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GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space Gravitational - Wave Antenna: DECIGO and Pre - DECIGO Masaki Ando (Univ. of Tokyo / NAOJ ) On behalf of DECIGO Working Group

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Page 1: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Space Gravitational-Wave Antenna:

DECIGO and Pre-DECIGO

Masaki Ando (Univ. of Tokyo / NAOJ )

On behalf of DECIGO Working Group

Page 2: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

DECIGO Members

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Masaki Ando, Seiji Kawamura, Naoki Seto, Takashi Nakamura, Kimio Tsubono, Shuichi Sato, Takahiro Tanaka, Ikkoh

Funaki, Kenji Numata, Nobuyuki Kanda, Kunihito Ioka, Takeshi Takashima, Jun'ichi Yokoyama, Tomotada Akutsu,

Mitsuru Musha, Akitoshi Ueda, Koh-suke Aoyanagi, Kazuhiro Agatsuma, Hideki Asada, Yoichi Aso, Koji Arai, Akito Araya,

Takeshi Ikegami, Takehiko Ishikawa, Hideharu Ishizaki, Hideki Ishihara, Kiwamu Izumi, Kiyotomo Ichiki, Hiroyuki Ito,

Yousuke Itoh, Kaiki T. Inoue, Ken-ichi Ueda, Takafumi Ushiba, Masayoshi Utashima, Satoshi Eguchi, Yumiko Ejiri,

Motohiro Enoki, Toshikazu Ebisuzaki, Yoshiharu Eriguchi, Naoko Ohishi, Masashi Ohkawa, Masatake Ohashi, Kenichi

Oohara, Yoshiyuki Obuchi, Kenshi Okada, Norio Okada, Koki Okutomi, Nobuki Kawashima, Fumiko Kawazoe, Isao

Kawano, Kenta Kiuchi, Naoko Kishimoto, Hitoshi Kuninaka, Hiroo Kunimori, Kazuaki Kuroda, Sachiko Kuroyanagi,

Hiroyuki Koizumi, Feng-Lei Hong, Kazunori Kohri, Wataru Kokuyama, Keiko Kokeyama, Yoshihide Kozai, Yasufumi

Kojima, Kei Kotake, Shiho Kobayashi, Rina Gondo, Motoyuki Saijo, Ryo Saito, Shin-ichiro Sakai, Masaaki Sakagami,

Shihori Sakata, Norichika Sago, Misao Sasaki, Takashi Sato, Masaru Shibata, Kazunori Shibata, Ayaka Shoda, Hisaaki

Shinkai, Aru Suemasa, Naoshi Sugiyama, Rieko Suzuki, Yudai Suwa, Kentaro Somiya, Hajime Sotani, Tadashi Takano,

Kakeru Takahashi, Keitaro Takahashi, Hirotaka Takahashi, Fuminobu Takahashi, Ryuichi Takahashi, Ryutaro Takahashi,

Takamori Akiteru, Hideyuki Tagoshi, Hiroyuki Tashiro, Nobuyuki Tanaka, Keisuke Taniguchi, Atsushi Taruya, Takeshi

Chiba, Dan Chen, Shinji Tsujikawa, Yoshiki Tsunesada, Morio Toyoshima, Yasuo Torii, Kenichi Nakao, Kazuhiro

Nakazawa, Shinichi Nakasuka, Hiroyuki Nakano, Shigeo Nagano, Kouji Nakamura, Yoshinori Nakayama, Atsushi

Nishizawa, Erina Nishida, Yoshito Niwa, Taiga Noumi, Tatsuaki Hashimoto, Kazuhiro Hayama, Tomohiro Harada, Wataru

Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Mitsuhiro Fukushima, Ryuichi Fujita, Masa-Katsu

Fujimoto, Toshifumi Futamase, Mizuhiko Hosokawa, Hideyuki Horisawa, Kei-ichi Maeda, Hideo Matsuhara, Nobuyuki

Matsumoto, Yuta Michimura, Osamu Miyakawa, Umpei Miyamoto, Shinji Miyoki, Shinji Mukohyama, Toshiyuki Morisawa,

Mutsuko Y. Morimoto, Shigenori Moriwaki, Kent Yagi, Hiroshi Yamakawa, Toshitaka Yamazaki, Kazuhiro Yamamoto,

Shijun Yoshida, Taizoh Yoshino, Chul-Moon Yoo, Yaka Wakabayashi

(On June 18th, 2015)

Page 3: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Outline

・DECIGO

・Pre-DECIGO

Page 4: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO

Page 5: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Space GW Antenna DECIGO

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO (DECI-hertz interferometer Gravitational wave Observatory)

Purpose: To Obtain Cosmological Knowledge.

Direct observation of the origin of space-time

and matter in Big-bang Universe.

Page 6: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

DECIGO Observation Band

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Space GW antenna

Obs. band around 0.1 Hz

10–4

10–2

100

102

104

10–26

10–24

10–22

10–20

10–18

10–16

Frequency [Hz]

Str

ain

[

1/H

z1/2

]

Terrestrial Detectors (Ad. LIGO, KAGRA, etc)

DECIGO

LISA

‘Bridge’ the obs.gap between

LISA and Terrestrial detectors

Page 7: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Targets and Science

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO (1 unit)

Merger

Frequency [Hz]

GW

am

plit

ude [

Hz-

1/2]

10-4 10-2 100 102 104

10-24

10-22

10-20

10-18

10-26

DECIGO (Correlation)

NS inspiral (z~1)

Merger

3month

IMBH binary inspiral

NS binary inspiral

Stochastic background

Galaxy formation (Massive BH)

Cosmology (Inflation, Dark energy)

Fundamental physics

Page 8: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Observation of GW from Inflation

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

CMB B-mode polarization

observation by micro-wave

telescope.

Original figure by Tajima (Kyoto 2011)

CMB pol. telescope

GW telescope

Gravitational Wave

BICEP2, (POLARBEAR,…)

GWB observation by

GW telescope.

DECIGO, (KAGRA, aLIGO,…)

EM Wave (microwave)

Primordial

Gravitational

Wave

Inflation

Page 9: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GW from Inflation

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Stochastic background GWs by quantum fluctuation

Earlier-generated GWs in inflation period

entered later into the horizon of the universe.

Nakayama+,

Journal of Cosmology

and Astroparticle Physics

06 (2008) 020.ln 𝑎

~380 kyr.

CMB B-mode

~10-24 sec.

DECIGO

Page 10: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GWs from Inflation

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Enter the horizon earlier High frequency GW.

Freq [Hz]

𝛀𝐆𝐖

(GW

Energ

y d

ensi

ty r

atio)

Kuroyanagi+ PRD (2009)

GWs from Inflation

Earlier into the horizon

Later into the horizon

~10-24 sec~0.4 Myr

Page 11: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Probing the Early Universe by GW

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

・GWs will carry direct information on the early universe.

・Spectrum : Initial fluctuation + Evolution history

Depends on 𝑟 (tensor-

to-scalar ratio), which

may be also pinned-down

by CMB B-mode

polarization observation.

Different age in different freq.

Higher freq. Earlier universe

- Reheating temperature

- Thermal history of the universe

….

Page 12: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GW from Inflation

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Energy density ∝ Tensor-Scalar Ratio (𝑟).

Power spectrum : Evolution history of the Universe.

Nakayama+,

Journal of Cosmology

and Astroparticle Physics

06 (2008) 020.

・Spectrum Power.

Energy scale

of inflation

・Cut-off freq.

Energy scale

of Reheating

DECIGO Correlation

Page 13: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

ℎGW2 𝑓 =

3𝐻02

10𝜋2𝑓3 ΩGW 𝑓

Amplitude and Energy Density Ratio

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Freq. [Hz]

ℎGW

[Hz-

1/2]

Freq. [Hz]

ΩGW

𝑓−1.5

Larger amplitude in low-freq.

GW energy density ratio

[ Dimensionless ]

Equivalent GW

amplitude [ Hz-1/2 ]

Page 14: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Foreground GWs

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Unresolvable GWs from too many binaries

GW Foregrounds at 10-10 – 0.1 Hz freq. band.

Freq. [Hz]

𝛀𝐆𝐖

(GW

energ

y d

ensi

ty r

atio)

Kuroyanagi+, PRD (2009)

GW from Inflation

Pablo, PRD (2011)

MBH-MBH

WD-WD

WD-NSNS-NS

PPTAeLISA

DECIGO

KAGRA

Page 15: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

‘Window’ Band for Primordial GWs

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

・Large amplitude GWs expected at low-frequency

・Foreground GWs below 0.1Hz

Freq. band of 0.1 -1 Hz is advantageous

for observation of GWs from inflation

ΩGW ~ 10−16 − 10−15

ℎGW ~ 10−24 Hz-1/2 (@ 0.1Hz)

Page 16: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Pre-Conceptual Design

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Interferometer Unit:

Differential FP interferometer

Laser

Photo-

detector

Arm cavity

Drag-free S/C

Mirror

Arm length: 1000 km

Finesse: 10

Mirror diameter: 1 m

Mirror mass: 100 kg

Laser power: 10 W

Laser wavelength: 532 nm

S/C: drag free

3 interferometers

Page 17: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Space GW antenna

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

eLISA(Laser Interferometer Space Antenna)

DECIGO(Deci-hertz Interferometer

Gravitational Wave Observatory)

Laser

Photo-detector

Arm cavity

Drag-free S/C

Mirror

- Target: SMBH, Binaries.

GWs around 1mHz.

- Baseline : 1-5M km.

Constellation flight by 3 S/C

- Optical transponder.

- Target: IMBH, NS binaries.

GWs around 0.1Hz.

- Baseline : 1000 km.

Formation flight by 3 S/C.

- Fabry-Perot interferometer.

Page 18: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Interferometer Design

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Transponder type vs Direct-reflection type

10–4

10–3

10–2

10–1

100

101

102

10310

–25

10–24

10–23

10–22

10–21

10–20

10–19

10–18

Frequency [Hz]

Str

ain

[

1/H

z1/2

]

LCGT

LISA

DECIGO(LISA type, 5x10

4km)

DECIGO(FP type, 1000km)

Laser: 10W, 532nmMass: 100kgMirror: 1m dia.

Compare : Sensitivity curves and Expected Sciences

Decisive factor: Binary confusion noise

Page 19: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Arm length

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Cavity arm length : Limited by diffraction loss

Effective reflectivity (TEM00 TEM00)

Laser wavelength : 532nm

Mirror diameter: 1m

Optimal beam size

101

102

103

104

105

106

107

108

109

101010

–4

10–3

10–2

10–1

100

Arm Length [m]

Ra

tio

of

av

ail

ab

le p

ow

er

LISALCGTTAMA DECIGO Dif

fra

cti

on

Lo

ss

(5x109m)(3x10

3m)(300 m)

Mirror diameter : 1m

Optimal beam profile

(1x106m)

Nd:YAG laser : 532nm

1000 km

is almost max.

Page 20: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Cavity and S/C control

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

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 (+Laser freq.)

Relative motion between mirror and S/C

Local sensor S/C thruster

Page 21: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Requirements

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Displacement Noise

Shot noise 3 x 10-18 m/Hz1/2(0.1 Hz)

Acceleration Noise

Force noise 4x10-17 N/Hz1/2(0.1 Hz)

Other noises should be well below the shot noise

Laser freq. noise: 1 Hz/Hz1/2(1Hz)

Stab. Gain 105, CMRR 105

x 10 of KAGRA in phase noise

x 1/50 of LISA

External force sources

Fluctuation of magnetic field, electric field,

gravitational field, temperature, pressure, etc.

Page 22: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Orbit and Constellation

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Record-disk orbit around the Sun

Relative acc. 4x10-12 m/s2

(Mirror force ~10-9 N )

Separated

unit

Constellation

4 interferometer units

2 overlapped units Cross correlation

2 separated units Angular resolution

overlapped

units

Separated

unit

Candidate of orbit:

Page 23: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Foreground Cleaning

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO obs. band: free from WD binary foreground

Open for cosmological observation

DECIGO will watch

~ 105 NS binaries

Foreground for GWB

Require waveform

Accuracy Δm/m < ~10-7 %

In principle, possible

to remove them.

Fig: N. Kanda

Page 24: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Design Update Possibility

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

By T.Akutsu

Page 25: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Pre-DECIGO

Page 26: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

2014 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Missio

nPurp

ose

Interferometer in Space

(Obs. Of GW and Earth Gravity)

Long-baseline

Precise Formation Flight

(GW Observation)

GW Astronomy

and Cosmology

Desig

n

One Small Satellite

Short FP cavity + Drag-free

FF with 3 S/C

1 IFO unitFF with 3 S/C

3-4 IFO units

Previous Roadmap for DECIGO

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Figure: S.Kawamura

DECIGO Pathfinder(DPF)

Pre-DECIGO DECIGO

R&DFabrication

R&DFabrication

R&DFabrication

SDS-1/SWIM

Page 27: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

DECIGO Pathfinder

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO Pathfinder (DPF)

- Space demonstration satellite for

Pre-DECIGO and DECIGO.

- Working group since 2005.

- Has been a candidate of

‘Small Mission by Epsilon’ in JAXA.

- Mission proposal submitted in

Feb. 2014.

Failed in the selection

Page 28: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

2014 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Missio

nPurp

ose

Demonstration and test

of space IFO technique

Sciences by GW

observation

GW Astronomy

and Cosmology

Desig

n

Micro-g experiment

FP cavity + Drag-free 3 S/C , 3 arms.FF with 3 S/C

3-4 IFO units

Updated Roadmap for DECIGO

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Figure: S.Kawamura

DECIGO Pathfinder(DPF)

Pre-DECIGO DECIGO

R&DFabrication

R&DFabrication

R&DFabrication

SDS-1/SWIMGround test+ Piggy-back opportunity.

Page 29: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Sciences by Pre-DECIGO

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

(1) Inspiral of NS-NS binaries [‘Promised’ target]

- ~10 binaries/yr.

- Estimation of binary parameters and merger time

a few month before merger.

Key role in multi-messenger astronomy.

(2) Inspirals and mergers of IMBHs [Original science]

- Cover most of the universe.

Formation history of SMBH and galaxies.

(3) Foreground understandings for DECIGO [for Cosmology]

- Parameter estimation and subtraction of binaries.

- Characteristics of foreground.

- Is the any eccentric binaries?

Page 30: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Pre-DECIGO Design (Preliminary)

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

・Mission Requirement

- Strain sensitivity of 2x10-23 Hz-1/2 at 0.1Hz.

- >3-years observation period.

・Conceptual Design

- Laser interferometer by 3 S/C

- Baseline : 100 km

Laser source : 1W, 515nm

Mirror : 300mm, 30kg

- Drag-free and Formation flight.

- Record-disk Orbit around the earth??

Page 31: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Sensitivity of Pre-DECIGO

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

重力波に対する感度SN~14 for NS-NS@300Mpc数~数十events/year

干渉計感度比較DECIGOより 1~2桁↓DPFから 6桁↑

pre-DECIGO 干渉計感度

第5回DECIGOワークショ ッ プ( 2007/04/18@国立天文台、 三鷹)

10-24

10-23

10-22

10-21

10-20

10-19

10-18

10-17

10-16

10-15

Str

ain

se

nsit

ivit

y [

1/rH

z]

10-3

10-2

10-1

100

101

102

103

Frequency [Hz]

DPFDPFDPFDPF

NS-NS inspiral (@300Mpc)

pre-DECIGO

DECIGO

By S.Sato

Page 32: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Mission Opportunities (JAXA Roadmap)

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

From file submitted to the government by ISAS/JAXA (Sept. 19th 2013)

Pre-DECIGO

DPF

Page 33: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Interferometer Module

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

IO Optics

Test mass module

Quad-RFPD SpW signal-processingboard

Interferometer Module

IFO length~30cm

Quadrant PD + Demod. circuits forlength and alignmentcontrol signals

Monolithic opt. bench by silicate bonding TM, Capacitive

Sensor/Actuator,Launch lock

SpW FPGA +16bit AD/DA

Page 34: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Frequency Stabilization Module

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

- Use absorption line of Iodine molecule.

- Satisfy requirement (0.5 Hz/Hz1/2)

in error-signal measurement.

・Frequency Stabilization module BBM2 (at UEC)

TECPBS

Prism Mirror

AOM

PBS

I2 Cell

Prism Mirror

Mirror

PC

500mm

300mm

- Preparing one-more module for

relative stability evaluation.

Freq. Stab module

Page 35: Space Gravitational-Wave Antenna: DECIGO and Pre-DECIGO · DECIGO Observation Band GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka) Space GW antenna Obs. band around 0.1 Hz 10 ± 10

Space Demonstration by SWIM

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

CPU: HR5000(64bit, 33MHz)

System Memory:

2MB Flash Memory

4MB Burst SRAM

4MB Asynch. SRAM

Data Recorder:

1GB SDRAM

1GB Flash Memory

SpW: 3ch

SpaceCube2: Space-qualified Computer SWIMmn : User ModuleProcessor test board

GW+Acc. sensor

FPGA board

DAC 16bit x 8 ch

ADC 16bit x 4 ch

32 ch by MPX

Torsion Antenna x2

~47g test mass

Size: 71 x 221 x 171

Weight: 1.9 kg

Power: 7W

Power ±15V, +5V

SpW x2 for CMD/TLM

Data Rate : 380kbps

Size: 124 x 224 x 174

Weight: 3.5 kg

Power: ~7W

Power +28V

RS422 for CMD/TLM

GPS signal

SDS-1

Bus System

Photo by JAXAPhoto by JAXA

SWIM (Space wire demonstration module) on SDS-1 satellite

Launched in Jan. 2009, 1.5 years operation

Successful as a tiny space GW detector

Photo:JAXA

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Test mass

Photo sensor

Coil

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

Reflective-type optical displacement sensor

Separation to mass ~1mmSensitivity ~ 10-9 m/Hz1/2

6 PSs to monitor mass motion

~47g Aluminum, Surface polishedSmall magnets for position control

Spin Axis(46.5mHz)

80mm

Space GW detector : SWIMmn

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Photo:JAXA

Small freely-floating test mass

Space demonstration of

control and data processing

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GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

Summary

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Summary

GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

DECIGO : Fruitful Sciences

Very beginning of the Universe

Dark energy, Dark matter

Galaxy formation

Will be realized at last.

Pre-DECIGO : Original Sciences

Key role for multi-messenger astoronomy.

Information on SMBH and galaxy formation.

Prospects for future mission : DECIGO.

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GWPAW2015 (June 19th, 2015, INTEX-Osaka, Osaka)

EndOriginal Picture : Sora