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2014 European Frequency and Time Forum (EFTF)最新文献

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X-ray analysis of surface and pseudo-surface acoustic waves propagation in disordered La3Ga5SiO14 and ordered Ca3TaGa3Si2O14 crystals 无序La3Ga5SiO14和有序Ca3TaGa3Si2O14晶体中表面和伪表面声波传播的x射线分析
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331428
Olga Plotitcyna, D. Roshchupkin, D. Irzhak, E. Emelin, L. Ortega
{"title":"X-ray analysis of surface and pseudo-surface acoustic waves propagation in disordered La3Ga5SiO14 and ordered Ca3TaGa3Si2O14 crystals","authors":"Olga Plotitcyna, D. Roshchupkin, D. Irzhak, E. Emelin, L. Ortega","doi":"10.1109/EFTF.2014.7331428","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331428","url":null,"abstract":"X-ray diffraction on disordered La<sub>3</sub>Ga<sub>5</sub>SiO<sub>14</sub> (LGS) and ordered Ca<sub>3</sub>TaGa<sub>3</sub>Si<sub>2</sub>O<sub>14</sub> (CTGS) crystals modulated by surface (SAW) and pseudo-surface acoustic waves (PSAW) with wavelength of A=6 μm was studied using a double axis X-ray diffractometer at the BESSY II synchrotron radiation source. The propagation of SAW and PSAW leads to sinusoidal modulation of the crystal lattice and gives rise to diffraction satellites on the rocking curve, with the intensity and angular divergence between the diffraction satellites depending on the wavelength and amplitude of the crystal lattice acoustic modulation. The analysis of diffraction spectra enables the determination of the amplitude and acoustic wavelengths, power flow angles of acoustic energy propagation.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133001873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The three corner hat measurement of three hydrogen masers in remote locations via fiber based frequency synchronization network 基于光纤频率同步网的远距离氢脉泽三角帽测量
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331481
C. Gao, B. Wang, X. Zhu, J. Miao, Y. Bai, T. Li, L. J. Wang
{"title":"The three corner hat measurement of three hydrogen masers in remote locations via fiber based frequency synchronization network","authors":"C. Gao, B. Wang, X. Zhu, J. Miao, Y. Bai, T. Li, L. J. Wang","doi":"10.1109/EFTF.2014.7331481","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331481","url":null,"abstract":"As the first step of Beijing regional time and frequency network, Currently, Tsinghua University (THU) and the Changping site of National Institute of Metrology (NIM-Changping) have been linked and synchronized via the fiber network. The frequency stability of the hydrogen maser in NIM and the ultra-stable crystal oscillator steered by a cesium atomic clock in THU was measured. More atomic clocks from the Beijing Institute of Radio Metrology and Measurements, Hepingli site of NIM and Peking University (PKU) will join the synchronization network soon, with these clocks we can get the stability of each clock though three-corner-hat method.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"23 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131972732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Surveillance of NTP-servers in customer's network 客户网络ntp服务器监控
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331542
K. Jaldehag, C. Rieck, P. Hedekvist, Jan Backefeldt
{"title":"Surveillance of NTP-servers in customer's network","authors":"K. Jaldehag, C. Rieck, P. Hedekvist, Jan Backefeldt","doi":"10.1109/EFTF.2014.7331542","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331542","url":null,"abstract":"During the last three years, the NTP servers hosted by the largest Telecommunications and Internet Service Provider in Sweden have been monitored and logged with traceability to UTC(SP), including an estimated uncertainty calculated from the measurements, stratum-level, and synchronization source. The surveillance is ongoing and provides updated information on NTP-synchronization status and network congestions.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132051720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Cryogenic single crystal silicon cavity 低温单晶硅腔
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331555
J. Millo, C. Lacroûte, A. Didier, E. Rubiola, Y. Kersalé, J. Paris
{"title":"Cryogenic single crystal silicon cavity","authors":"J. Millo, C. Lacroûte, A. Didier, E. Rubiola, Y. Kersalé, J. Paris","doi":"10.1109/EFTF.2014.7331555","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331555","url":null,"abstract":"In this paper we present a study on an ultra-low noise cavity-stabilized-laser developed at the laboratory. The project aims to realize an ultra-stable cavity with a flicker frequency noise floor expected to be at ~ 4×10-17. This level of frequency noise can be achieved by making the cavity from a high mechanical quality factor material: single crystal silicon. The cavity needs to be cooled down to 17K with a cryocooled cryostat in order to cancel the coefficient of thermal expansion. Finite elements modeling helps to design a vibration insensitive cavity to be compatible with the objectives.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130797096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Absolute calibration of GNSS time transfer systems at CNES CNES的GNSS时间传输系统的绝对校准
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331535
A. Kanj, D. Valat, J. Delporte
{"title":"Absolute calibration of GNSS time transfer systems at CNES","authors":"A. Kanj, D. Valat, J. Delporte","doi":"10.1109/EFTF.2014.7331535","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331535","url":null,"abstract":"Nowadays, the GNSS time transfer is the most widespread technique for remote atomic clock comparison used for the International Atomic Time (TAI) calculation. In order to insure the TAI links accuracy and long-term stability, calibration of the GNSS reception chain is a must. Since 2005, French Space Agency (CNES) has developed an absolute calibration technique based on the Naval Research Laboratory (NRL) approach. The receiver is calibrated using GNSS signals generated by a satellite simulator while the antenna calibration is done using a specific anechoic chamber with Vector Network Analyzer (VNA) signals. The results of this technique have shown that accuracy around 1 nanosecond for the whole chain composed by a receiver, an antenna, and a cable can be achieved. The purpose of this paper is to present several methods to validate such low an accuracy.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130977692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Rydberg spin-squeezing for a strontium optical lattice clock 锶光学晶格钟的Rydberg自旋压缩
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331530
E. Bridge, D. Boddy, D. P. Sadler, A. Bounds, C. Adams, M. Jones, L. Gil, R. Mukherjee, T. Pohl
{"title":"Rydberg spin-squeezing for a strontium optical lattice clock","authors":"E. Bridge, D. Boddy, D. P. Sadler, A. Bounds, C. Adams, M. Jones, L. Gil, R. Mukherjee, T. Pohl","doi":"10.1109/EFTF.2014.7331530","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331530","url":null,"abstract":"We present a new technique for achieving high levels of squeezing in strontium optical lattice clocks using the long-range van der Waals interactions between high-lying Rydberg states. This technique requires only one additional laser and could provide over 10 dB of squeezing in large atomic ensembles, in just a few microseconds, without significantly affecting the subsequent clock interrogation. We outline this spin-squeezing technique and report on our experimental progress towards demonstrating this method. Significant experimental milestones include development of a versatile UV laser system for demonstrating this technique, and the first observation of the Rydberg blockade effect in a divalent atom.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122754201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
6 GHz range SAW tags and sensors 6ghz范围SAW标签和传感器
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331451
V. Plessky, S. Suchkov, Z. Davis, M. Lamothe
{"title":"6 GHz range SAW tags and sensors","authors":"V. Plessky, S. Suchkov, Z. Davis, M. Lamothe","doi":"10.1109/EFTF.2014.7331451","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331451","url":null,"abstract":"The feasibility of using 6 GHz frequencies for passive SAW-tags and sensors type devices is demonstrated. An example of the in-line 6 GHz SAW tag design is presented. Supposing that Ultra-Wide-frequency Band (UWB, B=775MHz) can be used, the tag dimensions can be significantly reduced and the loss of reflected response remains at an acceptable level of approximately 50dB. The SAW-tags and sensor test device has been manufactured using E-beam lithography and Nano-Imprint technology and demonstrate performance close to predicted, including the loss level of approximately 55dB. The possibility of high throughput manufacturing by combining Nano-Imprint and E-beam Lithography (NIL) is discussed. SAW sensor test devices produced using NIL are demonstrated.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131563479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Two-way satellite time and frequency transfer: Overview, recent developments and application 卫星双向时频传输:综述、最新发展及应用
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331442
Wu Wenjun, Dong Shaowu, L. Huanxin, Zhang Hong
{"title":"Two-way satellite time and frequency transfer: Overview, recent developments and application","authors":"Wu Wenjun, Dong Shaowu, L. Huanxin, Zhang Hong","doi":"10.1109/EFTF.2014.7331442","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331442","url":null,"abstract":"Two-way satellite time and frequency transfer(TWSTFT) has been recognized as one of the most accurate means for remote clock comparisons. The advantage is that the symmetry of the signal paths of two earth stations makes the errors to be mostly canceled. In two-way links, it is found that there are diurnal variety error whose magnitude is 1-3ns in most TWSTFT results. Combined with the character of diurnal variety, the diurnal variety error is removed by function fitting method and the precision is improved to about 0.3ns. TWSTFT is widely used in time and frequency community, satellite navigation and satellite orbit determination. TWSTFT has been developing continually in recent years and the future.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131936820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Exploration of 1/f noise origin using time measurements 利用时间测量探索1/f噪声源
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331511
S. Ghosh, F. Sthal, M. Devel, G. Cabodevila, J. Imbaud, R. Bourquin, P. Abbé, D. Vernier, A. Bakir, G. Cibiel
{"title":"Exploration of 1/f noise origin using time measurements","authors":"S. Ghosh, F. Sthal, M. Devel, G. Cabodevila, J. Imbaud, R. Bourquin, P. Abbé, D. Vernier, A. Bakir, G. Cibiel","doi":"10.1109/EFTF.2014.7331511","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331511","url":null,"abstract":"Noise measurements of quartz crystal resonators have been done by using a passive phase noise measurement technique. The tested resonators have been fabricated with exactly the same process. The short-term stabilities of a large portion of these resonators are measured to be lower than 8E-14. However, rest of them shows much worse results around few 1E-12. We are consequently carrying investigations on the origin of these differences. In this paper, high speed measurements of the acoustic wave attenuation achieved on the best and worse resonators are presented. Acoustic damping due to nonlinear effects such as, interaction of the acoustic wave with crystal defects is a well-known phenomenon. Hence, we explore the possibility to extract a damping contribution with the same physical origin as 1/f noise, by studying what is left after subtraction of the classical viscoelastic exponential damping. Preliminary results are presented in this paper.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133050246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Towards accurate optical fibre time transfer in UTC 迈向精确的UTC光纤时间传输
2014 European Frequency and Time Forum (EFTF) Pub Date : 2014-06-23 DOI: 10.1109/EFTF.2014.7331473
Z. Jiang, A. Czubla, J. Nawrocki, W. Lewandowski, F. Arias
{"title":"Towards accurate optical fibre time transfer in UTC","authors":"Z. Jiang, A. Czubla, J. Nawrocki, W. Lewandowski, F. Arias","doi":"10.1109/EFTF.2014.7331473","DOIUrl":"https://doi.org/10.1109/EFTF.2014.7331473","url":null,"abstract":"Accurate time transfers are now fully based on space techniques. The recently developed optical fibre technique is expected to be used in the UTC generation in the future. Some UTC labs operate optical fibre links using different approaches. In particular, the here called Two-Way Optical Fibre Time (and Frequency) Transfer (TWOFT/TWOTFT) is of special interest. The symmetry of the propagation conditions in both directions allows to substantially reducing the instability due to fluctuations of the propagation, and its capability of self-calibration. The first operational TWOTT between the UTC laboratories has been established in Poland between AOS and GUM since January 2012. The result has being submitted to the BIPM since March 2013. The BIPM started the monthly data processing and compares to the GNSS links. The TWOTT can reach an accuracy of hundred ps in a few minutes and therefore provide an effective new tool for the assessment of GNSS and TWSTT CP time link calibration and bring substantial improvement to the [UTC-UTC(k)]. However, time transfer by optical fibres today does not match the structure of the UTC time transfer network with a unique pivot. This requires the new network configuration, algorithm and will provoke fundamental changes in the UTC time link computation.","PeriodicalId":129873,"journal":{"name":"2014 European Frequency and Time Forum (EFTF)","volume":"35 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114112767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
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