bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prognostics and health management of FAST cable-net structure based on digital twin technology
Authors: Li Qing-Wei , Jiang Peng , Li Hui 
Published: May 2020

Abstract
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) will be fully commissioned later in 2019. Once commissioned, operation and maintenance of FAST will be the most prominent task. The unique working mode of active shape-changing of FAST cable-net structure makes the traditional maintenance way, which combines routine inspection with preventive maintenances not only expensive, but also unable to effectively avoid potential risks in operations. Therefore, it is necessary to develop an economical and reliable operation/maintenance technology for FAST cable-net structure. In this paper, a Prognostics and Health Management (PHM) system is proposed based on the advanced Digital Twin (DT) technology. Through the finite element analysis of DT model, the current safety status of FAST cable-net is evaluated, and the fatigue life of components in the cable-net is predicted. Hence Condition-Based Maintenance (CBM) of FAST cable-net structure can be realized. The PHM system described in this paper can effectively guarantee the healthy and safe operation of the FAST cable-net structure, greatly improve the maintenance efficiency and reduce the cost for maintenance works.
A motion planning algorithm for the feed support system of FAST
Authors: Yao Rui , Jiang Peng , Sun Jing-Hai , Yu Dong-Jun , Sun Chun 
Published: May 2020

Abstract
The paper relates to a motion planning algorithm for the feed support system of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). To enhance the stability of the feed support system, the start/termination planning segments are adopted with an acceleration and deceleration section. The source switching planning adopts a combination of a line segment and focal segment to realize stable control of the feed support system. Besides, during the observation trajectory, a transition segment which is not used for observation data is planned with a required time. Through an example simulation, a smooth change is realized via the motion planning algorithm and presented in this paper.
Simulation of FAST EM performance for both the axial and lateral feed defocusing
Authors: Gan Heng-Qian , Jiang Peng , Zhu Kai , Sun Jing-Hai , Yao Rui , Yu Dong-Jun 
Published: May 2020

Abstract
Five-hundred-meter Aperture radio Spherical Telescope (FAST) is the world’s largest single dish radio telescope, which is located in Guizhou Province, in southwest China. The FAST feed cabin is supported and positioned by six steel cables. The deviation of the feed position and orientation would lead to loss in the telescope efficiency. In this paper, a series of electromagnetic (EM) simulations of the FAST facility with varying feed positions and orientation offsets was performed. The maximum gain of FAST is about 82.3 dBi and the sibelobe is –32 dB with respect to the main beam at 3 GHz. The simulation results have demonstrated that the telescope efficiency loss is more sensitive to the lateral feed deviation compared with the axial deviation. The telescope efficiency would decrease by 8.2% due to the FAST feed position deviation of 10 mm rms when the observing frequency is 3 GHz. The FAST feed deviation basically has no effect on the sidelobes and cross polarization characteristic according to the simulations.
Design and optimization of cross bow-tie dipole feed with cavity for FAST
Authors: Yu Jing-Long , Yue You-Ling , Li Jian-Bin 
Published: May 2020

Abstract
A cross bow-tie dipole feed with cavity and symmetrical E and H plane pattern is presented for the Five hundred-meter Aperture Spherical radio Telescope (FAST). In this paper we describe the design, optimization and simulation results of a wide-band cross dipole feed with cavity covering the frequency range from 300 MHz to 600 MHz for FAST. The main goals of our design are to ensure that, (1) we cover the octave bandwidth, (2) the feed has symmetrical E and H plane pattern, and (3) the physical dimension is suitable for mounting it in the reserved position of the FAST feed cabin. The initial results indicate that we have met most of our design goals. This kind of feed had been equipped with the multi-beam receiver to carry out observation on the platform of FAST cabin.
Development of wideband orthomode transducers for FAST cryogenic receiver system
Authors: Fan Jin , Zhu Kai , Gan Heng-Qian , Jiang Peng , Yang Jian , Cao Yang , Liu Hong-Fei , Zhang Hang , Guo Ming-Lei , Shi Xiang-Wei 
Published: May 2020

Abstract
This paper describes the design, construction, and performance of the wideband orthomode transducers (OMTs) for the L- (1.2–1.8 GHz), the S- (2–3 GHz) and the P- (0.56–1.12 GHz) band receiver systems of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These OMTs operate at the cryogenic temperature of 70K to reduce their thermal noise contribution to the receiver chains. The development on the FAST L- and S-band quad-ridged waveguide (QRWG) OMTs is carried out based on the theoretical mode analysis. In view of the miniaturization of FAST cryogenic receiver system at P-band, a novel wideband compact bowtie dipole OMT is designed with an octave bandwidth as well as a length of only quarter wavelength. The proposed L-, S- and P-band OMTs are designed and optimized by using Ansys High Frequency Structure Simulator (HFSS), and then manufactured, tested at room temperature. Measurement of FAST cryogenic receiver system noise is also performed with the L-, S- and P-band OMTs installed. The measured results fully comply with the design specifications.
The time and frequency standard system for FAST receivers
Authors: Zhu Kai , Fan Jin , Liang Kun , Tang Wei , Gao Zhi-Sheng , Zhu Yan , Feng Yi , Zhu Wei-Wei , Qian Lei , Yue You-Ling , Song Jin-You , Shi Xiang-Wei , Wang Xing-Yi , Guo Ming-Lei , Zhang Hang , Gan Heng-Qian , Liu Hong-Fei , Jin Cheng-Jin , Jiang Peng 
Published: May 2020

Abstract
This paper reports on the time and frequency standard system for the Five-hundred meter Aperture Spherical radio Telescope (FAST), including the system design, stability measurements and pulsar timing observations. The stability and drift rate of the frequency standard are calculated using 1-year monitoring data. The UTC-NIM Disciplined Oscillator (NIMDO) system improves the system time accuracy and stability to the level of 5 ns. Pulsar timing observations were carried out for several months. The weighted RMS of timing residuals reaches the level of less than 3.0 μs.
Opportunities to search for extraterrestrial intelligence with the FAST
Authors: Li Di , Gajjar Vishal , Wang Pei , Siemion Andrew , Zhang Zhi-Song , Zhang Hai-Yan , Yue You-Ling , Zhu Yan , Jin Cheng-Jin , Li Shi-Yu , Berger Sabrina , Brzycki Bryan , Cobb Jeff , Croft Steve , Czech Daniel , DeBoer David , DeMarines Julia , Drew Jamie , Emilio Enriquez J. , Gizani Nectaria , Korpela Eric J. , Isaacson Howard , Lebofsky Matthew , Lacki Brian , MacMahon David H. E. , Nanez Morgan , Niu Chen-Hui , Pei Xin , Price Danny C. , Werthimer Dan , Worden Pete , Gerry Zhang Yunfan , Zhang Tong-Jie , Collaboration FAST 
Published: May 2020

Abstract
The discovery of ubiquitous habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, has ushered in a renaissance in the search for extraterrestrial intelligence (SETI). Large scale SETI activities are now underway at numerous international facilities. The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the largest single-aperture radio telescope in the world, and is well positioned to conduct sensitive searches for radio emission indicative of exo-intelligence. SETI is one of the five key science goals specified in the original FAST project plan. A collaboration with the Breakthrough Listen Initiative was initiated in 2016 with a joint statement signed both by Dr. Jun Yan, the then director of National Astronomical Observatories, Chinese Academy of Sciences (NAOC), and Dr. Peter Worden, Chairman of the Breakthrough Prize Foundation. In this paper, we highlight some of the unique features of FAST that will allow for novel SETI observations. We identify and describe three different signal types indicative of a technological source, namely, narrow band, wide-band artificially dispersed and modulated signals. Here, we propose observations with FAST to achieve sensitivities never before explored. For nearby exoplanets, such as TESS targets, FAST will be sensitive to an EIRP of 1.9 × 1011 W, well within the reach of current human technology. For the Andromeda Galaxy, FAST will be able to detect any Kardashev type II or more advanced civilization there.
Recent progress in developing efficient monolithic all-perovskite tandem solar cells
Authors: Wang Yurui , Zhang Mei , Xiao Ke , Lin Renxing , Luo Xin , Han Qiaolei , Tan Hairen 
Published: May 2020

Abstract
Organic–inorganic halide perovskites have received widespread attention thanks to their strong light absorption, long carrier diffusion lengths, tunable bandgaps, and low temperature processing. Single-junction perovskite solar cells (PSCs) have achieved a boost of the power conversion efficiency (PCE) from 3.8% to 25.2% in just a decade. With the continuous growth of PCE in single-junction PSCs, exploiting of monolithic all-perovskite tandem solar cells is now an important strategy to go beyond the efficiency available in single-junction PSCs. In this review, we first introduce the structure and operation mechanism of monolithic all-perovskite tandem solar cell. We then summarize recent progress in monolithic all-perovskite tandem solar cells from the perspectives of different structural units in the device: tunnel recombination junction, wide-bandgap top subcell, and narrow-bandgap bottom subcell. Finally, we provide our insights into the challenges and scientific issues remaining in this rapidly developing research field.
Comprehensive first-principles studies on phase stability of copper-based halide perovskite derivatives AlCumXn (A = Rb and Cs; X = Cl, Br, and I)
Authors: Sun Zhongti , Chen Xiwen , Yin Wanjian 
Published: May 2020

Abstract
Recently, inorganic copper-based halide perovskites and their derivatives (CHPs) with chemical formulas A
l
Cu
m
X
n
(A = Rb and Cs; X = Cl, Br and I; l, m, and n are integers.), have received increasing attention in the photoluminescence field, due to their lead-free, cost-effective, earth-abundant and low electronic dimensionality. Ascribed to flexible valence charge of Cu (Cu1+ and Cu2+) and complex competing phases, the crystal structures and phase stabilities of CHPs are complicated and ambiguous, which limits their experimental applications. Via comprehensive first-principles calculations, we have investigated thermodynamic stabilities of possible crystal phases for A
l
Cu
m
X
n
by considering all the possible secondary phases existing in inorganic crystal structure database (ICSD). Our results are in agreement with existing experiments and further predicted the existence of 10 stable CHPs, i.e. Rb3Cu2Br5, Rb3Cu2I5, RbCu2Cl3, Rb2CuI3, Rb2CuBr4, RbCuBr3, Rb3Cu2Br7, Cs3Cu2Br7, Cs3Cu2Cl7 and Cs4Cu5Cl9, which have not yet been reported in experiments. This work provides a phase and compositional map that may guide experiments to synthesize more novel inorganic CHPs with diverse properties for potential functional applications.
Estimation on Pressure and Velocity Parameter in the Fuel Handling Pneumatic Design of RDE
Authors: Dibyo Sukmanto , Setiadipura Topan , Pancoko Marliyadi 
Published: May 2020

Abstract
The RDE is small size of High Temperature Gas-Cooled Reactor type. It’s being designed that have a power of 10 MW thermal, which is intended to produce the electricity and heat utilization. The reactor uses helium gas as a system of coolant at the pressure of 3.0 MPa. The fuel pebble of spherical shape are transported by the pneumatic system in the pipes and recharged from the reactor core continuously without shut-down the reactor. During the process of transportation, the fuel pebble is lifted perpendicularly along the pipe into the reactor core. Therefore, fuel pebble transportation in the pneumatic system is an important effect to stability the fuel handling operation. This paper to estimate the fuel pebble velocity through a vertical pipe with respect to the pressure of pneumatic system in the design of RDE. The pneumatic vertical pipe has 23 m length, 65 mm inner diameter and fuel pebble of 60 mm diameter, weight of one fuel pebble is 200 gr and contains an uranium kernel coated in matrix graphite. The pneumatic system of carrier gas compressed as the conveying medium must be able to transport the fuel pebble through the pneumatic pipe one by one continuously, so that it could be loaded into the reactor core safely. In the pneumatic conveying, the general equation for the velocity of an object movement, drag force of flow and Bernoulli principle were used in the analysis. An initial velocity in range of 20 to 23 m/s was analysed, meanwhile, the fuel pebble discharged from the pneumatic pipe was determined at low velocity around of 0.1 to 5.0 m/s. In this case a collision at high velocity with the reactor core that causes pebble damage can be avoided. Result shows that the pneumatic transportation for the operational requirements of the fuel handling system when the carrier gas pressure in the range of 0.09 to 0.11 MPa higher than the reactor pressure system. In order to perfectly calculation in the future, it will consider the drag coefficient on the fuel pebble with a pipe wall.
Design Conceptual of 800MWt Long Life Pressurized Water Reactor Using (Th-U)O2 Fuels with Gd2O3 and Pa-231 as Burnable Poisons
Authors: Hariyanto Duwi , Permana Sidik 
Published: May 2020

Abstract
A long-life pressurized water reactor (PWR) has been reviewed as an innovative reactor design that can fulfill electricity demand. This study aimed to find out the optimum design of 800MWt long life PWR using Thorium-Uranium dioxide (Th-U)O2 fuels with Gadolinium (Gd2O3) and Protactinium-231 (Pa-231) as the burnable poisons. An established computer code of SRAC 2006 with JENDL 4.0 as data nuclear library had been used for the analysis. A two-dimensional R-Z geometry and fuel volume fraction of 40% were used for core geometry analysis. The different fraction of Uranium dioxide, Uranium-235, Gadolinium, and Protactinium-231 had been carried out. The result of this study was a design of PWR 800MWt using Uranium dioxide fuel of 60% with enrichment 11%-12%-13% Uranium-235 and the addition of 0,025% Gd2O3 and 1,0% Pa-231 that could operate for ten years without refueling. The reactor could produce a power density of 45,4 watts/cc with excess reactivity about 3,6% dk/k. This study is expected to be a reference for a long-life pressurized water reactor using the Thorium-Uranium fuel cycles.
Simulation of VMAT (Volumetric Modulated Arc Therapy) Delivery techniques on Cylinder Phantom Based on DICOM Data using Monte Carlo Method - EGSnrc
Authors: Ramdani Ridwan , Kurniawati Dian , Perkasa Yudha Satya , Subkhi Moch Nurul , Syajaah Khoerun Nisa , Rhani Mohamad Fahdillah , Haryanto Freddy , Yani Sitti 
Published: May 2020

AbstractThis research aims to study one of the radiotherapy techniques of VMAT and calculate the dose distribution on phantom cylinders using the Monte Carlo EGSnrc method. VMAT is one of radiotherapy technique where is all the fractions of the dose are given continuously when the gantry rotates around the patient with manages gantry rotation speed, MLC leaf position and the dose fraction is given. The simulation process begins with head linac modeling using BEAMnrc, and using the Monte Carlo VMAT simulation uses DOSXYZnrc software. The parameters for the BEAMnrc and DOSXYZnrc simulations using information from DICOM data set rtplan AAA are read using the pycom code. The results of this study provide information about the characteristics of 6 MV photon files such as fluence, fluence energy, spectral distribution, and fluence energy distribution, and dose distribution in phantom cylinders. The VMAT Monte Carlo simulation was carried out using 300 million particles which resulted in a VMAT dose distribution in the form of a dose profile curve and an isodose curve, the result shows that the curve of VMAT simulation using phantom cylinders produced the maximum dose distribution in the isocenter
Assessment of Gamma and Neutron Dose of Optimizing the Radiation Protection in TRIGA 2000 BATAN Bandung.
Authors: Oméga Rakotovao Lovanantenaina , Permana Sidik , Oetami Rini Heroe , Rasito  
Published: May 2020

Abstract
The TRIGA 2000 reactor is a nuclear installation which is operated at 1000 kW. Gamma and neutron radiation exposure will contribute to occupational doses that will be received by operators and other radiation workers. To maintain the safety of radiation workers, assessment of gamma and neutron radiation is needed in the TRIGA 2000 reactor. survey in the hall reactor using the RTD 30 and RadEye NL detectors. In addition to the direct measurement, calculations are also carried out with simulation data dose using Monte Carlo MCNPX for the calculation and followed by PHITS to get the graphical dose distribution of gamma and neutron. The study will focus on the assessment of the diffusion Gamma and neutron doses by doing the measurement and simulation data collect for the aim of the optimization of the Radiation protection policy in the reactor TRIGA 2000 Bandung. The result of the measurement is shown with graph in different power taken during the measurement and the simulation is the graphical distribution dose of gamma and neutron using PHITS code. A preventive dose reduction technique, worker and publics protection elaborate to optimise the Radiation protection program.
Fast Nuclear Reactor Fuel Depletion Analysis Using Fourth Order Runge-Kutta Method
Authors: Mulyadi Lutfi , Su’ud Zaki 
Published: May 2020

Abstract
Calculation of fuel depletion involved processing of nuclear data as a microscopic cross section. Macroscopic cross section calculations were performed by multiplying the microscopic cross sections by the density of the nuclide and all materials involved in the reactor itself. Diffusion equation calculations were performed in a two-dimensional cylindrical coordinate system, which involved macroscopic cross sections to obtain the distribution of neutron fluxes, neutron source densities, power densities, and k-eff. The calculation resulted in the k-eff of 1,0017918649. Thus, we concluded that the reactor was in super critical condition. Next, we used the maximum flux to be calculated in the depletion equation to get a new nuclide density for 10 years. The process of calculating depletion involved a system of twenty-eight differential equations, obtained from the nuclear transmutation chain. It took a long time and was difficult to solve analytically. In this research, the system of differential equations was numerically solved by the Fourth order Runge-Kutta Method to get the nuclide density curve with respect to time.
A Comparative Study of Th-U233 and Th-Pu Molten-Salt Reactor (MSR) with 2-region core
Authors: Ifthacharo M , Permana S , Saputra G 
Published: May 2020

Abstract
Sustainable closed fuel cycle and inherent safety are one of the key aspects of Generation IV reactor design. Hence Molten salt reactor (MSR) is chosen as one of the candidates of Generation IV reactor concepts. FUJI-U2 or MSR-2R is a 2-region core MSR design that was proposed as a possible simplification of FUJI-U3 (3-region core). Taking into consideration that uranium−233 doesn’t exist naturally, FUJI-U2 utilize both plutonium and uranium−233 as a fissile material. To understand the characteristics further, a comparative study of 2-region core MSR with Th-U233 and Th-Pu as fuel has been carried out. Nuclear analysis code SRAC2006 with the nuclear data library of JENDL4.0 was used, and CITATION was employed to validate the core. The design parameters set for each region are fuel composition, core radius, and fuel fraction. The simulation burn up calculation is set to 2000 days in total, with 21 step each for 100 days cycle. Neutron multiplication factor, fuel elemental, burn up calculation, conversion ratio, and neutron flux in each core will be discussed.
Comparison of Irradiation Effect of ThO2 and ThZrH on Neutronic Parameter of the TRIGA 2000 Reactor
Authors: Rasito  , Permana S. , Ilham Y. P. 
Published: May 2020

Abstract
The present work discusses two different models of thorium irradiation in the TRIGA 2000 reactor core to compare the neutronic characteristics of irradiation of thorium dioxide (ThO2) and thorium zirconium hydride (ThZrH). The Monte Carlo N-Particle (MCNP) Transport code, based on the Monte Carlo method, is used to design three dimensional models for TRIGA reactor core at typical operating power 2 MW. These models are used to determine the effective multiplication factor (keff) and neutron flux distribution. The ORIGEN code is used to calculate the 233U isotope production. It is found that decreasing of keff from the effect of hydride irradiation rod is a little lower than the oxide irradiation rod.
Evaluation of the Pump Capability of the Primary Cooling of TRIGA 2000 Research Reactor
Authors: Umar E. , Kamajaya K. , Ramadhan A.I. 
Published: May 2020

Abstract
The TRIGA 2000 research reactor has been operating since mid 2000. Currently, there are plans to convert the reactor core from cylindrical fuel element to plate type fuel element. The conversion process is expected to not change too many existing systems, including the primary cooling systems. For this reason, it is necessary to evaluate the pump capability of the primary cooling system. Based on experimental studies, then merging with the existing installation system head, it has been obtained the main and the redundant pump mass flow rate of 45 and 45.5 kg/s, respectively. The pump capability decreased by around 5 % compared to the results of its commissioning. If the two pumps are combined in parallel, the combined mass flow rate can increase to 62 kg/s. The existing primary pumps cannot be used for primary cooling system if the reactor core is converted into a plate type, even though both pump are installed in parallel. These results need to be considered in designing a new core of the Bandung TRIGA 2000 research reactor with primary cooling systems that are slightly modified because they have to add the decay tank.
Actinide Minor Addition on Uranium Plutonium Nitride Fuel for Modular Gas Cooled Fast Reactor
Authors: Syarifah Ratna Dewi , Su’ud Zaki , Basar Khairul , Irwanto Dwi 
Published: May 2020

Abstract
This study has made a calculation of Actinide Minor Addition on Uranium Plutonium Nitride Fuel for Modular Gas Cooled Fast Reactor. The purpose of this study was to determine the characteristics of minor actinides when incorporated into plutonium nitride uranium fuel. Neutronics calculation was design by using SRAC Code version 2006 (Standard Reactor Analysis Code) with the data nuclides from JENDL-4.0 under the Linux Operating System with nuclear data library JENDL4.0. Neutronic calculations were done through some steps of parameter survey to obtain the ultimate optimization results. The initial calculation was calculation of fuel cell (PIJ calculation) by using hexagonal cell and then followed by calculation of core reactor (CITATION calculation) by using program code SRAC2006. The addition of minor actinide has been calculated in this research. The minor actinides which were added were americium (Am-241 and Am-243) and neptunium 237. They were put into the uranium plutonium nitride material to decrease the k-eff value. The addition of minor actinide into the reactor aimed to reduce the number of minor actinides in the world. Minor actinide is a nuclear waste fuel or often called spent nuclear fuel (SNF) which has high toxicity. Neptunium 237 is a minor actinide with the highest percentage of SNF.