Giorgio Ambrosio

TL;DR: In this article, a 3.6 m long structure based on the LBNL subscale common-coil magnet design was fabricated, assembled, and tested with aluminum-plate "dummy coils".

Abstract: Large-aperture, high-field, Nb3Sn quadrupoles are being developed by the U.S. LHC accelerator research program (LARP) for the High luminosity upgrade of the Large Hadron Collider (HiLumi-LHC). The first 1 m long, 120 mm aperture prototype, HQ01, was assembled with various sets of coils and tested at LBNL and CERN. Based on these results, several design modifications have been introduced to improve the performance for HQ02, the latest model. From the field quality perspective, the most relevant improvements are a cored cable for reduction of eddy current effects, and more uniform coil components and fabrication processes. This paper reports on the magnetic measurements of HQ02 during recent testing at the Vertical Magnet Test Facility at Fermilab. Results of baseline measurements performed with a new multilayer circuit board probe are compared with the earlier magnet. An analysis of probe and measurement system performance is also presented.

TL;DR: In this article, the impact of the coil shimming on field quality is evaluated, with special emphasis on the warm magnetic measurements and the correlation to field measurements at cold and nominal field.

TL;DR: The High-field Quadrupole (HQ) program as mentioned in this paper was used to demonstrate reproducibility in the coil fabrication process and to remedy the fabrication issues that led to discarding several HQ02 coils.

TL;DR: The first one-meter long common coil dipole model (HFDC-01) has been fabricated and tested at Fermilab as discussed by the authors, which has several innovative features such as: single-layer racetrack coils, a 22mm wide 60-strand Rutherford-type cable made of 0.7mm Nb/sub 3/Sn strands, and a stainless steel coil-support structure reinforced by horizontal bridges inserted between coil blocks.