Activity report from NICT

Transcription

1 Activity report from NICT APMP 2015 / TCTF meeting 2-3 November, 2015 National Institute of Information and Communications Technology (NICT) Japan 1 1

2 Space time standards laboratory Atomic Frequency Standards G Precise Atomic clocks development Opt. clock Opt. comb VLBI Generation, Measurement, and dissemination of the T&F standard Space-Time Measurement G at Kashima VLBI technique for precise T&F transfer Japan Standard Time G TWSTFT at Koganei T&F transfer Techniques by using the Optical fibers And satellites GNSS Cs primary Generation and Dissemination Of Japan Standard Time Opt. fiber 2

3 Space time standards laboratory Atomic clock & Precise freq. measurement RM: T. Ido H. Ishijima, S. Itoh M. Mizuno Sr opt. lattice H. Hachisu T. Ido In + ion-trap (K. Hayasaka) N. Ohtsubo Y. Li THz S. Nagano M. Kumagai M. Kajita Cs primary M. Kumagai VLBI at Kashima 34m Antenna Japan Standard Time RM: K. Imamura RM: M. Sekido M. Tsutsumi Super wideband Feed Analysis software E. Kawai H. Ujihara K. Takefuji T. Kondo Space time standards lab. Director: Y. Hanado H. Nezu (Technical Expert) (M. Hosokawa) (Y. Koyama) RM: T. Iwama Timescale F. Nakagawa LF station K. Matsubara TelJJY, NTP, Calib. Service H. Narita S. Tsuchiya (A. Machizawa) H. Usui N. Kotake H. Usui, H. Narita T & F transfer at Koganei RM: J. Amagai M. Aida R. Tabuchi GNSS T. Gotoh H. Takiguchi TWSTFT M. Fujieda RM: T. Ido Wireless 2way (Ext. budget) N. Shiga K. Kido T. Yasuda 3

4 Timescale JST : Time scale generation Clocks for generating UTC(NICT) : Cs 5071A : 18 (ensemble timescale) Anritsu H Masers : 3 (signal source) The behavior of UTC(NICT) : UTC UTC(NICT) < 20 ns. Stability ~ 2E 10 30d. UTC UTC(NICT) (ns) Adj. freq. to trce UTC ( x 1E-15) Allan deviation (log scale) UTC(NICT) -HM3 (=HM4+AOG ) HM4 NET HM3- HM Year Averaging time (sec) 4

5 JST : Time scale generation Distributed system for Japan Standard Time generation Features NET from all distributed clocks linked via satellites Multiple generation of NET by common database at remote sites (NET: NICT Cs Ensemble Timescale) 現在の状況 Sub-station at Kobe * Rooms, Measurement systems Completed * Clocks Installed (Cs x 4, HM x 1) * GPS link Regular operation has started * Generation of UTC(Kobe) Test has started * Dissemination system 時刻比較データ欠損による制御停止期間 σ~ 0.4ns ( 制御停止期間を除く ) -2 15/3 15/4 15/5 15/6 15/7 15/8 15/9 15/10 5

6 JST : Dissemination and Calibration LF stations LF40 : 1999 ~ LF60 : 2001 ~ System renewal (FY2012 FY2015) hagane-yama station 60kHz 23kW Ohtakadoya -yama station 40kHz 13kW Time stamping service ISO /IEC :2015 Calibration service Peer review (2016 Mar) Telephone JJY Access > 1.4E5 /month. Accesses are increasing. 1,5,10M On site : 31 Remote: 1 ( ) FPGA based NTP server can accept up to 1 million requests / sec. Public NTP Leap second adjustment Accesses > 15 billion / day. 6

7 T&F Transfer Regular operation GPS time link: Septentrio dual freq. receivers are used for TAI TWGPPP link. TWSTFT: Asia : Eutelsat 172A Asia EU : AM 2 Asia Hawaii US : Eutelsat 172A Advanced techniques TWSTFT Carrier Phase VLBI for T&F transfer ACES project 7

8 T&F Transfer : TWSTFT CP TWSTFT carrier phase 2013 ~ 2015 Modified Allan deviation 1E-13 1E-14 1E-15 1E-16 H-maser H-maser Common-clock, 0 km SYRTE-PTB, 700 km NICT-PTB, 9000 km 1E-17 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 Averaging time [s] Common-clock Eutelsat 172A, 9/24-27/2015 SYRTE-PTB T11N, 9/1/2015 NICT-PTB AM2, 6/24/2013, ionosphere-delay compensated 8

9 T&F Transfer : VLBI VLBI for T&F transfer Quasar (Radio object) (common radio source) Super-wideband system: Super wideband feed for 34m antenna ( GHz) Direct sampler, Analysis software (Very Long Baseline Interferometry) 34m Kashima Preliminary result of obseravtion Observation in 1GHz bandwidth showed a measurement precision in same level as GPS carrier phase. Better precision is expected by using this broader bandwidth (~10GHz). 9

10 T&F Transfer : ACES Join to ACES mission by ESA NICT/NMIJ/Univ. Tokyo will join to ACES for a global link of optical clocks. One of 7 MW ground terminals will be settled at NICT (delegate of Japan). ACES (Atomic clock ensemble in space) Laser cooled Cs atomic clock & Active H maser in ISS. Launch in 2017, operation for 3yrs. CV Non-CV Ground Station NMIJ NICT UT Google map Developing optical clocks Univ.Tokyo: Sr, Hg NICT: Sr, Ca+ NMIJ: Yb, Sr 10

11 Atomic clocks and Advanced techniques Microwave clocks Cs Fountain Toward the THz standard NICT CsF1 (2006~) Optical clocks NICT CsF2 (under development) z r U THz comb Ultrastable laser Ion trap Optical lattice Optical comb 11

12 In + ion with two Ca + as coolant Optical clocks 1 P 1 Detection? 159nm 204MHz 1 S 0 detection 230nm 360kHz 3 P 1 3 P 0 clock transition =237 nm =0.20 s 0.8Hz In operation since 2011 Uncertainty lately reduced to Correctio n(10-17 ) Uncer. (10-17 ) Blackbody radiation Lattice scalar/tensor dc Stark New trap installed. Tight confinement to reach Lamb Dicke regime Gold plated to avoid stray charge Quadratic Zeeman Density Line pulling Servo error Total New absolute frequency measurement (47) Hz 1 S 0-3 P 1 fluorescence (230nm) obtained Ready to probe the clock transition Agreement with others of various institutes Uncertainty reduced to using the TAI-link 12

13 New approaches to THz standard Generation of THz cw signal Tunable THz synthesizer cw radiation from 0.1 to 3.2THz. HWHM < 1kHz THz freq, measurement system THz comb Measurement precision : sub THz region: 1E 17 order THz region : better than 1E 9 THz comb application 1THz THz > MW synthesizer THz < > Optical synthesizer THz transfer techniques 13

14 Summary of topics Japan Standard Time: Preliminary timescale at Kobe sub station has started. System renewals at both LF stations is progressing. T&F transfer: TWSTFT CP : System noise reaches at low level of 10 VLBI : Evaluation with super wideband system is progressing. ACES : 1/7 Ground stations will be settled at NICT (in 2016). Atomic clocks and advanced technique: In + : 1 S 0 3 P 1 transition detected, ready to probe the clock transition. Sr : Accuracy improved to ~ Abs. Freq. 1.1 x THz : Freq. Measurement system for 0.1 3THz has constructed. 14