HQ02A2 TEST RESULTS November 7, 2013 FERMILAB

HQ02 test at Fermilab 2  First HQ quadrupole with coils (#15-17, #20) of the optimized design o Only coil #15 previously tested in a mirror structure at Fermilab (HQM04). See “Test of Optimized 120-mm LARP Nb 3 Sn Quadrupole Coil Using Magnetic Mirror Structure”, IEEE Trans. on Applied Supercond., vol. 23, no. 3, p , June 2013 ) HQ coil cross-section HQ02 parameters

HQ02 test at Fermilab (cont’d) 3  HQ02(a) tested in May-Jun., 2013 o 15 kA header assembly with a lambda plate was used in this test o Test both at 1.9 K and 4.5 K o The magnet successfully reached the maximum allowed current of 15 kA at all temperatures  HQ02a2 test in Sep.-Oct., 2013 o 30 kA header assembly w/o lambda plate o Test at 2.2 K and 4.5 K  Test facility upgrades for the HQ02a2 test o External energy extraction system now provides 2.5 mΩ and 5 mΩ dump resistors o Additional wiring added to the header assembly to accommodate more heaters (16) Lambda plate magnet 15kA header

HQ02 voltage tap system  Voltage taps cover both the inner (IL) and outer (OL) coil layers  The magnet was equipped with the quench antenna and an acoustic sensor developed at LBNL (M. Marchevsky) 4

HQ02a2 quench training 5  Quench training performed at 2.2 K and with a regular ramp rate of 20 A/s  Excellent training memory demonstrated Ramp rate study PH tests QP study PH tests 89% of SSL T-dep. study 98% of SSL

HQ02 quench locations 6  All training quenches in the pole-turn segments  Mostly coils #16 & 20 participating in the training o Coil #15 previously trained up to 17 kA in a mirror structure HQM04

HQ02 ramp rate dependence study 7  Quenches at ramp rates of 150 A/s and above developed in the mid-plane area of coil 17. Low ramp rate quenches developed in the pole area of different coils  No ramp-down quenches at A/s (HQ02a test)

HQ02 temperature dependence study 8 Current limit  Mostly coil #16 quenching at intermediate temperatures 16.1 kA16.2 kA16.1 kA

HQ02 inductance measurements  HQ02a2 inductance measurement now is consistent with the HQ01 measurements at CERN  15 kA header assembly to be investigated for the possible issue with the whole coil signal used in the inductance measurements 9

More HQ02a2 tests results  No instability related issues. Hours of magnetic measurements performed at 80% of SSL (2.2 K) and at 90% of SSL (4.5 K) ( J. DiMarco )  Quench propagation speed estimated o Ramp 13 (2.2 K): ~25 m/s at 86% of SSL, IL of coil 16 o Ramp 21 (2.2 K): ~30 m/s at 87% of SSL, ramp area of coil 16 o Ramp 55 (4.5 K): ~50 m/s at 98% of SSL, both the IL and OL of coil 17  Voltage spike system, not functioning at the beginning, was fixed only for the second half of the test. Data analysis in progress  Due to possible issues with the whole coil signal in the previous test, AC loss measurements repeated in HQ02a2 (E. Ravaioli) 10

Quench Protection Study 11  Protection heater tests at currents up to 80% of SSL (T. Salmi)  Safe MIITs budget for the QP study o Postponed until HQ02b with increased pre-load o Based on previous HQ02a test MIITs were set as a safe budget  QI study with small dump resistors o 2.5 mΩ and 5 mΩ dump resistors introduced in addition to 10 mΩ used HQ02a test o Test at currents up to 80% of SSL  Study of the quench propagation from the OL to the IL coil segments at currents up to 80% of SSL

QI study with different dump resistors  Tests performed with 5 mΩ and 10 mΩ dump resistors, as well as without the dump at 2.2 K. Only OL heaters used for the magnet protection  Very good reproducibility of the QI measurements in the current range of (60-70)% of SSL  Data analysis in progress 12

OL to IL quench propagation  OL protection heater induced quenches w/o dump  OL to IL quench propagation time t = t(IL quench) – t(OL quench)  OL to IL quench propagation time spread between coils shown for HQ02a2 13

Summary  HQ02 magnet with the Nb 3 Sn coils of the improved design and a stainless steel (SS) core in the conductor successfully tested at Fermilab  The magnet demonstrated stable performance and reached 98% of SSL at 4.5 K and 89% at 2.2 K  Test results demonstrated that a SS core can be introduced in the Nb 3 Sn coils without causing performance degradation  Currently the magnet warm-up is completed. The magnet will be extracted from the dewar and disconnected from the header assembly this week. Horizontal magnetic measurements are expected next week  HQ02 will be ready for shipping to LBNL around Nov. 15,

Backup Slides 15

RRR measurements in HQ02a 16 Coil #15Coil #16 Coil #20Coil #17

HQ02 Short Sample Limit  Coil 17 with the lowest SSL at 4.6 K (~16.4 kA) 17 A. Godeke

HQ02 inductance measurement  Measurements performed at A/s 18