ELOG DESPEC

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

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Entry time:	Sat Mar 29 11:27:23 2025
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> Plan for the day was to connect a mechanical ground to the FEEs connected to DSSD0 1, 2, 3, 4, 9, 10, 11 and 12 > > This was done by connecting thick copper cable to the mechanical ground wires on the AIDA frame (These ground wires are connected to the platform ground which is earthed properly we are told) > Two thick copper wires were run each one for the top and right side and one for the bottom and left side. > Each cable was connected to the FEEs with a star of smaller cables going to the adapter boards. > Before connection the potential difference between the FEE ground and the mechanical ground was 16mV. > After connection the potential difference was 3-4mV. > It was checked that both the NIM ground and the PSU ground pins were on the same ground as the mechanical ground. It was just the FEE modules on a different ground. > Photos of connection at end of attachments. > > It was found later in the afternoon that the 3mV drop comes as a result of the resistance of the bolt used to connect all the thinner wires to the thicker copper braid. > > Very good rates observed in all p+n strips but high rates in n+n. > The large oscillations observed in waveforms yesterday are gone though. High frequency component remains > Statistics - attachment 1 > Rates spectra - attachment 2 > Zoomed in rates spectra - attachment 3 > p+n aida11 1.8.W - attachment 4 > n+n aida02 1.8.W - attachmeFEE Width > 9 60.25 > 1 64.18 > 10 55.76 > 11 64.81 > 3 56.21 > 12 48.54nt 5 > > We then reconfigured the PSU so that the FEEs for a given detector were all on the same PSU > Rates are observed to drop across all p+n fees > > Statistics - attachment 6 > Rates spectra - attachment 7 > Rates spectra y max 10 - Attachment 8 > p+n aida 12 1.8.W - attachment 9 > n+n aida 02 1.8.W - attachment 10 > > Pulser was then connected to all p+n channels but left off > Rates - attachment 11 > Rates spectra - attachment 12 > Rates spectra ymax10 - attachment 13 > > Pulser was then switched on > > Rates spectra - attachment 14 > Statistics - attachment 15 > Pulser peaks p+n - attachment 16 > > Pulser widths > FEE Width > 9 60.25 > 1 64.18 > 10 55.76 > 11 64.81 > 3 56.21 > 12 48.54 > > n=n pulser was then added to both 2 and 4 > Pulser peaks n+n - attachment 17 > Pulser peaks p+n - attachment 18 > > FEE Width > 9 62.88 > 1 65.30 > 10 55.18 > 11 64.47 > 3 51.77 > 12 50.22 > > 2 196.00 > 4 271.57 > > 29 October > > Test adding LK2,3,4 to n+n > n+n all LK1,2,3,4 > p+n all lk 2,3,4 > Makes p+n side worse - attachment 22 > > Remove LK3 from n+n > n+n 1,2,4 > p+n all LK2,3,4 > A slight improvement on previous > attachment 23 > > Remove LK2 and 4 from n+n > Remove LK3 from all p+n except 1 and 3 which are the two non isolated cables > attachment 24 Encoding: HTML ELCode plain Suppress Email notification

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