Sora

LISA8 @Stanford Univ. USA June 29, 2010

Seiji Kawamura, Masaki Ando, Naoki Seto, Shuichi Sato, Ikkoh Funaki, Takashi Nakamura, Kimio Tsubono, Jun'ichi Yokoyama, Kenji Numata, Nobuyuki Kanda, Takeshi Takashima, Takahiro Tanaka, Kunihito Ioka, Kazuhiro Agatsuma, Tomotada Akutsu, Koh-suke Aoyanagi, Koji Arai, Akito Araya, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, Masa-Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng-Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Kiwamu Izumi, Isao 　 Kawano, Nobuki Kawashima, Fumiko Kawazoe, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru 　 Kokuyama, Kei Kotake, Yoshihide Kozai, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei-ichi Maeda, Hideo Matsuhara, Nobuyuki Matsumoto, Yuta Michimura, Yasushi Mino, Osamu Miyakawa, Umpei Miyamoto, Shinji Miyoki, Mutsuko Y. Morimoto, Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano, Isao Naito, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Kazuhiro Nakazawa, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Taiga Noumi, Yoshiyuki Obuchi, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Kenshi Okada, Norio Okada, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Ryo Saito, Masaaki Sakagami, Shin-ichiro Sakai, Shihori Sakata, Misao Sasaki, Takashi Sato, Masaru Shibata, Hisaaki Shinkai, Ayaka Shoda, Kentaro Somiya, Hajime Sotani, Naoshi Sugiyama, Yudai Suwa, Rieko Suzuki, Hideyuki Tagoshi, Fuminobu Takahashi, Kakeru Takahashi, Keitaro Takahashi, Ryutaro Takahashi, Ryuichi Takahashi, Tadayuki Takahashi, Hirotaka Takahashi, Takamori Akiteru, Tadashi Takano, Nobuyuki Tanaka, Keisuke Taniguchi, Atsushi Taruya, Hiroyuki Tashiro, Yasuo Torii, Morio Toyoshima, Shinji Tsujikawa, Yoshiki Tsunesada, Akitoshi Ueda, Ken-ichi Ueda, Masayoshi Utashima, Kent Yagi, Hiroshi Yamakawa, Kazuhiro Yamamoto, Toshitaka Yamazaki, Chul-Moon Yoo, Shijun Yoshida, Taizoh Yoshino, Ke-Xun Sun

Outline

Japanese GW Roadmap DECIGO Roadmap to DECIGO DECIGO Pathfinder, etc. Organization, Collaboration, etc. Summary

Japanese Roadmapto GW Astronomy

Detecting GW

(International network)

LCGT

DECIGO

Opening a new window

(after LISA)

LCGT: $110M for 3 years approved!

(Thanks to support from international GW community)

What is DECIGO?Deci-hertz Interferometer Gravitational Wave Observatory Bridges the gap between LISA and ground-based detectors Low confusion noise -> Extremely high sensitivity

10-18

10-24

10-22

10-20

10-4 10410210010-2

Frequency [Hz]

Str

ain

[H

z-1/2]

LISA

DECIGO

Ground-based detectors

Confusion Noise

moved above

LISA bandTo be moved

into GBD band

Pre-conceptual designDifferential FP interferometer

Arm length: 1000 kmMirror diameter: 1 mLaser wavelength ： 0.532 mFinesse: 10Laser power: 10 WMirror mass: 100 kgS/C: drag free3 interferometers

Laser

Photo-detector

Arm cavity

Drag-free S/C

Arm cavity

Mirror

Why FP cavity?

Frequency

Str

ain

Radiation pressure

noise f -2

Shot noiseShot n

oise

f1Transponder type

Shot noise

Shortenarm length

Shot nois

e f1

Radiation pressure

noise f -2

Transponder typeShortenarm length Implement FP cavity

Implement FP cavity

FP cavity type Better shot-noise-limited

sensitivity

More stringent acceleration noise

requirement

Drag free and FP cavity: compatible?

Mirror

S/C IS/C II

Solar radiationpressure, etc

Solar radiationpressure, etc

Gravity force

Gravity force

Gravity force

Gravity force

1,000 km

FP cavity and drag free : compatible?

Local sensor

ThrusterThruster

Mirror

Relative position between mirror

and S/C

S/C II S/C I

Gravity force Gravity force

Drag free and FP cavity: compatible?

Local sensor

ThrusterThruster

Mirror

Relative position between mirror

and S/C

Actuator

Interferometer output (GW signal)

S/C II S/C I

No signalmixture

Gravity force

Orbit and constellation (preliminary)

Sun

Earth

Record disk

Increase angular resolution

Correlation for stochastic background

Formation of super-

massive BH

Verification of inflation

Science by DECIGO

Frequency [Hz]

Correlation(3 years)

Str

ain

[H

z-1/ 2]

10-3 10-2 10-1 1 10 102 103

10-19

10-20

10-21

10-22

10-23

10-24

10-25

10-26

(1000 M◎ z=1)

BH binary

Coalescence

5 years

NS binary (z=1)

Coalescence

3 months

Acceleration of Universe

Dark energy

Radiation pressure noise

Shot noise

1 cluster

Mini-black hole

Dark matter

Brans Dickeparameter

Inflation(GW~2×10-16)

Requirements

Force noise of DECIGO should be 50 times more stringent than LISA– Acceleration noise in terms of h:

comparable– Distance: 1/5000– Mass: 100

Sensor noise of DECIGO should be10 times looser than LCGT– Sensor noise in terms of h: comparable,– Storage time: 10

Conceptual Design of DECIGO

Optimize the design parameters to improve the sensitivity for the effective cleaning of the foreground– arm length, mirror diameter, mirror mass,

laser power, finesse, etc. – Lead by Tomotada Akutsu

Establish the design to realize the required performances– proof mass, mirror curvature, local

sensor/actuator, frequency stabilization

Roadmap2009 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Mission

Objectives

Test of key technologies

Detection of GW w/ minimum spec.Test FP cavity between S/C

Full GW astronomy

Scope

1 S/C1 arm

3 S/C1 interferometer

3 S/C,3 interferometer3 or 4 units

DICIGO Pathfinder ÞMasaki Ando’s talk on Thursday

Pre-DECIGO

DECIGO

R&DFabrication

R&DFabrication

R&DFabrication

SWIM Wataru Kokuyama’s poster

DECIGO Pathfinder (DPF)

Local Sensor

Actuator

Thruster

Single satellite Earth orbit Altitude: 500km Sun synchronous

Arm length: 1000 kmArm length: 30 cm

JAXA’s Small Science Satellite Series

Plan to launch 3 small satellites between 2011 and 2015– using next-generation solid rocket

booster Reduce time and cost by

“Standard bus system” – Bus weight : 200kg, Bus power :

800W– 3-axes attitude control– SpaceWire-based data processing

system

DECIGO Pathfinder

Stabilized. Laser source

Interferometer module

Satellite Bus system

Solar Paddle

MissionThruster head

On-boardComputer

Bus thruster

Satellite Bus (‘Standard bus’ system)

DPF PayloadSize : 950mm cubeWeight : 150kgPower : 130WData Rate: 800kbpsMission thruster x12

Power SupplySpW Comm.

Size : 950x950x1100mmWeight : 200kgSAP : 960W Battery: 50AHDownlink : 2MpbsDR: 1GByte3N Thrusters x 4

DPF Payload

Fabry-Perot interferometer 　 Finesse : 100 　 Length : 30cm 　 Test mass : ~1kg Signal extraction by PDH

Drag-free control Local sensor signal 　　 Feedback to thrusters

Mission weight : ~150kgMission space : ~95 x 95 x 90 cm

Laser source Yb:YAG laser (1030nm) Power : 25mW Freq. stab. by Iodine abs. line

Thruster

Goal sensitivity of DPF

10–2 10–1 100 101 10210–18

10–17

10–16

10–15

10–14

10–13

10–12

10–11

10–19

10–18

10–17

10–16

10–15

10–14

10–13

10–12

No

ise

leve

l

[1/H

z1/2 ]

Frequency [Hz]

Shot noise

Mirror thermal

Laser Radiation

Laser: 1064nm, 25mWFinesse: 100Mirror mass: 1kgQ–value of a mirror: 106

Cavity length: 10cm

pressure noise

Thruster noise

PM acceleration Noise

Geogravity

Laser Frequencynoise

Dis

pla

cem

ent

No

ise

[m

/Hz1/

2 ]

Detection range

103 104 105 10610–1

100

101

102

Ob

serv

able

Ran

ge

Mass [Msolar]

[kp

c,

SN

R=

5]

Galactic Center

BH QNM

BH Inspiral

Gravity of the EarthMeasure gravity field of the Earth

from Satellite Orbits, and gravity-gradiometer

Determine global gravity field

Density distribution

Monitor of change in time

　 Ground water motion

　 Strains in crusts by

earthquakes and volcanoes

GPS satellite

By Araya and Fukuda

Observation Gap

between GRACE and GRACE-FO

(2012-16)

　 DPF contribution

in international network

Ayaka Shoda’s poster

R&D for Subsystems Shuichi Sato’s talk on Thursday, Yuta Michimura’s talk on Thursday

Frequency-stabilized laser

ThrusterInterferometric sensor

Drag-freemodel

Electrostatic sensor/actuator

Test mass module

Funding Status

Advanced to the final hearing as one of the two candidates for the 2nd small science satellite mission, but not selected.

We will apply for the 3rd mission in 2011 (sometime after April).

SWIMTiny GW detector module Launched in Jan. 23, 2009

Test mass

Photo sensor

Coil

TAM: Torsion Antenna Module with free-falling test mass (Size : 80mm cube, Weight : ~500g)

Reflective-type optical displacement sensorSeparation to mass ~1mmSensitivity ~ 10-9 m/Hz1/2

6 PSs to monitor mass motion

~47g Aluminum, Surface polishedSmall magnets for position control

Photo ： JAXA

In-orbit operation

Pre-DECIGOPre-DECIGO

DECIGO

Arm length 100 km 1000 km

Mirror diameter 30 cm 1 m

Laser wavelength 0.532 m 0.532 m

Finesse 30 10

Laser power 1 W 10 W

Mirror mass 30 kg 100 kg

# of interferometers in each cluster

1 3

# of clusters 1 4

Sensitivity of Pre-DECIGO

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

Str

ain

sen

sit

ivit

y [

1/r

Hz]

10-3

10-2

10-1

100

101

102

103

Frequency [Hz]

DPFDPFDPFDPF

NS-NS inspiral (@300Mpc)

pre-DECIGO

DECIGO

S/N~14 for NS-NS@300Mpc, 10-20 events/year

Pre-DECIGO

• Science goal of Pre-DECIGO should be defined (with peter Bender’s suggestion: formation of galaxies)– Lead by Shuichi Sato

• Optimize the design of Pre-DECIGO both for the science goal and technology goal

DECIGO Interim OrganizationPI: Kawamura (NAOJ)

Deputy: Ando (Kyoto)

Pre-DECIGO

Sato (Hosei)

Spacecraft

Funaki (JAXA/ISAS)

Science & Data

Tanaka (Kyoto)Seto (Kyoto)

Kanda (Osaka City)

DECIGO Pathfinder

Leader: Ando (Kyoto)

Detector

A. Ueda (NAOJ)

Housing

Sato (Hosei)

Laser

K. Ueda (E.C.)

Musha (E.C.)

Drag-free Moriwaki (Tokyo)Sakai

(JAXA/ISAS)

Thruster

Funaki(JAXA/ISAS)

Bus

Takashima(JAXA/ISAS)

Data

Kanda(Osaka City)

Detector

Akutsu (NAOJ)Numata (Maryland)

Mission Phase

Design Phase

Executive Committee

Kawamura (NAOJ), Ando (Kyoto), Seto (kyoto), Nakamura (Kyoto),Tsubono (Tokyo), Sato (Hosei), Tanaka (Kyoto), Funaki (JAXA/ISAS),Numata (Maryland), Kanda (Osaka City), Ioka (KEK), Takashima (JAXA/ISAS), Yokoyama (Tokyo)

1st InternationalLISA-DECIGO Workshop

• Nov. 12-13, 2008 @ ISAS, Sagamihara, Japan• Participants:

– Danzmann, Heinzel, Gianolio, Jennrich, Lobo, McNamara, Mueller, Prince, Stebbins, Sun, Vitale, …

• Accomplishments:– Mutual understanding– Exposure of the missions to people in the

neighboring fields

• We are grateful for the strong support from the LISA community

Collaboration with Stanford

• MOU for the collaboration– UV LED discharge for DPF/DECIGO– Other R&D for DECIGO

• We appreciate the great help from the Stanford team (Ke-Xun Sun, Bob Byer, Dan DeBra, …)

Other Collaborations JAXA formation flight group

– Formation flight

Big bang center of the Univ. of Tokyo– DECIGO adopted as one of the main themes

Advanced technology center of NAOJ– Discussing the possibility of its becoming the nucleus of DPF

NASA Goddard– Fiber laser 　⇒　 started discussion

UNISEC (University Space Engineering Consortium)– Started discussion

DECIGO will bring us a variety of fruitful science.

The first step to realize DECIGO is to have DPF approved!

Conclusions