ESS MEBT Quadrupole magnets J L Muoz Bilbao

ESS MEBT Quadrupole magnets J. L. Muñoz Bilbao, 27 March 2019

Contents Quads requirements and specifications Tender/fabrication process review Design details Magnets characterization Box Incident Power supplies Some simulations Conclusions ESS MEBT Quads – Bilbao, 27 March 2019

MEBT line includes 11 quadrupole magnets, with integrated dipolar correctors All magnets share the same design and are identical, although operating gradients and F/D characteristics depend on position in line

Quadrupole magnets requirements Relevant documents in CHESS: MEBT Quadrupole magnet TDR Quad main drawing Quads DOORS L 4 check Characterization of pre-series magnet

Tender and contract timeline 24 Feb 2016: PDR at Bilbao. Preliminar design presented Comments and improvements noted 19 Sep 2016: Tender process launched Based on PDR design + L 4 + improvements 1+10, pre-series thorough characterization 13 Feb 2017: Contract awarded to Danfysik 25 Apr 2017: Kick-off meeting (admn. delays) 01 Jun 2017: PDR #1 (based on 3 D model) 14 Jun 2017: PDR #2 (based on 3 D model). PASSED.

Tender and contract timeline 01 Ago 2017: First set of documentation for FDR (drawings, assembly prodecures, cable sketches) 06 Oct 2017: Final set of documentaion for FDR 17 Oct 2017: FDR PASSED, with actions open 08 Feb 2018: First measurements of pre-series magnet Concerns on: Center-height of magnet (corrected) Mechanical-magnetic axis offset 16 Apr 2018: All measurements of pre-series magnet accepted, magnet sent to ESS-Bilbao premises. 02 May 2018: Pre-series magnet arrives at ESS-Bilbao (magnet 1/11)

Tender and contract timeline 11 May 2018: Local tests ran, report issued Visual inspection issues (labels, weldings) IP 2 X cover Magnet accepted with minor corrections for series 03 Oct 2018: Fabrication and tests for next set of 4 magnets, delivery after data package is accepted. 11 Oct 2018: Reception of 4 magnets (2 -5/11) 08 Nov 2018: Incident with transport of remaining magnets. New assembly, tests and correction actions 14 Dec 2018: Final data package for incident magnets 21 Dec 2018: Magnets arrive to ESS-Bilbao (6 -11/11)

Tender and contract timeline (Data package)

Design details

Design details Pole tip design

Design details Coils

Design details Coils

Design details Mechanical

Design details Mechanical (Industeel XC-06)

Design details Mechanical

Design details Mechanical

Characterization Documentation available for all magnets More than 600 files and 600 Mb of data

Pre-series magnet Tests done at Danfysik

Pre-series magnet Dimensional check

Pre-series magnet Thermo-switches tests (2 per coil) All coils tested: Dimensional control, resistance, insulation Before and after impregnation Pdf docs of all tests documents sent

Pre-series magnet After opening+assembly (3 times)

Pre-series magnet Complete magnet test document Visual inspection (paint, brazing, screws, photo) Dimensions Coil numbering Dissasembly/assembly test Resistance, insulation, hydraulic leak Full power test (250 A+steerers 6. 6 A, during 1 hour)

Pre-series magnet Complete magnet test document

Pre-series magnet Target position and mech-mag offset doc

Pre-series magnet Target position and mech-mag offset doc “Resistance based” measurements: Offset is measured in the SW bench First, magnetic center is found Then wire is moved in X and Y steps until electric contact is detected This measures mechanical aperture Process is repeated for all poles, and overall offset computed

Pre-series magnet Excitation curve measured with Hall probe

Magnetic measurements Integrated gradient and hamonics Measured with SSW device, rotating a wire in a 19. 5 mm radius circle, evaluating at 15. 0 mm radius Higher order harmonics are measured for different quadrupolar and dipolar coils excitation Excel files of all measurements provided

Magnetic measurements Summary of results, extracted from raw data

Magnetic measurements Summary of harmonics measured at I=10 A (L 4<1 %)

Magnetic measurements Summary of harmonics at I=250 A (L 4 < 1%)

Additional tests Local tests: one of the magnets was measured in CFAA (UPV/EHU) facility (Model built with poles interpolated from metrology)

Box incident On 1/11/18 Danfysik reported an incident with the box containing the last batch of six magnets

Box incident The box contained magnets numbered 17034, 17035, 17036, 17040, 17043 and 17044. A comparison of measurements (pole gap and shoulder) after reassembly was done. Problems (values worse than previous ones) found in three magnets (17035, 17036 and 17044). In particular, magnet 17036 presented values which are outside the required tolerances according to magnet specification. Magnet stands were also slightly bent from the laterals. Danfysik pointed out that this could be corrected when bolting the stand to the magnet support, straightening the stand this way.

Box incident The strategy that was devised to cope with this was to: 1. Start with the operation of opening/closing of the magnet. 2. Repeat all complete measurements of the magnets. 3. Deliver an updated complete data package for each magnet. ESS (JS) was informed and participated in all Skype meetings between ESS-Bilbao and Danfysik

Box incident 17034 17035 17036 17040 17043 17044 Before opening After opening Just after box incident After 1 st opening After 2 nd opening time

Box incident Some correction was needed for magnet #17035. The foot was re-machined and this has corrected the mechanical problems. After receiving all mechanical and magnetic measurements, we have found that all magnets are within specifications and that there is no significant difference between magnets before and after the incident. Anyway, this delayed quite a bit the magnets delivery to Bilbao

Simulations Extensive simulations activities have also been done

Power Supplies

Conclusions 11 magnets were build and tested All magnets are within L 4 requirements All mechanical restrictions (BPM, length, etc) are also met Fabrication has suffered several delays and incidents All the documentation has been collected and sent