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MP3 MIC-C test campaign in S1-2 Special guest: A22R1 (MB2413). MIC-C in the ARC results overview HVQH at cold Special Guest: A22R1, MB2413 Effect of cleaning PCB inside IFS box Other case…? Conclusion. MIC-C in the ARC results overview - IRC. IRC: Instrumentation Resistance Check
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MP3MIC-C test campaign in S1-2Special guest: A22R1 (MB2413) MIC-C in the ARC results overview HVQH at cold Special Guest: A22R1, MB2413 Effect of cleaning PCB inside IFS box Other case…? Conclusion
MIC-C in the ARC results overview - IRC • IRC: Instrumentation Resistance Check • Measure the resistance of Vtap / Itap • NC 1015519 initiated: MB2324, A26L2 Vtap EE211 found open. Similar problem occurred in SM18 (June2006) during cold test, NC 753118. Problem disappeared at warm. Used in old QPS, then according to QPS request, Elqa team bridged it with Vtap EE113 • MB2236, B13R1 vtap resistance of EE112 is higher by 4 Ohms. NC initiated, use as is, NC closed with warnings.
MIC-C in the ARC results overview - QHR • QHR: Quench Heater Resistance • Two known NCs: • NC 1004184: QN-ELQA-MIC-W-QHR-MB2395-001, Status: Closedwith warnings Quench heater YT111 of MB2395 (C14R1) was found open during the MIC-W campaign 2009. NC 947913 was already opened to report this problem in 2008. The quench heaters were reconfigured at that time, and used during powering phase. • NC 1004185: QN-ELQA-MIC-W-QHR-MB1372-001, Status: Closedwith warnings Quench heater YT111 of MB 1372 (C32R1) was found open during the MIC-W campaign 2009. NC 947915 was already opened to report this problem in2008. The quench heaters were reconfigured at that time, and used during powering phase.
MIC-C in the ARC results overview - HVQH • High Voltage test on Quench Heaters • One known NC from warm campaign: • NC 1004191: QN-ELQA-MIC-W-QHVQ-MB2413-001, Status: Initiated • Too high leakage current (11 E-6 A after 1 min) observed during high voltage tests on quench heaters versus coil and ground on MB 2413 (A22R1) MB2413: First measurement @ 1 bar MB2413: Second measurement @ 6 bars Courtesy of Mateusz Bednareck
HVQH at cold • High Voltage at cold: All QHs shorted, 2kV vs Coil+GND, 1min. A22R1, 500V 2413
Special guest: A22R1 – MB2413 • QHs High Voltage at warm: • All QHs shorted, 500V vs Coil+GND, 1min. • Leakage current 11e-6 A (1 bar) • repeated with 6 bars 3.8e-6 • QHs High Voltage at cold: • All QHs shorted, 500V vs Coil+GND, 1min. • Leakage current 14.7e-6 A • repeat with Megger, after 3 min, 6.55e-6 A
A22R1 – MB2413: investigation… • Warm part excluded: • Measurement of each individual QH with Megger on P10 • Removing IFS Box (MSC) • Measurement of each individual QH with Megger on feed through • Weakness confirmed inside cold part !
A22R1 – MB2413: in SM18… • Cold measurement in dec. 2006, after powering:
Effect of cleaning PCB inside IFS box • B8R1, A30R1 & B30L2… B8R1 2256 A30R1 2329 B30L2 2409
Effect of cleaning PCB inside IFS box • B8R1, A30R1 & B30L2…the PCB were found dusty inside IFS box…
Other case…? B19R1 – 2410 • High leakage current on B19R1 - 2413 B19R1 2410
Other case…? B19R1 – MB2410: Summary table • On MB2410, most of the leakage current of all QHs vs coil+GND comes from YT221 • Shall we change the nominal protection scheme on this magnet?
Conclusion • IRC at cold • MB2324, A26L2 Vtap EE211 found open, bridged with EE113 (NC 1015519 closed). • HVQH at cold • MB2413, A22R1 (500V), high leakage current for ¾ High Field quench heaters. Low Field quench heaters are healthy. Shall LFs be used as nominal protection instead of HFs? • Is the qualification of the RB line going to pass at 1.9kV? Coming in the next hours (ELQA). • MB2410, B19R1 has a weak high field quench heater (YT221). Shall a pair of LF QHs be used instead of YT221? • Cleaning PCB inside IFS boxes from dust improves the measurement.