ISTITUTO NAZIONALE DI FISICA NUCLEARE SEZIONE DI MILANO LABORATORIO ACCELERATORI E SUPERCONDUTTIVITA’ APPLICATA Magnet Test LASA, INFN-Milano Giovanni Volpini, CERN 12 March 2015

MAGIX & INFN participation to HL-LHC MAGIX WP1CORRAL Design, construction and test of the five prototyes of the corrector magnets for the HL interaction regions of HiLUMI WP2 PADS 2D & 3D engineering design of the D2 magnets WP3SCOW-2G Development of HTS coil for application to detectors and accelerators WP4SAFFO Low-loss SC development for application to AC magnets MAGIX is a INFN-funded research project, (GrV, «Call») whose goal is to develop superconducting technologies for application to future accelerator magnets. It includes four WP’s, two of which are relevant to HL-LHC , 1 M€ + personnel funds CERN-INFN Collaboration Agreement INFN already involved in FP7-HiLumi (UE-HILUMI, GrV) WP2 beam dynamics, LNF WP3 magnets, MI-LASA WP6 cold powering, MI-LASA 1 2 Approved by the INFN Board of Directors & signed by INFN President on June 2014; signed by CERN DG on July 17th. CERN endorses MAGIX WP1 & WP2 deliverables and milestones, contributing with 527 k€

Giovanni Volpini CERN 12 march 2015 Corrector magnet inventory From 6-pole to 12-pole magnets exist in both normal and skew form (the latter is shown) 150 OD OD460 The superferric design was chosen for ease of construction, compact shape, modularity, following the good performance of earlier corrector prototype magnets developed by Ciemat (Spain). Mechanical support Iron yoke SC Coils

Giovanni Volpini CERN 12 march 2015 LHCHL-LHC Order Type Aperture Stored energy Operating Current Inductance Aperture Mechanical Length Stored energy Operating Current Differential Iop mm[J][A][mH][mm] [kJ][A][H] 2SMQSX702, N MCSXMCSTX S MCSSX MCSOX N MCOX S MCOSX N S N MCTXMCSTX S LHC vs. HL-LHC corrector magnet comparison chart 187/II Rev 9 July 2014

Vertical cryostat D700 x 6500 mm May host magnet up to 10 ton x 5 m

Giovanni Volpini CERN 12 march 2015 ID MAGIX Test cryostat 2.5 ton design load Conduction cooled thermal shield Design option: ring to fix a λ-plate w/ reduces free bore

ID 460 CL’s 500 A Sub-cooled LHe operation Suitable for smaller magnet (6-pole, 8-pole, 10-pole) test Small Magnet Test Cryostat

Current sources Linear Power Converter 220 A x 6 V Switching Power Converter 500 A x 125 V Three 10 kA x 6 V switching power convertes. They can be operated in series or in parallel. Current measured through a 10 kA DCCT. External bus bars designed for 10 kA A system to operate the power supply in discharge mode is based on a diode bank which sinks the power, in parallel with Mosfet’s which short-circuit the diode bank during the current ramp-up. This allows for ~ -15 V during the discharge cycle.

1. QDS (MSS Magnet Safety System) Initiates a fast discharge or switches off the power supply incase some voltage thresholds on the magnet or on its electrical connection are exceeded. Includes a capacitor bank for firing quench heaters. 2. Current Control & Slow Acquisition Two different functions, implemented in the same hardware & software system. Slow acquisition monitors and records most important data (temperatures, current, voltage along critical items) from the cooldown to the operation. Data are avalilable to the operator and recorded at about 1 Hz. 3. Fast Acquisition Records voltages across the magnet under test with 1 kHz sampling frequence, in coincidence with a fast discharge 4. V*I AC losses measurement system A dedicated system which measures the AC losses by numerical integration of V*I product, measured by a couple of synchronized VMM. It is completely independent from other systems, from the voltage taps on. This allows to perform checks, modification on the ground, etc. without affecting other safety-critical systems. Control & Data Acquisition Architecture

Giovanni Volpini CERN 12 march Magnet Safety System 16 channels (may be expanded), each: optoinsulated input, bridge/single end independently configurable Voltage thresholds ±4V, ±1.25V, ±500mV, ±100mV Time validation ranges: 0-10 ms, ms, 0-1 s Input signal made available in copy Memory of fired channels

2. Slow Acquisition NI Compact Field Point

Giovanni Volpini CERN 12 march Fast Acquisition

Magnets to Test MAGIX INFN committment: 5 prototypes, cold tested, but w/o magnetic measurements RT meas + Cold meas Series Production, no formal committment exists yet for the manufacture 54 magnets (including spares) 6 quadrupoles 12 sextupoles, normal and skew 12 octupoles, normal and skew 12 decapoles, normal and skew 6 dodecapole normal 6 dodecapole skew TEST sequence Quadrupole 1 / cold run Dodecapole normal 2 / cold run Others 4 / cold run

Test Requirements TEST sequence for series magnets. All to be done in the larger cryostat Quadrupole 1 / cold run Dodecapole normal 2 / cold run Others 4 / cold run Issues to be clarified Free room in the top flange Cryostat internal access Operation shaft inserted and removed at warm? cool down requirements maximum pressure stray magnetic field cabling from the probe to data acquisition system interface with exsisting equipements (e.g. Current reading from power converter) reference (fiducials) on magnets for probe connection aob ?

Giovanni Volpini CERN 12 march 2015 Giovanni Volpini CERN 12 March Yoke laminations machined by laser cut followed by EDM (final accuracy 1/100 mm) on the relevant surfaces: poles, coil slots, alignment slots. 5.8 mm thick iron laminations Design & Assembly

Upper Flange

Net work Q performed by the power supply on the magnet between t 0 and t AC-loss measuring apparatus

experimental LASA

DISCORAP cryostat vertical cryostat magnet connection system cold mass ground floor Free ID 697 mm Max operating pressure 4.5 bar abs Thermal shield cooled by LN or evaporated GHe DUT max lenght 5 m max weight 10 ton

MAGIX Cryostat