HQ01e3 test summary December 2012 M. Marchevsky, LBNL

Original test plan Verify training and magnet status after CERN test -The primary objective for HQ01e3 -Correct operation of the newly installed SCRs, safety equipment (new valves), detection and acquisition systems (CryoDAC, fast event DAQ, acoustic piezo-sensors) following the upgrades will be verified. Validate and extend the magnetic measurements The plan is to use updated injection levels, test new MM probe and study connection between the flux jumps and field quality. AC loss studies with varying ramp rates will be conducted. Heater efficiency and MIITs studies We have several proposals that address: - heater efficiency through measuring quench delay and MIITs evolution as function of magnet current - resistance development in the magnet during fast rampdown and using provoked quenches - spontaneous quenches with increasing detection/protection delays, gradually increasing the MIITs - Study of self-protection capabilities of the magnet; also important for establishing operational margins of the MTF. -SCR operational issue has been discovered -Indirect assessment of magnet state has been done through flux jump analysis -FastDAC, acoustic data have been collected -Magnetic measurements have been conducted as planned, but only up to 9 kA current. -AC loss data analysis are underway -No dedicated MIITS studies were conducted, but the 2 high MIITS provoked extractions and one ramp-rate quench were conducted with effectively absent dump resistor.

Heater configuration PHA01PHA02PHB01PHB02 Coil / 1000/ /1000/ /660/ (**)/1000/ 890 Coil /960/ /1000/ /1000/ / 590/ 590 Coil 7797 (*) / 750/ /1000/ / 1000/ /450/ 366 Coil / 1000/ / 1000/ /550/ / 550/ 0 PHs to Coil Hi-Pot: LBL data (HQ01e) / CERN data (HQ01e2)/ HQ01e3 F5: C9A01+C8A02+C5A01+C7A01 -> powered to 190 V F6: C9A02+R+C7A02+C5A02 -> powered to 270 V F7: R+C8B01+C5B01+C9B02 -> powered to 150 V Heater circuits formed: ->Heater degradation since the CERN test: May be related to the -high MIITS quench -testing at 1.9 K However, some degradation was seen already in HQ01

01: 500 A V dump = 51 V 02: 995 A V dump = 101 V 04: 1000 A V dump = 94 V 05: 2000 A V dump = 181 V 06: 3000 A V dump = 274 V 08: 4000 A V dump = 378 V 09: 5000 A V dump = 406 V 10: 5700 A V dump = 407 V 11: 5717 A V dump = 408 V 12: 175 A V dump = 24V 13: 300 A V dump = 32 V 15: 498 A V dump = 50 V 16: 1052 A V dump = 98 V 17: 1552 A V dump = 137 V 18: 2065 A V dump = 172 V 19: 3141 A V dump = 256 V 20: 3083 A V dump = 274 V 21: 3567 A V dump = 326 V 22: 3064 A V dump = 275 V 23: 5598 A V dump = 409 V 24: 5086 A V dump = 163 V 25: 3743 A V dump = 119 V 26: 1202 A V dump = 39 V 27: 3344 A V dump = 74 V 28: 2995 A V dump = 96 V 29: 998 A V dump = 34 V 24: 5086 A V dump = 163 V 25: 3743 A V dump = 119 V 26: 1202 A V dump = 39 V 27: 3344 A V dump = 74 V 28: 2995 A V dump = 96 V 29: 998 A V dump = 34 V MM02: 1629 A V dump = 54 V MM07: 6642 A V dump = 218 V MM08: 5583 A V dump = 178 V RR01 (100 A/s): 7144 A V dump = 234 V RR02 (100 A/s): 7154 A V dump = 234 V RR04 (75 A/s): A V dump = 406 V Extractions / quenches summary R dump 120 m  R dump 30 m  R dump 30 m  Extraction system has malfunctioned at V dump >( ) V System tests Magnetic measurements Ramp-rate quenches

SysTest11: extraction at 5.6 kA  400 A Only ~0.5% of magnet energy was extracted Due to SCR malfunction, the extraction was interrupted at +38 ms and magnet re-connected back to the power supply

SysTest23: extraction at 5.7 kA Lost ~ 40L of LHe over ~130 s  15.7 MIITS

Flux jump statistics Each flux-jump event was assigned to one particular coil. For every event the selected coil was the one with the largest absolute value of integrated flux imbalance. The histogram shows the number of events assigned to each coil. Unusually large number of FJ events in Coil 7; was not seen in the HQ01d,e tests when quench antennas we re used to monitor flux jumps – possible degradation in C7 Each flux-jump event was assigned to one particular coil. For every event the selected coil was the one with the largest absolute value of integrated flux imbalance. The histogram shows the sum of the integrated flux imbalance of all the events that were assigned to each coil. 54/61 strands 108/127 strands MM ramp up to 9 kA and back down Coil Volt age Integrated Flux Imbalance

Ramp-rate quenches HQ01e ,5, ,8 Ramp-rate quench current values and also quenching coils are is consistent with the earlier HQ tests

RR04: A quench at 75 A/s Quench starts in the outer layer multi-turn of C MIITS

H. Bajas et. al., MT22 presentation Magnet resistance with no dump Effective R dump is very low, can be neglected Magnet resistance reached maximum of ~52 m  - another reference datapoint adding to the CERN data of R mag ~120 m  at 15.9 kA / 18.3 MIITS Independent coil resistance measurements

Current and sound at the triggered events Sound signals example at I mag = A Acoustic emission studies (RR04) Sensor 1 is installed at the bottom load plate; sensor 2 is installed at the top plate HQ magnet produces increased acoustic emissions (seemingly unrelated to FJ) and high-frequency (>50 kHz) vibration “bursts” when energized above 9kA. The latter are occasionally correlated with the short imbalance spikes and most likely caused by stick-slip motion of the conductor Inductive pickups sensors can be developed and used in conjunction with acoustic devices to improve selectivity for the specific mechanical and electrical events Also presented at WAMSDO 2013: &confId=199910