Thermal Stability and AC Losses in High-Field Superconducting Magnets

The study and the analysis of quench initiation and propagation is of paramount importance in the design of any superconducting magnets. Several disturbances such as ac losses, failures of the cryogenics or heat load may induce the quench initiation on a magnet and determine its irreversible transition to the normal state. Since the early days of magnet construction, the scientific community has devoted significant efforts in the study of quench. In the present work, numerical methodologies are presented and discussed for the analysis of electro-thermal stability, quench propagation and temperature margin on superconducting cables and coils. The proposed models are applied to the analysis of several superconducting magnets under development in different research groups in Europe (EU) and United States (US). The comparison of the numerical results with the experimental tests or with different computational approaches make the author confident about the applicability and reliability of the proposed modelling techniques

Dietary Supplementation with Boswellia serrata, Verbascum thapsus, and Curcuma longa in Show Jumping Horses: Effects on Serum Proteome, Antioxidant Status, and Anti-Inflammatory Gene Expression

Abstract: Intense exercise can cause inflammation and oxidative stress due to the production of reactive oxygen species. These pathophysiological processes are interdependent, and each one can induce the other, creating a vicious circle. A placebo-controlled blind study was carried out in show jumping horses (n. 16) to evaluate the effects of a commercial dietary supplement (Dolhorse® N.B.F. Lanes srl, Milan, Italy) containing Verbascum thapsus leaf powder (1.42%), Curcuma longa (14.280 mg/kg), and Boswellia serrata (Roxb ex Colebr) (14.280 mg/kg) extracts. Before and after 10 days of dietary supplementation, blood samples were collected to evaluate the protein levels, antioxidants, and inflammatory responses by proteomic analysis or real-time Reverse Transcriptase- Polymerase Chain Reaction (real-time RT-PCR). A total of 36 protein spots, connected to 29 proteins, were modulated by dietary supplementation, whereas real-time RT-PCR revealed a significant downregulation of proinflammatory cytokines (interleukin 1α (p < 0.05) and interleukin-6 (0.005), toll-like receptor 4 (p < 0.05), and IKBKB (p < 0.05) in supplemented sport horses. Immunoglobulin chains, gelsolin, plasminogen, vitamin D binding protein, apolipoprotein AIV, and filamin B were overexpressed, whereas haptoglobin, α-2-HS-glycoprotein, α2-macroglobulin, afamin, amine oxidase, 60S acidic ribosomal protein, and complement fragments 3, 4, and 7 were reduced. No effect was observed on the antioxidant defense systems. The present results suggest this phytotherapy may reinforce the innate immune responses, thus representing a valid adjuvant to alleviate inflammation, which is a pathophysiological process in sport horses

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Erratum: Towards a muon collider

The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

Performance and Quench Characteristics of a Pancake Coil Wound With the 2G YBCO Roebel Cable

The YBCO Roebel cable is a promising option for the high-energy accelerator magnets and tokamak devices with high-current carrying capability and compactness. Referring to the complex current sharing and normal zone propagation, it is difficult to apply the traditional superconductor quench measurement methodology to such a long Roebel cable (2 m) in an adiabatic condition. An alternative method for the quench measurement is to make a Roebel pancake coil cowound with ribbon fiberglass. This paper starts reporting the methodology to wind the coil with impregnation process and the wire installment for the quenchmeasurement. Some initial performancemeasurements and a first trial of the quenchmeasurement were processed in LN2 at 77 K to show the robust performance of this Roebel cable at all the current contacts while maintaining the cable effectively adiabatic or similar to real magnets

Electro-thermal modeling of quench in REBCO roebel cables

The possibility of REBCO Roebel Cables to carry a large amount of current in high external magnetic fields makes them suitable for application in future particle accelerator magnets. The physical phenomena related to the initiation and propagation of a quench event in Roebel cables have not yet been fully analysed and understood. In particular, given the peculiar architecture of these conductors, the features of the current redistribution and normal zone propagation after quench in individual tapes still require experimental and theoretical investigation. In this paper, an innovative quasi-3D electro-thermal FEM model is developed to analyse the effect of quench in HTS Roebel cables. The model is based on a reduced dimensionality approach, under the assumption of a negligible thickness of the individual REBCO tapes. While the tapes are meshed in an identical 1D pattern, the non-continuous electrical and thermal contacts among them are accounted for as a sources in the corresponding thermal and electrical equations. Notwithstanding these significant assumptions, the main physical aspects involved in the quench initiation and propagation are retained and correctly described by the reduced dimensionality approach. The Quench Energy and the Normal Zone Propagation Velocity are analysed for different cable configurations.</p

Electrothermal Modeling of Quench in REBCO Roebel Cables

The possibility of REBCO Roebel cables to carry a large amount of current in high external magnetic fields makes them suitable for application in future particle accelerator magnets. The physical phenomena related to the initiation and propagation of a quench event in Roebel cables have not yet been fully analyzed. In particular, given the peculiar architecture of these conductors, the features of the current redistribution and normal zone propagation after quench in individual tapes still require experimental and theoretical investigation. In this paper, an innovative quasi-3D electrothermal FEM model is developed to analyze the effect of quench in HTS Roebel cables. The model is based on a reduced dimensionality approach, under the assumption of a negligible thickness of the individual REBCO tapes. While the tapes are meshed in an identical 1-D pattern, the noncontinuous electrical and thermal contacts among them are accounted for as a sources in the corresponding thermal and electrical equations. Notwithstanding these significant assumptions, the main physical aspects involved in the quench initiation and propagation are retained and correctly described by the reduced dimensionality approach. The quench energy and the normal zone propagation velocity are analyzed for different cable configurations