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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 20:00:39 2025
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> Yesterday the sum/inverter was found to be a considerable source of noise in the system. > > Plugging it into an oscilloscope this morning it was clear there was a Vpp 17mv 60kHz sin wave in its signal - attachment 1 yellow trace > > Moved the inverter to a crate in the messheute and did not see same behaviour. This time see Vpp 5mV and a ~265Hz wave that looks much less clean. - attachment 2 yellow > > Put inverter back in CAEN crate in S4 and confirm similar behavior. > > Move CAEN crate to new mains port, same behaviour > > Move CAEN crate to AC voltage stabiliser, same behaviour > > Remove module one by one from CAEN crate. > Removing BIAS supply - No change > Remove Pulser - No change > Remove right most MACB - No change > Remove second right most MACB - Signal disappears - attachment 3 blue trace > Remove second right most MACB from the rack entirely > Put right most MACB back - Signal comes back - attachment 4 blue trace > Test MACB with and without HDMI connectors connected signal remains > Remove rightmost MACB from the rack - Signal disappears > > Put pulser and bias back - Signal does not return > Signal also doesn't return when ramping up bias or running the pulser > Power DAQ up - No change in performance from yesterday with inverter removed. > > MACB and Inverter don't share any voltages on NIM: > MACB +-6V and Gnd > Inverter +-24V and Gnd > > CAEN Crate does not have any easily accessible monitoring points. Anyone have any ideas? > > MACBs and inverter checked on another crate - no signal > > Inverter put back in CAEN crate and no noise observed on scope. > With waveforms disabled am able to get <100kHz on all FEEs with the pulser connected > > Tested adding bias filters - No change > > 15:30 Nic realised that one of the mains boxes is labelled measurement network so we connect the AIDA PSU to this via the ac stabiliser > We get ok stats even with waveforms on at 0xa- attachment 5 > > Waveforms still have the 100kHz oscillation in them though attachments 6 and 7 > > Without waveforms we get similar performance to before the switch to the new mains - attachment 8 > > 15:56 Move CAEN NIM crate across to this mains network > 300+kHz on all FEEs with waveforms on. Can recover waveform off performance though > > 16:01 Place CAEN NIM crate back onto platform mains but don't recover the ealier rates with waveform. Everything still around 300kHz. > > 17:43 Current best settings are waveforms off and we can run at 0xa on all FEEs - attachment 9 Encoding: HTML ELCode plain Suppress Email notification

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