Share

Shielding Superconductors with Thin Films as Applied to Rf Cavities for Particle Accelerators

2015
Download Shielding Superconductors with Thin Films as Applied to Rf Cavities for Particle Accelerators PDF Online Free

Author :
Release : 2015
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Shielding Superconductors with Thin Films as Applied to Rf Cavities for Particle Accelerators by :

Download or read book Shielding Superconductors with Thin Films as Applied to Rf Cavities for Particle Accelerators written by . This book was released on 2015. Available in PDF, EPUB and Kindle. Book excerpt: Determining the optimal arrangement of superconducting layers to withstand large-amplitude ac magnetic fields is important for certain applications such as superconducting radio-frequency cavities. In this paper, we evaluate the shielding potential of the superconducting-film-insulating-film-superconductor (SIS') structure, a configuration that could provide benefits in screening large ac magnetic fields. After establishing that, for high-frequency magnetic fields, flux penetration must be avoided, the superheating field of the structure is calculated in the London limit both numerically and, for thin films, analytically. For intermediate film thicknesses and realistic material parameters, we also solve numerically the Ginzburg-Landau equations. As a result, it is shown that a small enhancement of the superheating field is possible, on the order of a few percent, for the SIS' structure relative to a bulk superconductor of the film material, if the materials and thicknesses are chosen appropriately.

RF Superconductivity for Accelerators

2008-02-26 Technology & Engineering
Download RF Superconductivity for Accelerators PDF Online Free

Author :
Release : 2008-02-26
Genre : Technology & Engineering
Kind : eBook
Book Rating : 428/5 ( reviews)

GET EBOOK


Book Synopsis RF Superconductivity for Accelerators by : Hasan Padamsee

Download or read book RF Superconductivity for Accelerators written by Hasan Padamsee. This book was released on 2008-02-26. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces some of the key ideas of this exciting field, using a pedagogic approach, and presents a comprehensive overview of the field. It is divided into four parts. The first part introduces the basic concepts of microwave cavities for particle acceleration. The second part is devoted to the observed behavior of superconducting cavities. In the third part,general issues connected with beam-cavity interaction and the related issues for the critical components are covered. The final part discusses applications of superconducting cavities to frontier accelerators of the future, drawing heavily on the examples that are in their most advanced stage. Each part of the book ends in a Problems section to illustrate and amplify text material as well as draw on example applications of superconducting cavities to existing and future accelerators.

Superconducting Thin Films for the Enhancement of Superconducting Radio Frequency Accelerator Cavities

2017 Thin films
Download Superconducting Thin Films for the Enhancement of Superconducting Radio Frequency Accelerator Cavities PDF Online Free

Author :
Release : 2017
Genre : Thin films
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Superconducting Thin Films for the Enhancement of Superconducting Radio Frequency Accelerator Cavities by : Matthew C. Burton

Download or read book Superconducting Thin Films for the Enhancement of Superconducting Radio Frequency Accelerator Cavities written by Matthew C. Burton. This book was released on 2017. Available in PDF, EPUB and Kindle. Book excerpt: Bulk niobium (Nb) superconducting radio frequency (SRF) cavities are currently the preferred method for acceleration of charged particles at accelerating facilities around the world. However, bulk Nb cavities have poor thermal conductance, impose material and design restrictions on other components of a particle accelerator, have low reproducibility and are approaching the fundamental material-dependent accelerating field limit of approximately 50MV/m. Since the SRF phenomena occurs at surfaces within a shallow depth of ~1 μm, a proposed solution to this problem has been to utilize thin film technology to deposit superconducting thin films on the interior of cavities to engineer the active SRF surface in order to achieve cavities with enhanced properties and performance. Two proposed thin film applications for SRF cavities are: 1) Nb thin films coated on bulk cavities made of suitable castable metals (such as copper or aluminum) and 2) multilayer films designed to increase the accelerating gradient and performance of SRF cavities. While Nb thin films on copper (Cu) cavities have been attempted in the past using DC magnetron sputtering (DCMS), such cavities have never performed at the bulk Nb level. However, new energetic condensation techniques for film deposition, such as High Power Impulse Magnetron Sputtering (HiPIMS), offer the opportunity to create suitably thick Nb films with improved density, microstructure and adhesion compared to traditional DCMS. Clearly use of such novel technique requires fundamental studies to assess surface evolution and growth modes during deposition and resulting microstructure and surface morphology and the correlation with RF superconducting properties. Here we present detailed structure-property correlative research studies done on Nb/Cu thin films and NbN- and NbTiN-based multilayers made using HiPIMS and DCMS, respectively.

Thin Film Approaches to the SRF Cavity Problem

2017 Linear accelerators
Download Thin Film Approaches to the SRF Cavity Problem PDF Online Free

Author :
Release : 2017
Genre : Linear accelerators
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Thin Film Approaches to the SRF Cavity Problem by : Douglas B. Beringer

Download or read book Thin Film Approaches to the SRF Cavity Problem written by Douglas B. Beringer. This book was released on 2017. Available in PDF, EPUB and Kindle. Book excerpt: Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory’s CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency – 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m – there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (approximately 45 MV/m for Niobium) where inevitable thermodynamic breakdown occurs. With state of the art niobium based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio-frequency applications.

Superconducting NbTiN Thin Films for Superconducting Radio Frequency Accelerator Cavity Applications

2016
Download Superconducting NbTiN Thin Films for Superconducting Radio Frequency Accelerator Cavity Applications PDF Online Free

Author :
Release : 2016
Genre :
Kind : eBook
Book Rating : /5 ( reviews)

GET EBOOK


Book Synopsis Superconducting NbTiN Thin Films for Superconducting Radio Frequency Accelerator Cavity Applications by :

Download or read book Superconducting NbTiN Thin Films for Superconducting Radio Frequency Accelerator Cavity Applications written by . This book was released on 2016. Available in PDF, EPUB and Kindle. Book excerpt: Current superconducting radio frequency technology, used in various particle accelerator facilities across the world, is reliant upon bulk niobium superconducting cavities. Due to technological advancements in the processing of bulk Nb cavities, the facilities have reached accelerating fields very close to a material-dependent limit, which is close to 50 MV/m for bulk Nb. One possible solution to improve upon this fundamental limitation was proposed a few years ago by Gurevich [Appl. Phys. Lett. 88, 012511 (2006)], consisting of the deposition of alternating thin layers of superconducting and insulating materials on the interior surface of the cavities. The use of type-II superconductors with Tc> TcNb and Hc> HcNb, (e.g., Nb3Sn, NbN, or NbTiN) could potentially greatly reduce the surface resistance (Rs) and enhance the accelerating field, if the onset of vortex penetration is increased above HcNb, thus enabling higher field gradients. Although Nb3Sn may prove superior, it is not clear that it can be grown as a suitable thin film for the proposed multilayer approach, since very high temperature is typically required for its growth, hindering achieving smooth interfaces and/or surfaces. On the other hand, since NbTiN has a smaller lower critical field (Hc1) and higher critical temperature (Tc) than Nb and increased conductivity compared to NbN, it is a promising candidate material for this new scheme. Here, the authors present experimental results correlating filmmicrostructure with superconducting properties on NbTiN thin film coupon samples while also comparing filmsgrown with targets of different stoichiometry. In conclusion, it is worth mentioning that the authors have achieved thin films with bulk-like lattice parameter and transition temperature while also achieving Hc1 values larger than bulk for films thinner than their London penetration depths.

You may also like...