Papers by Alexander V Zlobin
IEEE Transactions on Applied Superconductivity, 2011
Conceptual designs of a superconducting dipole magnet for a Storage Ring of a Muon Collider with ... more Conceptual designs of a superconducting dipole magnet for a Storage Ring of a Muon Collider with a 1.5 TeV center of mass (c.o.m.) energy and an average luminosity of 10 34 cm-2 s-1 are presented. In contrast to proton machines, the dipoles for the Muon Collider should be able to handle ~0.5 kW/m of dynamic heat load from the muon beam decays. The magnets are based on Nb 3 Sn superconductor and designed to provide an operating field of 10 T in the 20-mm aperture with the critical current margin required for reliable machine operation. The magnet cross-sections were optimized to achieve the best possible field quality in the aperture occupied by beams. The developed mechanical structures provide adequate coil prestress and support at the maximum level of Lorentz forces in the coil. Magnet parameters are reported and compared with the requirements.
IEEE Transactions on Applied Superconductivity, 2001
Fermilab is developing a 2-in-1, 11 T block-type common coil dipole magnet for a future Very Larg... more Fermilab is developing a 2-in-1, 11 T block-type common coil dipole magnet for a future Very Large Hadron Collider. The common coil design concept allows a large bending radius at the coil ends and therefore is well suited for use of the react-and-wind technique with brittle superconductors. The magnet features one-layer flat Nb3 Sn coil wound using prereacted cable. A
IEEE Transactions on Appiled Superconductivity, 1997
Hadron Coll ider interact ion regions require quadrupoles wit h a 70 m m dia meter bore, a gradie... more Hadron Coll ider interact ion regions require quadrupoles wit h a 70 m m dia meter bore, a gradient of 250 TIm, and good cooli ng so that t he magnets ca n operate in a high radia tion backgrou nd witho ut quenc hi ng. In order to meet thesc stringent rccluircments, a two-layer magnct with a bigb aspect ratio cab le has been designed. This cable ulilizes Ihe S S C inner and outer layer strands, which have been optimized and are available in lal'ge quantities . The initial design parameters for both cab les are 15.2 mm width; the inner cable has 38 str ands 0 f 0.8 mill diam wire and a keystone a ng le of 0 . 99 deg. The ouler cable has 46 slrands of 0.65 mm diam wire and a keys lone angle of 0.69 deg. These cables bave been fabricaled a nd Ihe n subjected to a number of tests to insure t h eir performance in Ihe quadr upole.
IEEE Transactions on Applied Superconductivity, 2000
BSCCO-2212 round wires are being studied at Fermilab for possible use in accelerator magnets. Sev... more BSCCO-2212 round wires are being studied at Fermilab for possible use in accelerator magnets. Several billets were produced by OST with various fill factors in a diameter range between 0.7 mm and 1 mm. To allow for cabling the strands, a modified process was implemented as opposed to the regular process with oxygen anneal. Rutherford-type cables were fabricated and the performance of extracted strands was compared with that of virgin samples. Cables were also tested using a superconducting transformer.
IEEE Transactions on Applied Superconductivity, 2000
ABSTRACT Multistrand cables may exhibit two classes of parasitic magnetization both of which can ... more ABSTRACT Multistrand cables may exhibit two classes of parasitic magnetization both of which can distort the bore-field of the host magnet. They are: (1) a dynamic magnetization that is produced by interstrand coupling currents generated by time-varying magnet excitation and moderated by the interstrand contact resistances (ICR), (2) a static magnetization (??hysteretic??) resulting from the intrastrand persistent currents. This paper (i) compares the ICRs of two sets of cables with and without stainless steel cores and subjected to three levels of compaction during cabling, (ii) presents the results within the context the previously measured ICRs of a series of similar cables with cores of various widths, and (iii) concludes by comparing the LHC-ramp-rate induced coupling magnetization of a typical Rutherford cable with its transport-current-moderated persistent-current magnetizations at low and high fields.
IEEE Transactions on Applied Superconductivity, 2000
The US-LARP collaboration is developing a new generation of large-aperture high-field quadrupoles... more The US-LARP collaboration is developing a new generation of large-aperture high-field quadrupoles based on Nb 3 Sn superconductor for the LHC upgrades. The development and implementation of this new technology involves the fabrication and testing of series of model magnets, coils and other components with various design and processing features. New 120-mm HQ coils made of Rutherford cable, one with an interlayer resistive core, and both with optimized reaction processes, were fabricated and tested using a quadrupole mirror structure under operating conditions similar to those in a real magnet. The coils were instrumented with voltage taps and strain gauges to study the mechanical and quench performance. Quench antenna and temperature gauges were installed in the mirror structure to measure the coil temperature and locate quench origins. This paper presents details of the coil design and fabrication procedures, coil assembly and pre-stress in the quadrupole mirror structure, and coil test results.
2007 IEEE Particle Accelerator Conference (PAC), 2007
This paper analyses possible D2 magnet designs for the "dipole-first" option of the LHC luminosit... more This paper analyses possible D2 magnet designs for the "dipole-first" option of the LHC luminosity upgrade based on Nb 3 Sn superconductor and compares them in terms of the maximum field, field quality, and Lorentz forces in the coils.
This paper presents results of a thermal analysis and operation margin calculation performed for ... more This paper presents results of a thermal analysis and operation margin calculation performed for NbTi and Nb 3 Sn low-beta quadrupoles in collider interaction regions. Results of the thermal analysis for NbTi quadrupoles are compared with the relevant experimental data. An approach to quench limit measurements for Nb
Annual Review of Nuclear and Particle Science, 2015
One of the key systems of a Muon Collider (MC) - seen as the most exciting option for the energy ... more One of the key systems of a Muon Collider (MC) - seen as the most exciting option for the energy frontier machine in the post-LHC era - is its interaction region (IR). Designs of its optics, magnets and machine-detector interface are strongly interlaced and iterative. As a result of recent comprehensive studies, consistent solutions for the 1.5-TeV c.o.m. MC IR have been found and are described here. To provide the required momentum acceptance, dynamic aperture and chromaticity, an innovative approach was used for the IR optics. Conceptual designs of large-aperture high-field dipole and high-gradient quadrupole magnets based on Nb3Sn superconductor were developed and analyzed in terms of the operating margin, field quality, mechanics, coil cooling and quench protection. Shadow masks in the interconnect regions and liners inside the magnets are used to mitigate the unprecedented dynamic heat deposition due to muon decays (~0.5 kW/m). It is shown that an appropriately designed machine...
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
Fermilab is developing high field dipole magnets for post-LHC hadron colliders. Several designs w... more Fermilab is developing high field dipole magnets for post-LHC hadron colliders. Several designs with a nominal field of 10-12 T, coil bore size of 40-50 mm based on both shell-type and block-type coil geometry are currently under consideration. This paper presents a new approach to magnet design, based on simple and robust single-layer coils optimized for the maximum field, good field quality and minimum number of turns.
In the recent years, Nb3Sn has been widely used for the development of high field superconducting... more In the recent years, Nb3Sn has been widely used for the development of high field superconducting magnets. It is known that the unreacted Nb-Sn composite undergoes a volume expansion during heat treatment due to the formation of the Nb3Sn phase. In an as-received strand this expansion is isotropic. However, an anisotropic volume expansion was observed in the Rutherford-type cable samples.
Insulation is one of the critical components for high-field Nb3Sn magnets that follow wind-and-re... more Insulation is one of the critical components for high-field Nb3Sn magnets that follow wind-and-react approach. The insulation material has to withstand high bending stresses while winding the coil and high heat-treatment temperatures under pressure during coil reaction. At Fermilab we have developed a procedure and tested successfully the dry ceramic insulation tape with inorganic liquid binder to wind and cure
JOURNAL OF INSTRUMENTATION, 2009
This report summarises the conclusions from the detector group of the International Scoping Study... more This report summarises the conclusions from the detector group of the International Scoping Study of a future Neutrino Factory and Super-Beam neutrino facility. The baseline detector options for each possible neutrino beam are defined as follows:
The note describes a conceptual magnetic and mechanical design of the double aperture Nb3Sn quadr... more The note describes a conceptual magnetic and mechanical design of the double aperture Nb3Sn quadrupole magnets with cold iron yoke being developed at Fermilab for VLHC. The design is based on a two-layer shell-type Nb3Sn coil with the inner bore diameter of 43.5 mm. Both designs with vertical and horizontal bore arrangements have been developed. I. INTRODUCTION Magnetic system of the high field stage of VLHC (VLHC-2) is a FODO structure with separate functions. It consists of arc dipole and arc quadrupole magnets, multipole correctors and special magnets. The conceptual designs of arc dipole magnets developed for VLHC-2 at Fermilab are described in (1). All these designs utilize the 2-in-1 approach but use a different coil geometry (cos-theta or block common coil), different bore arrangements (vertical or horizontal) and different iron yoke designs (cold or warm). All magnets provide an accelerator field quality in the required operation field range. The final choice of magnet desig...
Physical Review Special Topics - Accelerators and Beams, 2011
Design of a muon collider interaction region (IR) presents a number of challenges arising from lo... more Design of a muon collider interaction region (IR) presents a number of challenges arising from low β* < 1 cm, correspondingly large beta-function values and beam sizes at IR magnets, as well as the necessity to protect superconducting magnets and collider detectors from muon decay products. As a consequence, the designs of the IR optics, magnets and machine-detector interface are strongly interlaced and iterative. A consistent solution for the 1.5 TeV c.o.m. muon collider IR is presented. It can provide an average luminosity of 10 34 cm -2 s -1 with an adequate protection of magnet and detector components.
IEEE Transactions on Magnetics, 1991
Superconducting transposed cables with different transverse resistivities have been investigated.... more Superconducting transposed cables with different transverse resistivities have been investigated. These cables consist of NbTi-Cu wires with different coatings. The magnitude of interwire resistance has been varied from 10-3 up to 10-7 Ω. The methods and results of measuring the transverse resistance and its dependence upon compression and external magnetic field are discussed. On the basis of the results obtained,
IEEE Transactions on Appiled Superconductivity, 2002
Fermilab is involved in the development of high field superconducting accelerator magnets for dif... more Fermilab is involved in the development of high field superconducting accelerator magnets for different applications based on Nb 3 Sn superconductor. Accelerator magnets have to withstand thousands of thermal and excitation cycles, significant mechanical stresses, and high voltages developed during quench while providing reliable operation for extended period of time. Insulation system is one of the most important elements of magnet design, which determines (and in some cases even limits) the electrical, mechanical, and thermal performance. Different elements of the magnet insulation system such as cable insulation, interlayer insulation, quench heater insulation, and ground insulation have been developed and studied. In this paper we will describe the insulation system used in the Fermilab shell-type dipole models followed by the high voltage test results.
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Papers by Alexander V Zlobin