RRP Nb3Sn strand studies for LARP

The Nb{sub 3}Sn strand chosen for the next step in the magnet R&D of the U.S. LHC Accelerator Research Program is the 54/61 sub-element Restacked Rod Process by Oxford Instruments, Superconducting Technology. To ensure that the 0.7 mm RRP strands to be used in the upcoming LARP magnets are suitable, extensive studies were performed. Measurements included the critical current, {sub e}, using the voltage-current (V-I) method, the stability current, I{sub S}, as the minimal quench current obtained with the voltage-field (V-H) method, and RRR. Magnetization was measured at low and high fields to determine the effective filament size and to detect flux jumps. Effects of heat treatment temperature and durations on I{sub e} and I{sub S} were also studied. Using strand billet qualification and tests of strands extracted from cables, the short sample limits of magnet performance were obtained. The details and the results of this investigation are herein described

Production and test of the first LQXB inner triplet quadrupole at Fermilab

Fermilab, in collaboration with LBNL and BNL, has developed a quadrupole (MQXB) for installation in the interaction region inner triplets of the LHC. This magnet is required to have an operating gradient of 215 T/m across a 70 mm coil bore, and to operate in superfluid helium at 1.9K. Two 5.5 m long MQXB magnets are combined with a dipole orbit corrector to form a single cryogenic unit (LQXB). This paper discusses the construction and test of the first full-scale production-quality LQXB

RRP Nb 3 Sn Strand Studies for LARP

Abstract-The Nb 3 Sn strand chosen for the next step in the magnet R&D of the U.S. LHC Accelerator Research Program is the 54/61 sub-element Restacked Rod Process by Oxford Instruments, Superconducting Technology. To ensure that the 0.7 mm RRP strands to be used in the upcoming LARP magnets are suitable, extensive studies were performed. Measurements included the critical current, , using the voltage-current ( ) method, the stability current, , as the minimal quench current obtained with the voltage-field ( ) method, and . Magnetization was measured at low and high fields to determine the effective filament size and to detect flux jumps. Effects of heat treatment temperature and durations on and were also studied. Using strand billet qualification and tests of strands extracted from cables, the short sample limits of magnet performance were obtained. The details and the results of this investigation are herein described. Index Terms-Critical current density, magnetic instability, Nb 3 Sn, restack rod process

RRP Nb3Sn Strand Studies for LARP

The Nb{sub 3}Sn strand chosen for the next step in the magnet R&D of the U.S. LHC Accelerator Research Program is the 54/61 sub-element Restacked Rod Process by Oxford Instruments, Superconducting Technology. To ensure that the 0.7 mm RRP strands to be used in the upcoming LARP magnets are suitable, extensive studies were performed. Measurements included the critical current, I{sub c}, using the voltage-current (V-I) method, the stability current, I{sub S}, as the minimal quench current obtained with the voltage-field (V-H) method, and RRR. Magnetization was measured at low and high fields to determine the effective filament size and to detect flux jumps. Effects of heat treatment temperature and durations on I{sub c} and I{sub S} were also studied. Using strand billet qualification and tests of strands extracted from cables, the short sample limits of magnet performance were obtained. The details and the results of this investigation are herein described

Round and Extracted Nb3Sn Strand Tests for LARP Magnet R&D

The first step in the magnet R&D of the U.S. LHC Accelerator Research Program (LARP) is fabrication of technology quadrupoles TQS01 and TQC01. These are two-layer magnets which use cables of same geometry made of 0.7 mm MJR Nb{sub 3}Sn. Through strand billet qualification and tests of strands extracted from the cables, predictions of magnet performance are made. Measurements included the critical current, I{sub c}, using the voltage-current (VI) method at constant field, the stability current, I{sub S}, as the minimal quench current obtained with the voltage-field (VH) method at constant current in the sample, and RRR. Magnetization was measured at low and high fields to determine the effective filament size and to detect flux jumps. Effects of heat treatment duration and temperature on I{sub c} and I{sub S} were also studied. The Nb{sub 3}Sn strand and cable samples, the equipment, measurement procedures, and results are described. Based on these results, strand specifications were formulated for next LARP quadrupole models

FERMILAB-Conf·92J98 Alternate Manufacturing Processes and Materials for the SSC Dipole Magnet Coil End Parts ALTERNATE MANUFACTURING PROCESSES AND MATERIALS FOR THE SSC DIPOLE MAGNET COn. END PARTS

ABSTRACT Modern magnet designs such as the SSC dipole utilize smaller bore diameter and wider superconducting cable. Challenging winding techniques place greater emphasis on the role of the coil end parts. Their complex configuration is derived from their function of confining the conductors to a consistent given shape and location. Present end parts, made of G-10 composite, are manufactured utilizing complex and expensive 5-axis machining techniques. Several alternate manufacturing processes and materials described in this paper will result in a substantial cost reduction for mass producing the end parts. The alternate processes are divided into two major groups. The composite group consists of Resin Transfer Molding (RTM), Compound Transfer Mold (CTM), Injection Molded Composite (IMC) and Compression Molded Composite (CMC). The base metal coated group consists of Chemical Vapor Deposition (CVD) dip coating and hard coatings/anodizing. The paper will provide an overview of the various processes and compare test performance and cost to that of the process currently used

Assessment of MQXF Quench Heater Insulation Strength and Test of Modified Design

The HL-LHC interaction region magnet triplets (Q1,Q2, and Q3) will be composed of superconducting Nb3Sn quadru-poles. The MQXF quadrupole protection system is based on CLIQ (Coupling-Loss Induced Quench system) and outer layer quench heaters.This paper reports a summary of quench heaters to coil high voltage tests performed on MQXF short and long coils in air after fabrication, and in air and He gas after magnet training. Breakdown voltage values demonstrate good marginwith respect to the Electrical design criteria for the HL-LHC inner triplet mag-nets. A modification in thequench heater installation-with an ex-tra layer of fiber glass between the coil and the quench heater trace-has been proposed and tested in a mirror magnet to further increase electrical margins. Results demonstrated improvements of high voltage margin at the expense of a clear increase of hot spot temperature.Thebaseline heater to coil insulation was assessed to be able to guarantee safe operation for the Nb3Sn quadrupole mag-nets for the interaction regions of HL-LHC.The HL-LHC interaction region magnet triplets (Q1, Q2, and Q3) will be composed of superconducting Nb3Sn quadrupoles. The MQXF quadrupole protection system is based on CLIQ (Coupling-Loss Induced Quench system) and outer layer quench heaters. This paper reports a summary of quench heaters to coil high voltage tests performed on MQXF short and long coils in air after fabrication, and in air and He gas after magnet training. Breakdown voltage values demonstrate good margin with respect to the Electrical design criteria for the HL-LHC inner triplet magnets. A modification in the quench heater installation- with an extra layer of fiber glass between the coil and the quench heater trace- has been proposed and tested in a mirror magnet to further increase electrical margins. Results demonstrated improvements of high voltage margin at the expense of a clear increase of hot spot temperature. The baseline heater to coil insulation was assessed to be able to guarantee safe operation for the Nb3Sn quadrupole magnets for the interaction regions of HL-LHC