIMENTAL FACILITY IN THIS SUMMER.
 NEUTRINO BEAMLINE UPGRADE TO MW POWER.
 STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT.
 STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET).
 PROGRAM ADVISORY COMMITTEE MEETING.

4. [Materials and Life Science Division]

 VARIOUS MAINTENANCE IS IN PROGRESS AS SCHEDULED.
 PROPOSALS FOR 2018B PERIOD WERE REVIEWED.
 ANNUAL MEETING OF INDUSTRIAL APPLICATION AT J-PARC MLF WAS HELD.
 THE THIRD WORKSHOP OF CONCEPT OF NEUTRON SOURCES (CoNS-III) WAS 
HELD.
 MUON SPIN ROTATION USING NEGATIVE MUONS IS READY TO GO.

 5. [Nuclear Transmutation Division]

 EXCHANGE THE TARGET WITHOUT MANUAL OPERATION.

 6. [Safety Division]
 
 FY2018 MEETING OF THE LIAISON COMMITTEE ON SAFETY AND HEALTH FOR 
CONTRACTORS WORKING AT J-PARC.
 THE CHANGES OF THE RADIOLOGICAL LICENSE WAS GRANTED AND THE "RAM" 
FACILITY STARTED.
 THE EMERGENCY DRILL ASSUMING A FIRE IN THE ACCELERATOR TUNNEL WAS 
HELD.

7. [Editorial Note]


---------------------------------------------------------------------
1. [Overview] by Naohito SAITO
---------------------------------------------------------------------

 POWER TO THE USERS, PRESENT AND FUTURE

 (This issue was delayed due to several activities in the last few 
months. ) 

     The beam operation has been successfully resumed after the 
summer maintenance, and the user program at the Material and Life 
science experimental Facility (MLF) has been successfully executed 
at over 500 kW stably. The Main Ring (MR) is still in the maintenance 
time taking the advantage of continuing upgrading work at both Hadron 
Experimental Facility (HEF) and Neutrino Experimental Facility (NEF) 
and Super-Kamiokande (SK). 
     I would like to report three major areas of progress: actions 
for more firm collaboration with users, targetry activities, 
and near future projects of J-PARC. 
     On November 13, we had a great honor to have His Excellency Mr. 
Magnus Robach, the Ambassador of Sweden visiting J-PARC on the 
occasion of the 3rd ESS-J-PARC Workshop held at the J-PARC Main 
Research Building. His Excellency visited the MLF and Neutrino 
Facility and discussed with the researchers, then encouraged us for 
even deeper collaboration between Sweden and Japan. 
     We have also been strengthening the tie with universities. Nagoya 
University has opened its branch at J-PARC on October 26. The Vice 
President, Prof. Takahashi visited us to sign the agreement to 
launch the branch office, and visited MLF, and the NEF, and the brand 
new branch office. It is the 4th university branch at J-PARC, and we 
are looking forward to even deeper collaborations with researchers 
from universities. 
     The target vessel for neutron production at MLF has been renewed 
to #9. The structure of the target vessel is identical to #8. The 
beam exposure onto the target started from 300 kW then moved to 500 
kW after careful confirmation of the target performance to be as 
expected. We keep accumulating various data to develop a more robust 
roadmap for future target vessels. A series of J-PARC-wide meetings 
are planned to discuss the future of the targetry gathering various 
experts. We should be able to report the outcome of the meetings in 
upcoming newsletters. 
     Looking at the future, we are hearing that Japan Science Council 
(JSC) is going to call for the proposal of large-scale research 
program to renew its Master Plan (Master Plan 2020). We have several 
proposals to enhance the J-PARC capability by upgrading accelerators 
as well as experimental facilities: beam power upgrades, extension of 
hadron hall, the 2nd target station at MLF, and Accelerator Driven 
System for nuclear transmutation, and more. We are going to organize 
J-PARC-wide discussion of the proposals to be ready for the 
submission to JSC. The progress will be reported in a future 
newsletter. 
     We hope to develop J-PARC science further by steady progress of 
the facilities as well as active science discussions with users from 
around the globe. 

 
---------------------------------------------------------------------
2. [Accelerator Division] by Kazuo HASEGAWA
---------------------------------------------------------------------

 BEAM OPERATION RESUMPTION AFTER SUMMER SHUTDOWN

     Beam operation was suspended for maintenance during the summer 
shutdown from July to September. Maintenance of the components and 
some improvement work were conducted in the accelerator facilities.

     The linac has been operated stably in these several months with 
improvement work such as stabilizing cooling water flow rates, high 
voltage power supply system for klystrons, etc. Although the trip rate
at the radio frequency quadrupole linac (RFQ) is high (about 10-20 
per day), the recovery time is short and it doesn't degrade the 
availability totally. To mitigate the number of trips, we installed 
three vacuum manifolds on the RFQ to consolidate the vacuum speed.
     We had a vacuum leak issue at one of the collimators at the 3 
GeV Rapid Cycling Synchrotron (RCS) in April 2016. We had operated 
with another collimator that does not have movable function as a 
temporary measure. We installed a new collimator with movable 
function this summer and prepare for higher power operation. 
At the Main Ring synchrotron (MR), upgrade work of the main magnet 
power supply was conducted to prepare for a high-power test.

     The J-PARC accelerator facilities resumed beam operation from 
the linac on October 7 as scheduled. After beam tuning and study of 
the accelerators, the user operation in the new period is expected to 
start at the middle of October for the Materials and Life science 
experimental Facility (MLF). The beam operation of the MR is 
suspended from October to December period due to upgrade work at the 
Kamioka site and the hadron experimental facility.

 
---------------------------------------------------------------------
3. [Particle and Nuclear Physics Division] by T. NOMURA, K. OZAWA, 
T. ISHIDA, T. KOBAYASHI, T. MIBE, S. MIHARA, and T. KOMATSUBARA
---------------------------------------------------------------------

 UPGRADES OF HADRON EXPERIMENTAL FACILITY IN THIS SUMMER 
(by T. NOMURA and K. OZAWA) 

     Upgrades of the KOTO experiment and a lot of construction work 
for a new beam line were performed in this summer. 

     The detector of KOTO experiment is upgraded. The main project is 
a calorimeter upgrade. The KOTO calorimeter consists of 2,716 undoped 
CsI crystals. Each of these is equipped with a photomultiplier on its 
downstream end. The calorimeter must have a good photon-to-neutron 
separation in order to reduce backgrounds from neutron interactions 
as well as energy and position measurements of photons from KL 
decays. A new idea for this purpose is a both end readout of each 
crystal; the time difference between upstream and downstream signals 
provides depth information of shower development and thus improves 
separation. 
Multi-Pixel Photon Counter (MPPC) is adopted as an upstream photo-
detection device. The MPPC installation is being done. The whole work 
will conclude by January 2019 and the KOTO experiment will be ready 
for beam by the end of February. 

     A new beamline to provide primary 30 GeV protons is under 
construction in the transport tunnel (Switch Yard) and the south area 
of the Hadron Experimental Facility. In this summer, septum magnets 
at a branching point were placed in the Switch Yard. In the Hadron 
Experimental Facility, the construction of an experimental area for 
the new beam line is in progress. A radiation shield door was set up, 
and the construction of the entrance part was completed. 

 NEUTRINO BEAMLINE UPGRADE TO MW POWER (by T. ISHIDA and 
T. KOBAYASHI) 

     In 2018 Neutrino Conference, T2K made a remarkable report that 
the CP symmetry might be broken in the lepton sector, through the 
measurement of appearances of electron neutrino and antineutrino. 
https://zenodo.org/record/1286752#.W7CQcPaYRPY 

     T2K collaboration is proposing to extend the data-taking period 
aiming at reaching more than three sigma sensitivity for maximum CP 
violation with the beam power upgrade to 1.3MW and near detector 
upgrade. The beam power upgrade is also essential for future Hyper-
Kamiokande experiment. A critical review of the beamline upgrade has 
been organized in the end of June by the committee members invited 
from world-wide high intensity proton accelerator and facility 
communities. Intensive discussion had taken place on the 
presentations relevant to the key components such as target, beam 
window, horns, beam monitors, DAQ (data acquisition), and radioactive 
waste treatment. The report can be found here: 
https://kds.kek.jp/indico/event/27832/. 

 STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34) 
(by T. MIBE) 

     The E34 collaboration prepares for precision measurements of the 
muon anomalous magnetic moment and electric dipole moment. The 
technical design of the experiment was reviewed by Program Advisory 
Committee (PAC), and readiness for the stage-2 was discussed. 
Construction of the surface muon beamline (H-line) is in progress. 
The collaboration prepares for measurements of longitudinal 
distribution of accelerated beam accelerating muon to 1 MeV with a 
IH-DTL test cavity, spin rotator, demonstration of spiral beam 
injection to the storage ring, and construction of the positron-
tracking detector. An international school on muon dipole moment and 
hadronic effects was organized at the Budker Institute of Nuclear 
Physics (BINP) (Russia) in September 17-21, 2018 to encourage young 
scientists who start working in this field around the world. 

 STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET) 
(by S. MIHARA) 

     The COMET experiment aims to search for the lepton-flavor 
violating muon reaction, mu-e conversion, with sensitivity better 
than 10^{-14} in Phase I. 
Construction of the COMET facility is in progress; proton beamline 
elements are installed and coil winding for the pion capture solenoid 
is in progress. Assembly of coils and installation to the cryostat 
will follow this process to complete the construction. 
The collaboration is working intensively on summarizing experiment 
details in the Technical Design Report (TDR). Concise version of the 
report will be published in this year. 

 PROGRAM ADVISORY COMMITTEE MEETING (by T. KOMATSUBARA) 

     The 26th Program Advisory Committee (PAC) meeting was held at
Tokai on July 18-20. The committee membership was renewed from April; 
Rik Yoshida (Jefferson Lab) was assigned as the new chairperson.
Status of the experiments was reported, and proposals and near-term 
machine time allocation were discussed.
https://kds.kek.jp/indico/event/28286/
      
     PAC report is available through the following web page.
http://j-parc.jp/researcher/Hadron/en/PAC_for_NuclPart_e.html 
The next PAC meeting will be held on January 16-18, 2019.


---------------------------------------------------------------------
4. [Materials and Life Science Division] by Toshiji KANAYA
---------------------------------------------------------------------

 VARIOUS MAINTENANCE IS IN PROGRESS AS SCHEDULED

     1) Neutron Source
     Various maintenance and overhauls planned for the summer shut-
down period are in progress as scheduled. The highlight is the target 
vessel replacement from #8 to #9. Prior to the replacement, a part of 
the beam window portion with 3-mm thickness was cut out with a 
remote-handling cutting device as a specimen to investigate the 
damage of that part. It was observed that an inner surface of the 
specimen facing with a high-speed mercury flow was eroded but not 
severely damaged. Further detailed inspection of damages on the 
specimen will be carried out in October. For the target vessel #8, 
the accumulated beam power on target was 1,812 MWh at average power 
of 434 kW. The measurements of the inspection such as depth of the 
damage will be very useful for us to make further plan for power 
upgrade. New target vessel #9 has the same structure as the target #8 
and will be in operation from October 20. 

 PROPOSALS FOR 2018B PERIOD WERE REVIEWED 

 ANNUAL MEETING OF INDUSTRIAL APPLICATION AT J-PARC MLF WAS HELD

 THE THIRD WORKSHOP OF CONCEPT OF NEUTRON SOURCES (CoNS-III) WAS HELD

     2) Neutron Instruments and Science
     The general/ new user promotion proposals for the 2018B period 
and long-term proposals were reviewed by the Neutron Science Proposal 
Review Committee on August 23. The total number of submitted neutron 
proposals was 302 (the general proposals: 285, the new users 
proposals: eight, long-term proposals: nine). Finally, 198 general 
proposals, eight new user promotion proposals and five long-term 
proposals were approved by the MLF Advisory Board on September 3. The 
total competition rate (the number of submitted/ approved proposals) 
for the general proposals become as high as 1.4 times gradually 
improving from the past crowded situation. From the 2018B period, we 
started to accept proposals from graduate students. In this round, 22 
proposals were submitted, and 17 of them were approved. Annual 
meeting of industrial application at J-PARC MLF was held on July 23 
and 24 at Akihabara Convention Hall. Total number in attendance has 
grown up to 303. The 10th anniversary celebration after the 
foundation of Industrial Users Society for Neutron Application and 
Report Session of Ibaraki prefecture beamlines were held on the first 
day. On the second day, according to the theme -Collaborative 
Creation of Innovation-, several examples of collaborative research 
between industry and the instrument group were reported as well as 
poster session and consultation of neutron beam usage for industrial 
purpose. 
     A J-PARC workshop, the 3rd workshop of Concept of Neutron 
Sources (CoNS-III), was held on concepts of new neutron sources not 
limiting spallation sources with proton on August 21 at the KEK Tokai 
Building No.1. Participants were 25 including three from abroad.

 MUON SPIN ROTATION USING NEGATIVE MUONS IS READY TO GO

     3) Muon Science Facility (MUSE)
     Positive muons have a great advantage over negative muons for 
probing magnetic field in matter, as the spin polarization for the 
former remains much higher than for the latter. However, it has been
demonstrated recently that negative muons could be useful for 
studying hydrogen diffusion in magnesium hydride. The rotational 
motion of spins monitored by muon decay into positrons/electrons 
tells the magnitude and distribution/fluctuation of internal fields 
that carry information on nearby atoms exerting fields to muons. In 
magnesium hydride, while the diffusion of hydrogen ions within the 
material should cause such fluctuation, the possibility for positive 
muons to exhibit diffusional motion via interstitial sites (that also 
leads to the fluctuation of internal field) makes it difficult to 
discern the cause of fluctuation. With negative muons that are deeply 
bound to magnesium nuclei as heavy electrons, researchers succeeded 
in observing the field fluctuations that can be uniquely attributed 
to hydrogen diffusion. The result also proves that the disadvantage 
of low spin polarization for negative muons can be overcome by their 
unprecedented high flux recently achieved at the D-line of J-PARC 
MUSE. 

 
---------------------------------------------------------------------
5. [Nuclear Transmutation Division] by Toshinobu SASA
---------------------------------------------------------------------

 EXCHANGE THE TARGET WITHOUT MANUAL OPERATION

     Spallation target for ADS technology developments requires heavy 
irradiation to prepare irradiation database. It means that targets 
are also heavily irradiated and should be replaced according to the 
injected proton beam strength. In present designed irradiation 
performance, we plan to replace target annually during long 
maintenance period in summer. Even the lead-bismuth eutectic alloy, 
LBE, is dumped into a drain tank, remaining target vessel should be 
changed by full remote operations like existing mercury target in 
J-PARC.
     The mercury target head in J-PARC has a special flange to 
connect the mercury loop mounted on the trolley. At first, we tried 
to use same method for our LBE target system. However, the operation 
temperature is extremely higher than that of mercury target. The 
special flange cannot be used because of temperature problems such as 
thermal expansion and/or thermal stress of a flange body and gaskets, 
and seizing of bolts/nuts. Finally, we decided to connect the target 
head and a target LBE loop by weld of piping under full remote 
operation condition.
     The method using automatic welding system, pipe cutters to 
minimize machining dusts, and master-slave manipulators, MSM, were 
almost established. Besides, we build up the mockup of target 
exchange procedure with two units of MSM along this method. 
Functional tests of remote target exchange technique, the world's 
first trial, will be performed. The development of remote welding 
inspection method will be continued.

 
---------------------------------------------------------------------
6. [Safety Division] by Yukihiro MIYAMOTO and Kotaro BESSHO
---------------------------------------------------------------------

 FY2018 MEETING OF THE LIAISON COMMITTEE ON SAFETY AND HEALTH FOR 
CONTRACTORS WORKING AT J-PARC

     Aiming to share safety-consciousness and ensure safety with the
contractors, the J-PARC Center has been holding a liaison meeting on 
safety and health for contractors annually. This year's committee 
meeting was held on June 29 and had 70 participants from 68 companies 
and 15 participants from J-PARC. Tetsuro Ishii, Deputy Director 
(Safety), introduced recent topics in J-PARC, good safety-activities, 
and troubles in J-PARC and JAEA.

 THE CHANGES OF THE RADIOLOGICAL LICENSE WAS GRANTED AND THE "RAM" 
FACILITY STARTED

     The application for minor changes of the radiological license 
was granted by the Nuclear Regulation Authority on Aug. 22. The 
approved changes in the application were a modification of the 
shielding configuration for the proton beam line in the Materials and 
Life Science Experimental Facility and a slight increase of the beam 
intensity for the Hadron Experimental Facility due to a change of the 
repetition time for slow extraction.
     The facility of the Radio-Activated Materials, abbreviated as 
"RAM", began operation officially as a radiation-controlled area on 
Aug. 29.

 THE EMERGENCY DRILL ASSUMING A FIRE IN THE ACCELERATOR TUNNEL WAS 
HELD

     The emergency drill assuming a fire in the accelerator tunnel of
LINAC was held on Sep. 6. Secure evacuation of workers from the 
tunnel area and procedure for fire extinguishing by suffocation were 
the most important points in this training, and these actions were 
executed successfully. In gathering information and communication, a 
number of improvement points were found for further strengthening the 
ability to respond in emergency situations.


---------------------------------------------------------------------
7. [Editorial Note]
---------------------------------------------------------------------

     In case you do not wish to receive this Newsletter in the future, 
please send an email to news-l-ctl at ml.j-parc.jp and simply write one 
sentence in the body of the message as unsubscribe.

     If you wish to receive, write one sentence in the body of the 
message as subscribe.

     You can get a help with a sentence of "help" in the body.
Information on the project can be also obtained at the web site:
http://j-parc.jp/index-e.html


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto at kek.jp 
Kaoru SHIBATA: shibata.kaoru@ jaea.go.jp 
Takashi ITO: itou.takashi at jaea.go.jp 
Dick MISCHKE (English Editor): mischke at triumf.ca 
Junko BEANBLOSSOM (Secretary): beanblossom.junko at jaea.go.jp
++++++++++++++++End of Letter++++++++++++++++++++++++++++++++++++++++




More information about the Neutron mailing list