Design of HQ—A High Field Large Bore ${\rm Nb}_{3}{\rm Sn}$ Quadrupole Magnet for LARP

Chlachidze

et al. 2017

Abstract-The U.S. LHC Accelerator Research Program, in close collaboration with CERN, has developed three generations of high-gradient quadrupole (HQ) Nb3Sn model magnets, to support the development of the 150 mm aperture Nb3Sn quadrupole magnets for the High-Luminosity LHC. The latest generation, HQ03, featured coils with better uniformity of coil dimensions and properties than the earlier generations. The HQ03 magnet was tested at FNAL, including the field quality study. The profiles of low-order harmonics along the magnet aperture observed at 15 kA, 1.9 K can be traced back to the assembled coil pack before the magnet assembly. Based on the measured harmonics in the magnet center region, the coil block positioning tolerance was analyzed and compared with earlier HQ01 and HQ02 magnets to correlate with coil and magnet fabrication. To study the capability of correcting the low-order non-allowed field errors, magnetic shims were installed in HQ03. The expected shim contribution agreed well with the calculation. For the persistent-current effect, the measured a4 can be related to 4% higher in the strand magnetization of one coil with respect to the other three coils. Finally, we compare the field errors due to the inter-strand coupling currents between HQ03 and HQ02.Index Terms-LARP, Nb3Sn quadrupole magnets, field quality.

Section: Introductionmentioning

confidence: 99%

Analysis of Field Errors for LARP Nb$_3$ Sn HQ03 Quadrupole Magnet

Wang

Chlachidze

et al. 2017

“…The design of MQXF magnet [11] is based on HQ magnet [12], by scaling up the bore diameter from 120 mm to 150 mm. HQ02 and HQ03 magnets were tested and performed very well.…”

Section: A Hq03 Coil End Analysismentioning

confidence: 99%

“…For the first four years, Technological Quadrupole (TQ) models, with 90mm aperture, were designed, fabricated and tested successfully [2]. For the second four years starting from 2008, High-gradient Quadrupole (HQ) models, with 120 mm aperture, were designed, fabricated and tested successfully [3]- [4]. In 2012, it was decided to upgrade the inner triplet magnets in the current LHC IRs using Nb3Sn magnets with 150 mm aperture (MQXF) [5]- [6].…”

Section: Introductionmentioning

confidence: 99%

Coil End Parts Development Using BEND and Design for MQXF by LARP

Bermúdez

et al. 2017

Abstract-End parts are critical components for saddle-shaped coils. They have a structural function where the cables are deformed in order to cross over the magnet aperture. Based on the previous design of the US LARP program for 90 mm aperture quadrupoles (TQ/LQ) and 120 mm aperture quadrupoles (HQ/LHQ) using BEND, the coil ends of the low-β quadruples (MQXF) for the HiLumi LHC upgrade were developed. This paper shows the design of the MQXF coil ends, the analysis of the coil ends during the coil fabrication, the autopsy analysis of the coil ends and the feedback to BEND parameters.

“…Previously LARP successfully fabricated and tested series of 90 mm and 120 mm aperture Nb3Sn magnets [3,4]. Based on this experience, LARP and CERN recently joined their efforts to fabricate and test a series of short and long, 1.5 m and 4.2 m long respectively, 150 mm diameter Nb3Sn magnets.…”

Section: Introductionmentioning

confidence: 99%

Performance of the First Short Model 150-mm-Aperture Nb3Sn Quadrupole MQXFS for the High-Luminosity LHC Upgrade

Chlachidze

Anerella

et al. 2017

Abstract-The US LHC Accelerator Research Program (LARP)and CERN combined their efforts in developing Nb3Sn magnets for the High-Luminosity LHC upgrade. The ultimate goal of this collaboration is to fabricate large aperture Nb3Sn quadrupoles for the LHC interaction regions (IR). These magnets will replace the present 70 mm aperture NbTi quadrupole triplets for expected increase of the LHC peak luminosity by a factor of 5. Over the past decade LARP successfully fabricated and tested short and long models of 90 mm and 120 mm aperture Nb3Sn quadrupoles. Recently the first short model of 150 mm diameter quadrupole MQXFS was built with coils fabricated both by the LARP and CERN. The magnet performance was tested at Fermilab's vertical magnet test facility. This paper reports the test results, including the quench training at 1.9 K, ramp rate and temperature dependence studies. Index Terms-Accelerator magnets, large hadron collider, Nb3Sn coils, superconducting magnets