sora cajagwr seminar july 29, 2008 @caltech seiji kawamura (national astronomical observatory of...
TRANSCRIPT
Sora
CaJAGWR Seminar
July 29, 2008 @Caltech
Seiji Kawamura
(National Astronomical Observatory of Japan)
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
10-18
10-24
10-22
10-20
10-4 10410210010-2
Frequency [Hz]
Str
ain
[H
z-1/2]
LISA
DECIGO
Terrestrial detectors (e.g. LCGT)
Confusion Noise
moved above
LISA band To be moved
into TD 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(e.g. LISA)
Shot noise
Shortenarm length
Shot nois
e 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
FP cavity and drag free : compatible?
Local sensor
ThrusterThruster
Mirror
Relative position between mirror
and S/C
S/C II S/C I
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
Orbit and constellation (preliminary)
Sun
Earth
Record disk
Increase angular resolution
Correlation for stochastic background
Inflation
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 unit
Acceleration of Expansion of the Universe
NS-NS (z ~ 1)GW
DECIGO
Output
Expansion + Acceleration?
Time
Str
ain
Template (No Acceleration)
Real Signal ?Phase Delay ~ 1sec (10 years)
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.
Roadmap200
708 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Missio
nO
bjectives
Test of key technologiesObservation run of GW
Detection of GW w/ minimum spec.Test FP cavity between S/C
Full GW astronomy
Sco
pe
1 S/C1 arm
3 S/C1 interferometer
3 S/C,3 interferometer3 or 4 units
DICIGO Pathfinder(DPF)
Pre-DECIGODECIGO
R&DFabrication
R&DFabrication
R&DFabrication
DECIGO Pathfinder (DPF)
Laser
PD
Floating Mirrors
Drag-free S/C
DECIGO DPF
20 cm
1,000 km
Shrink the arm lengthfrom 1,000 km to 20 cm
Conceptual design and Technologies to demonstrate
Thruster
Local Sensor
Floating mirrorStabilization
system
Laser
Actuator
Drag-free control system Laser source and stabilization system Control of Fabry-Perot interferometer Launch-lock system
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
lev
el
[1
/Hz1/
2 ]
Frequency [Hz]
Shot noise
Mirror thermal
Laser Radiation
Laser: 1064nm, 25mWFinesse: 100Mirror mass: 1kgQ–value of a mirror: 10 6
Cavity length: 10cm
pressure noise
Thruster noise
PM acceleration Noise
Geogravity
Laser Frequencynoise
Dis
pla
ce
me
nt
No
ise
[m
/Hz1/
2 ]
Expected sources
103 104 105 10610–1
100
101
102
Ob
serv
able
Ran
ge
Mass [Msolar]
[kp
c, S
NR
=5
]
Galactic Center
BH QNM
BH Inspiral
DPF S/C
Size : 900mm cubeWeight : 200kgSAP : 800W Battery: 50AHDownlink : 2MpbsDR: 1GByte3N Thrusters x 4
Stabilized Laser
Interferometer Module
Thruster Control Unit
Solar Paddle
Interfererometer Control Unit
Housing Control Unit
Mission Thrusters
Central Processing Unit
Bus Thrusters
Satellite Bus (‘Standard bus’ system)
DPF PayloadSize : 900mm cubeWeight : 100kgPower : 200WData Rate: 600kbpsMission thruster x16
Power SupplySpW Comm.
DPF Mission Outline
Orbit: Low-Earth (Altitude 500km), Sun-synchronous orbit (dusk-dawn)
Launcher: Single launch by M-V follow-on (solid rocket booster under development) PBS (Post-Boost stage) for fine orbit insertion
Launch: 2012 (target)Mission Lifetime: 1 year (nominal)
500km
DP
F
Attitude Control: Gravity-gradient stab. Drag-free control with mission thrusters (Safe hold control by bus thrusters)
DPF Payload
Fabry-Perot interferometer Finesse : 100 Length : 20cm Test mass : 1kg Signal extraction by PDH
Laser source Nd:YAG laser (1064nm) Power : 25mW Freq. stab. by reference cavity
Drag-free control Local sensor signal Feedback to mission thrusters
Weight : ~100 kgSize : ~90 cm cube
Upper half of the satellite
JAXA’s Small satellite seriesPlan 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
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, …
Image CG of TOPS (design has been changed now)
DPF Current status
Laser frequency stabilizationMirror and its housing Micro thrusterDrag-free control simulationDetailed design and noise investigation
Required to submit Phase-A proposal
R&D for core technologies
DPF Launch: 2012 or 2013 as 2nd or 3rd standard small satellite of JAXA
2005 Jan. Submit a proposal of small GW detector mission2006 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
Brief History
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
siti
vit
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
Interim organizationPI: 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
Ando (Tokyo)
Housing
Sato (Hosei)
Laser
Ueda (ILS)Musya (IL
S)
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-WGKazuhiro Agatsuma, Masaki Ando, 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, 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 InternationalLISA-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.