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LBDS commissioning – MKD tests. Viliam Senaj, 11/12/2013. MKD/B2 tests. HV tests (up to 5 TeV ) without major problems : noisy Trigout on Gen. H (up to 5V noise signal) – replaced chassis with PTU&PTC Noisy output on one PTU of Gen. D – replaced PTU
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LBDS commissioning – MKD tests Viliam Senaj, 11/12/2013
MKD/B2 tests • HV tests (up to 5 TeV) without major problems: • noisy Trigout on Gen. H (up to 5V noise signal) – replaced chassis with PTU&PTC • Noisy output on one PTU of Gen. D – replaced PTU • Triax cable connectors on Gen. B – difficult to insert – replaced cables • Triax cable and 3 kV HV PS cable not fully inserted on Gen. E (27/11) • No abnormal sparking activity observed - surveillance of retriggering pick-ups Cts2a&b – with the same settings for all generators • DC 7TeV test: erratics on B (3 erratics 2 GTOs broken), D (6 erratics no damage), G (1 erratic no damage), J (3 erratics 2 GTO broken), N (2 erratics no damage) • 48 hours ramp test: 10min 400 GeV; 10 min ramp to Emax; 90 min at Emax and (12h 6.5 TeV, 12h 6.75 TeV, 24h 7 TeV) - OK (without B&J)
Searching reasons of spontaneous firing • Abnormally dry air observed in UA67 during tests (dew point - 9 deg) • To find if it affects B1 – it was put in DC mode between 30/11-03/12: ~24h rising from 6 to 7 Tev; 36 h at 7 TeV and finally 24 h at 7.1 TeV; no self-firing observed
Searching reasons of spontaneous firing • Hypothesis of charging of plexiglass insulation rods by friction of dry air blown by ventilators towards GTO stacks: switched off ventilators in Gen D, E, F, G, H, I, J – during 7 days – not confirmed • Observation of noisy output of several PTU – even PTU signal before GTO current – on Gen. D:
Continuation tests • Generators B and J in laboratory for tests • DC test during Christmass • DC and ramp test in 2014 • Surveillance of PTU activity/retrigger propagation (thresholding)