Inter-University Research Institute Corporation
High Energy Accelerator Research Organization

Insight Through Accelerators.

KEK is a research institute that uses

a variety of accelerators to unravel themysteries of the universe, matter, and life.

Director General

Masanori Yamauchi

Particle accelerators that accelerate electrons, protons, and others have contributed
substantially to the remarkable development of science and technology in recent
years by providing essential tools for studying nuclei and elementary particles, aswell as means of understanding materials and biological phenomena, since it wasinvented in 1930’s.
Important results that deepen understanding of elementary particles have been
produced in Japan, such as confirmation of the Kobayashi-Maskawa theory andclarification of neutrino oscillations. Cutting-edge results have also been achieved inmaterials and life sciences, such as use of synchrotron radiation for structural analyses
of novel superconductors and drug-related proteins, and studies of novel properties
induced by hydrogen in matter using high-intensity neutron and muon beams.
Accelerators continue to achieve dramatic progress in many important ways, andplay a role as a powerful driving force that supports the frontiers of new science andapplied research.
In scientific research, being the first to develop new ideas and discover novel
phenomena is considered to hold the highest value. Discovering and broadly sharing
what no one else knew prompt subsequent discoveries, progressively expanding
the limits of our knowledge. This value placed on new knowledge is the mostfundamental driving force that has spurred the development of science. It has shedlight on the structures of various substances and the mechanisms driving chemical
reactions, and led to the development of materials with new functions, etc. So, howdoes one become “the first to discover?” Accelerators play an indispensable role
in research fields in which KEK participates. KEK’s contribution to science lies in theconstruction of accelerators with world-leading performance, delivering higher levelsof energy or intensity than ever before to discover as-yet-unknown universal truths.
I would like to express my gratitude for your support for KEK’s science efforts. We
will continue to maintain a strong awareness of our responsibilities as members ofsociety and devote ourselves to the further development of science and applied
technology.

What is KEK?
All matter comprises atoms and molecules formed by the bonding of atoms. An atom is made of a nucleus and electrons, a nucleus ismade of protons and neutrons, and protons and neutrons are made of quarks, a type of elementary particle.
Research into these types of elementary particles and nuclei is an important area of fundamental science, and research into elementary
particles illuminates the mysteries of the universe right after its beginning. Clarification of structures and functions of matter at themolecular level is an important area of material science and is essential for the development of practical materials such as battery-related
compounds and for drug discovery and other applications.
Accelerators make these types of studies possible. An accelerator is an apparatus that speeds up tiny particles such as electrons andprotons nearly to the speed of light, to create high-energy conditions. This leads to the discovery of elementary particles that can beproduced only under such extreme conditions. Synchrotron radiation and the beams of neutrons, muons (μ particles), and positronsobtained using accelerators are important also for studying the properties of matter.
KEK has been on the cutting edge of developing high-performance accelerators and detectors with the highest resolutions in space andtime. We are also collaborating with industry to develop in the fields of electricity, radiation, machinery, measuring instruments, computers
and materials.

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High Energy Accelerator Research Organization

Features of KEK
1. Contributing to the expansion of the intellectual assets of humanity
KEK explores the laws of nature and the basic structure of materials, and contributes to the expansion of the intellectual assets of humanity.
We promote experimental and theoretical research into the structure and function of elementary particles, nuclei, materials, and life using
high-energy accelerators.

2. An Inter-University Research Institute Corporation
KEK conducts collaborative studies with researchers both in Japanand abroad. We also provide a venue for collaboration, support
advanced education and research at universities, and help develop
cutting-edge research in accelerator science and research in related
fields.

3. An international research agency open to the world
KEK actively promotes international collaborative research. Weemphasize coordination and cooperation with overseas research
institutes, and serve as a hub for accelerator science in the AsiaOceania region as one of the world’s three major bases.

4. Promoting educational cooperation and humanresource development

panoramic view of KEK Tsukuba Campas

As a founding organization of the Graduate University for Advanced Studies (SOKENDAI), KEK trains human resources who will promoteaccelerator science and develop related cutting-edge research fields. We also provide education cooperation to graduate schools andother institutes to cultivate human resources in the accelerator science field.

Organization
1. Institute of Particle and Nuclear Studies
KEK conducts a wide range of particle physics and nuclear physics research from both experimental and theoretical approaches to explore
the behavior of elementary particles and nuclei, which are the fundamental building blocks of matter. In addition to clarifying the mysteriesof the microscopic world, such as elementary particles, we use high-energy accelerators to challenge the fundamental question of how theuniverse was born.

2. Institute of Materials Structure Science
KEK elucidates the structure and function of materials on a wide scale from the atomic level to the polymer and biomolecule level, byusing synchrotron radiation, neutrons, muons, and slow positrons generated from accelerators, and conducts research in materials andlife science from fundamentals to applications. Through collaboration between various quantum beam facilities, we promote multi-probe
research that enables the observation of the same substance from multiple perspectives, and contribute to the advance of materials
science through development and research of beam generation and application technologies.

3. Applied Research Laboratory
KEK researches and develops various technologies required for research using accelerators. We are engaged in protection from radiation,
environmental management, precision measurement, computer and software development, big data analysis, network management,
developmental research of superconducting electromagnets and precision instruments, liquid helium supply, etc.

4. Accelerator Laboratory
The Accelerator Laboratory provides researchers in Japan and abroad with a venue for collaborative experiments in fields such as
elementary particles, nuclei, materials, and life science, through design, construction, operating maintenance, and performance
improvement of the accelerators in KEK. The Accelerator Laboratory also conducts international research and development of cuttingedge accelerators for next-generation research, and promotes a wide range of activities, such as industrial and medical application ofaccelerators, and provision of superconducting technologies and other advanced accelerator technologies to general industry.

5. J-PARC Center
J-PARC (Japan Proton Accelerator Research Complex) is a research facility operated jointly by KEK and the Japan Atomic Energy Agency(JAEA). This multipurpose facility is open to the world, and conducts research in a wide range of fields, including particle physics, nuclear
physics, materials science, and life science, using a variety of secondary particle beams such as neutrons, muons, K mesons (kaons), andneutrinos generated by the world’s top-class proton beam.

High Energy Accelerator Research Organization3

B-Factory
KEK B-factory is an experimental apparatus that accumulates beams of electrons and their antiparticles, inindependent rings, and then collides them at a single intersection to observe the elementary particle reactions. To
produce a large number of elementary particle reactions, it is necessary to increase the intensity of the beams andto achieve a very small beam cross-section at the collision point. B-factory currently holds the world record among
electron and positron colliders for highest luminosity (rate of collisions), which is a measure of performance.

SuperKEKB accelerator

Electron-positron linear accelerator

The KEKB accelerator was a ring accelerator with a circumferenceof 3 km that creates head-on collisions of electrons and positrons.
Together with the Belle detector, it was used to discover violationsof the symmetry between B mesons and anti B mesons in
2001, and contributed to the 2008 Nobel Prize in Physics for Dr.
Kobayashi and Dr. Maskawa. SuperKEKB is a major modification of
KEKB, and reached a generation capacity (luminosity) of B mesons
and other particles tens of times higher than the value achieved by
KEKB. Following commissioning in 2016, a positron damping ring
was constructed and the Belle II detector and superconducting
beam final focus magnets were installed on the main ring. Collisionand other adjustments were then performed in March through July
2018, and full-fledged physics experiments commenced in March2019.

The KEK electron-positron linear accelerator has a total length of
600 m and supplies high-energy electron and positron beams to
SuperKEKB and the KEK synchrotron radiation accelerators (PF, PFAR). The electron beam uses electrons emitted when a powerfulpulsed laser is irradiated on a rare earth alloy. The positron beamuses positrons generated when the electron beam is collided withtungsten. Electrons and positrons with the required energy aresupplied almost simultaneously to the respective rings by adjusting
the acceleration tube parameters and the electromagnetic fieldstrength at about 20-millisecond intervals.

Belle II experiment
The Belle II experiment aims to discover new laws of physics by
upgrading the Belle experiment that contributed to the 2008 Nobel
Prize in Physics. B mesons generated by the SuperKEKB accelerator
are particles that contain heavy quarks called bottom quarks,
and decay into various lighter particles. By examining this decay
pattern in detail with the Belle II detector, the experiment attempts
to discover events that cannot be explained by current theory ofphysics. This experiment has over 1,000 researchers participatingfrom 26 countries and regions around the world. It aims to collect
50 times more data, such as on B meson decays, than the Belleexperiment. Through analysis of this data, the experiment aims tofurther illuminate the mysteries of the beginning of the universe,such as the reason why antimatter that should have existed thendisappeared, and physics beyond the standard model of particle
physics.

Belle II detector
The Belle II detector is a particle detector around 8 meters high,wide and deep and weighs about 1,400 tons. It is installed tosurround the area around the collision point of electron andpositron beams generated by the SuperKEKB accelerator andcollects various information such as energy, momentum, and typeof particles generated at the collision point. This detector was
made by significant improvements of Belle detector components.
It combines sensors with differing characteristics, such as a decay
vertex detector that makes use of semiconductor microfabrication
technology and a drift chamber made by manually stringing tensof thousands of metal wires.

4

High Energy Accelerator Research Organization

Belle II detector

Photon Factory
The Photon Factory (PF) is an experimental facility to observe materials and life on an atomic scale using
short-wavelength “synchrotron radiation” generated from an accelerator. Here, various research is conducted
to understand mechanisms of nature and to enrich our lives by nanoscale analysis of functional materials,
macromolecules such as proteins that make up life, extraterrestrial materials, materials from deep inside the earth,and all other materials.

Accelerator for synchrotron radiation
When the path of electrons traveling at close to the speed of light is bent by a magnetic field, part of the energy is emitted as bright“synchrotron radiation.” A synchrotron radiation ring is an accelerators that uses synchrotron radiation for research in materials and life
science. KEK has two synchrotron radiation accelerators: the Photon Factory (PF), which is a storage ring with a circumference of 187 meterswith an energy of 2.5 GeV, and the Photon Factory Advanced Ring (PF-AR), which has a circumference of 377 meters with an energy of 6.5
GeV. Together, PF and PF-AR supply synchrotron radiation to nearly 50 experimental stations.

Synchrotron radiation
Synchrotron radiation is light generated from anaccelerator in a wide wavelength range, from infraredto X-rays. Short wavelength light, such as vacuum
ultraviolet, soft X-rays, and X-rays, enable us toobserve the nanoscale world, i.e., the arrangementof atoms and the motion of electrons in moleculesand crystals. Synchrotron radiation is bright light withsmall divergence, enabling analysis of tiny samples
and accurate structural analysis. It also has properties
such as polarization and short pulse, and is effective
to investigate the orientation of molecules and thechanging state of materials such as chemical reaction.

Photon Factory

Slow Positron Facility
The positron is the antiparticle of the electron. The Slow Positron Facility carries
out materials science studies using a slow positron beam. The positron beam
is produced from a high-energy electron beam made by an electron linear
accelerator. The generated high-energy positrons are moderated by making
use of negative positron work function of metallic tungsten and then reaccelerated into a monoenergetic slow-positron beam with tunable energy.
We use positron diffraction to study the atomic arrangement of material
surfaces. Positron diffraction has high surface sensitivity and can reveal theatomic arrangements of the topmost surface and a few layers below it withhigh accuracy. We are also investigating the atomic physics of positronium andits negative ion. Positronium is a very light atom composed of a positron andan electron. In addition, we are investigating the electronic state of surfaces byusing the positronium time-of-flight method.

Slow Positron Facility

High Energy Accelerator Research Organization5

J-PARCAt the Tokai campus, where the high-intensity proton accelerator J-PARC is operated jointly with JAEA, research is
conducted to accelerate proton beams with the world’s highest intensity, and various particles generated from theaccelerated beams are used to research the origin of matter and life and the beginning of the universe. Protons areaccelerated by three stages of accelerators up to an ultimate speed of 99.95% of the speed of light. The accelerated
protons are sent to experimental facilities and used for experiments and the creation of various particles by striking
targets.

Linac

Rapid Cycle Synchrotron

Main Ring synchrotron

Proton acceleration starts from the Linac.
Negative hydrogen ions formed by theplasma of hydrogen gas reach up to
400 MeV in a linear accelerator with a
total length of 250 meters. The negativehydrogen ions then pass through a thinfilm of carbon to strip the electrons, andare injected to the Rapid Cycle Synchrotron(RCS) as protons.

The RCS is a ring accelerator synchrotron
with a circumference of about 350 metersthat accelerates the proton beam up to 3
GeV. Most of the extracted proton beams
are led to the Materials and Life Science
Experimental Facility (MLF) and used
to generate neutron and muon beams,
and some are sent to the Main Ring
synchrotron (MR) and accelerated to evenhigher energy.

The MR is a synchrotron with acircumference of about 1,600 meters that
accelerates the 3 GeV proton beam up to
30 GeV. This beam is used for generationof secondary particles such as kaons andπ-mesons in the Hadron Experimental
Facility. It is also used for neutrino beam
generation in the Neutrino Experimental
Facility.

Materials and Life Science Experimental Facility

Hadron Experimental Facility

Materials and Life Science Experimental Facility (MLF) is a user
facility which provides intense pulsed neutron and muon beams
for scientific and industrial researches. MLF produces neutrons
and muons with an accelerator-based system that delivers
proton pulses to a target/moderator system. State-of-the-art
experiment stations with the more intense and brighter source
provide a variety of capabilities for researchers across a broad
range of disciplines, such as physics, chemistry, materials science,and biology. MLF allows for measurements of greater sensitivity,
higher speed, higher resolution, and in more complex sample
environments than have been possible at existing neutron andmuon facilities. MLF stands as a leading facility in Asia-Oceania
region and is available to researchers from all over the world withvarying degrees of experience.

At the Hadron Experimental Facility, the origin and evolution ofmatter in the Universe are explored to answer questions suchas why matter is dominant over anti-matter and how states ofmatter are produced and were evolved from quarks to neutronstars. Various particle and nuclear physics experiments are being
conducted using secondary particle (hadrons, muon) beams
produced by a high-intensity proton beam from MR as well as
the primary proton beam. In particle physics, we explore physics
beyond “Standard Model” by search for CP violating kaon rare
decay phenomena (KOTO experiment) , and the search for muonto-electron conversion events (COMET experiment). In nuclear
physics, we investigate the “strong interaction” among hadrons,
especially those with strange quark(s), through spectroscopy ofhypernuclei with hyperon(s) and kaonic nuclei and by hyperon
scattering experiments. We also study the origin of hadron mass
by examining changes of the properties of hadrons within nuclei.
Experiments using primary protons commenced in 2020.

Neutrino Experimental Facility
The Neutrino Experimental Facility conducts the T2K experiment to examine the nature of “neutrino oscillations” in detail by theobservation of neutrinos generated by J-PARC with the Super-Kamiokande detector 295 km away. Neutrino oscillation was discoveredby Professor Takaaki Kajita and colleagues, who were awarded the Nobel Prize in Physics in 2015. The T2K experiment was the first in theworld to successfully obtain definitive evidence of muon neutrino to electron neutrino transformation in 2013. The experiment has been
examining the difference in the probability of oscillations for neutrinos and anti-neutrinos since 2014, and the results so far suggest that CP
symmetry violation occurs with a confidence level of 95%. Work has commenced to upgrade the accelerator, the neutrino generator, andthe near-detector for measurement with even higher accuracy, and in the future, the next-generation “Hyper-Kamiokande” detector will be
used to challenge the properties of elementary particles and the mystery of the disappearance of anti-matter from the universe.

T2K experiment

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High Energy Accelerator Research Organization

International Collaboration
Two thousand foreign researchers visit KEK
Around 2,000 researchers from some 45 countries andregions around the world have visited KEK for such
purposes as joint research and international conference
attendance. In the Belle II and T2K experiments, many
researchers from research institutes worldwide areparticipating. In the Photon Factory, the Indian Beamline(BL-18B) has been set up based on a memorandum of
understanding signed with the Indian Department of
Science and Technology (DST).

12,700

2,300
5,200

6,400
the Americas

Europe, Africa,
Middle East
Asia Oceania

1,400
11,000

Number of Researchers in
FY2019 (unit: person-day)Foreign researchers
KEK researchers

International Cooperation Projects
The US-Japan Science and Technology Cooperation Program, which began in 1979, has contributed greatly to the development ofaccelerator science and the development of young researchers in both countries. In addition to cooperating with the upgrade of theLarge Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), KEK also participates in international collaborative
research such as the ATLAS experiment together with Japanese universities and research institutes. In the Asian Forum for Accelerators andDetectors (AFAD), KEK cooperates in the R&D and application of accelerator and measuring instrument technology, which is particularly
demanded in the Asia region.

International Cooperation Experiments
KEK is participating in the MEG experiment conducted at the Paul Scherrer Institute (PSI) in Switzerland, the POLARBEAR experiment toobserve the cosmic microwave background (CMB) in the Atacama Highlands in Chile, and the TUCAN experiment to search for the neutron
electric dipole moment using ultra-cold neutrons (UCN), which is being conducted at TRIUMF in Canada.

Academic Exchange Agreements
KEK has concluded academic exchange agreements with many universities and research institutes, and actively conducts joint research andexchange of researchers. These include in the Asia region the Institute of High Energy Physics (IHEP, China), the Institute for Basic Science(IBS, Republic of Korea), the Synchrotron Light Research Institute (SLRI, Thailand), and research institutes under the India Department ofAtomic Energy, in North America the Fermi National Accelerator Laboratory (FNAL, the USA) and TRIUMF (Canada), and in Europe CERN,
the French National Centre for Scientific Research (CNRS, France), the German Electron Synchrotron (DESY, Germany), the National Institutefor Nuclear Physics (INFN, Italy), the University of Ljubljana (Slovenia), and the Budker Institute of Nuclear Physics (BINP, Russia). In particular,
KEK established the Toshiko Yuasa Laboratory (TYL) jointly with France in 2006 as a virtual collaboration laboratory and has actively andsystematically promoted joint research and exchanges of young researchers.

International Linear Collider (ILC)
The International Linear Collider (ILC) will be a necessary tool for
unlocking some of the deepest mysteries about the universe. By colliding
electrons and positrons at nearly the speed of light, the ILC will allow
physicists to precisely explore extremely high-energy regions. Some 50
countries and regions worldwide are collaborating to develop accelerator
technology and promote physics study. Japan is the leading candidate tohost the machine, and KEK is working with scientists around the world for
its timely realization. At its cutting-edge facilities: the Superconducting
RF Test Facility (STF), the Accelerator Test Facility (ATF) and the Cavity
Fabrication Facility (CFF), KEK is conducting various research anddevelopments essential to realize the ILC, such as the superconducting
accelerating systems, ultra-high quality beam generation and control,
having achieved numerous results already.

ILC conceptual drawing ©Rey Hori

International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP)
KEK has launched a new world premier international research center “International Center for Quantum-field Measurement Systems for
Studies of the Universe and Particles (QUP)”. QUP will integrate particle physics, astrophysics, condensed matter physics, measurement
science, and systems science in the works of invention and development of new systems for measuring quantum field. QUP has acharacteristic of the global and diverse nature of quantum-field measurement. In addition to basic science, it will promote interdisciplinary
research that transcends the boundaries of industry and academia.

High Energy Accelerator Research Organization

7

Statistics■ User Experimental Activities
FY2019Item
Applications

ExperimentB-factory

FY2020Approved

Conducted

Applications

Approved

Conducted

-

-

1

-

-

1

Photon Factory

378

376

754(923)323

312

590(863)

J-PARC (MLF・Neutron)

148

139

126

97

90

71

J-PARC (MLF・Muon)

114

110

80

79

73

51

J-PARC (Hadron)

1

1

16

3

3

16

J-PARC (Neutrino)

0

0

3

2

2

5

Multiprobe Experiment

0

0

1

0

0

1

Large Scale Simulation Program

17

17

17

9

9

9

KEK Isotope Separation System
Total

0

0

4

2

2

2

658

643

1,002

515

491

746

■ Number of Users (FY2020) [Person-days (Persons)]
Advanced
Accelerator and
Detector Technology
517 (50)

Other

Large Scale
Simulation
ProgramB-factory

6,327 (902)

4,753 (656)

38 (33)

KEK Isotope
Separation System
13 (12)Multiprobe
Experiment

J-PARC（Hadron）
4,393
(253)

■ Number of Users from Overseas Institutes(by country/region)Total
34,255(4,851)

France 34 (30)
Mexico 40 (10)Malaysia 45 (4)U.K. 187 (17)Italy 191 (69)Canada 207 (29)

PhotonFactory41 (7)

15,147(2,270)J-PARC（MLF・Neutron）
1,020 (153)
J-PARC（MLF・Muon）
934 (186)

Austria
Slovenia
PolandOthersGermany
292 (137)

Total
6,491
(755)

Australia
314 (21)■ Number of Users from Overseas Institutes(by research area)

Russia429 (39)
India
515
(60)

Advanced
Accelerator and
Detector Technology
146 (1)Other
2,390 (103)

Large Scale
Simulation Program
1 (1)KEK Isotope
Separation
System5 (5)J-PARC(MLF・Neutron)34 (34)
J-PARC (Hadron)
295 (23)

Total
6,491
(797)

U.S.A.
1,963 (101)

Taiwan261 (30)

J-PARC（Neutrino）
1,072 (329)

15 (15)13(13)11(11)
37(37)

Switzerland
535
(13)

China
814
(60)

South Korea
588 (59)

B-factory

3,066(566)

Photon Factory422 (55)
J-PARC (Neutrino)
132(9)■ Number of Special Inter-University Researchers
Aﬃliation

NumberInstitute/Laboratory

NumberNational University

17

Institute of Particle and Nuclear Studies

12

Public University

0

Institutes of Materials Structure Science4

Private University

1

Accelerator Laboratory

2

Total

18

Applied Research Laboratory0■ Number of International Agreement
Country/Region
South Korea
India
TaiwanChina
Thailand
Vietnam8

Number
9
10
3
10
3
0

Country/Region
Australia
U.S.A.
CanadaChile
RussiaFranceHigh Energy Accelerator Research Organization

Number
1
10
4
1
8
7

Country/Region
Germany
Italy
Slovenia
Georgia
U.K.
Switzerland
IsraelNumber
4
4
2
2
2
2
0

Country/Region
Austria
SwedenBelarus
PolandCERN
Multinational
Total

Number
0
3
1
1
27
11
125

■ Budget (FY2021) [Million JPY]
Withdrawal of reserves for speciﬁc purposes
451
Donation
1,656

Miscellaneous 287

Industry-academia
joint research
1,656

Construction
5,826

Facilities Improvement Subsidy from National Institution for
Academic Degrees and Quality Enhancement of Higher Education

40

Construction
5,786

Revenue
35,528

Expenditure
35,528Operation
16,598Grant
10,710Grant
10,710Operation
17,336

Researcher's education
17,336■ Number of staﬀ (April, 2021)
Director
GeneralExecutive
Director

AuditorResearch & Adjunct Faculty
Researcher
Academic Staff
Members

Executive and Permanent
Employee

1

5

2

337

-

Fixed Term Employee

-

-

-

22

19

■ The Graduate University for Advanced Studies (April, 2021)
School/Department
Quota
5-year doctoral course
School of High Energy
3rd year transfer admission
Accelerator Science
5-year doctoral course
Department of Materials
3rd year transfer admission
Structure Science
5-year doctoral course
Department of Particle and3rd year transfer admission
Nuclear Physics

Engineer &Technician

Oﬃcer

Total

-

155

157

657

148

71

170

430

Newly enrolled

2

Registered

Total enrolled

17

152

12

107

43

179

1
1
1
1
11
2

A few

3

A few

4

A few

■ Grants to scientiﬁ c research [10,000JPY]■ Joint research with private sector [10,000JPY]
FY

NumberAmount of money

FY

NumberAmount of money

2020

81

15,827

2020

193

136,844■ Academic consultation[10,000JPY]■ Grants to agencies [10,000JPY]

FY

NumberAmount of money

FY

NumberAmount of money

2020

6

1,274

2020

11

104,367■ Donations [10,000JPY]
Types of Donations■ Trust researchers [10,000JPY]
Number Amount of money

Specified Offering Donation

396

2,877

General Donation

84

237

International Privately Financed Students Scholarship

25

147

Request for support to gaining further understanding of the ILC Project

61

60

Promotion of KEK 50th Anniversary Commemorative Projects

177

1,960

Contribution to KEK for the future of Photon Factory

49

472

OthersFY

NumberAmount of money

2020

36

74,967■ Facility usage fees [10,000JPY]
FY
2020

7

NumberAmount of money

PF48

10,080Cryo-EM

21632■ Collection of books (April,2021)
Books

JournalJapanese books

Non-Japanese
books

Total

Japanese books

Non-Japanese
books

Total

14,083

26,47940,562

5,427

44,79650,223■ Facility (April, 2021) [m2]
Area

Total

Preprint/
Report90,785

131,765※ 10,253 copies of
e-books areavailable.

■ Number of Visitors (FY2020)
Site

Building

Purpose/destination of visit

Total

Oho

1,531,286

196,966

Guided tour

434

Tokai

106,80944,546

Exhibition hall

420

8,350

3,412

J-PARC

362

Total

1,216

Takezono
Azuma

31,226

26,948

Total

1,677,671

271,872※ Site of Tokai includes lease.
High Energy Accelerator Research Organization

9

Tsukuba Campus
1-1 Oho, Tsukuba, Ibaraki 305-0801 Japan029(864)1171(dial-in number service)/029(879)6047 (Public Relations Office)Superconducting RF Test Facility（STF）

Belle Ⅱ Detector

KEKB Accelerator

Accelerator Test Facility (ATF)

PF-AR

Photon Factory (PF)Cavity Fabrication Facility（CFF）

Mechanical Engineering Center

Radiation Science Center
Electron-Positron Linear Accelerator

10

High Energy Accelerator Research Organization

Compuring Research Center

Cryogenics Science Center

Tokai Campus
203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan029(284)4890

Linac

RCS

Neutrino Experimental Facility

Materials and Life Science Experimental Facility

MR

Hadron Experimental Facility

High Energy Accelerator Research Organization

11

The Inter-University Research Institute Corporation
The inter-university research institute system was born in Japan to promote collaborative research beyond
the university framework more than fifty years ago. The Inter-University Research Institutes are now providing
researchers across the country with most advanced large-scale research facilities available and also serve as acore function for network-type worldwide collaboration research programs for different fields. One of the four
independent Inter-University Research Institute Corporations is KEK, which has two inter-university research
institutes and two laboratories: the Institute of Particle and Nuclear Studies (IPNS), the Institute of Materials
Structure Science (IMSS), the Applied Research Laboratory, and the Accelerator Laboratory.

Kobayashi–Maskawa theory
KEK is a research institute with deep relations to the Nobel Prize. A number of KEK studies have been directly and indirectly
connected to past Nobel Prizes. Many cutting-edge studies are also currently underway that are may lead to future such awards.
The Belle experiment at the KEK B-factory experimentally proved the Kobayashi–Maskawa theory, for which the 2008 Nobel Prize inPhysics was awarded to Dr. Makoto Kobayashi and Dr. Toshihide Maskawa. In 2001, the Belle experiment demonstrated the slightdifference in the decay of B mesons and anti B mesons generated by colliding electrons and positrons. The experiment verified thecorrectness of the Kobayashi–Maskawa theory.

Structure and Function of Ribosome
In 2009, Dr. Ada Yonath, an Israeli scientist, was awarded the Nobel Prizein Chemistry for her accomplishment in clarifying the crystal structure of
ribosomes, which can be considered protein factories. In the mid-1980s, a
Weissenberg camera had been completed at the KEK Photon Factory for
examining protein structures by synchrotron radiation. Dr. Yonath quickly
applied for use to KEK, when she knew it. It was the beginning of joint
research with the facility.

Discovery of Neutrino Oscillation
In 2015, Dr. Takaaki Kajita was awarded the Nobel Prize in Physics for his
discovery of neutrino oscillation.
KEK succeeded for the first time in the world in verifying long-baseline
neutrino oscillations using artificial neutrinos in the K2K experiment that
detects neutrinos generated by the KEK Proton Synchrotron with the SuperKamiokande detector located in the town of Kamioka in Hida City, Gifu
Prefecture.

Dr. Makoto Kobayashi

Dr. Ada Yonath(Photo by Dan Proges)

Dr. Kobayashi and Dr. Yonath were awarded the title of KEK
Special Honorary Professor for their accomplishments.

Tsukuba Campus
About 20 minutes from “Tsukuba station” by bus, and about 30
minutes from “Sakura-Tsuchiura IC” of the Joban Expressway.
IbarakiPrefectureTokai

KEK Tokai Campus

JR Joban line
Mito
Mt. Tsukuba

Inter-University Research Institute Corporation

Ibaraki Airport

KEK Tsukuba Campus

High Energy Accelerator Research Organization

Tsukuba
Tsukuba Science City

◆ Tsukuba Campus
Tsuchiura

1-1 Oho, Tsukuba, Ibaraki 305-0801 Japan029(879)6047 (Public Relations Office)Tsukuba Express◆ Tokai Campus

Abiko
Ueno
Akihabara
Tokyo

Tokai Campus
About 10 minutes by taxi from Tokai station on the JR Joban line.
About 20 minutes from “Naka IC” and “Hitachiminami-Ota IC” ofthe Joban Expressway and about 10 minutes from “Hitachi-Naka IC”
of the Kita-Kanto Expressway.

203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan029(284)4851

Narita020

http://www.kek.jp/

40km

2022.03