The preliminary analysis of Tianqin mission and developments of key technologies

Transcription

1 The3 rd KAGRA International Workshop The preliminary analysis of Tianqin mission and developments of key technologies Hsien-Chi Yeh Tianqin Research Center for Gravitational Physics Sun Yat-sen University 21 st May, 2017 Academia Sinica (NTU Campus), Taipei

2 Outlines 1. TianQin mission concept 2. Key technologies 3. Development strategy 4. Current status & progress

3 Meanings of GW detection Fundamental physics: Test theories of gravity in the strong field regime. Gravitational-wave astronomy: Provide a new tool to explore black holes, dark matters, early universe and evolution of universe.

4 LIGO GW Antenna Merging of 2 black holes 1915:General Relativity 1916:prediction of GW 1962:interferometer antenna 1984:initiating LIGO 2002:LIGO started exp. 2010:upgrade aligo 2016:GW detected

5 Why we need space GW detections? GW spectrum and detectors Significances: p abuntant types of sources Binary systems(white dwarfs neutron stars black holes) merging of massive black holes primordial GW p stable sources Compact binaries p strongest sources Binary super-massive black holes

6 Space GW mission concepts elisa/ngo ASTROD-GW Solar orbit Geocentric orbit OMEGA LAGRANGE

7 TianQin Mission Concept Guidelines: Geocentric orbit, shorter arm-length, higher feasibility; Target a well-known GW source (location and GW frequency) first, as the calibrated source ;

8 TianQin GW Antenna Orbit: geocentric orbit with altitude of 100,000km; Configuration: 3-satellite triangular constellation, nearly vertical to the Ecliptic; Calibrated source: J , close to the ecliptic; Detection time window: 3 months;

9 Example of possible orbits (1*10 5 km) Panels 1,2,3,7 : Range rate (<10m/s) Panels 4,5,6,8: Variation of subtended angles (Short term <0.1 deg.; Long term <0.2 deg.) Panels 7,8: More detail in first few months.

10 Sensitivity goal Gravitational wave from RX J Masses (0.5, 0.27) Msun Period 321.5s (distance between stars 66000km) Distance (0.05 ~ 5) kpc Strain G.H.A.Roelofs et al, ApJ, 711, L138 (2010) T.E.Strohmayer, ApJ, 627,920(2005) Simbad data base Integrated strength (90days) Relation to noise (SNR=10) S_x Noise in distance measurement; S_a Noise in acceleration : Transfer function

11 Sensitivity Curve of TianQin Assuming 90 days of integration time for TIANQIN Para. elisa TianQin Arm Len km 1.7*10 5 km Sa 1/2 7*10-15 m/s 2 /Hz 1/2 3*10-15 m/s 2 /Hz 1/2 Sx 1/2 10 pm/hz 1/2 1 pm/hz 1/2

12 Configuration of Space GW Antenna Single Satellite Triangular constellation

13 Inertial sensing & Drag-free control m/s 2 /Hz 1/2 Space Interferometry 1pm/Hz 1/2 Key Technologies Requirements Specifications Proof mass magnetic susceptibility 10-5 Residual charge 1.7*10-13 C Contact potential 100uV/Hz 10mV Cap. Sensor Temp. stability 5uK/Hz 1/2 Residual magnetic field 1.7*10-6 pf/hz 1/2 (3nm/Hz 1/2 )@ 5mm 2*10-7 T/Hz 1/2 Satellite remanence 1Am un-thruster 100 un (max); 0.1 un/hz 1/2 Nd:YAG Laser Power 4 W, Freq. noise 0.1 mhz/hz 1/2 Telescope Phasemeter Diameter 20 cm Resolution 10-6 rad Pointing control Offset & jitter 10-8 rad/hz 1/2 Wavefront distortion thermal drift of OB l/10 5nm/K

14 Key Technologies n Femto-g Drag-free control: Ø Ultraprecision inertial sensing: ACC, proof mass Ø un-thruster: continuously adjustable, 5-year lifetime Ø Charge management (UV discharge) n Picometer laser interferometry: Ø Laser freq. stab.: PDH scheme + TDI Ø Ultra-stable OB: thermal drift 1nm/K Ø Phase meas. & weal-light OPLL: 10-6 rad,1nw Ø Pointing control: 10-8 rad@10 6 km n Ultrastable satellite platform: Ø Stable constellation: min. velocity and breathing angle Ø Environment control: temperature, magnetic field, gravity and gravity gradient Ø Satellite orbiting: position(100m), velocity(0.1mm/s) (VLBI+SLR)

15 Development Strategy Technology verification for every 5 years; One mission for each step with concrete science objectives.

16 Roadmap 0 E.P., 1/r 2, Ġ, LLR High-altitude satellite positioning 1 Test of E.P. Inertial sensing Drag-free control Laser interferometer 2 Global Gravity Intersatellite laser ranging Precision accelerometer 3 GW detection Precision satellite formation fly Picometer space interferometry Femto-g drag-free control

17 Four Steps to GWD Step-0: Lunar laser ranging Technology objectives Precision laser ranging to high orbit spacecrafts Science objectives Testing fundamental laws in physics Studying physics of the Earth-Moon system

18 Four Steps to GWD Step-1: Test of equivalence principle in space Science objectives Testing EP to Technology objectives Dragfree m/s 2 Inertial sensor m/s 2 Micro-thruster 100μN Spaceborne laser 100Hz J. Jpn. Soc. Microgravity Appl. 25(2008)

19 Four Steps to GWD Step-2: Next generation gravity satellite Technology objectives Inertial sensor m/s 2 10nm@100km Science objectives Earth Global climate change Rev. Sci. Instrum. 82, (2011)

20 Four Steps to GWD Step-3: TianQin Technology objectives Inertial sensor m/s 2 Dragfree m/s 2 1pm@10 7 m μn-thruster Science objectives General Relativity GW astronomy Class. Quantum Grav. 33, (2016)

21 Precision Inertial Sensing : develop flexure-type ACC : space test of flexure-type ACC launched in : develop electrostatic ACC : space test of electrostatic ACC launched in 2013

22 Space Laser Interferometry : (10m) nm laser interferometer : (200km) inter-satellite laser ranging system Picometer laser interferometer nw weak light OPLL nrad pointing angle measurement 10Hz space-qualified laser freq. stab. Thermal Shield

23 Large-aperture CCR & SLR Laser Ranging for CE 4 relay satellite Manufacturing next-generation laser ranging CCR Upgrading ground stations Yunnan station Large-aperture hollow CCR

24 Basic Infrastructure at Zhuhai ( ) Laser Ranging Station Research Center Cave Lab.

25 Conclusions 1. Tianqin will develop all key technologies required for space-based GW detection step by step in the following 15 years. 2. Aiming at frequency range of 1mHz-1Hz, Tianqin can provide joint observations with LIGO, KAGRA and LISA. 3. Collaboration with DESIGO should be considered seriously, including studying science cases and developing key technologies required for both missions.

26 Thanks for your attentions!