ELOG CIRCE

AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40

CIRCE

Fields marked with * are required
Entry time:	Sat Nov 24 15:07:00 2018
Author*:
Subject*:
<p>On 22/11/2018 in the afternoon:</p> <p>We increased the ADC thresholds to 40 (previously 8).</p> <p>For an alpha source with pulser connected, the event multiplicity dropped from ~63 to ~10. Dead time ~ 7%</p> <p>Checking the timing signals for the near S2:</p> <ul> <li>RAL X channels 0 - 5 bad, 6 and 7 good -> disconnected timing</li> <li>RAL U, XII, XIII, R, and S good</li> <li>RAL W channels 0 - 5 good, 6 and 7 bad</li> <li>RAL Q all bad -> disconnected timing</li> </ul> <p>Started alpha source run with pulser (same pulser settings as run before)</p> <ul> <li>Run # 181122161955</li> </ul> <p>After run the Far S2 RAL thresholds set to 10mV, the close S2 thresholds set to 50mV</p> <p>Started alpha source run, no pulser</p> <ul> <li>Run # 181122170947</li> </ul> <p>Stopped run due to poor alpha rate -> ECL-Nim ribbon cable disconnected.</p> <p>Checking bias:</p> <ul> <li>Far S2 bias = -130V, leak I = 1.91uA</li> <li>Close S2 bias = -129.9V, leak I = 13.11uA</li> <li>diode bias = -70V, leak I = 0uA</li> </ul> <p>Vented chamber and checked 12um mylar foil in front of close S2 - no visual damage. LEft</p> <p>Close detector changed: S2 2623-26 (505um) replaced with S2 2623-18 (508um). Mounted new S2 in close position with 12um mylar</p> <p>Removed alpha source - needed by other experiment. Otherwise target ladder configuration is same as eLog entry #47</p> <p>Checked grounding cables going from preamps to ICU boxes were tightly connected</p> <p>Attempted to bias close S2 -> no leak current! Left lab for the day.</p> <p>The next morning (23/11/2018):</p> <p>We found the BNC - SMC bulkhead connector attached to the near S2 preamp box is missing a pin. We dismounted the near S2.</p> <p>We observed ~50kHz noise on Far S2, this is removed when we lifted the preamp - ICU box ribbon cables away from the chamber vacuum gauges.</p> Encoding: HTML ELCode plain Suppress Email notification Resubmit as new entry

Attachment 1:
Drop attachments here...

ELOG V3.1.4-unknown