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 11:31:44 2025
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> I have an eight FEE64 system now in place on the LYCCA chamber with a PB-5 pulser going into the adapter cards > test input. The test capacitor is 30pF. > > I was going to explore the effect of the thresholds on the pulser peak. > > I notice that the spectra look like those taken in RIKEN and not a single peak. In the 1GeV range I would > interpret this as noise but since this is such a high energy i don't quite understand what is happening in the > ASIC. > > I thought i would share it with you. > > PB-5 input to 50R is 10v with no attenuation. Signal height on the inline 'scope is +5.2v > > ASICs are set to "default" with 1GeV range and 3uS shaping time. > > Let me know if anything useful can be gleaned by more tests on LYCCA. > > > > Q = CV = 30pF * 5V = 150pC => ~ 3.42GeV => ADC channel ~ 27880 > > The spectra imply a positive test input. The spectra imply an inconsistency between the data > supplied and the peak position. > > You display the spectra on a log scale ... so the majority of events are in the peak ... but > why do some channels so a peak and others a peak plus a small number of higher amplitude/events? > > What ASIC settings are you using? > > What is the PB-5 frequency? ... PB-5 settings? PB-5 is at 100Hz, fall time is 1 ms. ASIC settings default from VHDL. They are in the manual. See EDOC955 at npg.dl.ac.uk 29300 => 2.1GeV ( very approx ) so yes this doesn't make sense. Hard to have a specific calibration or will your beam time give that. I think the 30pF is correct but i can measure it on Wednesday...... Encoding: HTML ELCode plain Suppress Email notification

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