Japanese Future Gravitational Wave Projects on & off Earth !

Japanese Future Gravitational Wave Projects on & off Earth !

Nobuyuki Kanda (Osaka City Univ.)LCGT collaboration

DECIGO collaboration

26th Nov. 2009IUCAA, Pune

Thanks to DST and IUCAA for our visiting.

Plan of TalkIntroduction

• What is a Gravitational Wave ?• Why are we trying to measure? • GW detection

Ground-based detectors• World wide detectors• TAMA

300m, middle size, since 1995• CLIO

100m, prototype of LCGT, cryogenic test• LCGT

3km, underground, cryogenic, NS-NS range ~ 200Mpc

Space-based detectors• in General• DECIGO

Science, Conceptual design, DECIGO-Pathfinder2

Introduction :Gravitational Waves and its Detection

Gravity has some mysterious still now...• very week,• large error for the measurement of coupling constant,

• but dominant interaction of the universe,

• not yet quantized,• intermediate boson (graviton) is not yet discovered,

• not yet confirmed ‘(wave) propagation’

4

http://CPEPweb.org/

by F.Satoarbitrary error (ambiguity)co

stan

ts

http://CPEPweb.org

http://CPEPweb.org

Metric of the Space-Time

Flat Space-Time

Curved (distorted) Space-Time

5

<- t<- x<- y<- z

<-

t<

- x

<-

y<

- z

t (time)

x,y,z (space)

gµν = ηµν =

−1 0 0 00 1 0 00 0 1 00 0 0 1

ds2 = gµν dxµdxν

gµν �= ηµν

Gravity distorts the space-time.

Curved space-time

Propagation of the distortion• --> Waves !

6

Rµν − 12

gµνR = −κ Tµν

Gravity distorts the space-time.

Curved space-time

Propagation of the distortion• --> Waves !

6

Explosion of

the star ?

Rµν − 12

gµνR = −κ Tµν

Einstein Equation :

In case of small perturbation “h”, a wave equation is derived as;

• strain ‘h’• light speed• transverse• quadrupole

(tidal force)

Gravitational Waves

7

Rµν − 1

2gµνR = −κ Tµν

gµν = ηµν + hµν

�∇2 − 1

c2∂2

∂t2

�hµν = 0

h+ = h

0 0 0 00 1 0 00 0 −1 00 0 0 0

h× = h

0 0 0 00 0 1 00 1 0 00 0 0 0

Force (Displacement) by GW

Tidal force on masses

8

h+ = h

0 0 0 00 1 0 00 0 −1 00 0 0 0

h+ cos(�k · �x− 2πfGW t)

Proof of GW (indirect)Binary Pulsar PSR1913+16 observation (Hulse & Taylor)

• Pulsar is very stable clock.• Change of orbital period according

to a lost of kinetic energy by GW radiation.

Taylor, 1993(ノーベル賞講演より抜粋) 9

Direct measurements of GW, Why?

PhysicsTEST of Einstein’s general relativity in strong field.

Astronomy, Astrophysics• Radiation from compact / massive objects.

Physics of black-hole, neuron star, supernovae, etc...--> Graviational Wave Astronomy

Cosmology• Cosmic background radiation of GW• POP-III stars, star formation, etc...

Physics on early universe.

10

Expected GW sourcesEvent like:

• Coalescence of compact binaries• neutron star (NS)• black-hole (BH)

NS-NS is most promising.• Supernovae• BH ringdown

Continuous waves:• Pulsar rotation• Binaries

Stochastic Background• Early universe (i.e. Inflation)• Cosmic string

Unknown sources...

11

Coalescence of neutron star binary (NS-NS)

12

time

stra

in a

mp

litud

e

inspiral phase merger Blackholequasi-normal mode

distortion of space-time

=h =

δ�

�

amplitude ~10-24 for NS-NS at 200Mpc away!(in frequency spectrum, ~10-22~-23 [/√Hz] @10~100Hz)

13

-2

-1

0

1

2

x10-2

4

4.03.83.63.43.23.0s

stra

in a

mp

litud

e

time

1× 10−24

• small amplitude• Waveform can determine masses and absolute amplitude.

--> ‘standard candle’

amplitude ~10-24 for NS-NS at 200Mpc away!(in frequency spectrum, ~10-22~-23 [/√Hz] @10~100Hz)

13

-2

-1

0

1

2

x10-2

4

4.03.83.63.43.23.0s

stra

in a

mp

litud

e

time

-2

-1

0

1

2

x10-2

4

3.993.983.973.963.953.943.93s

‘chirp’ waveform

1× 10−24

f(t) --> mass --> absolute amplitude

• small amplitude• Waveform can determine masses and absolute amplitude.

--> ‘standard candle’

How to detect GW : Free Test Masses & Laser Interferometer

14

Mirror

Mirror

Laser Light

Beam Splitter

Interferencecos( 2 pi 2dL /lambda)

Michelson Interferometer

t

xFree mass = mirror

t

x

light

Schematic Figure

Free mass --> suspended mirror

To integrate strain ‘h’ --> long baseline arms.

Limited size --> Folding arms / Storage cavity

Against noises -->• high power laser• Cooling• etc..

15

h =δl

�

GW & detector sensitivities (spectrum)

16

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14

10-13

10-12

10-11

strain h [1/sqrt(Hz)]

10-4

10-3

10-2

10-1

100

101

102

103

104

frequency [Hz]

NS-NS (30kpc) NS-NS(200Mpc) Stellarcore collapse at Galactic centre WD confision noise

Stochastic GW from Inflation (! ~10-16

and ~10-15

)

LISA

Ultimate DECIGO

LCGT, adv.LIGODECIGO

LIGO I

DECIGO PathFinder

GW frequency

Str

ain

Sen

sitiv

ity =

Noi

se le

vel

On Earth !

World Wide Network of GW Detectors

AIGO (planned)

eLIGO (current upgarading)adv.LIGO (Start at 2014?)

LIGO (Hanford) 4km & 2km

TAMA 300m

CLIO 100m

LCGT 3km, budgetary request

LIGO (Livingston) 4km

VIRGO 3km

EGO

GEO 600m

18

Focus of Ground-based Detectors

19

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14

10-13

10-12

10-11


10-4

10-3

10-2

10-1

100

101

102

103

104

frequency [Hz]



and ~10-15

)

LISA

Ultimate DECIGO


LIGO I

DECIGO PathFinder

Focus of Ground-based Detectors

19

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14

10-13

10-12

10-11


10-4

10-3

10-2

10-1

100

101

102

103

104

frequency [Hz]



and ~10-15

)

LISA

Ultimate DECIGO


LIGO I

DECIGO PathFinder

10Hz ~ 10 kHz• Compact Binaries• Supernovae (Stellar-core collapse)• BH quasi-normal mode• Pulsars (Continuous wave)• Stochastic

Japanese experiments:TAMA --> CLIO --> LCGT

20

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14Strain equivalent noise spectrum [1/rHz]

10 100 1000 10000

frequency [Hz]

LCGT design : Broadband RSE Detuned RSE

Operated Detectors :

CLIO (current, in normal temperature) TAMA dt9 LIGO_I


20

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15


10 100 1000 10000

frequency [Hz]




TAMA

CLIO

LCGT


20

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15


10 100 1000 10000

frequency [Hz]




TAMA

CLIO

LCGT

since 1995-middle size (300m)establish interferometer technique and data analysis

prototype of LCGTundergroundto confirm a cryogenic technique

3kmundergroundcryogenic

TAMA300

Configuration• Fabry=Perot=Michelson, with Power Recycling• baseline: 300m• laser: Injection-lock Nd:YAG, 10W, 1064nmSite• National Astronomical Observatory,

Mitaka, Tokyo

21

TAMA

300m

300m

(1995- )middle size detector

TAMA300

22

Active seismic isolation systemBest Sensitivity of TAMA

23

GW searches in TAMA

24

Source or GW Search Method Results

Inspiral from binary Matched FilteringUpper Limit : ~20 event/yr for MWG

Phys. Rev. D 74, 122002 (2006).

BH Ringdown Matched FilteringTrigger Rate :< 1 event/day for MWG

Phys.Rev. D71 (2005) 103005

Burst from core collapse

Excess PowerUpper Limit: 6 x 103 ev/sec for MWG

Phys. Rev. D 71 (2005) 082002

Burst from core collapseALF

Upper Limit:0.55 ev/day for hrss ~ 10-17

Class. Quantum Grav. 23 (2006) S715Burst from core collapse

TF ClusterUpper Limit (partial data)1.4 x 10-3 ev/sec within 10pc

Class. Quantum Grav. 25 (2008) 184035

Burst from core collapse

Wavelet Success the Extraction of Unstable component

(Burst like noise) veto with AUX ch. Systematic trial was done.Class. Quantum Grav., 24 S405, (2007)

continuous GW from SN1987A remnant pulser integration h ~ 4 x 10-23

Class. Quantum Grav. 20 (2003) 645.

These will be extend/upgrade for LCGT.

TAMA

25

Reduction of noises ! Seismic disturbances --> UndergroundThermal motion --> Cryogenicenhance GW --> km baseline

26

CLIO (Cryogenic Laser Interferometer Observatory)

prototype of LCGT

Recent status : CLIO

Sensitivity reach to the thermal noise at room temperature.

28

10-19

10-18

10-17

10-16

10-15

10-14

10-13

Displacement [m/rtHz]

5 6 7 8 910

2 3 4 5 6 7 8 9100

2 3 4 5 6 7 8 91000

2 3

Frequency [Hz]

Mirror thermal noise (300K) 081105_5 (Current best) 090427_2 (15:30)

Search GW from Vela pulser

Vela pulser (PSR J0835-4510)• might radiate GW at ~ 22Hz• Search : Complex Heterodyne + Matched Filter• Using observation data in 2007

Upper limit : h0 ~ 5.3 x 10-20 (C.L.99.4%)

29

T.Akutsu et al., Class. Quantum Grav. 25 (2008) 184013

Location of LCGTLCGT is planed to be built underground at

Kamioka, where the prototype CLIO

detector is placed.

LCGT

Underground• in Kamioka, Japan• Silent & Stable environment

3km baseline

Cryogenic Mirror• 20K• saffhire substrate

30

Plan2011-2014 : construction2015-2016 : commissioning2017- : observation

LCGT collaboration

31

Man power OrganizationLCGT is hosted by ICRR under MOU with NAOJ and KEK. Its organization consists of 92 domestic researchers belonging to 17 universities or research institutes and 26 oversea membersbelonging to 14 universities or research institutes (118 researchers in total).

LCGT Board consists of representatives of ICRR, NAOJ, and KEK with other senior members

Optical design

32

Optical design of LCGT

Re-design is under going ;for example---removing the 180 m long mode cleaner cavity---flexibility change of possible adoption of detuned RSE

Broad band RSE installed in a power recycled FP-Michelson interferometer

33

Design of anti-vibration system

A B C

A)SAS(GASF 3stage)+cryo-sus:FM1、FM2、EM1、EM2

B)SAS(GASF 2stage)+non-cryo:BS、PRM、SEM、FM、MC2F、MC2E

C)STACK+2stages: MC1F、MC1E、MMT、PD

34

Design of Quiet refrigerator

Switching box

Pulse tube ref.1st & 2nd stages

To compressor4K cold head

40K cold stage

Soft heat links

Design Sensitivity

35

10-24

10-23

10-22

10-21

10-20

10-19

Strain equivalent noise spectrum [1/rHz]

10 100 1000

frequency [Hz]

Broadband RSE Detuned RSE

Binary inspiral:

1.4-1.4 Msolar, 200Mpc BH ringdown: Kerr param. a=0.95

2.8 Msolar 100 Msolar

Stellar core collapse at Galactic Centre

DFM waveforms

Detection Range

range >200 Mpc

36

S/N >8, optimal direction

typical neutron star mass (1.4Msolar)

Expected Number of NS-NS events

371.00.5 2.00.2 5.00.10.0

0.2

0.4

0.6

0.8

1.0

Observation time �yr�

Probabilityofdetection

�atleast1enent�

Detection Range (optimal direction, S/N>8)

Expected # of events/yr

LCGT (BRSE) 231 Mpc 3.9 +9.82 -3.11

LCGT (DRSE) 312 Mpc 9.2 +23.1 -7.29

Galactic DNS rate : 83.0+209.1 x10-6 (C.I.95%) -66.1V. Kalogera, ApJ, 601, L179 (2004)cf: Kim, C., AIP Conference Proceedings, vol. 983, pp. 576 (2008)

1 ye

ar o

bser

vatio

n

6 m

onth

s

1 m

onth

90% detection

38

Sensitivity for Continuous Waves

10-28

10-27

10-26

10-25

10-24

10-23

Strain h

1 10 100 1000frequency [Hz]

Broadband RSE, with 1yr integration 10yr integration 2weeks integration

Detuned RSE, with 1yr integration 10yr integration 2weeks integration

known pulsars with maximum allowed amplitude LMXB etc.

Other Possibe Sources

BH quasi-normal mode ringdown• Typical mass range : several 10 Msolar ~ 104 Msolar

Supernovae• up to ~ a few Mpc away• core collapse, core bounce• 3D instability• convection & SASI• PNS core g-mode

StochasticSingle detector can’t do...

• It must be done by international network.39

Network of Detectors

International Network of the GW detectors is important.

LCGT would like to contribute.

AIGO

LIGO (Hanford) 4km & 2km

TAMA 300mCLIO 100mLCGT 3km

LIGO (Livingston) 4km

VIRGO 3kmEGO

GEO 600m

90

0

-90-12 0 12

decl.[deg]

Quadratic Sum : LCGT+LIGO(Hanford)

Sky coverage by detector network

LCGT will make important role in the network,with a complemental sensitivity map.

zenith direction of detectorsLIGO HanfordLIGO LivingstonVIRGOLCGT

-12 0 12

LCGT90

0

-90

LIGO (Hanford)

R.A.[hour]

-12 0 12

90

0

-90

decl.[deg]

41R.A.[hour]

decl.[deg]

R.A.[hour]

R.A.[hour]

90

0

-90-12 0 12

decl.[deg]

Quadratic Sum : LCGT+LIGOx2+VIRGO

Sky coverage by detector network

zenith direction of detectors LIGO HanfordLIGO LivingstonVIRGOLCGT

-12 0 12

LCGT90

0

-90

LIGO x2 + VIRGO

-12 0 12

90

0

-90

42

LCGT will make important role in the network,with a complemental sensitivity map.

R.A.[hour]

decl.[deg]

R.A.[hour]

decl.[deg]

43

We have been developed :TAMA -> CLIO -> LCGT

LCGT is future Japanese ground-based detector.• underground• cryogenic mirror• long (km) baseline• NS-NS detection range will reach as over 200 Mpc.

for the first detection of GW in world-wide network.

Off Earth !

Future “Space” Detectors

45

LISA (NASA, ESA)

DECIGO (Japan), BBO(NASA)To escape from seismic noise, to achieve longer base-

line, we will place laser interferometers in space !

figure: LISA

sun

earth

Focus of Space-based Detectors

46

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14

10-13

10-12

10-11


10-4

10-3

10-2

10-1

100

101

102

103

104

frequency [Hz]



and ~10-15

)

LISA

Ultimate DECIGO


LIGO I

DECIGO PathFinder

Focus of Space-based Detectors

46

10-27

10-26

10-25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

10-14

10-13

10-12

10-11


10-4

10-3

10-2

10-1

100

101

102

103

104

frequency [Hz]



and ~10-15

)

LISA

Ultimate DECIGO


LIGO I

DECIGO PathFinder

mHz - deci-Hz• Stochastic background from eary univerise

• Binaries• BHs

drawn by Sora.K

DECIGO / DECIGO Path Finder

DECIGO collaboration

47

Seiji Kawamura, Takashi Nakamura, Kimio Tsubono, Takahiro Tanaka, Ikkoh Funaki, Naoki Seto, Kenji Numata, Shuichi Sato, Nobuyuki Kanda, Takeshi Takashima, Kunihito Ioka, Kazuhiro Agatsuma,

Tomotada Akutsu, Tomomi Akutsu, Koh-suke Aoyanagi, Koji Arai, Yuta Arase, Akito Araya, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Motohiro Enoki, Yoshiharu Eriguchi, Masa-

Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Katsuhiko Ganzu, 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, Shogo Kamagasako, Nobuki Kawashima, Fumiko Kawazoe, Hiroyuki Kirihara, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, Wataru Kokuyama, Kei Kotake, Yoshihide Kozai, Hideaki Kudoh, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei-ichi Maeda, Hideo Matsuhara,

Yasushi Mino, Osamu Miyakawa, Shinji Miyoki, Mutsuko Y. Morimoto, Tomoko Morioka , Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano,

Isao Naito, Noriyasu Nakagawa, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa,

Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Akira Okutomi, Kouji Onozato, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shin-ichiro Sakai, Shihori Sakata, Misao Sasaki,

Takashi Sato, Masaru Shibata, Hisaaki Shinkai, Kentaro Somiya, Hajime Sotani, Naoshi Sugiyama, Yudai Suwa, Hideyuki Tagoshi, Kakeru Takahashi, Keitaro Takahashi, Tadayuki Takahashi,

Hirotaka Takahashi, Ryuichi Takahashi, Ryutaro Takahashi, Takamori Akiteru, Tadashi Takano, Keisuke Taniguchi, Atsushi Taruya, Hiroyuki Tashiro, Mitsuru Tokuda, Masao Tokunari,

Morio Toyoshima, Shinji Tsujikawa, Yoshiki Tsunesada, Ken-ichi Ueda, Masayoshi Utashima, Hiroshi Yamakawa, Kazuhiro Yamamoto, Toshitaka Yamazaki,

Jun'ichi Yokoyama, Chul-Moon Yoo, Shijun Yoshida, Taizoh Yoshino

DECIGO

Bridge between mHz and 10Hz

48

Ω

DECIGO

DECIGO

49

Deci-hertz Interferometer Gravitational Wave Observatory

DECIGO

Science of DECIGO

Stochastic Background GW : Hearing a call of the early universe

Huge number of binary systems :Foreground (cleaning) problem

Probing dark energyNS formation

Black Hole related GWIMBH (intermediate mass blackhole)BH+NS

Others...

50

DECIGO

Science of DECIGO

Stochastic Background GW : Hearing a call of the early universe

Huge number of binary systems :Foreground (cleaning) problem

Probing dark energyNS formation

Black Hole related GWIMBH (intermediate mass blackhole)BH+NS

Others...

50

cosmological interests !

DECIGO

Deci-Hz band has fruitful info. Compact Binaries (NS, stellar mass BH, IMBH)

1 ~ several years before coalescence of NS-NS

Escape from WD-WD confusion noise around mHz51

TGW ∼�

f

0.2[Hz]

�−8/3 �M

1.2M⊙

�−5/3

[yrs]

f ∼�

Gρ ∼�

ρ

106[g/cm3]

�1/2

[Hz]

0.01

0.1

1

10

frequ

ency

[Hz]

3.0x1082.52.01.51.00.50.0time [sec]

1.4-1.4 Msolar 10-10 Msolar

DECIGOStochastic Background GW from early universe

Two (or more) set of DECIGO/BBO make possible to reach the sensitivity of stochastic GW from early universe.

52

Ω

Ω

Ω

DECIGO

Foreground GW from NS-NS binariesMany neutron star binaries are exist.

Roughly ~105 NS-NS binary mergers will appear on DECIGO for year(s) of observation.These signals called as NS-NS ‘foreground’.It appear as ‘confusion noise’ around 0.1Hz.

53

10-24

10-23

10-22

10-21

0.012 3 4 5 6 7 8 9

0.12 3 4 5 6 7 8 9

1Hz

DECIGO instrumental noise spectrum simulated signal : noise + 105 NS-NS binaries*

* 0-10 years before merge

How to remove is a problem.(In another words, we will use

many NS’s GWs !)

DECIGOCleaning requires ...Quite huge number of templates will be needed.

(Culter & Harms, Phys.Rev. D73 042001, for BBO)

Very acculate waveform parameters must be determined. → Δm/m < ~10-7 %

(in our estimation)

54

!"#$%

!"#$&

!"#$'

!"#$$

$ ' & % ( ) * +",!

$ ' & % ( ) * +!

-.

/012345/67896:8/;<8=>9?@/

/;AB;/CB8DA98/=E86FGF:H/;=E86F//<AI89/;<8=>9?@

//!@J@/K/!"#%/L

//!@J@/K/!"#(/L

//!@J@/K/!"#)/L

However, in principle, the

cleaning will be possible !

(total fitting parameters)/(data amount)

~(R x Tobs x n) / (f x Tobs)

DECIGO

NS-NS probe for ...NS formation

DECIGO might see z~5 NS binaries.S/N ~ (1+z)1/6

Good angular resolution~ λ/D ~ 109 m / 1AU ~ 10-2 rad (❨Diffraction limit. It will be slightly better with mode analysis.)❩

Dark energy, or Weak lensinggeometrical test of high-redshift universe

dL-z relation

55

Cutler&Holz, arxiv0906.3752

DECIGOAcceleration of Expansion of the Universe

NS-NS (z～1)GW

DECIGO

Output

Expansion ＋Acceleration?

Time

Stra

in

Template (No Acceleration)

Real Signal ?Phase Delay～1sec (10 years)

Seto, Kawamura, Nakamura, PRL 87, 221103 (2001)

DECIGO

More Massive Objects

IMBH (Intermidiate Mass Black Hole)Enough high S/N

1000Msolar-1000Msolar @ z=1 --> S/N ~ 103

BH + NSAlso enough S/N, better than NS-NS.

57

DECIGO

DECIGO conceptual design

58

Let’s focus on experimental apparatus.

Laser

Photo-detector

!"""#$%&$ '()*+,-

.&)/01&22'345

%&$ '()*+,-

Mirror

Deci-hertz Interferometer Gravitational Wave ObservatoryConceptual design :

Space-based, drag freeFabry=Perot IF, Finesse:10, 10W 532nm laser,3 interferometers1000 km base linemirror diameter : 1m, weight 100 kg

DECIGO

Why FP cavity?

Frequency

Stra

in

Radiation pressure

noise f -2

Shot noiseShot n

oise f1

Transponder type(e.g. LISA)

Shot noise

Shortenarm length

Shot noise

f1

Radiation pressure

noise f -2

Transponder type(e.g. LISA) Shorten

arm length Implement FP cavity

Implement FP cavity

FP cavity type Better best- sensitivity

DECIGO

Requirements

Acceleration noise should be suppressed below radiation pressure noiseForce noise: DECIGO = LISA/50 (Acceleration noise in terms of h: 1, Distance: 1/5000, Mass:

100)Fluctuation of magnetic field, electric field, gravitational field, temperature, pressure, etc.

Sensor noise should be suppressed below shot noise.Phase noise: DECIGO = LCGT×10 (Sensor noise in terms of h: 1, storage time: 10)

Frequency noise, intensity noise, beam jitter, etc. Thruster system should satisfy range, noise,

bandwidth, and durability.

DECIGO

Cavity and S/C control

Local Sensor

Actuator

Displacement signal between the two Mirrors

Thruster Thruster

Displacement Signal between S/C and Mirror

Mirror

S/C 1

S/C 2

Fig: S. Kawamura

Cavity length change PDH error signal Mirror position 　(and Laser frequency)

Relative motion between mirror and S/C Local sensor S/C thruster

DECIGO

Orbit and Constellation

Record-disk orbit around the Sun

Relative acc. 4x10-12 m/s2

Halo orbit around L2 (or L1)

Relative acc. 4x10-7 m/s2

(Mirror force ~10-9 N )

(Mirror force ~10-4 N )

Separated unit

Constellation

4 interferometer units

2 overlapped units Cross correlation

2 separated units Angular resolution

overlapped units

Separated unit

Candidate of orbit:

DECIGO

DECIGO-PF

DECIGO Pathfinder (DPF)

　　Single satellite

(Payload ~1m3 , 350kg)

Low-earth orbit (Altitude 500km, sun synchronous)

30cm FP cavity with 2 test masses　　Stabilized laser source

Drag-free control

Local Sensor

Actuator

Thruster

First milestone mission for DECIGOShrink arm cavity DECIGO 1000km DPF 30cm

DECIGO

DPF satellite

Stabilized. Laser source

Interferometer module

Satellite Bus system

Solar Paddle

MissionThruster head

On-boardComputer

Bus thruster

Mast structure

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

DECIGO

DPF mission 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 : ~90 x 90 x 90 cm

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

DECIGODPF Sensitivity

Satellite mass : 350kg, Area: 2m2

Altitude: 500kmThruster noise: 0.1μN/Hz1/2

Laser source : 1030nm, 25mW IFO length : 30cmFinesse : 100, Mirror mass : 1kgQ-factor : 105, Substrate: TBDTemperature : 293K (Preliminary parameters)

DECIGO

Possible GW target of DPF

Observable range reaches the Galactic center (SNR~5 )

BH QNM

h ~ 10-15 , f ~ 0.3 Hz Distance 1Mpc, m = 105 Msun

IMBH inspiral and merger

Obs. Duration (~1000sec)

h ~ 10-15 , f ~ 4 Hz Distance 10kpc, m = 103 Msun

KAGAYA

Blackholes events in our galaxy

Hard to access by others Original observation

DECIGOPossible GW target of DPF

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For equarl mass binary with S/N>5, a range reach to 100kpc for IMBH.

dete

ctio

n ra

nge

Galactic centre

by K.Yagi(Kyoto Univ.)

DECIGOPossible GW target of DPF

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IMBH binary in globular cluster in our galaxy would be targets.

velocity deviation

mass distance *Masses are estimated from velocity deviations.

DPF can detect!

not detectabledi

stan

ce

expected rate : 3.3 x10-9 events/yr by K.Yagi(Kyoto Univ.)

DECIGO

Gravity of the EarthMeasure gravity field of the Earth for Satellite Orbits

Determine global gravity field

Density distributionMonitor of change in time　 Ground water motion

　 Strains in crusts by

earthquakes and volcanoes

GPS satellite

東京大字地震研・新谷氏、京都大学・福田氏の資料/情報提供

Observation Gap

between GRACE and GRACE-FO (2012-16) 　 DPF contribution

in international network

DECIGO

R&D for DPF (1)

Stabilized Laser BBM development Yb:YAG (NPRO) source Saturated absorption by I2

Stability test, Packaging

By M.Musha

By S.SatoIFO and housing BBM-EM development Test of concepts　 + Earth gravity sensors

By A.Araya

DECIGO

R&D for DPF (2)

Attitude control and Drag-free Satellite structure (mass distribution) 　 Passive attitude stabilization

by gravity gradient　 Mission thruster position

Control topology

ByS.Moriwaki

DECIGO

R&D for DPF (2)

Attitude control and Drag-free Satellite structure (mass distribution) 　 Passive attitude stabilization

by gravity gradient　 Mission thruster position

Control topology

Thruster System design with existing tech. Noise meas. system (thruster stand) 　 Development of Slit FEEP

By I.Funaki

ByS.Moriwaki

DECIGO

Roadmap of DECIGO/DPF

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2009 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 technologiesTest of key technologiesTest of key technologiesTest of key technologiesTest of key technologiesTest of key technologiesTest of key technologiesTest of key technologiesTest of key technologies

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






Full GW astronomyFull GW astronomyFull GW astronomyFull GW astronomyFull GW astronomyFull GW astronomy

Scope 1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm1 S/C1 arm

3 S/C1 interferometer






3 S/C,3 interferometer

3 or 4 units


3 or 4 units


3 or 4 units


3 or 4 units


3 or 4 units


3 or 4 units

DICIGO Pathfinder (DPF) Pre-DECIGO

DECIGO

R&DFabrication

R&DFabrication

R&DFabrication

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DECIGOOrganization

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PI: Kawamura (NAOJ)Deputy: Ando (Tokyo)

Executive CommitteeKawamura (NAOJ), Ando (Tokyo), Seto (NAOJ), Nakamura (Kyoto), Tsubono

(Tokyo), Tanaka (Kyoto), Funaki (ISAS), Numata (Maryland), Sato (Hosei), Kanda (Osaka city), Takashima (ISAS), Ioka (Kyoto)

Pre-DECIGO

Sato (Hosei)

Satellite

Funaki (ISAS)

Science, Data

Tanaka (Kyoto)Seto (NAOJ)

Kanda (Osaka city)

DECIGO pathfinderLeader: Ando (Tokyo)

Deputy: Takashima (ISAS)

Detector

Ueda (NAOJ)

Housing

Sato (Hosei)

Laser

Ueda (ILS)Musya (ILS)

Drag free

Moriwaki (Tokyo)

Sakai (ISAS)

Thruster

Funaki (ISAS)

Bus

Takashima (ISAS)

Data

Kanda (Osaka city)

Detector

Numata (Maryland)Ando (Tokyo)

Mission phase

Design phase

DECIGO

Collaboration and support・Supports from LISA

　　 Technical advises from LISA/LPF experiences

Support Letter for DECIGO/DPF LISA-DECIGO workshop (2008.11) ・Collab. with Stanford univ. group

Drag-free control of DECIGO/DPF UV LED Charge Management System　for DPF

・Collab. with JAXA navigation-control section

formation flight of DECIGO, DPF drag-free control

・Research Center for the Early Universe (RESCEU), Univ. of Tokyo

　　 Support DECIGO as ones of main projects　(2009.4-)

・Collab. with UNISEC (University Space Engineering Consortium)

Call for active young engineers

DECIGO

DECIGO is a future space-based GW detector project :

Fabry-Perot IF, 1000km baseline, constellation flight

Deci-Hz band is a focus of DECIGO! (same to BBO)

Fruitful frequency band for not only astronomical sources but also cosmological studies.

DECIGO Path Finder is going now.

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Summary

LCGT:TAMA -> CLIO -> LCGTNS-NS at 200Mpc away is detectable.We will try first detection of GW.

DECIGO:Ambitious space mission.GW from early universe !

We would like to appreciate to DST & IUCAA. Our visit (exchange) program is supported by the

cooperation between DST and JSPS.

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Japanese Future Gravitational Wave Projects on & off Earth !

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