ELOG AIDA

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

AIDA

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Entry time:	Sat Mar 29 12:26:14 2025
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> > See https://elog.ph.ed.ac.uk/AIDA/555 > > Date files May2017/R1_0 to May2017/R_79 are an extended (c. 3.8 day) background run with > BNC PB-4 Pulser OFF and and a relatively high slow comparator threshold 0x64 to reduce > data volume. > > Attachment 1 - DSSSD#1-6 m_p versus m_n > > Attachment 2 - DSSSD#1-6 x versus y hit patterns > > Attachment 3 - DSSSD#1-6 E_p versus E_n (dispersion ~20-23keV/channel) > > Attachment 4 - DSSSD#1-6 E_p versus E_n (with tags) > > Attachment 5 - 2D contour levels & colours for all 2D spectra above > > Attachment 6 - MIDASsort subroutine > > Attachment 7 - MIDASsort namelist I/O variables > > Attachments 8-10 - ADC offset calculation logs etc > > Attachment 11 - spectrum titles > > MIDASsort calculates channel and ADC data as follows > > ch = channel + ( module - 1 ) * 64 + ( range * 2048 ) > adc_data = INT( RSHIFT( ABS( adc_data - 32768 ), 3 ) - offset(ch) + 0.5 ) > > where > > channel = FEE channel # (0-63) > module = FEE module # (1-24) > range = LEC or HEC (LEC = 0, HEC = 1) > > ADC offsets were calculated using the pulser walkthrough data of files May2017/R4 > and command > > cd ~/td/calibration > offsets /homes/npg/Spectra/R4 100 1400 15 10 > > where the peakfind peak search parameters are limits 100-1400 channels, fwhm=15 channels and acceptance=10% > > Probably ~10% of ADC offsets need manual checking/adjustment > > The 2D spectra (attachments 1-4) were produced for events with > > multiplicities 0 < m_p < 8 and 0 < m_n < 8 > all x-y combinations incremented > > no clustering, gain matching or software thresholds > > All DSSSDs show Uranium 4n+2 decay sequence background spectra from the intrinsic activity of the DSSSDs > and airborne decay products (e.g. 222Rn). Not clear why statistics are higher for DSSSD#1 cf. DSSSD#2-6. > One possibility is the activity of the aluminized Mylar window just upstream of DSSSD#1? Surrounding air > and Al snout would presumably affect DSSSD#1 and #6 about the same. Encoding: HTML ELCode plain Suppress Email notification

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