MQXFA 07 Preload Summary D Cheng C Myers

MQXFA 07 Preload Summary D. Cheng, C. Myers 4/19/2020 LBNL

MQXFA 07 Preload Plan § Azimuthal pre-load § Target pre-stress at cold is: 100 MPa § Ave. Measured pole key gap: 8 mil (~200µm) /side § This means pre-stress at warm of about 80± 8 MPa after creep § Assume 5 -10 MPa of creep after ~24 hours § We set as maximum coil stress to 110 MPa during loading § Axial pre-load § The total force at cold is: 1. 0 MN § The means the room temperature target on each rod is 950 με (total rod force is 0. 58 MN). MQXFA 07 Preload Operation Summary 2

MQXFA 07 SG Gauges Layout RE MID LE Shell 2 Shell 7 Shell 4 Coil Stations • Only HBM gauges are installed. • Shell gauges --- three axial locations: • Shell gauges (T & Z): on shell 2, 4, & 7 • Coil gauges (T & Z): on the axial location of 3989 mm (RE) from LE. • Rod stations are located on the RE • • Each station is full bridge with four individual gauges. ALL the gauges are working properly on MQXFA 07 Preload Operation Summary 3

MQXFA 07 Preload Sequence The pre-load sequence: 1. Pre-loaded axial rods with average ~50 µε; 2. 50% azimuthal pre-load (stopped azimuthal pre-load at 30 mil shims, or total 13. 51 mm); 3. 50% axial pre-load (Applied axial preload to the rods to ~472 µε); 4. 100% azimuthal pre-load (40 mil shims, or total 13. 77 mm), achieved average coil azimuthal stress is -77 MPa, (reached the target of ~ -80± 8 MPa); 5. 100% axial pre-load, achieved average Rod’s strain reading is 960 µε (reached the target of ~950± 95 µε). The pre-load process: • We preloaded this magnet quadrant by quadrant from the initial 15 mil shims (total 13. 14 mm) in 5 mil steps, reaching a peak bladder pressure of 4600 psi. MQXFA 07 Preload Operation Summary 4

Bladder Pressures MQXFA 07 Preload Operation Summary 5

MQXFA 07 Preload Results The stresses are average stress: (MPa) MQXFA 07 (Target) MQXFA 07 (Meas. ) Coil -80± 8 -77 (-75 after 20 hr) Shell 58± 6 56 (Avg. after ~20 hour) Coil -103 - Shell 110 - RT CD Data point, 20 hr after operations Target window • The proposed target window is defined as: • Shell stress: 58 ± 6 MPa; Coil stress: -80 ± 8 MPa • Slope of the measured TF is close to the FE results; • The final average load state is in the target window (use shell 7 to match the coil SG location). • The average azimuthal stress on each shell (after 20 hours): Shell 02 Shell 04 Shell 7 48 MPa 61 MPa 58 MPa MQXFA 07 Preload Operation Summary 6

TF Plots, individual coils MQXFA 07 Preload Operation Summary 7

Comparison of MQXF Magnets MQXFA 05/06 MQXFA 03 MQXFA 04 MQXFA 07 Preload Operation Summary 8

MQXFA 07 Gauge Readings --- Shell Target: 760 µε @RT Axial Preload Operations Notes: Polarity is corrected in calculations Shell 7 (L/R) gauges appear to have offset beyond what was seen after shell-yoke MQXFA 07 Preload Operation Summary 9

MQXFA 07 Gauge Readings --- Coil Notes: Polarity is corrected in calculations Target: -580 µε @RT Axial Preload Operations MQXFA 07 Preload Operation Summary 10

MQXFA 07 Axial Preloading Target: 950 µε ± 95 µε @RT Axial Preload • The maximum cylinder pressure is 6400 psi to achieve the target, 960 µe. • 20 hour reading ~950 µe • The measured rod’s force agrees the computation • Total rods force is ~0. 58 MN after preload based on the measurements. MQXFA 07 Preload Operation Summary 11