ELOG DESPEC

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

DESPEC

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Entry time:	Tue Apr 1 09:24:20 2025
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> 19 November > > Waiting for 40Ar beam to be delivered for tests. > Objective today is to assess degrader thickness suitable to stop 40Ar in 2nd DSSD layer. > Energy expected at 300 MeV/A, around 1E3-4 beam intensity - to be determined. > > Tomorrow fragments could be expected. > > DSSD / FEE64 pairing as follows > > DSSD3 (most downstream): FEEs 9,10,11,12 > DSSD2 (middle): FEEs 5,6,7,8 > DSSD1 (most upstream): FEEs 1,2,3,4 > +plastic scintillator furthest upstream > > New AIDA Google spreadsheet created with leakage current, to monitor them during beamtime. First entry added. Bias attached. > https://docs.google.com/spreadsheets/d/12hgbrywB10hGsKt5uc2HnLfZymh8_uvM6cEASbbqnBE/edit#gid=813167023 > > DESPEC platform has already been moved. No effect on rates - see attached. FEE1 is missing one channel. FEE9, 10 noisy as expected. See attached. > > > System wide checks all OK except > Master clock failed (normal) > ADC calibration fails on 6 and 12. Recalibrated via FADC Align. All OK now. > > MBS transfer OK. See attached. > > Good event statistics OK. See attached. > > FEE64 temperatures OK. See attached. > > Merger and data rate OK. See attached. > > Waiting for beam. > > > > 20 November > > 01:07 - Still no beam. > > System wide checks OK. > Stats OK. > Temps OK. > MBS OK. > Merger and data rate OK. > > > 02:35 - Beam is expected soon > Tried enabling writing data to disk. Merger crashed. FEE64 stopped responding to commands. > Reset Merger. FEE64 now respond to commands. > Tried enabling writing to disk again. Merger crashed once more. Reset merger. > Reset Tape Server interface. Now writing to disk. > > No data currently being sent to MBS, but operators say they "are adding a new detector". May be normal. > > DAQ & Merger going OK. Writing to Nov19/R1 > > No beam yet. > > Temperatures OK > System wide checks OK > Stats OK. See attached. > MBS not working. > Merger and data rate OK. See attached. > > ~02:48 Beam on. 40Ar. 300 MeV/A, 500 pps. Degrader settings unclear. > > 03:54 Degrader settings have been changing between 4.5, 1 and 6 ug/cm2 > Currently on 6 g/cm2. > AIDA seen through MBS shows no HE on detector 3, and Det 1 and 2 show no counts on positive y (FEE6 and 1). That is not the case from MIDAS. > > 04:30 The aim of the tests above was to have no 40Ar at all in DSSD3. It does not appear that 6 g/cm2 is sufficient, as we still see events. The reduction between 1 & 2 vs. 3 is about a factor of 2-10 depending on ADC channel. See attached. > > ~04:30 Moved to 6.2 g/cm2 degrader. See attached. > > ~04:45 Moved to 5.8 g/cm2. See attached. > > ~05:09 Moved to 6.4 g/cm2. See attached. > > 05:31 High energy channel spectra (1.8.H) for all FEE64 w/ 6.4 g/cm2 degrader - See attachments 13 & 14 > > 05:38: Moved to 1.0 g/cm2. See attached. Difference is not huge which may indicate these spectra are misleading, as partly expected. A more detailed analysis will be carried out off line. > > 06:00: Beam stopped. ~R77. AIDA keeps running background over the day. Beam should restart around 11 pm later today. Encoding: HTML ELCode plain Suppress Email notification

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