ELOG AIDA

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

AIDA

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Thu May 12 16:55:37 2016

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Continued work on beta-trigger for EURICA. However the system seems to have different noise condition than before, which 
we think appeared after we changed power source for FEE's PSU (https://elog.ph.ed.ac.uk/AIDA/220). This is high frequency 
noise of low amplitude, with a period of 10 usec.

The effect on the resolution measured with the pulser is not too large - thus our conclusion in elog entry 220 that noise 
conditions had not changed much - but the noise does create a large trigger rate that would not allow us to set a low 
trigger threshold (for MAC-B outputs from fast discriminators). The rate of singles from front or back, as well as coincidence of 
front-back strips, increased by more than a factor of ten compared to previous conditions (e.g. ~200 coincidences for one ASIC 
enables in each side of DSSD1, and fast threshold of 10).

Saved some data in this conditions, with a threshold of 16 for the fast discriminators (enabled in one ASIC for 8 of the 
FEEs). When fast discriminator lowering threshold to 9, the system got upset and lost synchronization. Tomorrow we'll 
attempt to revert to previous configuration of PSUs.

R16*gz:

DSSD HV: +100 for all.
Leakage current (uA): 4.2, 4.9, 3.7, 3.9, 4.2, 3.8, 10.7 (from Det#1 to veto)

Enabled fast discriminators in ASIC2 of DSSD1 and DSSD5 (NNAIDA#: 25, 30, 27, 32, 9, 13, 11, 16)

DSSD#1 is next to 207Bi source

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