Download
decigo pathfinder n.
Skip this Video
Loading SlideShow in 5 Seconds..
DECIGO Pathfinder PowerPoint Presentation
Download Presentation
DECIGO Pathfinder

DECIGO Pathfinder

141 Views Download Presentation
Download Presentation

DECIGO Pathfinder

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. DECIGO Pathfinder Masaki Ando (Department of Physics, The University of Tokyo) and DECIGO Pathfinder working Group International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  2. Introduction (1) • DECIGO roadmap LPF LISA Ad. LIGO LCGT International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  3. Test and demonstration for DECIGO (1) Drag-free control system (2) Laser source and its stabilization system (3) Control of Fabry-Perot interferometer (4) Launch-lock system Gravitational-wave observation (5) Observation for low-frequency (0.1-1Hz) GWs Mid.-scale BHs at the Galactic center DECIGO-PF (1) • DECIGO Pathfinder (DPF) DECIGO-PF One small satellite (Weight: ~200-300kg, Orbit: around the earth) 10cm Fabry-Perot cavity formed by free masses Stabilized laser source Drag-free control system Local Sensor Actuator Thruster International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  4. DECIGO-PF (2) • DPF diagram Drag-free control Local sensor signal  Feedback to thrusters/wheels Mission weight : ~100kg Mission space : ~90 x 90 x 90 cm Fabry-Perot interferometer Finesse : 100 Length : 10cm Test mass : 1kg Signal extraction by PDH Laser source Nd:YAG laser (1064nm) Power : 25mW Freq. stab. by reference cavity International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  5. DECIGO-PF (3) • DPF sensitivity (Preliminary parameters) Laser source : 1064nm, 25mW IFO length : 10cm Finesse : 100, Mirror mass : 1kg Q-factor : 105, Substrate: Fused Silica Temperature : 293K Satellite mass : 100kg, Area: 1m2 Altitude: 750km Thruster noise: 0.1μN/Hz1/2 International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  6. 750km DPF DECIGO-PF (4) • DPF orbit Selection of DPF orbit Launch chance (Cost, Launch window) Operation (Power supply, Telemetry) Stability, Noises Low-earth orbit Altitude 750km Polar sun synchronous orbit Sun No eclipse  Full-time operation Higher altitude will be desirable to reduce the effect of the earth (Earth’s gravity, terrestrial magnetism, residual atmosphere) Earth Depends on launch chance International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  7. Cut-off at 0.03Hz: originates in the model resolution  Unknown at higher frequency This will not be a problem: higher-order contribution will be negligible order of ~(Re/r) n Observe gravity field with higher resolution? DECIGO-PF (5) • Gravity-gradient noise Global gravity field model Public data obtained by GRACE Up to 150th-order in spherical harmonics Satellite velocity of 5km/sec  Estimate the noise spectrum Assume 2% vertical-horizontal coupling International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  8. Magnetic-field noise Effect of geomagnetic field: smaller than satellite self-field~10-7 T  noise level ~ 1.5 x 10-16 m/s2/Hz1/2 DECIGO-PF (6) • Geomagnetic noise Satellite self-field Two effect by geomagnetic field: Satellite motion in magnetic field Fluctuation in geomagnetic field Geomagnetic field model IGRF-10 model (10th generation of International Geomagnetic Reference Field) Altitude 750km Satellite velocity of 5km/sec Fluctuation in geomagnetic field Public data at Esashi observatory 1 sample/min data  Extrapolate for higher frequency International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  9. DECIGO-PF (7) • Survey of noise sources Acceleration Force Acceleration noise Displacement noise Magnetic field Residual Gas Thermal radiation Laser freq. noise International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  10. DECIGO-PF (8) • Comparison with other detectors Only a little observation data at low-frequency band Doppler tracking: h ~10-15(10-4-10-2 Hz) Pulsar timing: h ~10-14(10-8 Hz) Inspiral of Massive BH DPF limit LISA NS inspiral Galactic binary Core-collapse super nova ScoX-1 (1yr) Pulsar (1yr) Galactic binary Foreground noise GWs from Early universe (Wgw=10-14) LCGT DECIGO Gravity-gradient noise for terrestrial detectors International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  11. DECIGO-PF (9) • DPF targets Quasi-nomal mode oscillation of massive BH h ~ 10-15 , f ~ 0.3 Hz Distance 1Mpc, m = 105 Msun Binary inspiral of mid.-scale BHs h ~ 10-15 , f ~ 4 Hz Distance 10kpc, m = 103 Msun Events at Galactic center will be detectable with SNR~5 International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  12. DPF status (1) • Brief history 2004 December Call for suggestions of small satellite mission by JAXA2005  January Submit a proposal of small GW detector mission ~30 missions were submitted2006 October Call for proposals of small satellite mission by JAXA 2006 November Submit a proposal of GW-detector satellite as DECIGO pathfinder (DPF) 16 missions were accepted as working groups (10 science, 6 engineering missions), including DPF 2007 April Review meeting for these missions 2007 August DPF has been selected as one of 5 Pre-Phase-A missions R&D costs have been funded International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  13. DPF status (2) • DPF status JAXA is planning to launch 3 small satellite by the year 2013 using next-generation solid rocket booster under development Reduce time and cost by means of ‘Standard bus system’ Preliminary parameters Bus weight : ~ 200kg, Bus power : ~ 900W Downlink ~ 4Mbps, Data storage ~ 1GByte 3-axes angular control 1st mission (2011) has been decided to be TOPS (Space telescope mission for planet observation) 2nd and 3rd mission will be selected by 2009 March Candidate missions 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 International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  14. DPF status (3) • R&D plan for DPF (Under discussion) Required to submit Phase-A proposal by 2009 March R&D for core technologies Laser frequency stabilization Mirror and its housing (local sensor, actuator, launch-lock system) Micro thruster Drag-free control simulation Detailed design and noise investigation Target: launch in 2012 or 2013 as 2nd or 3rd standard small satellite of JAXA International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  15. Summary DECIGO pathfinder: First demonstration satellite for DECIGO One small satellite (Weight: ~200-300kg, Orbit: around the earth) 10cm Fabry-Perot cavity formed by free masses Stabilized laser source Drag-free control system Local Sensor Test and demonstration for DECIGO Gravitational-wave observation 0.1Hz-1Hz band BH QNM and Mid.-BH inspiral at Galactic center Actuator Selected and funded as one of the candidates of JAXA’s small satellite missions Hoping to be launched in 2012 - 2013 Thruster International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  16. Free-falling experiment using balloon BOV 2.5 : Free-falling vehicle from large balloon ~30 sec free-falling streach from 40km altitude Drag-free control system using gas-jet thrusters Prototype of SWIMmnis included in BOV Experiment module Diameter ~ 28cm Topics • Steps for DPF Small test-mass module Small module to be launched in 2008 Photo sensor Test mass SDS-I : Small (~100kg) satellite for demonstration of space technologies To be launched in 2008 summer by H-IIA as piggy-back satellite of GOSAT SWIMmn: very small GW detector module will be included in SWIM (SpaceWire Interface demonstration Module) Coil-magnet actuator International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )

  17. End International Conference on Topics in Astroparticle and Underground Physics (Sept. 11, 2007, Sendai, Japan )