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:	Sat Mar 29 11:24:34 2025
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> Offline analysis of S100 data files R21_0 - R21_99 (162Eu setting) > > first WR ts > First timestamp of R21_0 0x17CA09154AE3E636 > > Epoch converter says ... > > GMT: Saturday, April 27, 2024 4:36:35.223 AM > Your time zone: Saturday, April 27, 2024 5:36:35.223 AM GMT+01:00 DST > > last WR ts > First timestamp of R21_100 0x17CA16C1904150CE > > GMT: Saturday, April 27, 2024 8:47:08.772 AM > Your time zone: Saturday, April 27, 2024 9:47:08.772 AM GMT+01:00 DST > > > FEE64 configuration > > FEE64 a b c > g h > d e f > > a b c d e f g h > DSSSD#1 15 3 12 9 1 5 2 4 > DSSSD#2 11 7 16 10 14 13 6 8 > > n+n Ohmic FEE64s 2, 4, 6, 8 > > Data analysis assumes > > - all LEC ADC data channels with valid ADC offset included (1012 of 1024 channels) > LEC calibration ADC offset only > > - no clustering > > - no multiplex timestamp correction > > - no p+n junction side - n+n Ohmic side correlation time gates > > - FEE64 not DSSSD strip ordering > > - hardware - slow comparator setting p+n junction FEE64s 100keV, n+n Ohmic FEE64s 150keV > > - LEC energy difference +/-168keV > > - HEC energy difference +/- 1.68GeV > > - valid LEC events > > DSSSD #1 > p+n junction side multiplicity = 1 and n+n Ohmic side multiplicity = 1 > DSSSD #2 > 0 < p+n junction side multiplicity < 8 > and > 0 < n+n Ohmic side multiplicity < 8 > > 151keV < LEC energy < 1008keV > to select candidate beta events and veto higher energy events e.g. light ions > standalone analysis of AIDA data, no downstream veto detector > > - valid HEC events > p+n junction side multiplicity > 0 and n+n Ohmic side multiplicity > 0 > > (x,y) strips corresponding to maximum energy > p+n junction and n+n Ohmic side HEC > > - HEC veto > p+n junction side multiplicity > 0 or n+n Ohmic side multiplicity > 0 > > - per pixel implant-decay correlations > > - end of event > difference in WR timestamp between successive ADC data items > 2500 > > Attachments 1-4 > per DSSSD p+n junction - n+n Ohmic strip time difference for HEC and LEC events (2us/channel) linear and log scale > > - observe large (> 32us) time differences (on log scale) > > - range of time differences increases with multiplicity ( DSSSD#1 cf. DSSSD#2 LEC events) > > - distribution of HEC time differences can probably be understood in terms of most/all channels of ASIC being active during HEC event with low LEC thresholds > > - AIDA is a triggerless DAQ producing streams of ADC data items not events > at high instantaneous rates when events are constructed they may become aggregated in time i.e. > 32us readout time of all channels of one ASIC > > - To investigate impose additional end of event criterion > difference in first and last WR timestamp of event < 33us > > Attachments 5-6 > per DSSSD p+n junction - n+n Ohmic strip time difference for HEC and LEC events (2us/channel) linear and log scale > > - blue original end of event criteria, cyan new end of event criteria > > - as expected range of time differences is restricted to +/- 32us > > - observe somewhat higher fraction of events with low time differences > > DSSSD #1 10363098 of 16104322 (64%) events +/-2us > > DSSSD #2 860454912 of 1766618199 (49%) events +/-2us > > Attachment 7 > per DSSSD p+n junction - n+n Ohmic strip time difference for LEC events - x-axis 2us/channel, y-axis 20keV /channel > > > Attachment 8 per FEE64 LEC data rate (Hz) 268ms/channel > Attachment 9 per FEE64 LEC data rate (Hz) 268ms/channel: 150keV < energy < 1500keV > Attachment 10 per FEE64 LEC data rate (Hz) 268ms/channel: energy > 1500keV > > - observe high instantaneous rate on spill > - rate dominated by low energy (<1500keV) events > - rate of higher energy events dominated by on spill events i.e. light ions as expected > - significant deadtime on spill for n+n Ohmic FEE64s, low deadtime off spill > - deadtime low/zero for p+n junction FEE64s on/off spill > > Attachment 11 per FEE64 LEC hit pattern: 150keV < energy < 1500keV > Attachment 12 per FEE64 LEC hit pattern: energy > 1500keV > > > Attachment 13 per FEE64 HEC data rate (Hz) 268ms/channel > Attachment 14 per FEE64 HEC data rate (Hz) 268ms/channel: 100MeV < energy < 1000MeV > Attachment 15 per FEE64 HEC data rate (Hz) 268ms/channel: energy > 1000MeV > > - rate dominated by low energy (>1GeV) events > - all HEC events on spill as expected (note FEE64 #7 has a single hot channel which can be disabled in software) > - significant deadtime on spill for n+n Ohmic FEE64s, low deadtime off spill > - deadtime low/zero for p+n junction FEE64s on/off spill > > Attachment 16 per DSSSD p+n junction versus n+n Ohmic LEC energy - x-axis & y-axis 20keV/channel > > Attachment 17 per DSSSD p+n junction versus n+n Ohmic HEC energy - x-axis & y-axis 20MeV/channel > > Attachment 18 per DSSSD p+n junction versus n+n Ohmic HEC strip hit pattern: all HEC events > > Attachment 19 per DSSSD p+n junction versus n+n Ohmic HEC strip hit pattern > DSSSD #1 ions stopped in DSSSD #1 i.e. DSSSD #2 HEC multiplicity = 0 > DSSSD #1 shows x-y gate used ( 270 < x < 370, 20 < y < 90 ) to identify 166Tb implants > DSSSD #2 ions stopped in DSSSD #2 and in transmission (can establish which ions stop in DSSSD#2 from DSSSD#2 HEC energy versus DSSSD#1 HEC energy - see https://elog.ph.ed.ac.uk/DESPEC/672 > > Attachment 20 > > DSSSD#1 HEC energy (20MeV/channel) versus HEC-LEC dt (1s/channel) > > DSSSD#1 LEC energy (20keV/channel) versus HEC-LEC dt (1s/channel) > > DSSSD#1 HEC strip # versus HEC-LEC dt (1s/channel) > > - Observe # events in every third channel is lower > - Probably reflects implant-decay correlation livetime > For example (choosing some numbers for illustrative purposes) > on spill: HEC livetime 75%, LEC livetime 75% (FEE64 deadtime common for HEC and LEC data) => implant decay correlation livetime 56% > off spill: HEC live time 75%, LEC livetime 100% => implant decay correlation livetime 75% > - Observe 'hot' x channels 315, 318, 321, 324 - disabled for further analysis > - Do not observe any 'hot' y channels > > > Attachments 21 & 22 > > DSSSD#1 per pixel HEC-LEC time (1s/channel): x,y,z gated to select 166Tb events > > Naive (parent-daughter decay only, flat background) fit for data t=0-26s ( t1/2 = 27.1(3)s ) > > Fit ignores data for t=0, 3, 6, 10, 13, 16, 19, 22s to avoid bias of differences in implant-decay correlation deadtime > > Suggestion of structure at c. 30s period? Does this reflect spill stucture? 10x spill cycles (30s), 9s spill off, ... etc > > Sum of x,y,z gated HEC events (s2112 - see attachment 19) = 670441 > > Elapsed time of dataset 4h11m = 15060s > # pixels = 100 x 70 = 7000 > => # x,y,z gated HEC events per pixel = 670441/7000/15060 = 0.0064/s or mean time between x,y,z gated HEC event = 157s (estimate needs to be corrected for HEC deadtime) > > Sum of implant decay correlations (s2220 - see attachment 21) t=0-150s = 273508 - flat background estimated as 150 x 500 = 75000 = 198508 > > => efficiency c. 30% (presumably low due to implant-decay deadtime, LEC multiplicity, per pixel correlations and no clustering) > > > Summary > > $64,000 question - what is the origin of the high instantaneous rate on spill for DSSSD#1 ? On my to do list. > > > Attachment 23 > > LEC multiplicity with/without HEC data in event > > per DSSSD LEC p+n junction multiplicity versus n+n Ohmic multiplicity > per DSSSD LEC p+n junction multiplicity versus n+n Ohmic multiplicity z_hec=1 and z_hec=2 > > > With HEC data > > DSSSD#1 p+n junction multiplicity ~ 17, n+n Ohmic multiplicity ~28 > DSSSD#2 p+n junction multiplicity ~ 40, n+n Ohmic multiplicity ~23 > > Assume 200Hz HEC events => DSSSD#1 LEC rate = 200 x ( 17 + 28 ) => 9k LEC data items cf. >100k LEC data items (attachments 8 & 13) > > i.e. not due to HEC events > > > > > > > > > > > > > > > > > > > > > Encoding: HTML ELCode plain Suppress Email notification

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