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The CSC Presentation Library exists to preserve and disseminate video lectures, discussions, and presentations from the conferences and workshops that the Council supports. Since its inception in 2012, the library has become a rich repository highlighting many of the key advancements in superconductivity and is available free of charge in collaboration with IEEE.tv.
Feel free to browse or search the library below.
In the fall of 2013, NASA's Lunar Laser Communication Demonstration successfully demonstrated high-rate laser communications between a lunar-orbiting satellite and terrestrial ground stations. The MIT Lincoln Laboratory-designed and built system included a number of novel features both in the space segment and in the ground segment. The 622 Mbps downlink was made possible with only relatively small receive telescopes by employing a novel receiver based on Superconducting Nanowire Single-Photon Detector (SNSPD) arrays. In this presentation, we will present an overview of the mission, the drivers on downlink performance, and the Lincoln Laboratory-built SNSPD system that enabled it, including its basic specifications and its supporting electronics.
Cryogenic cooling system, including both cryogenic source and thermal coupling to application, is a critical component of any applied superconductivity device. End users require high reliability, high efficiency, and low and easy maintenance to optimize system availability and minimize acquisition and operation cost. Depending on the superconductor, operation temperature ranges from 1.8 K up to 77 K and depending on application cooling power ranges from milliWatts up to tens of KWatts: different technologies will obviously be required! The experience learned from decades of NbTi based applications operation will be remained. For new HTS potential applications, state of the art of commercially available cooling technologies will be summarized and ongoing developments and potential new solutions will be discussed both for cryorefrigerators and their integration.
The United States' National High Magnetic Field Laboratory (MagLab) hosts an international user community that spans condensed matter physics, materials research, chemistry, biology and biomedicine. We have developed a variety of unique magnets in service to our user community, ranging from the highest fields (21T) available for vertebrate MRI to the non-destructive generation of pulsed magnetic fields exceeding two million times the Earth's magnetic field. This talk seeks to answer the question "Why would anyone want to do such things?", which is curiously the same question taken up by the recent NRC "MagSci" study. Particular focus will be given to the role of high-temperature superconductors (HTS) and HTS technologies required for the development of next-generation magnets proposed in the MagSci study.
More information provided here.
SQUIDs and superconducting detectors are now widely deployed in cosmic microwave background (CMB) telescopes, which has led to a dramatic improvement in the sensitivity of CMB measurements. The BICEP-2 experiment at the South Pole recently reported the most sensitive measurement to date of the polarization of the CMB, and the first detection of a curl, or "B-mode" pattern in the polarization of the CMB at degree angular scales. Primordial B-mode polarization is the distinctive signature of gravitational waves from inflation at the energy scale of Grand Unification, but additional non-primordial sources of B-mode polarization also exist, including polarized dust and gravitational lensing. I will describe the role of SQUIDs and superconducting detectors in reaching this important milestone, and their use in efforts to further understand B-mode signals in the CMB. Constraints on both primordial and gravitational-lensing B-mode signals will play an increasingly important role in our understanding of inflation, the properties of neutrinos, and the fundamental physics of the universe.
Where did Earth's water come from? Although we can't yet fully answer this question, a comet whose water has the same D/H ratio as the Earth's oceans has now been found. Water vapor from the dwarf planet Ceres has also been detected recently, boosting anticipation of the arrival of NASA's ion-propelled Dawn spacecraft at Ceres in February 2015. And on March 17, 2014, the BICEP2 team made international headlines with their announcement of evidence for gravitational waves produced during a sudden inflationary expansion of the universe when it was only 10^-35 seconds old. These three spectacular scientific discoveries are just a few examples of the impact that superconducting detectors are now making on the fields of cosmology, astrophysics, and planetary science. I will review the historical development of several types of superconducting detectors, discuss their role in major astronomy projects and the discoveries mentioned above, highlight the wide variety of superconducting phenomena exploited in these devices, indicate the impact on other fields, and close with some thoughts about future developments in this area.
50 years of incessant SQUID research afford a good opportunity to ask for the impact that SQUIDs have made on the general technical progress. This paper highlights the SQUID applications in geophysics and in particular the efficient and eco-friendly exploration of the Earth's resources, where SQUID technology provides a fundamentally new approach and allows acquiring qualitatively new data sets. After a brief introduction into the history of SQUIDs in geophysics, two applications and according examples will be introduced and discussed which are making an impact in mineral exploration today: transient electromagnetics and full tensor gradiometry. A short outlook of the exciting opportunities and perspectives of the use of SQUIDs in other geophysical applications in years to come will be presented.
The compound MgB2 (Tc = 39K) occupies an intermediate position between LTS and HTS superconductors. It is a two-band superconductor with a complex, non-BCS behavior of the anisotropic properties as a function of magnetic field and temperature. On the other hand, some properties can be described by a conventional phonon-mediated mechanism of superconductivity. The application range of this material is restricted by its low irreversibility field, which does not exceed 25T, even in wires with carbon additives. However, for intermediate fields and T 25K this disadvantage with respect to HTS materials is compensated by production costs being more than one order of magnitude lower (< 3$/kAm): for selected applications, MgB2 appears thus increasingly as an alternative solution to HTS materials. Various powder metallurgical approaches are known for the fabrication of multifilamentary MgB2 wires up to lengths beyond 10 km. It has been found that the optimization of Jc in wires requires nanosize powders (this holds particularly for B as well as for carbon dopants). An additional requirement is a high mass density in the filaments, leading to enhanced grain connectivity. The presently applied processing techniques are reviewed. The first industrial application of MgB2 was the production of open-sky MRI magnets operating at 20K. The great potential of this material for the transmission of electrical power has been recently demonstrated at CERN, where a 20 meter MgB2 cable carrying 20 kA in He gas at 24K was successfully tested in view of current leads for the High-Luminosity LHC project. In the Ignitor fusion project, the two outer poloidal field coils will be based on MgB2 strands. Future projects will also include LH2 cooled MgB2 cables: a first MgB2 cable carrying 3 kA at 20K has already been successfully tested in Moscow. Recently, a new hybrid energy storage concept has been proposed at KTI (D), which combines the use of liquid hydrogen as the bulk energy carrier with superconducting magnetic energy storage (SMES). With the expected increase of the share of renewable power in the energy mix, efficient long-distance electricity transport infrastructure has become a strategic priority: MgB2 cables as an alternative to standard HVDC (High Voltage Direct Current) power lines are under study. Finally, calculations have shown that MgB2 would be the most cost-effective option in view of large rotating machines, e.g. wind turbine generators at 5 MW. Cost-efficiency is the driving force behind the future applications of MgB2, which will be briefly presented.
Superconducting digital electronics is experiencing one of the largest transformations in the last two decades. This dramatic change is triggered by the recent shift from performance to energy efficiency as the primary metric dictating the course of computing progress across all technologies from CMOS to new nano-devices. This was caused by the runaway increase of power requirements of modern data centers and the next generation of supercomputers. Until recently, superconducting digital circuits based on conventional Rapid Single Flux Quantum (RSFQ) logic were aimed at achieving higher and higher speed. Now, the low power and high energy-efficiency dominate the requirements for computing from high-end supercomputers to circuits controlling qubits and processing cryogenic detector outputs. As a result, a number of low-power post-RSFQ logic families have been introduced. The ultimately low power dissipation can even reach below the thermodynamic limit in physically and logically reversible circuits. Furthermore, the augmentation of traditional Josephson junctions with spintronic elements, the inclusion of ferromagnetic layers, and hybridization with semiconductor elements significantly enhance the functional capabilities of superconducting digital technologies. These lead to solving long-standing, hard problems of cryogenic dense memories capable of working with SFQ digital circuits and high-bandwidth interfaces from cryogenic to room temperature electronics, which were the biggest impediments for the growth of superconducting digital electronics. Among these new devices are superconductor-ferromagnetic magnetic Josephson junctions combining superconductivity and ferromagnetism, two antagonistic order parameters, leading to the device characteristics unattainable in pure superconducting or magnetic structures. The properties of such magnetic junctions can be made compatible with traditional Josephson junctions and integrated into a single circuit. High complexity superconductive computing is impossible without a high-yield, high integration density fabrication process capable of producing complex microprocessor and memory chips. The recent resurgence of process techniques paves the way to integrating digital processing and memory circuits, leading to computing microarchitecture options unavailable earlier. Careful selection and adaptation of architectures for the implementation of superconductive computing circuits and systems can achieve better utilization of a potential offered by superconductivity and provide a significant advantage compared to other technologies. These innovations happened just within the last few years dramatically increase the potential of superconductivity addressing many known critical problems which prevented the insertion of superconductivity into computing applications in the past.
In this talk, I will review recent progress in biosensing using SQUID and magnetic markers. Magnetic markers consisting of polymer-coated magnetic nanoparticles have been widely used for biomedical applications. In biomedical diagnosis, a detecting antibody, which is conjugated on the surface of the marker, is bound to a biological target. The binding reaction between them is detected with the magnetic signal from the bound markers. Since the signal from the bound markers becomes very weak at the early stage of disease, it is necessary to develop a highly sensitive detection system. Several SQUID systems have so far been developed for this purpose. Measurement methods, including AC susceptibility, harmonic signal, magnetic relaxation and remanence, have also been developed, depending on the properties of the markers. The SQUID systems have been applied to both in vitro and in vivo diagnosis and high sensitivity of the system has been successfully demonstrated by the detection of several disease-related proteins. For in vitro diagnosis, magnetic immunoassay techniques have been developed for liquid-phase detection of biological targets. With this method, we can magnetically distinguish bound and unbound (free) markers by using the Brownian relaxation of the markers. As a result, we can eliminate time-consuming washing processes for marker separation, unlike the case of the conventional optical method. This method also allows the study of how the binding of targets and markers proceeds in time, i.e., perform a quantitative evaluation of the binding kinetics. For in vivo diagnosis, the position and quantity of the markers, which have accumulated in the affected area inside an animal or human body, are detected. This method is called magnetic particle imaging (MPI). When we apply MPI to the detection of breast cancer or sentinel lymph node, it is necessary to detect the markers locating at 3 to 5 cm in depth. The small amount of markers, e.g.. 1 g, should be detected with reasonable spatial resolution. Several systems have been developed for this purpose.
Within a few years of Josephson's seminal paper on superconducting tunneling, devices were being fabricated to measure a wide variety of electromagnetic quantities. Before the end of the decade, SQUID devices were being offered for sale. In the 1970s, SQUIDs began transitioning from laboratory instruments to applications in medicine, geology and materials science. Over the last 40 years of commercial sales, SQUID systems have generated well over a half billion dollars in product revenues. This paper discusses the evolution of the many small businesses that began to offer SQUIDs as commercial products, their product areas, and their successes and failures.
