I. Terechkine

Investigation of cable insulation and thermo-mechanical properties of epoxy impregnated Nb/sub 3/Sn composite

Within the framework of the Fermilab high field magnet program, cable insulation and thermo-mechanical properties of epoxy impregnated Nb/sub 3/Sn composite were studied. As a part of cable insulation development, a new wrappable ceramic insulation was investigated to understand its mechanical properties and its influence on magnet fabrication technology. Measurements of modulus of elasticity and Poissons ratio of Nb/sub 3/Sn composite made out of ten-stack samples were performed under compression at room temperature and at 4.2 K. The results from both monotonic and cyclic loading tests are presented. Finally, measurements of the coefficient of thermal contraction for the composite using strain gauges is discussed.

Fabrication of the shell-type Nb/sub 3/Sn dipole magnet at Fermilab

A 43.5 mm aperture dipole magnet with a nominal field of 11 T is being fabricated at Fermilab. The design is based on a two-layer shell-type coil structure made of Rutherford-type Nb/sub 3/Sn cable with wind and react technology. The mechanical support structure consists of vertically split iron yoke locked by two aluminum clamps and a 8 mm thick stainless steel skin. This paper summarizes the fabrication details of the first dipole model and test results from a 2110 mm long mechanical model.

Magnetic design of the Fermilab 11 T Nb/sub 3/Sn short dipole model

High field accelerator magnets for a future Very Large Hadron Collider are being developed at Fermilab in collaboration with LBNL and KEK. The goal of this work is to elaborate a cost-effective Nb/sub 3/Sn dipole magnet design and technology which provide the nominal field of 11 T. This paper presents a description of the magnetic design of the first short model including cable and strand parameters, coil and yoke cross-section and magnet end geometry. The results of field distribution and field quality calculations including geometrical and random harmonics, coil magnetization and iron saturation effects are also reported.

Development and test of single-bore cos-/spl thetav/ Nb/sub 3/Sn dipole models with cold iron yoke

Two short Nb/sub 3/Sn dipole models based on a single-bore cos-theta coil with a cold iron yoke were fabricated and tested at Fermilab. This paper summarizes the details of magnet design and fabrication procedure, and reports the test results including quench performance and quench heater studies, and the magnetic measurements.

Development of the 11 T Nb/sub 3/Sn dipole model at Fermilab

A one meter long Nb/sub 3/Sn dipole model with 11 T nominal magnetic field in a 43.5 mm bore is being developed at Fermilab in collaboration with LBNL and KEK as part of the R&D efforts for a future Very Large Hadron Collider. This paper describes the magnet design and fabrication procedure as well as summarizes the results of magnetic, mechanical and quench protection analyses. The main parameters of superconducting strand and cable are also reported.

Superconducting Solenoid Magnet Test Results

Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab high intensity neutrino source (formerly known as proton driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab magnet test facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests.

Conceptual design study of high field magnets for very large hadron collider

During the last year, Fermilab in collaboration with LBNL and KEK was conducting an extensive design study of a superconducting magnet with a two-layer cosine-theta coil for a post-LHC hadron collider. For the 30-50 mm magnet bore range, two superconducting cable types and various current block arrangements and iron yoke outer diameters were considered. This paper summarizes results of the study including field and force distributions, systematic and random field errors, coil magnetization and iron saturation effects.

HINS Superconducting Lens and Cryostat Performance

Fermi National Accelerator Laboratory is involved in the development of a 60 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5 K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. A prototype solenoid cryostat was built and tested at the Fermilab Magnet Test Facility. This paper discusses the test results of the prototype and compares the measured and estimated performance of the cryostat. We also present the methods and results for measuring and fiducializing the axis of the solenoid lens.

Designing Focusing Solenoids for Superconducting RF Accelerators

The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.

HINS Linac Front End Focusing System R&D

This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.