Intelligence Monthly of Shanghai Superconductor

Sep. 2015

The new Institute of Physics discovered a new high-temperature superconducting phase in LaOFeAs

■Hefei Institute of Physical Science completed heat treatment for superconducting outsert coils of hybrid magnet

■Ad Astra Rocket Company and National Aeronautics and Space Administration completed the contract negotiation

■3-Cs successfully deposited superconducting materials on the cylinder continuously and seamlessly

■American Superconductor gave a financial report of the first quarter in the fiscal year of 2015

■HTS-LLO built a high-temperature superconducting vector magnet for University of Otago

■Mainz University began to manufacture superconducting RF modules

■The electrified system of Japan’s passenger transport line passed the test successfully

■The good situation of expanding the scale of photovoltaic power station by 30% in 2015 will probably last for five years

■China vigorously developed smart grid and cable industry, showing an explosive growth

Civil Status

Institute of Physics discovered a new high-temperature superconducting phase in LaOFeAs

According to the report on the official website of Chinese Academy of Sciences on 29 Sep., researchers from Institute of Physics, Chinese Academy of Sciences / Beijing National Laboratory of Condensed Matter Physics (preparation) discovered a new high-temperature superconducting phase in iron-based materials keeping away from antiferromagnetic order. Moreover, the maximum superconducting transition temperature Tc exceeds the superconducting phase of the same matter near magnetic order, reaching 41 K (defined according to resistivity data).

The iron-based compound superconductor was found by Hosono Research Group of Tokyo Institute of Technology in 2008. Its parent material LaFeAsO has a phase of antiferromagnetic order. After fluorine elements are used to replace some oxygen elements, the magnetic order is restrained and the superconducting state appears. The superconducting transition temperature Tc changes with the doping content x of fluorine, forming a vaulted superconducting area; x can reach 0.2 only. When x = 0.06, Tc of the sample reaches the maximum value which is 27 K. At this time, very strong low-energy spin fluctuations exist. This naturally makes people believe that the superconducting state in iron-based superconductor is caused by spin fluctuations.

Recently, Associate Researcher Yang Jie et al. from Institute of Physics, Chinese Academy of Sciences / SC9 Group of State Key Superconductor Laboratory of Beijing National Laboratory of Condensed Matter Physics (preparation) cooperated with Academician Zhao Zhongxian and Li Jianqi Research Group of Chinese Academy of Sciences, to synthetize a series of highly doped samples of LaFeAsO1-xFx via the high-pressure sample preparation technique. The doping content x can reach 0.75, far exceeding people’s cognition. Through the measurement on resistivity, magnetic susceptibility and nuclear magnetic resonance, it is found that the superconducting transition temperature Tc will form a new superconducting area with x. Under the optimum doping content (x = 0.5-0.55), Tc is even higher than the original value under x = 0.06 (Tc defined according to resistivity and resistance data is 41 K. Tc defined according to magnetic susceptibility is 30 K).

It’s even more surprising that in this new-found superconducting area, the physical properties are totally different from the first superconducting area reported previously. Firstly, according to the 1/T1T measurement of NMR spin-lattice relaxation rate, no trace of spin fluctuations exists. Secondly, according to NMR and electron microscope, a new type of structural phase transition exists in the samples. During phase transition, the quadruple rotational symmetry is damaged. The variation curve of phase transition temperature with doping content can extend to the optimum doping. Meanwhile, resistivity presents a linear temperature change near the optimum doping, indicating a new quantum fluctuation.

This implies that high-temperature superconductor might be an extremely universal phenomenon. Besides spin fluctuations discussed by people during recent 30 years, other mechanisms like orbital fluctuations might also trigger high-temperature superconductor. This achievement has provided a brand-new clue for the exploration of high-temperature superconductor. This research result is published on Chin. Phys. Lett., 32, 107401 (2015) in the form of Express.

This research has obtained supports from “973” Project of Ministry of Science and Technology, Class-B Pilot Project of Chinese Academy of Sciences, and National Natural Science Foundation.

Phase diagram of LaFeAsO1-xFx. AF, SCI and SCII represent antiferromagnetic area, superconducting area I and superconducting area II respectively. The superconducting transition temperature Tc is decided by the magnetic susceptibility; the structural phase transition temperature Ts and Xs are decided by the NMR experiment and electron microscope experiment.

Hefei Institute of Physical Science completed heat treatment for superconducting outsert coils of hybrid magnet

According to the news of Hefei Institute of Physical Science on 17 Sep., the 40-Tesla class hybrid magnet of SHMFF is composed of internal water-cooling magnet and external superconducting magnet. Many technological problems are involved in the design and development of external superconducting magnet, and heat treatment technology is an important link. On 15 Sep., High-Intensity Magnetic Field Center of Hefei Institute of Physical Science, Chinese Academy of Sciences completed heat treatment for all coils of external superconducting magnet, and final assembly of the 40-Tesla class hybrid magnet will be carried out comprehensively.

The coil of external superconducting magnet is composed of seven coils which are A, B and C as well as D1, D2, D3 and D4 respectively. After experiencing a series of links covering cable stranding, poling and enwinding in the early stage, it will enter the link of heat treatment. According to the design requirements, heat treatment should be conducted for six times, and 22 to 25 days are needed every time. The whole heat treatment work was started on 12 Jan. 2015 and ended on 15 Sep. 2015, lasting for 8 months. According to the test on annealed samples, key indexes of coils, like critical current density and remaining resistivity value, have reached the design requirements during all heat treatment processes.

Heat treatment is conducted to realize mutual diffusion of niobium and tin in braided wire materials, and to generate a chemical reaction. The ultimate goal is to produce the Nb3Sn compound superconductor. The heat treatment result of Nb3Sn materials will finally decide the performance of superconducting magnet, so it is a key job to decide the success of superconducting magnet project. This job will lay a foundation for the next step of external superconducting magnet, and provide a solid foundation for the completion of hybrid magnet.

Heat treatment for coil D is completed

Global View

Ad Astra Rocket Company and National Aeronautics and Space Administration completed the contract negotiation

According to the report of Superconductor Week on 17 Aug., Ad Astra Rocket Company and National Aeronautics and Space Administration successfully completed contract negotiation about the Next Step award. Moreover, this project has entered the execution phase. This contract is a three-year agreement of fixed price, and its total value exceeds 9 million dollars. The structure of this agreement is a one-year contract plus two one-year extension contracts. It is a milestone based on both parties’ mutual recognition.

Background of the event: During this period, Ad Astra Rocket Company will comprehensively develop a VASIMR engine of updated version with flight conditions. Under a high-intensity magnetic field, such as the magnetic field generated by superconducting magnet, ions will rotate at a fixed frequency. The VASIMR ion engine has taken full advantage of this principle, to make the second-stage rocket heat ions with 1 million degrees. This temperature is equivalent to the temperature of the solar core. Thus, high thrust will be produced. 

3-Cs successfully deposited superconducting materials on the cylinder continuously and seamlessly

According to the report of Superconductor Week on 17 Aug., Malvern 3-Cs Company successfully deposited the YBCO layer of high-temperature superconducting material on the hastelloy base band around the cylinder wall continuously and seamlessly via the method of pulsed laser deposition. This event represents the breakthrough of preparation for cylindrical coated conductors, and the company has developed this technology for more than ten years.

The cylindrical coated conductor is a totally different method to realize the production of electric devices based on high-temperature superconducting coated conductors. As a result, the original technology of winding superconducting strips into coils is replaced by thin film deposition and photolithography of directly using multi-layer superconducting coils on the cylindrical substrate. University of Birmingham has already cooperated with 3-Cs to develop coated conductor technology for multiple years.

3-Cs successfully deposited YBCO on the strip substrate surface with a width of 1 cm around the cylinder continuously, and induced a continuous large current to flow past this cylinder. At present, the size of cylinder adopted by 3-Cs can hold 7 strips with a width of 1 cm. Meanwhile, the number of layers can change with different applications of every strip. Only one layer is needed for many applications to magnetic shielding strips.

PLD adopted the deposition method of preferential development. The whole process is compatible with different production methods of initial texture layer, including ISD and IBAD. After trial operation of ISD for many years, 3-Cs tends to conduct deposition on the initial high-quality texture layer produced by iBeam Material Company. This company was founded by Vladimir Matias who once worked in Los Alamos National Laboratory. Meanwhile, there are many other different deposition methods applied to the follow-up texture buffer layer and YBCO layer. 3-Cs tends to use PLD.

American Superconductor gave a financial report of the first quarter in the fiscal year of 2015

According to the report of Superconductor Week on 17 Aug., American Superconductor declared that its income of the first quarter in the fiscal year of 2015 increased by 102.6%, rising from 11.7 million dollars in the first quarter of 2014 to 23.7 million dollars. Its net loss of Generally Accepted Accounting Principles decreased from 13.5 million dollars to 9.1 million dollars. The company’s sales volumes in wind power technology and superconducting power grid technology fields also increase. The share price of American Superconductor decreased from 4.95 dollars to 4.39 dollars by 11.3% on the day of issuing the financial report.

HTS-LLO built a high-temperature superconducting vector magnet for University of Otago

According to the report of Superconductor Week on 17 Aug., HTS-LLO has successfully entrusted the superconducting electromagnet project to University of Otago in New Zealand. This magnet is the company’s first three-axis vector magnet (a type of magnetic field and the orientation can be taken in all directions). This magnet is the company’s first three-axis vector magnet, and the magnetic field can point to any direction. After operating to the maximum power, main coil of the magnet will produce a vertical z-axis magnet of 0.3 Tesla, and the auxiliary coil will generate x-axis and y-axis of 10 milli Tesla. Swivel adjustment can be realized for the direction of main field, to match the axial direction of the sample. Though the auxiliary field is very small, the coil producing auxiliary field has already approached the limit of carrying capacity.

Mainz University began to manufacture superconducting RF modules for the energy recovery superconducting accelerator of Mainz

According to the report of Superconductor Week on 17 Aug., a team of JGU has started to manufacture two superconducting accelerator modules for the electron accelerator planned, energy recovery superconducting accelerator (MESA) of Mainz. MESA will contain the accelerator technology of energy recovery linear accelerator (ERL), which will recycle some energy applied to the beam of accelerated electrons, thus the operating cost can be reduced. Members of the project team include RI engineers, physicists and manufacturing specialists from Nuclear Physics Institute and Manufacturing Company of JGU.

Professor Kurt Aulenbacher from Nuclear Physics Institute of JGU said, “In an ERL, the energy of electron beams is increased to 105 MEV in the RF superconducting cavity. Therefore, the beam power with the electric current of 10 mA in MESA can reach 1 megawatt.” After the experiment, this electron beam will slow down in the cavity. Hence, the kinetic energy of electrons will be recovered and stored in the RF superconducting cavity as RF energy to accelerate the follow-up beam of particles. The recovery efficiency during speed reduction, including wasted energy in the test, exceeds 99%. However, the electron beam cannot slow down to zero, and it still retains the energy of 50 kilowatts in the RF system. In order to operate the MESA, liquid helium and wall socket with the power consumption of about 1 megawatt need to be set as supports. Without energy recovery, the numerical value would be tripled. For a bigger facility, saving will be more obvious.

News In Brief

The electrified system of Japan’s passenger transport line passed the test successfully

Recent news: RTRI reported that the application of superconducting wires to the elevated electrified system for passenger transport line passed the test successfully. This test was conducted on the line with a direct voltage of 1.5 kV. This is a passenger transport line on Izu Railway with a length of 20 km, leading to Shuzenji. The superconducting wire (cooled to about 77 K) was used to connect AC-DC transformers in the transformer substation of tractive power supply system.

Seatitan superconducting fan of American Superconductor

Recent news: Via the technology of marine propulsion motor in the navy project of America and leading technology in superconducting field, the output power of Seatitan fan generator set technology of American Superconductor can double the maximum output power of existing wind driven generators in theory, reaching 10 MW. The high-temperature superconducting direct drive motor with a diameter of about 5 m and weight of about 160 t will be the key to success of this project. Comparatively speaking, under the same output power, the diameter of permanent magnetic direct drive motors should reach 10 m and the weight must exceed 200 t. A wind turbine generator with big rated power can reduce the generating cost for unit megawatt in the completed wind field, and the power density of superconducting wind driven generator can realize a high-power and economic wind turbine generator.

Meanwhile, AMSC declared that attention was paid to the Seatitan system of 10 MW at present, but it was feasible to design a draught fan of 20 MW with high-temperature superconducting technology.


Concept map for Seatitan superconducting fan

 

SUPRAPOWER under the joint leadership of 3Technalia & Karisruhe

Recent news: The research target of SUPRAPOWER subsidized by European Union is to develop wind energy via superconductor. Nine partners from industrial and scientific research fields have participated in this project. Technical Institute of Physics of KIT will build a rotary cryostat for this project. The Gifford – McMahon radiator will be utilized to cool the superconducting coil to -253.15 degrees Celsius through pure heat conduction. Under this temperature, the superconductor has no resistance phenomenon, and lossless electric conduction can be realized.

Lexus exhibited a superconducting hoverboard recently

Recent news: Recently, Lexus exhibited a superconducting hoverboard, named “slide” in Barcelona. The professional skateboarder Ross McGouran tested this device in a track of 220 meters equipped with magnets. Magnetic levitation technique was adopted for the sliding block: the insulating superconducting core moved above the magnetic field. Cooled liquid nitrogen was embedded into the cryostat, to cool the plate to 76 K. This plate remained electrified for about 20 minutes, till evaporation of the liquid nitrogen. This project was started with the cooperation between scientists from evico and Leibniz Institute of Solid Materials (IFW) 18 months ago.

The sliding plate video uploaded by this company and played for several months has triggered a hot discussion. Lexus clearly expressed that this slide was an unannounced automobile marketing gimmick, and could not be used for commercial purposes. This sliding plate is the fourth project in the promotion activity of “Amazing in Motion” organized by Lexus.

 

The good situation of expanding the scale of photovoltaic power station by 30% in 2015 will probably last for five years

Recent news: On 28 Sep., National Energy Administration issued Notification on the Expansion of Photovoltaic Power Station Construction Scale in Some Regions in 2015 (hereinafter referred to as Notification). It requires the state to increase the photovoltaic power station construction scale by 5.3 million kilowatts. Compared with the target of 17.8 million kilowatts for the whole year established previous, the scale has been increased by 30%. It is even doubled when compared with last year.

Such good situation will probably last for five years in the future. According to the journalist’s data, competent departments of the state are studying the “13th Five-Year Plan”. Three associations of photovoltaic industry in China have jointly submitted a policy about photovoltaic industry development. They suggest that the generation target should be increased. It is generally expected that the photovoltaic installation scale on the market will increase from 100 GW to 150 GW. Therefore, the industry prosperity will turn better continuously.

According to the data, an installed photovoltaic power generation capacity of 7.73 million kilowatts was added in the first half of this year, completing 43% of the full-year target which is 17.8 million kilowatts. The installed capacity of photovoltaic power station was increased by 6.69 million kilowatts, and the distributed photovoltaic capacity was increased by 1.04 million kilowatts. According to the accumulative installed power-generating capacity, the target established for the “12th Five-Year Plan” of solar energy has been completed in advance.

However, the problem of power generation absorption still exists. In the first half of this year, about 1.8 billion KWHs of electricity were discarded, which mainly happened in Gansu and Xinjiang. In Gansu Province, 1.14 billion KWHs of electricity were discarded, showing a discarding rate of 28%. In Xinjiang (including Xinjiang Corps), 541 million KWHs of electricity were discarded, showing a discarding rate of 19%. “We have to abandon many electric powers as they cannot be transmitted. Therefore, the problem of electric transmission should be solved first in the ‘13th Five-Year Plan’,” said Meng Xiangan (Vice Chairman of Chinese Renewable Energy Society).

China vigorously developed smart grid and cable industry, showing an explosive growth

Recent news: National Development and Reform Commission and National Power Bureau issued a definite opinion to advance the development of smart power grids a few days ago. They put forward that a secure and reliable, open and compatible, two-way and interactive, efficient and economic, and clean and environmental smart grid system should be completed by the beginning of 2020.

The annual production value of China’s electric wire industry exceeded 1 trillion Yuan in 2011 and reached 1.1 trillion Yuan. It has become the second largest industry in mechanical electrical engineering, second only to vehicle manufacturing industry. The variety satisfaction rate and domestic market share have exceeded 90%. From the global view, the total output value of China’s electric wires has already surpassed that of America, turning into the world’s largest country of origin in electric wires.

Some large electric wire companies in China have started to explore the category of intelligent cable. At present, the cable is extensively applied to the categories of power transmission network, power distribution network, consumer side, distributed power use, solar energy and distributed wind power. Meanwhile, under the general environment of smart power grids, the third industrial revolution has integrated information, renewable power and distributed application skills. Owing to the requirement for cable intelligence in the link, the intelligent cable is born at the right moment. Under the drive of smart power grids construction, cable industry is changing constantly. The cable industry “presenting an entirely new appearance” is bound to greet the arrival of smart power era with a calm posture. With the extensive application and continuous improvement of this skill, the system cost will be reduced substantially. Moreover, it will become an important industry around the world in the 21st century.

Superconductivity Patent

Patent name: Ion beam assisted deposition equipment and ion beam assisted deposition method

Applicant: Fujikura Electric Cable Works

International publication date: 31 Mar. 2015

International publication number: US8992740

Abstract: This invention provides a type of ion beam assisted deposition equipment. It has the following components: target material; sputtering ion source strafing the stated target material and sputtering target material ions, used to deposit particles from the target material during strafing into the film formation area of the substrate; the auxiliary ion source will strafe the thin film from the direction forming a certain angle with the normal direction in film formation area; the sputtering ion source in film formation area is provided with a group of ion guns which can be arranged from the end of one target material side to the end of the other side.

Patent name: Superconducting cable

Applicant: LS Cable Co., Ltd.

International publication date: 7 Apr. 2015

International publication number: US9002423

Abstract: This invention involves a cable. The stated cable includes: a core with a winding mold located in the center of the core; one or several superconducting transmission layers with all conductive phases, established in the radial direction; insulating layer, established in the outside of every conducting layer along the radial direction; shielding layer, established in the outermost surface of the stated insulating layer; low-temperature thermostat, established in the outside of the stated core along the radial direction (the first space is set up between the stated low-temperature thermostat and the stated core, including a vacuum part and electric wire connected to the neutral electrode (N electrode)).

Patent name: Superconducting cable

Applicant: Furukawa Electric; International Superconducting Technology Center

International publication date: 14 Apr. 2015

International publication number: US9006146

Abstract: This invention involves an AC superconducting cable. The stated superconducting cable is covered with insulating materials on the surface. The insulating layer includes three layers: the first insulating layer, the second insulating layer and the third insulating layer from inside to outside. The insulating layer is soaked in liquid nitrogen. The product of dielectric constant ε1 and dielectric loss tangent value tanδ1 of the first insulating layer and the product of dielectric constant ε2 and dielectric loss tangent value tanδ2 of the second insulating layer meet the relation of ε1×tanδ1>ε2×tanδ2. Besides, the product of dielectric constant ε2 and dielectric loss tangent value tanδ2 of the second insulating layer and the product of dielectric constant ε3 and dielectric loss tangent value tanδ3 of the third insulating layer meet the relation of ε2×tanδ2<ε3×tanδ3.

(☆Editor: Copywriting Group of Shanghai Superconductor Monthly)

onductor team to carry out the strategic layout of the high temperature superconducting industry