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2019.08.09

J-PARC Project Newsletter No.75, July 2019 dispatch

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     J-PARC Project Newsletter
                                                   No.75, July 2019
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

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HEADLINES AND CONTENTS

1. [Overview]

  SUMMER SHUTDOWN TO ENTER NEW PHASE OF BEAM POWER

2. [Accelerator Division]

  STABLE AND 1 MW DEMONSTRATION FOR MLF, AND HD OPERATION BUT
  MR SUSPENSION.

3. [Particle and Nuclear Physics Division]

  BEAM TIME FOR THE HADRON EXPERIMENTAL FACILITY.
  STATUS OF THE COHERENT MUON TO ELECTRON TRANSITION (COMET).
  STATUS OF THE MUON G-2/ ELECTRIC DIPOLE MOMENT (EDM) (E34).
  DEVELOPMENTS FOR HORN AND TARGET UPGRADES AND NEUTRINO
  INTERACTION STUDIES AT NEAR DETECOR SYSTEM.

4. [Materials and Life Science Division]

  STABLE USER PROGRAM OPERATION HAD BEEN CONTINUED AT 500 KW.
  THREE HUNDRED SEVENTY NINE NEUTRON GENERAL PROPOSALS HAVE
  BEEN  RECEIVED FOR THE 2019B PERIOD.
  CONSTRUCTION OF ELECTRIC POWER SUBSTATION FOR H-LINE
  IN PROGRESS.

5. [Nuclear Transmutation Division]

  SECOND INFORMATION EXCHANGE MEETING ON ACCELERATORS FOR
  ADS BETWEEN SCK•CEN AND J-PARC WAS HELD.

6. [Safety Division]

  FY2019 SAFETY DAY AT J-PARC.
  THE APPLICATION FOR A LICENSE OF THE OPERATION WAS GRANTED.

7. [Editorial Note]

 

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1. [Overview] by Naohito SAITO
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  SUMMER SHUTDOWN TO ENTER NEW PHASE OF BEAM POWER

    We entered the summer shutdown after about three months of beam
time in this fiscal year 2019. While the operation of MLF was very
successful with the high availability of 94% or more, it is our deep regret
that we had to postpone the Main Ring (MR) beam time, which corresponds
to about two months or more, due to the malfunction of the bending
magnet in the Beam Transport from 3 GeV Synchrotron to the Main Ring
(3-50-BT). This beam time at the MR, which was divided into slow and fast
extraction roughly 1 to 2, had to be delayed until the beam time in autumn,
when the newly made coil for the bending magnet will be ready for operation.
Hadron Experimental Facility (HEF) is going through the replacement of the
target system, where the cooling power is almost doubled to reach its
acceptable beam power of 80 kW or more. We are very excited about the
possibility to come back to the SX beam with a higher beam power in next
February.
    In the beginning of July, we performed more than 10 hours of continuous
operation of the MLF with 1 MW. The accelerator and the target systems both
for neutron and muon performed with the excellent stability as expected.
Some neutron scattering measurements were also done to show an extremely
high- quality measurement in a short time period thanks to the higher power
beam. We think we have gained a good experience and accumulated a good
confidence by this 10 hour-trial run, which will benefit the higher power run in
autumn beam time. With the successful trial operation of MLF at 1 MW, and
the new target in the HEF to go to higher beam power, and furthermore,
ongoing construction of the power supply for MR, we are getting more
ready for higher power operation at entire J-PARC facility, which we expect
to result in qualitatively new results. We are very happy to share the
excitement of this new phase of stable and high power beams with all users!
More beams for more excitements!

 

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2. [Accelerator Division] by Kazuo HASEGAWA
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  STABLE AND 1 MW DEMONSTRATION FOR MLF, AND HD OPERATION
  BUT MR SUSPENSION.

    After the replacement of the ion source at the end of March, we
started new Run#82. We delivered beams for user operation of the
Materials and Life Science Experimental Facility (MLF) at the beam
power of 500 kW. The user operation for the MLF ended in the morning
of July 3. The operation was very smooth and the availability from April
was high at about 96%. We had an accelerator study time until the
morning of July 8 and stopped the operation as summer shutdown. In
the beginning of the study time, we successfully delivered 1 MW to the
MLF for ten and half hours. The linac, the 3 GeV Rapid Cycling
Synchrotron (RCS), and the neutron target were very stable during this
1 MW operation. We had only three short beam stops and the
availability was roughly 99%. We have demonstrated the 1 MW
operation for one hour last year. We have experienced the longer time
operation and accumulated the experiences toward the goal of the MLF
operation.
    The failure of the bending magnet, which occurred in March, in the
beam transport line from the RCS to the Main Ring (MR) was patched
up and beam was resumed on April 4 for the hadron experimental
facility (HD). The beam power was 50 kW as before the suspension. But
on April 24, it was observed that the field strength dropped by 2 %,
which was much severe than that in March. After the investigation, we
found insufficient insulation between conductors in coils. As a result,
we had a conclusion that continuation of the stable operation of the MR
was difficult. Therefore, user operation of the MR will be resumed in the
beginning of November, after the replacement of the failed coil.

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3. [Particle and Nuclear Physics Division] by T. NOMURA,
T. TAKAHASHI, K.OZAWA, S. MIHARA, T. MIBE, T. ISHIDA, M. HARTZ
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  BEAM TIME FOR THE HADRON EXPERIMENTAL FACILITY.
 (by T. NOMURA, T. TAKAHASHI, K. OZAWA)
 
    Slow extraction (SX) beams from Main Ring were delivered
for user operation from Feb. 9 to Mar. 18 and from Apr. 4 to Apr. 24.
    In the beam time, three experiments were conducted. The
E14/KOTO experiment resumed taking physics data. KOTO had
successfully finished detector upgrades before the beam time. One
of the new features is a both-end readout scheme for the
electromagnetic calorimeter. It provides a depth information of the
particle shower in the calorimeter and helps to distinguish a
photon-induced shower from a neutron-induced one. A quick analysis
during the run shows that a sufficient reduction power against neutron
backgrounds can be achieved.
    At the K1.8 beamline, a new experiment E40 was conducted to study
hyperon nucleon interactions using scatterings of Sigma hyperons on
proton. In the experiment, Sigma hyperons are produced by the (pi, K+)
reaction on a liquid hydrogen target and are scattered by protons in
the same target. The emitted K+ is detected by the KURAMA
spectrometer, and a Sigma-hyperon proton scattering is reconstructed
with a newly installed detector system, CATCH. E40 collected
Sigma- proton data and a half of Sigma+ proton data.
    At the K1.8BR beamline, a pilot run of the E57 experiment was
conducted. The E57 experiment aims at measuring of X-rays from
Kaon-deuteron atoms. In this beam time, the E57 acquired data for
Kaonic-hydrogen atoms to confirm the performance of detector and
backgrounds.

 

   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 along with detector R&D
is in progress. Status and plan of construction was intensively
discussed in a collaboration meeting held in June 10-14 at J-PARC.
    The KEK-IPNS muon group co-hosted an international conference,
CLFV2019 https://conference-indico.kek.jp/indico/event/70/>
held in Fukuoka. Status report of the COMET experiment was given by
a COMET collaborator and many poster presentations were made to
report research status ongoing in the COMET collaboration.
Organization of this conference was supported by KEK International
Cooperation Office.

 

  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.
Following an approval on stage 2 status for the experiment, the
experiment works with KEK for funding request.
    A task force was formed under the J-PARC center to discuss
technical issues on extending the H-line area.
    The collaboration had an open collaboration meeting in Seoul
National University on June 24-27 to share the overall schedule and
development progress including realization of a thermal-energy muon
source and other areas.

 

  DEVELOPMENTS FOR HORN AND TARGET UPGRADES AND NEUTRINO
 INTERACTION STUDIES AT NEAR DETECOR SYSTEM
 (BY T. ISHIDA, M. HARTZ)

    The Main Ring operation was terminated in late April due to a
trouble of a bending magnet. The fast extraction mode operation for
T2K experiment will be resumed from autumn after fixation of the
problem.
    The electromagnetic horns and neutrino production target are
developed and fabricated with firm international collaboration. In the
beginning of 2019, 3rd generation horn-1, assembled at University of
Colorado at Boulder, U.S.A., and a new production target, fabricated at
STFC Rutherford Appleton laboratory, were imported and delivered to
J-PARC, and integration work is now in very good progress. From this
June, long-term test operation of the new horn has been started, and
operation with 320kA current is successfully continuing. With the current,
more than 10% gain is expected at far detector flux in comparison with
current 250 kA operation.
    To reduce systematic errors on neutrino interactions is another key to
achieve CP violation measurement. The T2K near detector system,
located 280m downstream of the target, has been making world-leading
researches on neutrino-nucleus interactions with unprecedented statistics
delivered from the J-PARC beam.
    Recent publication: “Characterization of nuclear effects in muon-
neutrino scattering on hydrocarbon with a measurement of final-state
kinematics and correlations in charged-current pionless interactions at
T2K” Phys. Rev. D 98, 032003 (2018), DOI: 10.1103/PhysRevD.98.032003
    The modeling of nuclear effects in neutrino nucleus scattering
introduces the largest systematic uncertainties in neutrino oscillation
measurements. By measuring the recoil hadrons from neutrino-nucleus
interactions, it is possible to better constrain these nuclear models.
In this result, T2K has measured the kinematic properties of both final
state muons and recoil protons using the ND280 near detector.  T2K also
studies interesting projections of the data in the direction transverse
to the neutrino beam that more directly probe the physics of the target
nucleus.  T2K finds that the data is best described by initial state
models of the nucleus that account for correlations between the Fermi
motion of constituent nucleons and their position or energy level in the
nucleus.

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4. [Materials and Life Science Division] by Toshiji KANAYA
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  STABLE USER PROGRAM OPERATION HAD BEEN CONTINUED AT
  500 KW

    1) Neutron Source
    The beam operation of 500kW is going very well with a good
availability of 96.2% since April 1, as of June 12 in 2019. At the end
of this run time, 1MW beam operation with the duration time of
12 hours is going to be held on July 3 from 10:00 to 22:00 which is
much longer than the 1MW operation of 1 hour last year. Much
facility data of high power operation are expected to be obtained.

 

  THREE HUNDRED SEVENTY NINE NEUTRON GENERAL PROPOSALS HAVE
  BEEN RECEIVED FOR THE 2019B PERIOD

    2) Neutron Instruments and Science
    Neutron Instruments and Science Call for General proposals and
New User Promotion proposals for the 2019B period was closed on
June 7 and we received 379 neutron proposals. In the Long Term
Proposal starting with 2019B, 6 projects were proposed and as a
result of document review, 4 of them were sent to the listening
board. Those proposals will be sent to the Neutron Science Proposal
Review Committee / the Proposal Evaluation Committee for
reviewing process. Final results will be sent to users in September.
The first half of user program of 2019A period was ended in the
morning of July 3. The second half will be resumed from November 5.

 

  CONSTRUCTION OF ELECTRIC POWER SUBSTATION FOR H-LINE
  IN PROGRESS

    3) Muon Science Facility (MUSE)
    Among the muon beamlines envisaged in the original plan of MLF,
the H-line in experimental hall No. 1 has been in the stage of waiting
for funding from MEXT for years.  Given such a situation, the J-PARC
head quarter decided to provide a partial support for putting the plan
forward.  The support is primarily for the construction of new electric
power substation to cover the huge demand of electricity expected
upon the full operation of the H-line.  Following the installation of
cable racks, pitting of MLF building wall, and outdoor structures in
FY2017, the civil engineering work for the substation site near the MLF
building continued towards the end of FY2018. Now the installation for
the access to electricity is in progress on the substation site.

 

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5. [Nuclear Transmutation Division] by Hayanori TAKEI
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  SECOND INFORMATION EXCHANGE MEETING ON  ACCELERATORS FOR
  ADS BETWEEN SCK•CEN AND J-PARC WAS HELD.

     Second information exchange meeting on accelerators for ADS
between SCK•CEN and J-PARC was held at Cyclotron Resources Centre
of Louvain-la-Neuve, Belgium from April 10 to 11, 2019. SCK•CEN has
been working on the MYRRHA (Multipurpose hYbrid Research Reactor
for High-tech Applications) project. MYRRHA is about 100 MWth
(MW thermal) research and demonstration facility for ADS concept.
About 10 researchers from SCK•CEN mainly from the accelerator
development team and 4 researchers from J-PARC took part in the
meeting. Many topics such as the current status of accelerator
development at MYRRHA, accelerator-operation experiences and future
development plans at J-PARC were presented in this meeting. In
particular, participants discussed how to achieve the high reliability
required of the ADS accelerator. One of the methods was the
development of the solid state RF reported from SCK•CEN. Since the
exchanging information meeting had great benefits for both sides, we
decided to hold the next meeting at J-PARC about one year later.

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6. [Safety Division] by Kotaro BESSHO and Yoshihiro NAKANE
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  FY2019 SAFETY DAY AT J-PARC

    The J-PARC Center sets "the Safety Day" around May 23 on which
the radioactive material leak incident occurred in 2013. The Safety
Day in FY2019 was held on May 24.
      The meeting for exchanging information on safety efforts was held
in the morning. Some good-practices were awarded by the J-PARC
director. Furthermore, three talks were presented; (1) A scientific
talk related to quick evaluation of high-level personal doses exposed
in an accelerator tunnel during beam operations, (2) Consideration to
safe transportation of highly-activated target vessel used at Materials
and Life Science Experimental Facility (MLF), and (3) Safety measures
after the fire of a temporary power generator.
      In the afternoon, the Workshop for Fostering Safety Culture was
held. The main talk entitled "Human power required for strong and safe
organization" was given by Dr. Yayoi Nagai (Office KAZE NO MICHI).

  THE APPLICATION FOR A LICENSE OF THE OPERATION WAS GRANTED

    The application for changes of the radiological license was
granted by the Nuclear Regulation Authority (NRA) on June 12. The
approved changes in the application were the materials irradiation
experiment at the Main Ring Synchrotron, the minor change of the
radiation safety interlock system of the Rapid Cycling Synchrotron
and so on.

 
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7. [Editorial Note]
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  Information on the project can be also obtained at the web site:
  http://j-parc.jp/c/en/topics/project-newsletter/index.html

 

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Editorial Board:
Toshifumi TSUKAMOTO (Chair): toshifumi.tsukamoto@kek.jp
Kaoru SHIBATA: shibata.kaoru@ jaea.go.jp
Takashi ITO: itou.takashi@jaea.go.jp
Dick MISCHKE (English Editor): mischke@triumf.ca
Tomoko KAWAMURA (Secretary): kawamura.tomoko@jaea.go.jp
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