Latest News

November 15th, 2021

[9 November 2021 update; next update by 15 March 2022]

LIGO, Virgo, and KAGRA are closely coordinating to start the O4 Observing run together. We plan to start the O4 Observing run in mid-December 2022, despite local and global adversities.

LIGO projects a sensitivity goal of 160-190 Mpc for binary neutron stars. Virgo projects a target sensitivity of 80-115 Mpc. KAGRA should be running with greater than 1 Mpc sensitivity at the beginning of O4, and will work to improve the sensitivity toward the end of O4.

If you have any questions, please contact the Spokespersons:

  • Patrick Brady (Spokesperson, LIGO Scientific Collaboration)
  • Giovanni Losurdo (Spokesperson, Virgo Collaboration)
  • Jun’ichi Yokoyama (Board Chair, KAGRA Scientific Congress)

(Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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November 8th, 2021

LIGO-Virgo-KAGRA international gravitational-wave network released GWTC3 (Gravitational-Wave Transient Catalog 3) which covers all the convinced gravitational wave events until the end of Observing run 3 (March, 2020) and posted the articles. GWTC-3 added 35 events in the latter half period of O3, and now we have 90 convinced events after the first discovery of gravitational wave in 2015.

LIGO-Virgo-KAGRA will soon post the associated papers related to this catalog: test of general relativity, and also of the observational results of the joint run of KAGRA and GEO600 in April 2020.

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September 15th, 2021

[15 September 2021 update; next update by 15 November 2021]

The LIGO-Virgo-KAGRA Collaboration is continuing to evaluate and respond to the ongoing impacts of COVID-19 and adverse weather on preparations for the O4 observing run. As a result, we reiterate that O4 will not start before August 2022 and note that it may be further delayed. We will provide a more concrete plan in our next update, by 15 November 2021.

The readiness of both the LIGO-Hanford and the LIGO-Livingston detectors remains uncertain as delays due to COVID-19 and Hurricane Ida hitting Louisiana have affected the construction schedule for the Frequency Dependent Squeezing system. Hurricane Ida has also impacted the LIGO Livingston Observatory staff and their families. The full impacts are still being evaluated and mitigations are being identified.

Virgo has completed the integration of the upgrades for O4 and is now in a commissioning phase. The uncertainty in readiness of the Virgo detector is mainly driven by the progress of the instrument commissioning.

KAGRA is working to join O4 with Virgo and LIGO. A later start than August 2022 is preferable due to COVID-19 and staff limitations.

If you have any questions, please contact the Spokespersons:

● Patrick Brady (Spokesperson, LIGO Scientific Collaboration); lsc-spokesperson_AT_ligo/org
● Giovanni Losurdo (Spokesperson, Virgo Collaboration); virgo-spokesperson_AT_ego-gw/it
● Jun’ichi Yokoyama (Board Chair, KAGRA Scientific Congress); kscboard-chair_AT_icrr/u-tokyo/ac/jp
  (Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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August 29th, 2021

KAGRA Scientific Congress announces the new board chair Jun’ichi Yokoyama (RESCEU, Univ. Tokyo).
He will lead KSC for the next two years after Hisaaki Shinkai (Osaka Inst. Tech.).

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July 15th, 2021

[15 July 2021 update; next update by 15 September 2021]

The LIGO-Virgo-KAGRA collaborations are making good progress in the updates of the Virgo (where installation of new hardware is complete), KAGRA, and LIGO detectors in preparation for O4. It is not yet possible to give a definitive start date for O4, as there are some continued supply chain delays and the impact of COVID continues. We can say at this time that the O4 observing run will not begin before August 2022. We expect to be able to give a better estimate for the start of O4 by 15 September 2021 and will issue an update then.

If you have any questions, please contact the Spokespersons:
● Patrick Brady (Spokesperson, LIGO Scientific Collaboration);
● Giovanni Losurdo (Spokesperson, Virgo Collaboration);
● Hisaaki Shinkai (Board Chair, KAGRA Scientific Congress);
(Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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June 29th, 2021


On January 5th 2020, the Advanced LIGO detector in Livingston, Louisiana in the US and the Advanced Virgo detector in Italy observed gravitational waves produced by the last few decaying orbits (inspiral), followed by the merger of the neutron star with the black hole. Just ten days later a second gravitational-wave signal from the inspiral and merger of a neutron star with a black hole, was observed, this time by both Advanced LIGO detectors (in Livingston and also in Hanford, Washington) and the Virgo detector. This is the first time gravitational waves have been observed from a mix of neutron stars and black holes. These new discoveries are nick-named GW200105 and GW200115.

The masses of neutron stars and black holes measured through
gravitational waves and electromagnetic observations.
(Image credit: LIGO-Virgo & Frank Elavsky, Aaron Geller, Northwestern University)
(See the science summary for details.)

Summary of our knowledge of the component masses of the objects
that produced GW200105 and GW200115.
(See the science summary for details.)


Read a free preprint of the full scientific article here.


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April 21st, 2021

The 8th KAGRA international workshop (KIW) will be held on July 7-9 2021, hosted by the Korea Astronomy and Space Science Institute (KASI).

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December 9th, 2020

December 9, 2020

Hi All:

The LIGO-Virgo-KAGRA collaborations have reviewed the readiness status of the detectors improvements and A+/AdV+ modifications in preparation for O4. As of November 2020, the O4 observing run is projected not to begin before June 2022, due to both key procurement delays and COVID-related delays. A number of significant modifications to detector systems during the next six months will refine the understanding of COVID impacts on the schedule. A revised projection of the O4 start date will be given in Spring 2021, based on lessons learned.

Patrick, Giovanni, Hisaaki, Dave, Albert, Stavros, Takaaki, Masatake

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April 17th, 2020

KAGRA Scientific Congress Newsletter No.7 is now online.

p.1 KAGRA entered the observing mode!
p.3 LVK Committee on Climate Change by Luca Baiotti
p.4 What made you decide to study gravitational waves? 
by Heather Fong
p.5-9 COVID-19 report from each region
by Zhoujian Cao, Ray-Kuang Lee, Chunglee Kim, Flavio Travasso,
Sachiko Kuroyanagi, Quynh Lan Nguyen, Hisaaki Shinkai, and Yoshihisa Obayashi
p.6 Newly Joind KASI by Sungho Lee
p.10 retirement of Prof. Yoshio Saito by Takashi Uchiyama
p.11 previous F2F
p.12 Poster Award, PhD thesis
p.14 We hear that …

Download high resolution PDF (47.3MB)

Download low resolution PDF(6.1MB)

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February 25th, 2020

February 25, 2020

On February 25, 2020, KAGRA started observing run after its commissioning procedures and engineering runs.

KAGRA is a large-scale cryogenic gravitational-wave telescope developed in Kamioka, Hida City, Gifu Prefecture, Japan under the leadership of the University of Tokyo’s Institute for Cosmic Ray Research (ICRR) with contributions from the National Astronomical Observatory of Japan (NAOJ) and the High Energy Accelerator Research Organization (KEK). The construction started in 2010 and completed in the last year [press release].

KAGRA’s control room just after the observation start

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December 1st, 2019

KAGRA Scientific Congress Newsletter No. 6 is now online.

p-1: KAGRA joined International GW Network
p-2: LVK-MoA and Our required actions
p-3: New KSC board started
p-4: KSC organization chart (as of November 2019)
p-4: New EO members, SEO set Run Coordinator
p-5: Count down for the start of joint observation
p-5: Operator shift & Collaborator shift from December 17
p-6: Brief Guide to Mozumi, KAGRA office
p-8: Mass of media propagate KAGRA’s completion, Cafe KAGRA returns, Science Cafe in Gifu City
p-9: Face-to-Face 23 at Univ. Toyama, August 22-24
p-9: Face-to-Face 24 at RESCEU, December 4-5
p-10: Probing Our Universe with Quantum Technologies
p-10: Six topics in the Frontiers of Science symposium
p-11: Poster Award Winners at F2F23
p-12: Poster Prize at TAUP2019, Poster Prize at GWPAW2019
p-13: Jun’ichi Yokoyama was elected to the president of AAPPS
p-13: Keiko Kokeyama in Malaysia
p-14: Student Presentation Award of the PSJ, September
p-15: Proposals of KAGRA as a dark matter detector
p-16: Masafumi Kurachi, research administrator of ICRR Kamioka
p-17: We hear that….
p-18: New collaborators

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November 28th, 2019

KAGRA’s promotion video English version is now online!

(c) 2019 ICRR, The Universiti of Tokyo / Iwanami Audio-Visual Media Inc.

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October 4th, 2019

KAGRA celebrated the completion of its work to build the underground detector on Oct. 4, 2019, a milestone in an international effort to advance gravitational-wave astronomy and significantly deepen our understanding of the universe. Later in the day, the signing of a memorandum of agreement (MoA) on a research collaboration between KAGRA, LIGO and Virgo were held at the city of Toyama.

Read The University of Tokyo’s news for the details.

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August 20th, 2019

The fifth issue of KAGRA Scientific Congress Newsletter is now online.

Contents of this issue:

p-1: O3 started
p-2: Directions: On our very near future
p-4: Outreach Activities
p-6: Next Face-to-Face, Previous Face-to-Face
p-7: Previous KIW at Wuhan, China
p-8: Poster Awards
p-9: Newly Joined: National Chiao Tung University
p-10: Newly Joined: National Astronomical Observatories, Chinese Academy of Sciences
p-11: Life in Cambridge and Boston
p-12: Awarded: Hyung Mok Lee, Takaaki Kajita, Yutaro Enomoto
p-13: Links: How much are you ready for O3?
p-14: We found that, published
p-15: New Collaborators
p-16: We hear that …


High Resolution PDF 39.4MB
Low Resolution PDF 8.2MB

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June 21st, 2019

The 6th KAGRA International Workshop was held in Wuhan, China on 21 – 23 June, 2019.

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June 1st, 2019

On May 29, approximately 120 students from Taichung Municipal Taichung First Senior High School in Taiwan visited Kashiwa Campus of the University of Tokyo and listened to the lectures by KAGRA members.

Students of Taichung First Senior High School listening Bin-Hua Hsieh’s lecture

The students arrived at Kashiwa campus early morning on 29th. KAGRA Observatory’s PhD student Bin-Hua Hsieh, who graduated Taichung First Senior High School, took them to the Media Hall in UToko’s Kashiwa Library after touring around buildings of the Institute for Cosmic Ray Research and Kavli Institute for the Physics and Mathematics of the Universe. In the Media Hall, Bin-Hua told the students about the life in the University of Tokyo as a introduction and Assistant Professor Takafumi Ushiba explained about KAGRA’s observation of gravitational waves. Then, Professor Hideyuki Tagoshi lectured on Astrophysics especially about black holes and gravitational waves. In the Q&A session, students asked so keen questions that surprises the lecturers.

The students will visit a high-school in Tokyo to communicate with Japanese students and visit lake Kawaguchi to see beautiful scene of Mt. Fuji after this visit of Kashiwa Campus.


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May 13th, 2019

Samyang Group in Korea announced three winners of the 28th Sudang Prize, including KAGRA’s collaborator Professor Hyung Mok Lee at Seoul National University. The award ceremony was held at the Lotte Hotel in Sogong-dong, Seoul on May 9 and a prize of 100 million won was given to each winner.

The Samyang Group’s web page notes the Prizes are presented to individuals who have made exemplary contributions in basic sciences, applied sciences and humanities & social sciences categories.  Professor Hyung Mok Lee leads Korean Gravitational Wave Group (KGWG) which is a member of the LIGO Scientific Collaboration. Financial News in Korea says Lee’s outstanding research achievements in various fields of astronomy, especially the contribution to the first detection of gravitational wave in 2015, are highly regarded.

Related Links

Financial News (Korean)

Sudang Foundation and Sudang Prize


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April 17th, 2019

The fourth issue of KAGRA Scientific Congress Newsletter is now online.

Contents of this issue:

p.2 Directions: bKAGRA installation (almost) finished !!
p.3 Future: Upgrading KAGRA?
p.4 Kamioka Local: Hida Space Science Museum
p.5 Report: Demographic Survey 2018 by diversity committee
p.8 Meetings: F2F at NAOJ, F2F at ICRR, KIW6 at Wuhan, China
p.10 Poster Award Winners
p.11 Newly Joined: Aoyama Gakuin Univ., KIAA Peking Univ.
p.13 New collaborators, We hear that ..


High Resolution PDF 15.4MB
Standard Resolution PDF 6.8MB
Low Resolution PDF 3.8MB


Third Issue of KAGRA Scientific Congress Newsletter (Dec. 2018)

Second Issue of KAGRA Scientific Congress Newsletter (Aug. 2018)

Premiere Issue of KAGRA Scientific Congress Newsletter (Apr. 2018)

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December 1st, 2018

The third issue of the KAGRA Scientific Congress Newsletter is now available online.

Contents of this issue:

p-2 We did it!
p-3 Directions: KSC in the KAGRA organization chart
p-4 Public Outreach, Kamioka Local
p-6 Meetings: F2F at Toyama, F2F at NAOJ, KIW5 at Perugia
p-8 Poster Award Winners
p-9 Newly Joined: UNIST
p-10 We hear that …
p-11 The Laureates
p-13 We found that …


High resolution version (96.3MB)
Standard resolution version (10.0MB)
Low resolution version (4.3MB)


August Issue of KAGRA Scientific Congress Newsletter

Premiere Issue of KAGRA Scientific Congress Newsletter

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November 20th, 2018

The 5th KAGRA International Workshop will be held in Perugia the 14th and 15th of February followed by a connected workshop on KAGRA, Virgo and 3G Detectors the 16th of February. (さらに…)

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November 9th, 2018

Professor Masaru Shibata, Director of Max Planck Institute for Gravitational Physics and Professor of Yukawa Institute for Theoretical Physics, Kyoto University, is awarded the 2018 Nishina Memorial Prize. The title of his research achievement is “Study of Binary Neutron Star Mergers by Numerical Relativity Simulations.”

Professor Saito is a collaborator of KAGRA Gravitational Wave Telescope experiment. Congraturations!

The award ceremony is held on December 5. The Nishina Memorial Prize 2018 is awarded to Professor Shibata and Professor Koichiro Tanaka of Kyoto University.

Link to Nishina Memorial Foundation’s announcement

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September 20th, 2018

Dr. Yuichiro Sekiguchi, KAGRA’s collaborator and Associate Professor at Toho University is awarded the 12th Yukawa-Kimura prize for his research on study of “Numerical-relativity simulation of binary neutron star mergers with realistic microphysics.” Congraturations!

Yukawa-Kimura Prize Homepage

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August 3rd, 2018

The second issue of KAGRA Scientific Congress Newsletter is released and now online at

KAGRA Scientific Congress (KSC) is the decision making body of KAGRA collaborators. The aims of KSC are to discuss and to make decisions upon KAGRA science(Seeherefor the details).


page-1 From Phase 1 to Phase 2
page-2 Directions: Steps to the 2019 observation
page-3 Kamioka Local: Subgroup orientation, Kagra River, Science Cafe
page-5 Recent meetings: F2F at Osaka City Univ. , KIW at Ewha Womans Univ.
page-6 Poster Award Winners
page-7 Next F2F at Toyama, LOGOs
page-8 Visit Virgo
+ KAGRA meeting schedule, We hear that …, etc.

Related topic:

Premiere Issue of KAGRA Scientific Congress Newsletter

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May 25th, 2018

May 25, 2018

The 4th KAGRA International Workshop will be held in Ewha Woman’s University, located in Seoul, Korea in June 29-30, 2018.

The main theme of the KAGRA International Workshop (KIW) centers on the KAGRA project, but also encompasses all related fields such as other gravitational wave experiments, gravitational wave sciences, and multi- messenger astronomy. Everybody interested in contributing to the KAGRA project and gravitational wave science in general is welcome to join the meeting.

A public lecture by Prof. Takaaki Kajita, the PI of KAGRA Project on the topic of “Gravitational wave astronomy with KAGRA” is also held during the workshop.

Visit workshop website for the details and registration (deadline: June 15) .

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April 11th, 2018

On March 30, Louisiana State University’s Professor Gabriela González, the former Spokesperson of LIGO Scientific Collaboration, visited the experimental site of KAGRA.  Assistant Professor Keiko Kokeyama, who moved from LSU to ICRR in 2015, guided her in the KAGRA underground site. Prof. González enjoyed to see the status of preparation of the experiment.

Professor Gabriela González(center) and Dr. Keiko Kokeyama(left) in the KAGRA arm tunnel.

Visitors are carefully watching the installation work of sapphire mirror in the cryogenic vessel.

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April 1st, 2018

The premiere issue of KAGRA Scientific Congress Newsletter is released and now online at

KAGRA Scientific Congress (KSC) is the decision making body of KAGRA collaborators. The aims of KSC are to discuss and to make decisions upon KAGRA science(See here for the details).

Today April 1st, some members of KSC released KSC NewsLetter in order to exchange and share KSC’s activities. It’s free and open to public. Please enjoy!

page-1 Phase-1 operation starts on April 23
page-2 Directions: Towards joining LIGO/Virgo’s O3
page-3 Kamioka: New office is open!
page-4 Upcoming meetings: KIW Ewha Womans Univ.
page-4 Upcoming meetings: Face-2-Face at Osaka City Univ.
page-5 Lab. interview:  Academia Sinica
page-6 Physics: What Stephen Hawking did in Relativity?
+ Recent review talks, KAGRA meeting schedule, We hear that …,  etc

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February 12th, 2016

Feb. 12th, 2016

Message from KAGRA on the discovery of Gravitational Wave signal by LIGO-Virgo collaborations

We, the KAGRA collaboration, congratulate the LIGO and Virgo collaborations for the discovery of the gravitational wave signal. It is a historic discovery where the whole field of gravitational waves and general relativity have been waited for.

It is really exciting news, because it is now clear that the studies of gravitational waves and massive compact objects, such as black holes and neutron stars, can be made by the present generation gravitational wave detectors including KAGRA.

KAGRA would like to complete the construction, achieve the high sensitivity and join the international gravitational wave network as soon as possible so that KAGRA can contribute to the new field of gravitational wave astronomy. Because KAGRA is located underground and going to use cryogenic mirrors, KAGRA is particularly suited to study gravitational wave signals below about 100 Hz, where many signals of mergers of black hole binaries are expected, as observed by LIGO.

In addition to the merger of black hole binaries, there are many astronomical objects to be studied with gravitational waves. For example, KAGRA wants to detect a birth of a black hole created by a coalescence of binary neutron stars and resolve the mystery of short gamma ray bursts with the other gravitational wave detectors and with the partners of multi-messenger astronomy.

Takaaki Kajita,
for the KAGRA collaboration

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October 7th, 2015

Professor Kajita, who is the PI of KAGRA, won the Nobel prize in physics !!

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June 13th, 2014

Our research proposal entitled ” First detection of Gravitational Waves using Cryogenic Laser Interferometer” was selected as a Specially Promoted Research of JSPS in 24th April 2014. The leader of this research is T.Kajita who is also a PI of KAGRA project.

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March 31st, 2014

Excavation of KAGRA’s 7 km Tunnel Now Complete
March 31, 2014

On March 31, 2014, the team of the Large-Scale Cryogenic Gravitational Wave Telescope (KAGRA) completed the excavation of its L-shaped tunnel with two 3 km arms. Including two access tunnels, a total length of 7,697 m has been hollowed out 200 m below the surface of Mt. Ikenoyama in Kamioka—beside the site of Super-Kamiokande—where the construction of a 3-km-scale cryogenic interferometer will soon begin. This interferometer has been designed to directly detect gravitational waves for the first time ever.

KAGRA is an international project involving 231 scientists from 31 institutions, principally operated by ICRR(Institute for Cosmic Ray Research) with two main joint-research institutions, KEK (High energy accelerator research organization) and NAOJ (National Astronomical Observatory). Its aim is to construct 3-km-scale Fabry-Perot Michelson Interferometer underground at Kamioka to detect gravitational waves. Gravitational waves, derived from Einstein’s general theory of relativity, are ripples in the curvature of spacetime that propagate at the speed of light. The first indirect proof of their existence was proposed by Dr. Hulse and Dr. Taylor in 1974 who found a binary system of neutron stars, whose decrease in orbital period was well described by the loss of energy through gravitational radiation. In addition, the astronomers of the BICEP2 experiment at the South Pole recently reported that they had found the signature of primordial gravitational waves imprinted in the B-mode polarization of the Cosmic Microwave Background—further evidence of gravitational waves if confirmed. However, gravitational waves have yet to be detected directly in a form in which their waveforms are evident. The direct detection of gravitational waves will not only validate our understanding of gravity and spacetime but also open up a whole new field of gravitational wave astronomy by enabling the physics of strong gravitational fields to be tested, and enabling direct observations of mysterious objects such as black holes, which are not possible through the observation of electromagnetic waves.

Gravitational waves manifest themselves as extremely small changes in the distance between two points in spacetime. Direct gravitational wave detectors therefore detect a change in the metric. However, even the strongest gravitational waves produced during the merger of binary neutron stars and binary black holes typically cause a variation of length of the size of a hydrogen atom over the distance between the Earth and the Sun. Furthermore, such mergers occur once every 100,000 years in our Galaxy. KAGRA aims to increase the detection frequency to several times per year by employing an ultra high-sensitivity metric-variation detector (that can detect change of one part per trillion of trillion) to expand the observation range to include many galaxies. The key to a successful gravitational wave detector is to minimize background noises such as seismic noise and thermal noise to achieve extremely high sensitivity limited only by the quantum noise of the laser used in the interferometer. KAGRA will be constructed 200 m underground to reduce seismic noise to a hundredth of that at the ground surface, and its mirrors that reflect lasers back and forth will be cooled to temperature of 20 K to reduce thermal noise. KAGRA’s quiet underground environment under Mt. Ikenoyama—also known for its lithological characteristic of hard Hida gneiss rock—is now, after 20 months of excavation, ready to host the world’s most sensitive gravitational wave detector.

KAGRA’s construction started in 2010. The L-shaped tunnel with two 3 km arms and two access tunnels is located 200 m under the surface of Mt. Ikenoyama and has a slope of 0.3% to drain spring water effectively. A construction company, Kashima, started to excavate the access tunnels from the Mozumi area in May 2012, and from the Atotsu area in June 2012. After the excavation of central laboratory area near the Atotsu entrance, the crew split into two groups; one working on the “X-arm”, which extends 3 km in the east-northeast direction, and the other working on the “Y-arm”, extending in the north-northwest direction. The Mozumi crew continued to excavate from the other end of the Y-arm up to a distance of 1,165 m, where they stopped to deal with a possible abnormal amount of spring water at the fault. In December 2013, the Y-arm was finally blasted open from the Atotsu side. Following the completion of the Y-arm, the X-arm continued to be extended from one direction and was completed on March 31, 2014. The full excavation length is 7,697 m. During the construction, no serious lithological issues arose; however, on several occasions an unexpectedly large quantity of spring water hampered smooth operations during the excavation period. Kashima coped with such problems efficiently and professionally, even breaking the national record for the excavation speed by the NATM method, achieving a rate of 359 m per month.

The collaboration plans to install laboratory facilities and the detector components in the coming fiscal year, in preparation for the initial operation at the end of 2015. The full-scale operation is planned to start in JFY2017.

Media Contact for Further Inquiries
PR Office: Misato Hayashida
TEL: 04-7136-5148

This announcement are reported in home pages in The University of Tokyo (UT), High energy accelerator research organization (KEK), and National Astronomical Observatory Japan (NAOJ).
UT :

Fig1. The red line shows the seismic vibration level at the ground (Kashiwa Campus) and the green line shows that of 1,000 m underground at Kamioka (CLIO). It has been shown that the seismic vibration level at 200 m below the mountain surface is nearly the level shown in green.

Fig 2. A bird’s eye view of the Large-Scale Cryogenic Gravitational Wave Telescope (KAGRA), an L-shaped laser interferometer with two 3 km arms.

Fig 3. A panorama photo taken in December 2012 at the central branching point near the Atotsu entrance.

Fig 4. KAGRA’s Y-arm that extends from the Atotsu side to the Mozumi side was blasted open in December 2013.

Fig 5. A view of KAGRA’s Y-arm.

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March 5th, 2014

GWADW2014 in which we discuss about the future technique for GW detection will be held in Takayama-city, Gifu-prefecture, Japan from 25th May to 31st May.
The web page is here.

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December 5th, 2013

Since 2012 May, the Y arm tunnel of KAGRA was excavated from Mozumi area and Atotsu area. In Dec/5/2013, this Y arm tunnel finally became one tunnel.

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November 25th, 2013

Prof. Somiya’s article has been selected by the Editorial Board of Classical and Quantum Gravity (CQG) to be one of the journal’s Highlights of 2012-2013.

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October 17th, 2013

MOU between KAGRA and Dept. of Phys. Hanoi Nat. Univ. of Education
was signed on Oct. 11, 2013. You can find the MOU at;

People from Dept. of Phys. Hanoi Nat. Univ. of Education would join KAGRA in the near future.

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July 23rd, 2013

The KAGRA talk event is being held in Inotani-sekisho museum in front of the JR inotani station. The lecturer are S.Miyoki, T.Uchiyama, M.Ohashi, S.Kawamura and O.Miyakawa. Especially, in September 8th, two talks about KAGRA will be presented in a festival “Inotani-sekisyo friendly festival “.

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July 9th, 2013

Yoshiki high school students visited CLIO and SK in July 9th. This event was also reported in a local newspaper.

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June 10th, 2013

The 4th Korea-Japan Workshop was held in Osaka Univ. The web site is here

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May 13th, 2013

The doctor thesis of Dr.Izumi who use to be a doctorial student of NAOJ got Braccini Prize 2012 ( ).
The award ceremony and lecture will be presented in May 24th 2013 in the
Pisa university.

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April 22nd, 2013

April 19th 2013, an Italy-Japan Workshop about gravitational wave physics has been held in the Embassy of Italy. This is one of events related with Italy year 2013 in Japan for their cultural communication.

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April 9th, 2013

Pro. Takahashi was awarded a prize for encouragement of Yamanashi Academy as a promising young researcher in the field of research, education and technology in Yamanashi prefecture.

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January 30th, 2013

In Jan/30/2013, the project titled “The construction of Gravitational Wave Astronomy” was selected as one of Core to Core program of JSPS. The leader is Pro.Kawamura.

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January 18th, 2013

KAGRA Data analysis school wiil be held in NAOJ during Fev 20th ~ 22th.
You can find application form and information in this page.

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December 23rd, 2012

3rd Korea-Japan Workshop was held in Dec 21~22 2012.
The program was here.

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November 1st, 2012

Pro. Endo, the president of Toyama University visited CLIO. After that young scientists in GW group had a meeting with Pro. Endo, Pro.Moriwaki, Pro.Hirobayashi and Pro.Matsushima who are members of Toyama University at GWPO Kamioka branch building.
The President of Toyama University visited CLIO.1
The President of Toyama University visited CLIO.2
The President of Toyama University visited CLIO.3

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August 31st, 2012

ET-KAGRA thermal noise workshop was held in Jena University, Germany.
The workshop report is in here

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August 17th, 2012

KAGRA Advisory Board Meeting was held in ICRR Kashiwa Campus. KAGRA EO members were evaluated about the progress of KAGRA, management, and got many suggestions from the Advisory Board members.

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July 8th, 2012

In 8th July, a workshop about KAGRA with the department of physics and engineer of Toyama University was held in the Toyama University.

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June 27th, 2012

In June 17th, Uchiyama-kun who is ICRR member gave a lecture on KAGRA in the GSA seminar promoted by Hida academy.

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June 18th, 2012

New Atotsu tunnel excavation has started. The excavation of Mozumi is also all right.

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May 22nd, 2012

The blasting at the Mozumi entrance has started.



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April 17th, 2012

An External Review for KAGRA project was held in ICRR from 17th April to 20th. The committee chaired by Dr. Michael E. Zucker evaluated the KAGRA designs, progress, and risks of each subgroup and made some advices. We would like to make assure the success of KAGRA project with these External Review’s reports.

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March 27th, 2012

The KAGRA logo was selected.

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March 13th, 2012

KAGRA project PI, Pro.Kajita was awarded a prize of the Japan Academy of
2012 for “the discovery of atmospheric neutrino oscillation”.

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March 2nd, 2012

Yuki Susa, a member of the KAGRA collaboration at Tokyo Tech,
has been chosen as the representative of master students in
the Department of Physics. Title of his master thesis is
“Optimal signal amplification by weak measurement.”

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February 29th, 2012

In 28th February, A Master thesis of T.Sekiguchi got an ICRR Director Award in the ICRR Master and Doctor Thesis Workshop.
His master thesis title is “Modeling and Simulation of Vibration Isolation System”.

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February 18th, 2012

Members of the House of Councilors, who belong to committee on education, visited in Kamioka Observatory, Super Kamiokande, XMASS and CLIO.

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February 15th, 2012

Thermal noise reduction in CLIO was published in Physical Review Letters.

Summary by Author T.Uchiyama.

“Thermal fluctuation, as evidenced by Brownian motion, has been a well-known phenomenon, and it remains the fundamental limitation for certain ultraprecise measurements such as interferometric gravitational wave (GW) detectors and laser frequency stabilisation using a rigid Fabry-Perot reference cavity. One promising approach for reducing such fluctuations is to use a low-mechanical-loss material at a low temperature. Here, we experimentally demonstrate for the first time a reduction in a mirror’s thermal fluctuation in a GW detector with suspended sapphire mirrors from the Cryogenic Laser Interferometer Observatory (CLIO) at 17K and 18K. The majority of previous efforts to reduce thermal fluctuations in such mirrors have focused on the use of low-loss materials at room temperature. Thus, this achievement provides a new method for overcoming the limitations by thermal fluctuations at room temperature. This cryogenic mirror technology will be used in advanced GW detectors such as KAGRA formerly called the Large-Scale Cryogenic Gravitational Wave Telescope (LCGT), the construction of which began in 2010 in Japan, and the Einstein Telescope in Europe.”

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January 28th, 2012

LCGT finally got new nickname “KAGRA”. KA means “Kamioka”, and GRA means Gravity and Gravitational wave.

A detail report is shown in this page.

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January 21st, 2012

LCGT ground breaking ceremony was held in Mozumi, Kamioka-cho, Hida-city, Gifu prefecture.
Some photos about ceremony are shown in this page.

LCGT ground breaking ceremony was written up in several newspaper.
(web page on Gifu newspaper).

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January 14th, 2012

Korea-Japan Workshop was held in Korea University to promote LCGT project. Collaborations in laser development, vibration isolation, quantum measurement and so on were discussed.

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October 12th, 2011

In 2011 November 5th, a lecture entitled ” Challenge to the Mystery of the Universe from Yamanashi !” will be presented by Dr. H. Takahashi and Mr. Tsugane in the Yamanashi-Eiwa school festival.
Please find in detail in,

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October 3rd, 2011

The European Gravitational Observatory (EGO) and the Institute for Cosmic Ray Research (ICRR) organize a meeting, under the patronage of the Italian Embassy in Tokyo, with the aim to explore the collaboration between Italy and Japan on the Gravitational Wave research with the future interferometric detectors in Italy (advanced Virgo) and Japan(LCGT). The 3rd generation perspectives, thanks to the Einstein Telescope (ET) project will be investigated too and the ELiTES Japanese-European collaborative FP7 project, between ET and LCGT, will be prepared.

University of Tokyo, Kashiwa-campus, Frontier Sciences, Environmental Studies Building, 1st Floor, SF Hall.

Conference Page :

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September 14th, 2011

Dr.Miyakawa (ICRR.UT staff) will give a lecture in Nagoya University GCOE program named as “Quest for fundamental principles in the universe”.
The title is “Detection of gravitational waves from underground in Kamioka-mine”.
Please see this page in detail.

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July 11th, 2011

In the afternoon July 24th, a science cafe live about LCGT project will
be broadcasted in the home page of Niconico-douga. This program is
organized in cooperation with Asahi newspaper and ICRR UT.

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June 17th, 2011

Yoko Ogawa-san who is a japanese famous novelist kindly accepted to be a chairman of a LCGT naming committee, and selected a new hypocrism for LCGT project from about 630 applications. We are very sorry, but please wait until around August~September 2011 for public announcement about this new hypocrism.

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May 12th, 2011

An explanatory meeting about LCGT vacuum ducts temporary stock in the Kamioka-railway tunnels will be held in Higashimozumi, Kamioka-cho, Hida-city in 18th May.

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May 12th, 2011

A meeting for LCGT new name selection was put off due to 3.11 earthquake will be held in 16th June 2011.

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April 21st, 2011

Students and their teachers of Sizhuoka-Kita high school visited Super-Kamiokand, XMASS and CLIO as an event of Super Science High school (SSH). In the morning, they received lectures about SK, XMASS, CLIO and their related physics of neutrino, dark matter, gravitational waves. In the afternoon, they entered the Kamioka mine and visited each facilities.

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April 19th, 2011

An explanatory meeting about LCGT vacuum ducts temporary stock in the Kamioka-railway tunnels will be held in Urushiyama, Kamioka-cho, Hida-city in 22nd April.

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April 12th, 2011

Yamanashi nichi-nichi newspaper wrote up a company in this region accepted an order for LCGT vacuum system in April 8th.

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April 1st, 2011

Gravitational Wave Project Office was established in April 1st 2011.

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March 31st, 2011

Gravitational Wave Project Office will be established in April 1st 2011.

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March 29th, 2011

An Emeritus professor of Tokyo-toritsu University Ikemoto and members of ABCEJ visited Super-Kamiokande, XMASS and CLIO. The members of ABCEJ are mainly private middle school and high school chemistry teachers around Tokyo.

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February 18th, 2011

LCGT MOUs between LIGO and VIRGO were formally concluded.

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February 6th, 2011

Mainichi newspaper wrote up the new name application for LCGT.

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December 16th, 2010

Physics today Journal wrote up LCGT on the 35th page in December issue.

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November 24th, 2010

Staff of Italy embassy visited CLIO with Desalva-sensei.

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November 19th, 2010

“Thermal-noise-limited underground interferometer CLIO” was selected as an oustanding article in the Classical and Quantum Gravity hilight of 2009-2010.

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November 18th, 2010

The film about the construction of LCGT has started.

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November 17th, 2010

The department chief of the academic organization section of the Ministry of Education, Culture, Sports, Science and Technology of Japan visited CLIO. Professor Jim Hough who is one of leader of GEO600 also visited CLIO.

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November 9th, 2010

Technical staff and postdoctoral researche recuruiting has started.

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November 5th, 2010

Yoko Ogawa-sensei who is a famous award-winning novelist agreed to be a chairman to decide the new LCGT name.

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November 5th, 2010

An assistant researcher recruiting has started.

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November 3rd, 2010

A key to understand the Universe – Gravitational Wave detection” by a LCGT collaborator, Dr. Kentaro Somiya was introduced

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November 3rd, 2010

LCGT call for a new charming name!

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October 15th, 2010

A public lecture about LCGT will be held in November 27th. This lecture is one of the National University Festa.

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September 25th, 2010

University of Tokyo, Executive Management Program students (20) visited CLIO.

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September 15th, 2010

The President of the University of Tokyo, Professor Hamada and the regent of the University of tokyo, Professor Kozima visited CLIO.

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June 21st, 2010

Professor Takeda and Assistant Professor Miyamaru and their students (Shinshu University, Department of Science, Physics division, Solid state physics division) visited CLIO.

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