First result of orbit verification of Taiji-1 hall micro thruster

2021 ◽  
pp. 2140013
Author(s):  
Shu-Yan Xu ◽  
Lu-Xiang Xu ◽  
Lin-Xiao Cong ◽  
Yong-Gui Li ◽  
Cong-Feng Qiao ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Test Mass ◽  
Dual Frequency ◽  
Dual Mode ◽  
Cathode Voltage ◽  
Precision Control ◽  
Z Domain ◽  
Altitude Control ◽  
First Time ◽  
Reference Sensor

The Hall Micro Thrusters (HMTs) use cold gas or accelerated plasma dual mode to provide ultra-precise spacecraft altitude control. They were operated in space for the first time as part of the demonstration payloads on Chinese Academy of Science’s (CASs) Taiji-1 spacecraft since September 2019. Hall Micro Thruster Assemblies (HMTAs) were the actuators in drag-free control, and will compensate the nonconservative force for gravity wave observatories. The HMTAs meet the requirements of operating at 5–100 [Formula: see text]N of thrust with 0.7 [Formula: see text]N resolution and [Formula: see text]0.6 [Formula: see text]N/Hz[Formula: see text] (0.01–1 Hz) noise to deliver the nanometer-level precision control as fast as 30 ms measured by Gravitational Reference Sensor (GRS). A transfer function model in z-domain was fit and used to filter HMTs cathode voltage to predict GRSs thrust noise response. Simulations of a single or dual-frequency disturbance and the corresponding compensation demonstrated that HMTAs could deliver the required thrust profile expected. The capability to meet the requirements of thruster noise in drag-free control is critical for future missions because the acceleration noise on test mass directly relates to the gravity wave signa l. Preliminary in-orbit verification of Taiji-1 has showed HMTAs’ great potential in future, and the data in the experiments are presented in this paper.

In-orbit performance of the laser interferometer of Taiji-1 experimental satellite

2021 ◽  
pp. 2140004
Author(s):  
He-Shan Liu ◽  
Zi-Ren Luo ◽  
Wei Sha ◽  
Keyword(s):  
Laser Interferometer ◽  
Fused Silica ◽  
Test Mass ◽  
Frequency Range ◽  
Space Antenna ◽  
Satellite Platform ◽  
Laser Interferometer Space Antenna ◽  
Key Technologies ◽  
Carrier Rocket ◽  
Reference Sensor

Taiji-1, which is the first experimental satellite for space gravitational wave detection in China, relies on key technologies which include the laser interferometer, the gravitational reference sensor (GRS), the micro-thruster and the satellite platform. Similarly to the Laser Interferometer Space Antenna (LISA) pathfinder, except for the science interferometer, the optical bench (OB) of Taiji-1 contains reference and test mass (TM) interferometers. Limited by the lower mechanical strength of the carrier rocket and by the orbit environment, the OB of Taiji-1 is made of invar steel and fused silica, and it is aimed to achieve a sensitivity of the order of 100[Formula: see text]pm/[Formula: see text]. The experimental results from in-orbit tests of Taiji-1 demonstrate that the interferometer can reach a sensitivity of 30[Formula: see text]pm/[Formula: see text] in the frequency range of 0.01–10[Formula: see text]Hz, which satisfies the requirements of Taiji-1 mission.

scholarly journals Evaluation of HOCl-generating anticancer agents by an ultrasensitive dual-mode fluorescent probe

2019 ◽  
Vol 10 (13) ◽  
pp. 3715-3722 ◽  
Author(s):  
Donglei Shi ◽  
Shuqiang Chen ◽  
Biao Dong ◽  
Yanhui Zhang ◽  
Chunquan Sheng ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Anticancer Agents ◽  
Dual Mode ◽  
First Time

Probe C7 for the first time presents different modes of fluorescence signals to both nanomolar and micromolar concentrations of HOCl.

scholarly journals The Terahertz Controlled Duplex Isolator: Physical Grounds and Numerical Experiment

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Konstantin Vytovtov ◽  
Said Zouhdi ◽  
Rostislav Dubrovka ◽  
Volodymyr Hnatushenko
Keyword(s):  
Oblique Incidence ◽  
Faraday Effect ◽  
Harmonic Wave ◽  
Analytical Form ◽  
Electromagnetic Properties ◽  
Anisotropy Axis ◽  
Dual Frequency ◽  
Plane Harmonic Wave ◽  
Axis Orientation ◽  
First Time

Electromagnetic properties of an anisotropic stratified slab with an arbitrary orientation of the anisotropy axis under an oblique incidence of a plane harmonic wave are studied. The dependence of the eigenwave wavenumbers and the reflection coefficient on an anisotropy axis orientation and frequency is investigated. For the first time, the expression for the translation matrix is obtained in the compact analytical form. The controlled two-way dual-frequency (duplex) isolator based on the above described slab is presented for the first time. It is based on the properties of the anisotropic structure described here but not on the Faraday effect.

scholarly journals DIVERSITY MONOPULSE ANTENNA BASED ON A DUAL-FREQUENCY AND DUAL MODE CRLH RAT-RACE COUPLER

2009 ◽  
Vol 14 ◽  
pp. 87-106 ◽  
Author(s):  
David De Castro-Galan ◽  
Luis Enrique Garcia Munoz ◽  
Daniel Segovia-Vargas ◽  
Vicente Gonzalez-Posadas
Keyword(s):  
Dual Frequency ◽  
Dual Mode

scholarly journals Superimposed disturbance in the ionosphere triggered by spacecraft launches in China

2015 ◽  
Vol 33 (11) ◽  
pp. 1361-1368 ◽  
Author(s):  
L. M. He ◽  
L. X. Wu ◽  
S. J. Liu ◽  
S. N. Liu
Keyword(s):  
Wavelet Analysis ◽  
Physical Effect ◽  
Chemical Effect ◽  
Gps Tracking ◽  
Dual Frequency ◽  
First Time ◽  
Second Period

Abstract. Using GPS dual-frequency observations collected by continuously operating GPS tracking stations in China, superimposed disturbances caused by the integrated action of spacecraft's physical effect and chemical effect on ionosphere during the launches of the spacecrafts Tiangong-1 and Shenzhou-8 in China were firstly determined. The results show that the superimposed disturbance was composed of remarkable ionospheric waves and significant ionospheric depletion emerged after both launches. Meanwhile, we found for the first time that the ionospheric waves were made up of two periods of wave by wavelet analysis. The first period of ∼ 4 min shows one event in the near stations and two sub-events in the few far stations. The second period of ∼ 9 min shows only one event in all the observed stations. Finally, the time characteristics for ionospheric waves and depletions were examined.

Dual-frequency geometric phase metasurface for dual-mode vortex beam generator

2019 ◽  
Vol 52 (25) ◽  
pp. 255002 ◽  
Author(s):  
Kaiyue Liu ◽  
Guangming Wang ◽  
Tong Cai ◽  
Baojiang Dai ◽  
Yu Xiao ◽  
...  
Keyword(s):  
Geometric Phase ◽  
Vortex Beam ◽  
Dual Frequency ◽  
Dual Mode

Dual-Frequency and Dual-Mode Circular Patch Antennas Based on Epsilon-Negative Transmission Line

2013 ◽  
Vol 55 (10) ◽  
pp. 2393-2398 ◽  
Author(s):  
Quanwen Hou ◽  
Hangfei Tang ◽  
Yahong Liu ◽  
Xiaopeng Zhao
Keyword(s):  
Transmission Line ◽  
Patch Antennas ◽  
Dual Frequency ◽  
Dual Mode ◽  
Circular Patch

scholarly journals Derivation of gravity wave intrinsic parameters and vertical wavelength using a single scanning OH(3-1) airglow spectrometer

2018 ◽  
Vol 11 (5) ◽  
pp. 2937-2947 ◽  
Author(s):  
Sabine Wüst ◽  
Thomas Offenwanger ◽  
Carsten Schmidt ◽  
Michael Bittner ◽  
Christoph Jacobi ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Gravity Waves ◽  
Spatial Information ◽  
Rotational Transition ◽  
Horizontal Wind ◽  
Vertical Temperature ◽  
Vertical Wavelength ◽  
Broadband Emission ◽  
Wind Measurements ◽  
First Time

Abstract. For the first time, we present an approach to derive zonal, meridional, and vertical wavelengths as well as periods of gravity waves based on only one OH* spectrometer, addressing one vibrational-rotational transition. Knowledge of these parameters is a precondition for the calculation of further information, such as the wave group velocity vector. OH(3-1) spectrometer measurements allow the analysis of gravity wave ground-based periods but spatial information cannot necessarily be deduced. We use a scanning spectrometer and harmonic analysis to derive horizontal wavelengths at the mesopause altitude above Oberpfaffenhofen (48.09∘ N, 11.28∘ E), Germany for 22 nights in 2015. Based on the approximation of the dispersion relation for gravity waves of low and medium frequencies and additional horizontal wind information, we calculate vertical wavelengths. The mesopause wind measurements nearest to Oberpfaffenhofen are conducted at Collm (51.30∘ N, 13.02∘ E), Germany, ca. 380 km northeast of Oberpfaffenhofen, by a meteor radar. In order to compare our results, vertical temperature profiles of TIMED-SABER (thermosphere ionosphere mesosphere energetics dynamics, sounding of the atmosphere using broadband emission radiometry) overpasses are analysed with respect to the dominating vertical wavelength.

Achieving efficient Tb3+ dual-mode luminescence via Gd-sublattice-mediated energy migration in a NaGdF4 core–shell nanoarchitecture

2015 ◽  
Vol 3 (21) ◽  
pp. 5372-5376 ◽  
Author(s):  
Mingye Ding ◽  
Daqin Chen ◽  
Zhongyi Wan ◽  
Yang Zhou ◽  
Jiasong Zhong ◽  
...  
Keyword(s):  
Energy Migration ◽  
Core Shell ◽  
Dual Mode ◽  
First Time

Efficient dual-mode luminescence from identical Tb3+ in single NaGdF4 nanoparticles has been successfully realized for the first time with the help of Gd-sublattice-mediated energy migration and core–shell engineering techniques.

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