The Advanced Technology Center supports research activities at NAOJ by providing technology
and support for instruments to observe the Universe. We conduct research and development
for both basic and applied technologies to support the telescopes and instruments currently
operated by NAOJ, as well as for technologies intended for future projects. We also promote joint
development activities with other institutes and support their development of new instruments.

Ultra-sensitive superconducting
detec tors, necessar y for radio
astronomy obser vations, aredeveloped in the cleanroom. Stateof-the-art high-frequency circuits
and optical elements for theterahertz band are fabricated onquartz and silicon substrates using
microfabrication technologies suchas photolithography.

The optical design team executes optical design
and analysis to achieve the ultimate optical
performance. The mechanical design team designs
structures and mechanisms to maintain the highprecision and stability of the optics in extreme
conditions such as cr yogenic temperatures,
ultra - high vacuum, and s trong v ibrations .
These two teams work together for integrated
optomechanical design.

DesignIntegrated
Production

Microfabrication cleanroom

2 mm

Silicon-based superconducting
monolithic microwave integrated circuit(MMIC)

50 μm

Silicon micromachined anti-reflection
layers for silicon optical window

Ion-beam sputtering system

SystemIntegration
After assembling all the parts and devices into an
instrument, integration tests are conducted toverify that the required performance criteria canbe met under conditions which simulate the actual
operational environments. Resilience to vibration
caused by a launch or an earthquake, and operationaland control testing under low-temperature andvacuum conditions are checked here.
Some tests use the large cleanroom or the large
vacuum chamber of ATC to avoid contaminationfrom materials and dust.

Europe, ESO
Taiwan, ASIAA

The manufacturing design group is in charge of
production and inspection of mechanical components forexperimental equipment and key components to be usedin the observational instruments which are mounted on
telescopes. This group not only manufactures based on
detailed blueprints but also helps shape the designs basedon ideas from clients. Along with conventional cutting
techniques, the new technology additive manufacturing is
included in the group mission
to aid the development ofadvanced equipment.

Fabrication
Astronomical instrument development
is divided into four categories:(1) instrument design to meet therequirements for observations,(2) fabrication of parts and components,(3) evaluation and verification, and(4) system integration tests conductedunder conditions simulating
operational environments.
Successful development requires along-term perspective about these
activities.

Evaluation

In collaboration with industry, we aredeveloping CCD and CMOS sensors
and near-infrared array detectors,
which are necessary for visible andinfrared astronomy observations.
Development of the control electronics
and evaluation of each detector is done
in-house, leading to flexible and rapid
development of new instruments.
We also provide control electronics toother organizations and support for
installing detectors in instruments.

Near-infrared detector under testing

Dedicated electronics for detectors

Material characterization system at millimeter-wave

Various specifications, such as dimensions, weight,
mechanical characteristics, optical properties, anddurability, must be met for an instrument, including its
subsystems and components. If it is unclear whether
the required specifications are met at the designphase, a prototype is produced for evaluation andwe conduct checks and examine the feasibility of therequirements. ATC has various devices and apparatus
for measurement and evaluation, and we develop
new measurement equipment ourselves as needed.
Durability test of a worm gear

US, White Sands
Chile, Atacama
Hawaii, Hilo

CCD evaluation system

Overhead view of the large clean roomG ravitat i o na l Wave Ob s er v a t i o n sGravitational-wave astronomy observes the Universe through extremely weak gravitational waves.
It aims to discover new aspects of the Universe that are unobservable by conventional methods.
While gravitational-wave astronomy is a new frontier, it is already proving its latent capabilities. ATC
is in charge of designing and developing key components (optical equipment, vibration isolation
system, etc.) necessary for KAGRA (Japan’s large-scale cryogenic gravitational-wave telescope).

KAGRA
Located under Mt. Ikenoyama, Kamioka-cho, Hida city, Gifu Prefecture, KAGRA is Japan's first full-scale large gravitational wave telescope. Its firstobservation run began in the spring of 2020. Unlike the conventional image suggested by the word "telescope," this is a large-scale Michelsoninterferometer having two 3-km arms installed within a group of vacuum vessels, in an L-shape tunnel excavated under the mountain.
Gravitational waves are propagating periodic weak space–time distortions. To achieve sufficient sensitivity to such tiny signals, the optics in theinterferometer should be isolated from noise of all kinds. For this reason, we have constructed the interferometer at a stable site with low groundvibration (less than one-100th that of Tokyo) and have suspended the mirrors from vibration isolators made of multi-stage pendulums. The mostimportant mirrors are cooled to nearly -250°C to suppress thermal noise.
ATC applied technological capabilities accumulated during the development of other types of telescopes and detectors to the design, production,and installation of most of the various components that enabled the KAGRA interferometer to become what it is today. This includes equipment
integrating the optical and mechanical systems such as beam monitors for the 3-km laser optical axes and stray light countermeasures as well as
the vibration isolators. We also contribute to the development of new sapphire mirrors, which will be necessary for KAGRA's next goal of improving
performance.

Optical equipment and vibration isolators
Transmitted light monitoring systems
Systems to detect misalignment in the optical axes of the 3-kmlong optical cavities. The system is a combination of a beamreducing telescope and a vibration-isolation stage. The laser beamdiffuses as it propagates over a long distance so it is focused by thetelescope to 1/10th size while the stage is used to avoid a spurious
signal for optical axis misalignment. ATC supported the entire
process from design to assembly, testing, and onsite installation.

Main mirrors and optical baffles
The cryostat interior, housing the main mirror. The
main mirror, which is cooled to about -250 °C, issuspended from a pendulum 14 m above for vibration
isolation. The anti-vibration optical baffle developed
by ATC is visible to the left of the main mirror.

Optical components
A reflecting telescope with a reduction ratioof 10. The optical axis is folded to fit in a 1-m
diameter vacuum vessel. The glass material
selection was important to make the opticalsystem compact.

Vibration-isolation stage during testing
A combination of passive and active vibrationisolation controls, a pendulum structure
supports the stage with on-board sensors andactuators. Assembly and operation tests wereconducted in a clean booth at ATC in Mitaka.

© KAGRA Collaboration / Rey.Hori

O p tic al a nd I nfra re d Ob s e r v a t i o n s
Optical and infrared astronomy is one of the major fields for exploring the Universe.
ATC has been playing an important role in developing astronomical instruments for the
Subaru Telescope, located at the summit of Mauna Kea in Hawaii, as well as for the Thirty
Meter Telescope (TMT), which is a state-of-the-art telescope that is under construction.

TMT
We are currently designing two astronomical instruments for TMT: the Infrared Imaging Spectrograph (IRIS) and the Wide Field Optical Spectrometer(WFOS). They will produce images and spectra of celestial objects, respectively using infrared light and optical light.

IRIS is being developed through international collaboration

among institutes in Japan, the United States, Canada, and China. ATCis specifically responsible for delivering an infrared camera system. We
are solving technical challenges such as a diffraction-limited opticalsystem that functions at liquid nitrogen temperatures, cryogenic
driving mechanisms that can operate for more than 20 years withoutmaintenance, and a method to measure the positions of celestial objects
with an accuracy of 1/100 millionths of a degree.

WFOS

will uncover large-scale structures of gases in inter-galactic
space by offering imaging and spectroscopy functions. WFOS has beendeveloped through international collaboration among institutes inJapan, the United States, China, and India. ATC is working on the design
study for a mask exchanger. Additionally, we are studying an integral
field unit (IFU) for WFOS as a future upgrade.

Mask exchanger

Infrared wavefront
sensorLight fromthe telescope

Supportstructure

3D model of WFOS
(Provided by Caltech)

3D model of IRIS
An infrared camera
system developed at ATC
will be housed in thevacuum chamber
Vacuum chamber© NRC Herzberg Astronomy &Astrophysics ／ TMT-IRISIFU for the optical imaging spectrograph, FOCAS,
on the Subaru Telescope. The IFU of WFOS is being
developed based on our experience with FOCAS.
A rotary stage, which functions
reliably at liquid nitrogentemperatures

Subaru Telescope
Hyper Suprime-Cam (HSC) is a wide-field digital camera, mounted on theprime focus of the Subaru Telescope. The camera system developed at ATC contains 116 CCDs with 870
million pixels in total. The CCDs are sealed in a vacuum chamber,cooled to -100°C, and operated by dedicated electronics, whichwere also developed at ATC. HSC demonstrates overwhelming
performance for discovering new objects and phenomena in the
Universe with its wide-field, high-resolution, and high-sensitivity
capabilities. The instrument is also used to search for dark matter,by using the gravitational lensing effect.

HSC map http://hscmap.mtk.nao.ac.jp/

116 CCDs tiled on the focal plane in thevacuum chamber

R adio Wave O b s er v a t i o n s
Radio astronomy studies the invisible Universe by detecting radio waves emitted by celestial objects. ATC develops instruments
for the radio telescopes of NAOJ research facilities, including the Nobeyama Radio Observatory (NRO) in Nagano, Japan, and
the Atacama Large Millimeter/submillimeter Array (ALMA), built in northern Chile, through an international collaboration
among East Asia, North America, and Member States of the European Southern Observatory, with the support of the Republicof Chile. ATC also provides support for the development of radio astronomy instruments by universities and related institutes.

ALMA

ASTE and 45-m Radio Telescope

ATC has developed and produced three types of ultra-sensitive
superconducting receivers currently used in ALMA. After approximately
10 years of development and production, ATC completed the deliveryof 219 receivers in February 2014. These receivers have been mounted
on the antennas and have been used for observations by astronomers
around the world. ATC provides maintenance and repair services for
the ALMA receivers produced in Japan. In addition, ATC has continued
to work to improve measuring systems to characterize the receiver
performance.

The Atacama Submillimeter Telescope Experiment (ASTE) is a 10-m
submillimeter telescope operated by NAOJ, located approximately 10
km north of ALMA. The largest millimeter-wave radio telescope in Japanis the 45-m telescope which has been operated at the NAOJ Nobeyama
Radio Observatory for more than 30 years. ATC develops, improves, andprovides support for the new cryostats and receivers of these telescopes
in cooperation with domestic and overseas research institutes anduniversities.
(Left) Multicolor TES Bolometer Camera (under development)This camera, using cryogenic superconducting devices cooled to almost absolute zero(−273 °C), will investigate numerous mysteries related to the birth of stars and galaxies.
(Right) Interior of the new cryostat for ASTE, which can be equipped with threecartridge-type receivers.
The cryostat used previously had one fixed-type port and one cartridge-type port.
ATC developed the new cryostat to accommodate three cartridge-type receivers,
enhancing the flexibility, and simplifying the installation and maintenance of receivers.

Development of New Technologies

Chan

nel 3

ATC promotes the development of novel technologies and new receivers for observations
at higher frequencies (>1 THz), over wider frequency ranges, and using multiple pixels.
ATC aims to use the fruits of these developments in space and ground-based telescopes
in Japan and overseas, including ALMA, ASTE, and the Nobeyama 45-m Radio Telescope.

Chan

nel 2

20mm

ut

Chan

nel 1

inp

1mm

RF

ALMA receivers developed at ATC
From Left to Right: Band 4 (125–163 GHz), Band 8 (385–500 GHz),
and Band 10 (787–950 GHz)
Each of the 66 ALMA antennas can be equipped with receivers of ten different types.

Waveguide filter circuit for wide instantaneous bandwidth observations

Multi-pixel MMIC-based superconductor-insulatorsuperconductor (SIS) receiver under development

1mm(Left) 1.25–1.5 THz band corrugated horn beam pattern measurement(Top Right) Scanning electron microscope (SEM) image of theaperture of a THz corrugated horn
(Bottom Right) Beam pattern measurement result at 1.48 THz

Microwave Kinetic Inductance Detectors (MKID)
When millimeter-wave photons break superconducting
Cooper pairs, the kinetic inductance and resistance in the
superconducting transmission lines change. Based on
this effect, MKIDs can use superconducting microwave
resonators to detect millimeter-wave radiation.

Spa ce - b a s e d O bs e r v a t i o n s
From space, astronomical objects can be observed at any wavelength without
being affected by the Earth's atmosphere. To conduct observations at thebest locations possible, ATC combines mature technology for ground-based
observations with space technology to develop observational instrumentsthat can be mounted on sounding rockets, balloons, and satellites.

Solar-C (EUVST)
Solar-C（EUVST）is a next-generation solar-observing satellite planned for completion in the mid2020s. With a high-resolution and high-sensitivity instrument, the EUVST will perform spectroscopic©NAOJ / JAXA (Solar-C WG)
observations of the solar atmosphere seamlessly from the chromosphere at 10,000 degrees to thecorona, which is heated to over several million degrees. We aim to elucidate the mechanisms of solar activity phenomena induced by the magnetic
energy, through this advanced observation capturing the plasma and energy flow. The design study, assembly, and evaluation tests for the instrument
are conducted using ATC's functions and facilities.

JASMINE
JASMINE, the world's first infrared astrometry satellite, is expected to launch in 2028.
It will measure stellar positions and motions with high precision of a few tens of micro-arcseconds in thecentral region of the Milky Way Galaxy, which is difficult to measure using visible light. Such measurements
will reveal the evolution of the entire Milky Way Galaxy through exploration of the traces of the Galactic
evolution hidden in the central region. JASMINE will also explore terrestrial planets in the habitable zone
around stars smaller than the Sun.
©NAOJ

SUNRISE III
SUNRISE III is an international balloon project with a flight planned for2022. The project observes the Sun from the stratosphere using a 1 m
aperture optical telescope. Through high-resolution and high-precisionnear-infrared spectro-polarimetric observations, we will measure thethree-dimensional structure of solar magnetic fields and investigate
the transport and dissipation processes of magnetic energy in the solar
atmosphere. In addition to opto-mechanical design and fabrication of
the instrument to achieve high performance in the thermal-vacuum
environment of the balloon flight, its performance was verified using
the clean-room and thermal-vacuum test facilities at ATC.

CLASPThis program aims at direct measurement of magnetic fields in thechromosphere and transition region through observations of thepolarization in the UV spectral lines emitted by the solar chromosphereand transition region (the thin layer between thechromosphere and corona) with high precision(<0.1%). Launched on NASA sounding rockets,
CLASP (2015) and CLASP2 (2019, 2021) succeededin the first spectro-polarimetric observationsof the hydrogen Lyman-α line at 121.6 nm andof ionized magnesium at 280 nm, respectively,
revealing the magnetic field in the chromosphereand the transition region. Integration and testingof these instruments were conducted at ATC.
(Image Credit: NAOJ, JAXA, and NASA/MSFC)

CLASP
High-precision Lyman-alpha
spectropolarimeter

SUNRISE balloon ready to fly
The SUNRISE balloon-borne telescope is launchedfrom the ESRANGE in Kiruna, Sweden. The telescopecontinuously observes the Sun at an altitude higher than
35 km over the Atlantic Ocean, Greenland, and Canada.
©MPS

Testing the SUNRISE III near-infrared
spectro-polarimeter
The high-precision opto-mechanicaland polarimetric system were integrated
and tested in the clean room.

Optical alignment in progress
Integration and testing of CLASP and
CLASP2 were conducted in the large
clean room.

CLASP on the launch pad
Launched by a NASA sounding rocket
in September 2015, CLASP conducted
observations for only 5 minutes
while it was flying outside the Earth’s
atmosphere.

Undergraduate and Graduate Student Education
Through the Department of Astronomical Science, the Graduate University for
Advanced Studies (SOKENDAI), ATC provides a graduate course, mainly aimed
at obtaining a degree in astronomical instrumentation. Graduate students fromother universities such as the University of Tokyo, Toho University, Universityof Tsukuba, and Osaka Prefecture University are also accepted to work on
the development of astronomical instruments. They can take full advantage
of opportunities to participate in state-of-the-art astronomical instrument
programs, and to obtain know-how from researchers and engineers with broad
experience in research and development. We also support undergraduates whoare interested in the development of astronomical instruments through various
opportunities such as summer student programs.

Members of ATC
Technical staff, research staff, administrative staff, and graduate students work in
ATC. All research and development activities related to instrumentation, including
concept creation, feasibility studies, design, fabrication, assembly, adjustment,
and performance verification, are supported by many specialists with a variety ofskills and expertise, as well as an administrative staff that manages the resources(budget, time, personnel, and facilities) necessary for daily work at ATC. We are
seeking motivated persons for each of the above positions. If you are interested
in joining ATC, please refer to the recruitment information posted from time totime on the NAOJ website.

Clericalstaff
Graduatestudents
Research
staff

Technical
staff

Access Map to ATC, Mitaka Campus, NAOJ

Instrument Development Building
No.1

Main Gate

No.3

Rear Gate

Bus Stop(Tenmondai Mae)
To Chofu Station

No.2

From the South Exit of Musashi-sakai station(JR Chuo Line)Take Odakyu bus (91) at the No.3 bus stopand get off at “Tenmondai Mae” bus stop
From the North Exit of Chofu station(Keio Line)Take Odakyu bus (91), (51) at the No.14 bus stopor Keio Bus (91) at the No.13 bus stopand get off at “Tenmondai Mae” bus stop

Bus Stop(Tenmondai Ura)To Musashi-sakai Station

National Astronomical Observatory of Japan, National Institutes of Natural Science

Advanced Technology Center
2-21-1 Osawa, Mitaka, Tokyo, 181-8588 Japan
phone: +81-422-34-3865 fax: +81-422-34-3864
URL: http://atc.mtk.nao.ac.jp/en/index_e.html
Cover image/a jelly fish galaxy ©HSC-SSP, NAOJ

Inner image/NGC5713 and NGC5719 ©HSC-SSP, NAOJ

2022.01