Transcript The Japanese Space Gravitational Wave Antenna

CaJAGWR Seminar
July 29, 2008 @Caltech
Seiji Kawamura
(National Astronomical
Observatory of Japan)
Sora
What is DECIGO?
Deci-hertz Interferometer Gravitational Wave Observatory
(Kawamura, et al., CQG 23 (2006) S125-S131)
 Bridges the gap between LISA and terrestrial detectors
 Low confusion noise -> Extremely high sensitivity
Strain [Hz-1/2]
10-18
10-20
Terrestrial
detectors
(e.g. LCGT)
LISA
DECIGO
10-22 Confusion
Noise
10-24
10-4
10-2
100
102
Frequency [Hz]
104
Pre-conceptual design
Differential FP interferometer
Arm length: 1000 km
Mirror diameter: 1 m
Laser wavelength：0.532 m
Finesse: 10
Laser power: 10 W
Mirror mass: 100 kg
S/C: drag free
3 interferometers
Arm cavity
Arm cavity
Laser
Photodetector
Drag-free S/C
Mirror
Transponder type
(e.g. LISA)
Why FP cavity?
Shorten
arm length
Implement FP cavity
Strain
Shorten
arm length
Shot noise
Shot noise
Transponder type
(e.g. LISA)
Implement FP cavity
FP cavity type
Frequency
Better bestsensitivity
Drag free and FP cavity:
compatible?
S/C I
S/C II
Mirror
FP cavity and drag free :
compatible?
Relative position
between mirror
and S/C
S/C II
Local
sensor
S/C I
Mirror
Thruster
Thruster
Drag free and FP cavity:
compatible?
Relative position
between mirror
and S/C
S/C II
Local
sensor
No signal
mixture
S/C I
Mirror
Thruster
Thruster
Actuator
Interferometer
output (GW signal)
Orbit and constellation
(preliminary)
Earth
Correlation
for stochastic
background
Record disk
Sun
Increase angular
resolution
Science by DECIGO
10-19
Formation of 10-20
Supermassive BH 10-21
Coalescence
5 years
1 unit
3 months
10-22
10-23
10-24
10-25
Verification
of inflation 10-26
10-3
Inflation
10-2
Acceleration
of Universe
Shot noise
⇓
Correlation
Dark energy
(3 years)
Coalescence
10-1
1
10
Frequency [Hz]
102
103
Acceleration of Expansion
of the Universe
Expansion ＋Acceleration?
DECIGO
GW
NS-NS (z～1)
Output
Strain
Template (No Acceleration)
Real Signal ?
Phase Delay～1sec (10 years)
Time
Seto, Kawamura, Nakamura, PRL 87, 221103 (2001)
Requirements

Acceleration noise should be suppressed below
radiation pressure noise
– Force 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.
Roadmap
2007 08
09
10
11
12
13
Mission
R&D
Fabrication
14
15
16
17
18
19
R&D
Fabrication
DICIGO Pathfinder
(DPF)
20
21
22
23
24
25
26
R&D
Fabrication
Pre-DECIGO
DECIGO
Objectives
Test of key technologies
Observation run of GW
Detection of GW w/
minimum spec.
Test FP cavity
between S/C
Full GW astronomy
Scope
1 S/C
1 arm
3 S/C
1 interferometer
3 S/C,
3 interferometer
3 or 4 units
DECIGO Pathfinder (DPF)
DPF
DECIGO
Floating Mirrors
Laser
1,000 km
20 cm
PD
Shrink the arm length
from 1,000 km to 20 cm
Drag-free S/C
Conceptual design and
Technologies to demonstrate
Stabilization
system
Floating mirror
Thruster
Laser
Actuator
Local
Sensor
Drag-free control system
 Laser source and stabilization system
 Control of Fabry-Perot interferometer
 Launch-lock system

–12
1/2
Cavity length: 10cm
Laser: 1064nm, 25mW
Finesse: 100
Mirror mass: 1kg
6
Q–value of a mirror: 10
–12
10
–13
10
rav
og
Ge
–14
10
–15
PM
ac
ce
ler
–16
rn
ste
10
–17
ois
10
e
–18
–2
10
–1
10
n
La
ru
Th
10
10
at
io
ity
Noise level [1/Hz ]
10
No
ise
–13
10
–14
10
–15
10
–16
Laser Frequency
noise
10
Shot noise
10
se
prr R
es ad
su iat
re ion
no
ise
0
10
Frequency [Hz]
Mirror
1
10
–17
–18
therma
10
l
–19
10
2
10
1/2
–11
10
Displacement Noise [m/Hz ]
Goal sensitivity of DPF
[kpc, SNR=5]
Observable Range
Expected sources
2
10
BH QNM
BH Inspiral
1
10
Galactic Center
0
10
–1
10
3
10
4
10
5
10
Mass [Msolar ]
6
10
DPF S/C
DPF Payload
Size :
900mm cube
Weight : 100kg
Power :
200W
Data Rate: 600kbps
Mission thruster x16
Stabilized Laser
Thruster
Control Unit
Central
Processing Unit
Mission
Thrusters
Housing
Control Unit
Power Supply
SpW Comm.
Interferometer
Module
Satellite Bus
Interfererometer
Control Unit
(‘Standard bus’ system)
Size :
900mm cube
Weight : 200kg
SAP :
800W
Battery:
50AH
Downlink : 2Mpbs
DR:
1GByte
3N Thrusters x 4
Bus Thrusters
Solar Paddle
DPF Mission Outline
Launch: 2012 (target)
Mission Lifetime: 1 year (nominal)
Launcher:
Single launch by M-V follow-on
(solid rocket booster under development)
PBS (Post-Boost stage)
for fine orbit insertion
DPF
500km
Orbit:
Low-Earth (Altitude 500km),
Sun-synchronous orbit (dusk-dawn)
Attitude Control:
Gravity-gradient stab.
Drag-free control with mission thrusters
(Safe hold control by bus thrusters)
DPF Payload
Upper half of the satellite
Weight : ~100 kg
Size :
~90 cm cube
Laser source
Nd:YAG laser (1064nm)
Power : 25mW
Freq. stab. by reference cavity
Drag-free control
Local sensor signal
 Feedback to mission thrusters
Fabry-Perot interferometer
Finesse : 100
Length : 20cm
Test mass : 1kg
Signal extraction by PDH
JAXA’s Small satellite series
Plan to launch 3 small satellites by the year 2015
using next-generation solid rocket booster
Reduce time and cost
by means of ‘Standard bus system’
Bus weight : ~ 200kg, Bus power : ~ 800W
Downlink ~ 2Mbps, Data storage ~ 1GByte
3-axes attitude control
SpaceWire-based data processing system
Image CG of TOPS
(design has been changed now)
1st mission (2011) :
decided to be TOPS (Planetary science)
2nd and 3rd mission will be selected by 2009 March
15 Candidate missions (5 important candidates)
DPF: GW observation
DIOS: X-ray telescope for dark baryon investigation
ERG: Plasma and particle detector for geo-space investigation
Satellite for Magnet-plasma sail technology demonstration, …
DPF Current status
Brief History
2005 Jan. Submit a proposal of small GW detector mission
2006 Nov. Submit a proposal of GW-detector satellite as
DECIGO pathfinder (DPF)
2007 Aug. Selected as a Pre-Phase-A mission
R&D costs funded
Required to submit Phase-A proposal
R&D for core technologies
Laser frequency stabilization
Mirror and its housing
Micro thruster
Drag-free control simulation
Detailed design and noise investigation
DPF Launch: 2012 or 2013 as
2nd or 3rd standard small satellite of JAXA
Pre-DECIGO
PreDECIGO
DECIGO
Arm length
100 km
1000 km
Mirror diameter
30 cm
1m
Laser wavelength
0.532 m
0.532 m
Finesse
30
10
Laser power
1W
10 W
Mirror mass
30 kg
100 kg
# of interferometers 1
in each cluster
3
# of clusters
4
1
Sensitivity of Pre-DECIGO
S/N~14 for NS-NS@300Mpc, 10-20 events/year
-15
10
Strain sensitivity [1/rHz]
-16
10
DPF
-17
10
-18
10
pre-DECIGO
-19
10
-20
10
NS-NS inspiral (@300Mpc)
-21
10
-22
10
-23
10
DECIGO
-24
10
-3
10
-2
10
-1
10
0
10
1
10
Frequency [Hz]
2
10
3
10
Interim organization
PI: Kawamura (NAOJ)
Deputy: Ando (Tokyo)
Executive Committee
Kawamura (NAOJ), Ando (Tokyo), Seto (NAOJ), Nakamura (Kyoto),
Tsubono (Tokyo), Tanaka (Kyoto), Funaki (ISAS), Numata (Maryland),
Sato (Hosei), Kanda (Osaka city), Takashima (ISAS), Ioka (Kyoto)
Detector
Science, Data
Numata
(Maryland)
Ando (Tokyo)
Tanaka (Kyoto)
Seto (NAOJ)
Kanda (Osaka city)
Pre-DECIGO
Sato (Hosei)
Satellite
Funaki (ISAS)
Design phase
DECIGO pathfinder
Leader: Ando (Tokyo)
Deputy: Takashima (ISAS)
Mission phase
Drag free
Detector
Laser
Housing
Ando
(Tokyo)
Ueda (ILS)
Musya
(ILS)
Sato
(Hosei)
Moriwaki
(Tokyo)
Sakai
(ISAS)
Thruster
Bus
Data
Funaki
(ISAS)
Takashima
(ISAS)
Kanda
(Osaka
city)
DECIGO-WG
Kazuhiro Agatsuma, Masaki Ando, Koh-suke Aoyanagi, Koji Arai, Akito Araya, Hideki Asada, Yoichi
Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Yumiko Ejiri, Motohiro Enoki, Yoshiharu Eriguchi, MasaKatsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Ikkoh Funaki, 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, Kunihito Ioka, Koji Ishidoshiro, Hideki Ishihara,
Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Nobuyuki Kanda, Seiji Kawamura,
Nobuki Kawashima, Fumiko Kawazoe, 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, Kouji Nakamura, Takashi Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi
Nakasuka, Yoshinori Nakayama, Kazuhiro Nakazawa, Erina Nishida, Kazutaka Nishiyama, Atsushi
Nishizawa, Yoshito Niwa, Kenji Numata, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Kouji
Onozato, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shin-ichiro Sakai,
Shihori Sakata, Misao Sasaki, Shuichi Sato, Takashi Sato, Naoki Seto, Masaru Shibata, Hisaaki
Shinkai, 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, Takeshi
Takashima, Takahiro Tanaka, Keisuke Taniguchi, Atsushi Taruya, Hiroyuki Tashiro, Mitsuru Tokuda,
Yasuo Torii, Morio Toyoshima, Kimio Tsubono, Shinji Tsujikawa, Yoshiki Tsunesada, Akitoshi Ueda,
Ken-ichi Ueda, Masayoshi Utashima, Hiroshi Yamakawa, Kazuhiro Yamamoto, Toshitaka Yamazaki,
Jun'ichi Yokoyama, Chul-Moon Yoo, Shijun Yoshida, Taizoh Yoshino
1st International
LISA-DECIGO Workshop
• Nov. 12-13, 2008 @ ISAS, Sagamihara, Japan
• Objectives:
– Mutual understanding
– Possible collaboration
– Exposure of the missions to people in the neighboring fields
• Plenary talks:
– Science of LISA & DECIGO, status of LPF & DPF
• 1st circular w/ web page will be ready on Aug. 1
Summary
• DECIGO can detect GWs from the
inflation as well as can bring us
extremely interesting science.
• DPF has been selected as one of the 5
important mission candidates for small
science satellite series; they plan to
launch 3 missions in 5 years starting from
2011.
Let DPF fly!