Helene Felice HQ Test Results Review Thursday December 16 th Overview of HQ coils and Magnet

Outline 12/16/20102H. Felice - HQ Test Results Review HQ Magnet overview Coil Design and Fabrication HQ01a / HQ01b / HQ01c main features

HQ Overview 12/16/20103H. Felice - HQ Test Results Review 4.4 K1.9 K Short sample current I ss (kA) Gradient at I ss (T/m) Peak field at I ss (T) Stored energy at I ss (MJ) Fx / Fy at I ss per octant (MN/m)2.7/ /-4.7

Coil Design 12/16/20104H. Felice - HQ Test Results Review Bare cable width: mm Bare cable mid-thickness: 1.44 mm Keyston angle: 0.75 Insulation thickness: 100 microns Coil 6 Coil 6 LE RE End design

Coil fabrication status Coil # Cable number Strand type Reaction Potting Status 1992R54/61LBLHQ01a/HQ01b/HQ01c 3rd 2992R54/61BNLHQ01a 3991R108/127LBLHQ01a/HQ01c / at FNAL 41000R108/127BNLHQ01a/HQ01b 51000R108/127BNLHQ01b/HQ01c 3rd 61000R108/127BNLHQ01b 71000R108/127LBLHQ01c 3 rd assembly 8996R54/61BNLHQ01c 3 rd assembly 9996R54/61BNLImpregnated 10996R54/61LBLReacted – broken strands RCDP 108/127 (Ti)BNLPrep for impregnation /61 (Ta) with SS coreLBLPrep for reaction /61 (Ta) 1 passBNLShipped to BNL (1turn less) or /61 (Ta) 1 pass or (Ta) 1 passLBLStart in May 11 15??BNLStart in June 11 16??LBLStart in July 11 12/16/20105H. Felice - HQ Test Results Review

Coil fabrication process Winding and curing layer 1 Winding and curing layer 2 12/16/20106H. Felice - HQ Test Results Review Reaction

Impregnation and Instrumentation Hipoted Trace placed on top of reacted coil - Layer 1 and Layer 2 -Protection heaters - Voltage taps Layer 1 Layer 2 - Voltage taps wiring - Strain gauges mounting and wiring 12/16/20107H. Felice - HQ Test Results Review

HQ Assembly Coil pack assembly Collar / Pad bolting 12/16/20108H. Felice - HQ Test Results Review Bladder operation Axial loading

HQ01a Azimuthal stress distribution 12/16/20109H. Felice - HQ Test Results Review After cool-down:    (MPa) At 14 kA   Agreement with SG measurements

Protection Heaters – General scheme 12/16/201010H. Felice - HQ Test Results Review Rstrip = 6 ohm VHFU IHFU = 4 X Iheater A Layer 2 Layer 1 Lead A01A02 B02 B01 A01 A02 B01 B02 4 circuits of PH powered by capacitor banks (Heater Firing Units HFU) MIITS kept below 11 during the tests => hot spot T around 150 K

Instrumentation 10 vtaps per layer Layer 1 Layer 2 12/16/201011H. Felice - HQ Test Results Review Mid-plane vtap missing in some coils => impact quench location conclusion

Splice Design Splice monitoring in all HQ tests 2 NbTi leads Nb 3 Sn coil lead 2 NbTi leads Nb 3 Sn coil lead Splice monitoring in next coils Unreliable splice signals 12/16/201012H. Felice - HQ Test Results Review

Splices in HQ magnets 7581 Layer 1 L L1 L2 Impact on current distribution? Will be fixed in next magnet 12/16/201013H. Felice - HQ Test Results Review Dual NbTi leads stacked on the VCL flags

HQ01a (+) Coil 2 54/61 BNL Coil 4 108/127 BNL Coil 3 108/127 LBL Coil 1 (-) 54/61 LBL 12/16/201014H. Felice - HQ Test Results Review Limiting coil: coil #3 Visual inspection: coil 3: no damage observed coil 2: trace damage Led to: structure inspection modification of the ground insulation thickness to improve the matching between coil OD and collar ID impulse test performed after test => failure of coil #2 Replacement of coils #2 and #3 in HQ01b

Coil distribution per magnet HQ01aHQ01b (+) Coil 2 54/61 BNL No pole gap Coil 4 108/127 BNL Gap - pinned Coil 3 108/127 LBL Coil 1 (-) 54/61 LBL (+) Coil 6 108/127 BNL Coil 4 108/127 BNL Coil 5 108/127 BNL Coil 1 (-) 54/61 LBL 12/16/2010H. Felice - HQ Test Results Review15

HQ01b – Observations and Csqs Observation and questions Strong noise recorded during test => arcing Test ended due to coil #6 failure Visual inspection: coil 6 damaged => hole seen at RE insulation failure Consequence on the coil layout Thicker interlayer insulation Interlayer of the shoe were softened - layer 1 OD - layer 2 ID => Only starting with coil 10 12/16/201016H. Felice - HQ Test Results Review Coil voltages Derivative mode

Impulse test Implemented in HQ001c - Requirements for all coils to pass the impulse test at 1000 V 12/16/201017H. Felice - HQ Test Results Review Coil 7 Example of a failure (coil 4)  s Failing coils coils 2 after HQ01a disassembly coil 4 after HQ01b disassembly coil 3 passed after HQ01a assembly but failed after subsequent assembly/disassembly

HQ01c - Hipot results 12/16/201018H. Felice - HQ Test Results Review HQ01aHQ01bHQ01c Hipot procedure: -Coil to end-shoe 500 V - Layer 1 end-shoe to Layer 2 end-shoe500 V implemented in HQ01c - Coil to PH 1000 V - Coil to coil 500 V - Coil to structure 1000 V Coil to all PHs Coil to LE shoes LE shoe to PH L2 RE L1/L2 shoe Coil 1 Coil to PH LE shoe to PH L2 Coil 1 Coil to PH Coil 4 Coil 5 Coil 6 OK Coil to L1 PHs RE L1/L2 shoe Coil 8 LE L1/L2 shoe RE L1/L2 shoe Coil 5 Coil 7 OK Coil to LE L2 shoe LE shoe to PH L2 Coil 1 Coil to LE L2 shoe Coil 2 Coil to LE L2 shoe Coil 4 Coil 3 OK

Coil distribution per magnet HQ01aHQ01bHQ01c (+) Coil 2 54/61 BNL Coil 4 108/127 BNL Coil 3 108/127 LBL Coil 1 (-) 54/61 LBL (+) Coil 6 108/127 BNL Coil 4 108/127 BNL Coil 5 108/127 BNL Coil 1 (-) 54/61 LBL (+) Coil 7 108/127 LBL Coil 8 54/61 BNL Coil 5 108/127 BNL Coil 1 (-) 54/61 LBL 12/16/201019H. Felice - HQ Test Results Review

Coil 10 after reaction 12/16/201020H. Felice - HQ Test Results Review Layer 1 RE Layer 1 and 2 RE Coil 6 Inspection of limiting /failing coils in HQ tests - Coil 6: failing coil in HQ01b After etching of the copper => no sign of fractured strand - Coils 3 and 1 under investigation - Variable reaction condition investigated

Summary 12/16/201021H. Felice - HQ Test Results Review 3 tests: HQ01a, b and c with common features Coil fabrication procedures Instrumentation Assembly and mechanical coil preload Clear insulation integrity failure exhibited in HQ01b modification of the interlayer insulation scheme Electrical QA improvement: Impulse test High rate of impulse test failure in the first coils (post-tests/loading): 2, 3 and 4 Some coil weaknesses/defect caused by the fabrication process (coil 10) being investigated with “test coils” => future coil review